REGULAR SUBMISSION Sirolimus is effective for primary relapsed/refractory autoimmune cytopenia: a multicenter study Hongmin Li a , Jiang Ji a , Yali Du a , Yuzhou Huang a , Hao Gu b , Miao Chen a , RunHui Wu b , and Bing Han a a Department of Hematology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China; b Hematology-Oncology Center, Beijing Children’s Hospital, Capital Medical University, National Center for Children’s Health, Beijing, China (Received 7 April 2020; revised 31 July 2020; accepted 2 August 2020) Autoimmune cytopenia includes autoimmune hemolytic anemia (AIHA), immune thrombocy- topenia (ITP), and Evans syndrome (ES) caused by abnormal activation of autoimmunity and has a considerable refractory/relapse rate. To evaluate the efficacy and toxicity of siroli- mus of primary relapsed/refractory autoimmune cytopenia, records of 45 patients with pri- mary relapsed/refractory AIHA, ES, or ITP from October 2016 to January 2019 in two institutions, were collected; there were 3 pediatric patients and 42 adult patients. The median age at diagnosis was 31 (1-84) years. Patients were treated for a median of 14 (6-39) months and followed-up for a median of 18 (10-40) months. Thirty-eight patients responded to sirolimus, with 28 complete responses (CRs) and a median of 2 (2-5) months to response. Five patients had mucositis; the incidences of other adverse events were all less than 5%. Four patients relapsed, making the CR and overall response rate 46.7% and 75.6% at the end of follow-up. There were no differences in patient age, sex, time from diag- nosis to sirolimus, serum sirolimus concentration, and disease distribution between CR and non-CR patients, or between responders and nonresponders, though AIHA patients were likely to relapse less and respond better. In conclusion, sirolimus is effective for patients with primary relapsed/refractory autoimmune cytopenia with a low relapse rate and good tolerance. © 2020 ISEH – Society for Hematology and Stem Cells. Published by Elsevier Inc. All rights reserved. Autoimmune cytopenia is a heterogeneous group of disor- ders characterized by immune-mediated destruction of hematologic cell lineages [1] and results in single- or multi- lineage cytopenia. Immune-mediated destruction can be sec- ondary to other illnesses such as autoimmune disease, immune deficiency, and lymphoproliferative disorders [2,3], but are mostly idiopathic. Immune thrombocytopenia (ITP), autoimmune hemolytic anemia (AIHA), and Evans syn- drome (ES) are common autoimmune cytopenias, with con- siderable proportions of child patients. Glucocorticoid is the first-line therapy and can induce remission in 80%-90% of patients [4,5]. However, the relapse rate of glucocorticoid therapy is high, especially after dose decrement, and some patients are refractory to glucocorticoids at the very beginning. Second-line therapies include rituximab and immunosuppressants such as cyclosporine A (CsA), cyclophosphamide (CTX), and azathioprine. Unfortu- nately, the response rate is limited, and some patients are intolerant to the aforementioned treatments [4]. Sirolimus is a product of Streptomyces hygroscopi- cus and has been reported to have an immunosuppres- sive effect in preventing acute graft rejection in HL and JJ contributed equally to this work. HL, JJ, and BH designed the study and wrote the article. HL and JJ collected and analyzed the clinical data. YD, YH, HG, and RW helped to collect the data. MC provided critical suggestions. All authors reviewed the article, and finally, all authors approved the final submission of the article. Offprint requests to: Bing Han, Peking Union Medical College Hospital, No. 1 ShuaiFuYuan, Dongcheng District, Beijing 100730, China; E-mail: [email protected] 0301-472X/© 2020 ISEH – Society for Hematology and Stem Cells. Published by Elsevier Inc. All rights reserved. https://doi.org/10.1016/j.exphem.2020.08.001 Experimental Hematology 2020;89:87-95
Sirolimus is effective for primary relapsed/refractory autoimmune cytopenia: a multicenter study
Dec 17, 2022
Welcome message from author
This document is posted to help you gain knowledge. Please leave a comment to let me know what you think about it! Share it to your friends and learn new things together.
Transcript
Sirolimus is effective for primary relapsed/refractory autoimmune cytopenia: a multicenter studyy relapsed/refractory autoimmune
cytopenia: a multicenter study
Hongmin Lia, Jiang Jia, Yali Dua, Yuzhou Huanga, Hao Gub, Miao Chena, RunHui Wub, and Bing Hana
aDepartment of Hematology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College,
Beijing, China; bHematology−Oncology Center, Beijing Children’s Hospital, Capital Medical University, National Center for Children’s Health,
Beijing, China
(Received 7 April 2020; revised 31 July 2020; accepted 2 August 2020)
HL and JJ contr
Autoimmune cytopenia includes autoimmune hemolytic anemia (AIHA), immune thrombocy-
topenia (ITP), and Evans syndrome (ES) caused by abnormal activation of autoimmunity
and has a considerable refractory/relapse rate. To evaluate the efficacy and toxicity of siroli-
mus of primary relapsed/refractory autoimmune cytopenia, records of 45 patients with pri-
mary relapsed/refractory AIHA, ES, or ITP from October 2016 to January 2019 in two
institutions, were collected; there were 3 pediatric patients and 42 adult patients. The
median age at diagnosis was 31 (1−84) years. Patients were treated for a median of 14
(6−39) months and followed-up for a median of 18 (10−40) months. Thirty-eight patients
responded to sirolimus, with 28 complete responses (CRs) and a median of 2 (2−5) months
to response. Five patients had mucositis; the incidences of other adverse events were all less
than 5%. Four patients relapsed, making the CR and overall response rate 46.7% and
75.6% at the end of follow-up. There were no differences in patient age, sex, time from diag-
nosis to sirolimus, serum sirolimus concentration, and disease distribution between CR and
non-CR patients, or between responders and nonresponders, though AIHA patients were
likely to relapse less and respond better. In conclusion, sirolimus is effective for patients
with primary relapsed/refractory autoimmune cytopenia with a low relapse rate and good
tolerance. © 2020 ISEH – Society for Hematology and Stem Cells. Published by Elsevier Inc.
All rights reserved.
ders characterized by immune-mediated destruction of
hematologic cell lineages [1] and results in single- or multi-
lineage cytopenia. Immune-mediated destruction can be sec-
ondary to other illnesses such as autoimmune disease,
immune deficiency, and lymphoproliferative disorders [2,3],
but are mostly idiopathic. Immune thrombocytopenia (ITP),
ibuted equally to this work. HL, JJ, and BH
and wrote the article. HL and JJ collected and
l data. YD, YH, HG, and RW helped to collect
ed critical suggestions. All authors reviewed the
all authors approved the final submission of the
to: Bing Han, Peking Union Medical College
aiFuYuan, Dongcheng District, Beijing 100730,
[email protected]
6/j.exphem.2020.08.001
drome (ES) are common autoimmune cytopenias, with con-
siderable proportions of child patients. Glucocorticoid is the
first-line therapy and can induce remission in 80%−90% of
patients [4,5]. However, the relapse rate of glucocorticoid
therapy is high, especially after dose decrement, and
some patients are refractory to glucocorticoids at the
very beginning. Second-line therapies include rituximab
and immunosuppressants such as cyclosporine A (CsA),
cyclophosphamide (CTX), and azathioprine. Unfortu-
nately, the response rate is limited, and some patients
are intolerant to the aforementioned treatments [4].
Sirolimus is a product of Streptomyces hygroscopi-
cus and has been reported to have an immunosuppres-
sive effect in preventing acute graft rejection in
by Elsevier Inc. All rights reserved.
different transplantations [6]. In a prospective multi-
institutional trial, sirolimus was effective in relapsed/
refractory autoimmune cytopenia, particularly autoim-
mune lymphoproliferative syndrome (ALPS) [7]. Other
studies have also reported its efficacy in AIHA, ES or
ITP [8,9]. However, previous studies included only
limited numbers of patients, and few studies have
included and compared the data for AIHA, ES, and
ITP for the same period. In this study, we pooled the
data from two institutions to evaluate the effects of
sirolimus on primary AIHA, ES, and ITP in both adults
and children, and compared risk factors that possibly
affect the complete response (CR) or overall response
(OR) rate.
from October 2016 to January 2019 at Peking Union Medical
College Hospital and Beijing Children’s Hospital, National
Center for Children’s Health, and treated with sirolimus were
analyzed retrospectively; patients with secondary autoim-
mune cytopenia were excluded from this study. Refractori-
ness was defined as lack of response after receiving a
sufficient number of courses of standard therapy. Clinical
data including sex, age, previous therapies, clinical symp-
toms, hematological parameters, and biochemical parameters,
were collected before and after sirolimus treatment.
This study was performed in accordance with the 1964
Declaration of Helsinki and its later amendments or compara-
ble ethics standards and was approved by the ethics commit-
tee of Peking Union Medical College Hospital and Beijing
Children’s Hospital, National Center for Children’s Health.
Informed consent was obtained from each patient before data
collection.
Treatment
Sirolimus was given at a dose of 1−3 mg/d for adults and
1−2.5 mg/d for children, and dose was adjusted if necessary
to maintain the serum concentration of sirolimus at 4−15 ng/mL
during the treatment period. All patients were treated with siroli-
mus for at least 6 months, and those who responded continued the
treatment for at least 1.5 years and tapered gradually afterward.
Evaluation of response and toxicity
Response to sirolimus and adverse events were evaluated
every month after therapy initiation and then every 2 months
when the serum concentration of sirolimus could be main-
tained at a steady level. The response criteria for AIHA, ITP,
and ES were in accordance with the consensus of an interna-
tional group [10,11]: CR = complete response or normaliza-
tion of all cytopenias (anemia and/or thrombocytopenia),
lasting longer than 2 months; PR = partial response, an increase
of 20 g/L in hemoglobin or 30£ 109/L in thrombocytes and at
least a twofold increase in the baseline count of thrombocytes,
lasting longer than 2 months, without bleeding or significant
anemia-related symptoms; OR = overall response, achievement of
CR or PR; NR = no response, a failure to achieve CR or PR;
relapse = shift from CR/PR to NR. For the evaluation of toxicity,
patients were asked about known adverse effects of sirolimus,
and their blood lipid, liver function, and kidney function were
examined. Adverse events were evaluated according to the
National Cancer Institute Common Toxicity Criteria for Adverse
Events (version 4.0) [7].
Evaluation of risk factors
responding (CR + PR) and non-responding (NR) patients.
Examination of regulatory T cells
Regulatory T (Treg) cells were defined as CD4+CD25+foxP3
+ co-expression and expressed as a percentage of the total
CD4+ T-cell population. Peripheral blood samples were taken
immediately before sirolimus and after 6 months of treat-
ment, and were determined by cytometry. Treg cells were
stained with the markers CD4-fluorescein isothiocyanate
(FITC), CD25-phycoerythrin (PE), and foxP3-allophycocya-
nin (APC) and subsequently analyzed with a Beckman Coul-
ter (Brea CA) FC500 flow cytometer. Anti-CD4 conjugated
to FITC, anti-foxP3 conjugated to APC, and anti-CD25 con-
jugated to PE antibodies were obtained from BD Biosciences
(Franklin Lakes, NJ). Total events of 50,000 were gated based
on forward- and side-scatter characteristics, and dotplots for Treg
cells were gated on CD4+ cells.
Statistical analysis
Qualitative data were expressed as the frequency (percent-
age), and continuous data as the median or mean (range) or
mean § SD. One-way analysis of variance (ANOVA) and
the Kruskal−Wallis test were used to compare quantitative
data. The x2 test or Fisher’s exact test was used to compare
categorical variables in risk factor analysis. Comparison of
laboratory values before and after sirolimus treatment was
performed using the Wilcoxon matched-pairs signed rank test
or paired t test. All tests were two-tailed, and a p value < 0.05
was considered to indicate statistical significance. Kaplan−Meier
curves were generated using GraphPad (San Diego, CA) Prism
Software. SPSS Statistics (version 25; IBM, Armonk, NY) and
GraphPad Prism software (version 5.00) were used.
Results
The 45 patients included 8 males and 37 females; there
were 3 children (<14 years old) and 42 adults, and
their baseline characteristics are summarized in Table 1.
Among them, 14 (31.1%) patients were diagnosed with
AIHA, 12 (26.7%) with ES, and 19 (42.2%) with ITP.
The median age at the time of diagnosis was 31 years
(range: 1−84 years) for all patients. All patients had
been treated with glucocorticoids as first-line therapy
before sirolimus; 30 had achieved a response but
relapsed during steroid weaning, 14 had no response,
Table 1. Patient baseline characteristics
Patient characteristics Total (n = 45) AIHA (n = 14) ES (n = 12) ITP (n = 19) p value
Male sex 8 (17.8) 2 (14.3) 2 (16.7) 4 (21.1) 1.000
Age at diagnosis, y 31 (1−84) 33 (1−84) 28 (8−50) 28 (17−68) 0.317
Previous therapies
Glucocorticoid 45 (100) 14 (100) 12 (100) 19 (100) — Cyclosporine A 11 (24.4) 2 (14.3) 3 (25.0) 6 (31.6) — Cyclophosphamide 4 (8.9) 1 (7.1) 1 (8.3) 2 (10.5) — Danazol 13 (29.9) 0 1 (8.3) 12 (63.2) — Intravenous immunoglobin 4 (8.9) 0 0 4 (21.1) — rhTPO 5 (11.1) 0 0 5 (26.3) — Azathioprine 2 (4.4) 0 1 (8.3) 1 (5.3) — Rituximab 1 (2.2) 0 1 (8.3) 0 —
Time on previous therapies, mo 21 (1−600) 19 (2−600) 34 (4−84) 21 (1−120) 0.705
Time on sirolimus, mo 14 (6−39) 12 (6−35) 16 (7−39) 12 (6−33) 0.139
Patient trough level of sirolimus, ng/mL 6.7 (2.7−19.5) 6.1 (2.7−10.7) 6.0 (3.6−10.8) 7.2 (2.9−19.5) 0.403
Follow-up time, mo 18 (10−40) 12 (12−40) 18 (10−39) 18 (10−33) 0.241
Results are expressed as the number (%) or median (range).
AIHA=Autoimmune hemolytic anemia; ES=Evans syndrome; ITP=immune thrombocytopenia; rhTPO=recombinant human thrombopoietin.
H. Li et al. / Experimental Hematology 2020;89:87−95 89
and 1 was intolerant to glucocorticoids. Second-line
therapies such as CsA, CTX, danazol, intravenous
immunoglobulin (IVIG), and recombinant human
thrombopoietin (rhTPO) were given solely or in combi-
nation to some patients as well, and the majority did
not respond to these therapies; 2 patients had a tran-
sient response to CsA, but relapsed when weaned off
the drug, and 1 patient had a response to danazol but
stopped taking the medication because of side effects
including menopause and severe acne. All patients had
stopped second-line therapy for at least 6 months and
glucocorticoids were stopped or tapered as previously
scheduled when sirolimus started. The median follow-
up time was 18 months (range: 10−40 months) after
sirolimus. The median time on previous therapies was
21 months (range: 1 month−50 years), and the median
time on sirolimus was 14 months (range: 6−39 months).
No significant difference was detected in the proportion of
males (p = 1.000), patient age distribution (p = 0.317), time
on previous therapy (p = 0.705), time on sirolimus
(p = 0.139), median trough level of sirolimus (p = 0.403),
and follow-up time (p = 0.241) between patients with
AIHA, ES, and ITP (Table 1).
Efficacy
Patient responses at 3, 6, and 12 months and at the end
of follow-up are reported in Table 2. Thirty-eight
(84.4%) of the 45 patients responded to sirolimus,
among whom 28 (62.2%) achieved an optimal response
(CR) and the remaining 10 (22.2%) had a PR. The
median time to response was 2 months (range: 2−5
months), and the time to optimal efficacy was 2 months
(range: 2−18 months). Twenty-one (75.0%) of the 28
CR patients reached optimal efficacy within 6 months
of sirolimus treatment (Figure 1A,B). The majority of OR
patients had been on sirolimus for at least 12 months;
patients who stopped sirolimus treatment within 1 year did
so mainly because of no response (Figure 1C). Three
patients were lost to follow-up as they terminated hospital
visits and could not be reached by telephone. CR and OR
rates peaked at 12 and 6 months of follow-up, respec-
tively, for the entire cohort, at 16 and 6 months of follow-
up for AIHA patients, at 6 and 6 months of follow-up for
ES patients, and at 12 and 3 months of follow-up for ITP
patients (Table 2). Of the 3 pediatric patients, 1 achieved
a CR and 1 a PR at the end of follow-up. Most patients
achieved a durable response; 1 ES patient and 3 ITP
patients relapsed at the end of follow-up. The cumulative
relapse rates at the end of follow-up for patients with
AIHA, ES, and ITP were 0, 25.0%, and 25.3%, respec-
tively (p = 0.139, Figure 1D). Consequently, the CR and
OR rates at the end of follow-up were 46.7% and 75.6%
for the whole cohort, and the CR/OR rate was 57.1%/
85.7% for AIHA patients, 25.0%/83.3% for ES patients,
and 52.6%/63.2% for ITP patients. For patients with
AIHA and ES, the level of bilirubin generally decreased
during sirolimus treatment, and the bilirubin level 3
months after treatment was significantly lower than the
baseline level before treatment (p = 0.005) and remained
stable thereafter (p = 0.022, Figure 1E). There were no
differences in patient characteristics such as age, sex,
time from diagnosis to sirolimus, serum concentration of
sirolimus, and type of disease between responders and non-
responders, or between CR and non-CR patients (Table 3).
Treg cell levels before and after treatment
Only 11 adult patients (1 AIHA, 2 ES, and 8 ITP
patients) gave their consent to test Treg cells before
and after sirolimus treatment (Table 4); a significant
increase in Treg cell levels was observed after 6 months
of treatment in tested patients (Treg/CD4+ T cells: 4.66 § 1.73% vs. 6.10 § 1.73%, p = 0.000; Figure 2).
Patient no. Disease Response during follow-up (mo) Trough sirolimus
(ng/mL)
1 AIHA PR PR CR CR 6.7 (4.1−8.8)
2 AIHA PR PR PR PR 4.2 (2.5−8.1)
3 AIHA CR CR CR CR 4.9 (3.0−5.7)
4 AIHA PR PR PR PR 7.3 (6.0−8.4)
5 AIHA CR CR CR CR 5.2 (5.0−7.9)
6 AIHA CR CR CR CR 4.2 (2.3−6.1)
7 AIHA PR PR PR CR 4.5 (3.4−6.1)
8 AIHA CR CR CR CR 2.7 (0.3−4.8)
9 AIHA CR CR CR CR 10.7 (7.3−13.1)
10 AIHA NR NR NR NR 6.3 (1.7−9.4)
11 AIHA PR CR CR CR 8.9 (5.6−11.3) Mucositis 1 Recovery without
medication
12 AIHA NR NR NR NR 7.4 (4.3−9.2)
13 AIHA NR PR PR PR 9.7 (6.8−10.5) Mucositis 1 Recovery without
medication
14 AIHA PR PR PR PR 5.8 (4.6−7.2) Upper respiratory
infection
15 ES CR CR PR PR 4.6 (2.9−9.9)
16 ES PR PR CR NR 4.7 (2.7−13.5) Headache 1 Recovery without
medication
17 ES PR PR PR CR 5.0 (2.6−6.6) Gastrointestinal
disorder
18 ES PR PR PR PR 3.6 (2.5−5.3)
19 ES CR CR PR PR 4.5 (4.1−5.8)
20 ES CR CR CR PR 4.8 (3.6−10.6)
21 ES PR PR PR PR 8.2 (5.8−10.7)
22 ES CR CR CR CR 6.9 (5.8−9.1) Urethral infection 2 Recovery with symp-
tomatic treatment
23 ES PR PR PR PR 10.8 (5.2−14.2)
24 ES PR PR PR PR 7.0 (5.9−9.6)
25 ES NR CR CR CR 8.4 (6.0−12.8) Mucositis 1 Recovery without
medication
CR rate (%) of ES 33.3 41.7 33.3 25.0
OR rate (%) of ES 83.3 91.7 91.7 83.3
27 ITP NR PR PR CR 6.2 (4.8−7.9) Rash 1 Recovery with symp-
tomatic treatment
28 ITP PR PR CR CR 5.0 (3.2−6.4)
29 ITP CR CR CR CR 9.2 (7.6−10.8)
30 ITP PR NR NR NR 4.3 (3.6−5.6)
31 ITP NR NR LTF NR 19.5 (11.5−23.3)
32 ITP PR CR CR CR 5.2 (4.0−26.7)
33 ITP PR PR PR PR 5.9 (0.3−8)
34 ITP CR CR CR NR 2.9 (2.2−20.2) Fatigue 2 Stable
Mucositis 1 Recovery without
36 ITP NR NR NR NR 4.5 (4.2−6.3) Irregular
menstruation
tomatic treatment
37 ITP NR NR LTF NR 6.5 (5.0−11.4) Hyperlipidemia 2 Recovery with symp-
tomatic treatment
38 ITP PR PR PR PR 10.2 (8.6−14.4)
39 ITP CR CR CR CR 8.9 (5.3−13.5) Mucositis 1 Recovery without
medication
40 ITP CR CR CR CR 8.7 (5.9−12.4)
41 ITP CR CR CR CR 7.7 (1.8−13.6) Hyperlipidemia 2 Recovery with symp-
tomatic treatment
(ng/mL)
42 ITP CR PR PR NR 8.9 (3.0−15.4)
43 ITP CR CR CR CR 6.9 (1.3−14.4)
44 ITP CR CR CR CR 9.4 (3.9−14)
45 ITP CR CR CR CR 7.2 (4.7−8.1)
CR rate (%) of ITP 47.4 47.4 52.6 52.6
OR rate (%) of ITP 73.7 73.7 73.7 63.2
p value for CR ratea 0.741 1.000 0.551 0.207
p value for OR rateb 0.903 0.552 0.552 0.338
AIHA=Autoimmune hemolytic anemia; CR=complete response; ES=Evans syndrome; ITP=immune thrombocytopenia; LTF=lost to follow-up;
OR=overall response; PR=partial response. aComparison of CR rate between patients with AIHA, ES, and ITP. bComparison of OR rate between patients with AIHA, ES, and ITP.
H. Li et al. / Experimental Hematology 2020;89:87−95 91
Toxicity
cohort are recorded in Table 2. Mucositis was the most
common AE with an incidence of 11.1%; the inciden-
ces of other AEs were less than 5%. Generally, only
one type of AE was observed in a single patient,
except for one patient who presented with both mucosi-
tis and fatigue. Among the 3 children, 1 presented with
mucositis and recovered without medication. The
majority of AEs occurred within the first 3 months of
treatment and resolved with or without medication.
Pharmacokinetics
reached the ideal range within the first month of treat-
ment. There were 12 patients whose sirolimus concen-
trations were out of range in the first month of
treatment and 10 patients whose sirolimus concentra-
tion was ideal in the beginning yet fell out of range
afterward (Table 2). For all of these patients, usually
one dose adjustment was enough. Only 1 patient with
AIHA, 2 with ES, and 1 with ITP experienced stepwise
sirolimus dose adjustments to raise the sirolimus con-
centration to >4 ng/mL.
nia remains a challenge, as patients’ responses to cur-
rent therapies are often unsatisfactory [12]. Sirolimus
has with the ability to inhibit the mammalian target of
rapamycin (mTOR) and regulate T-cell proliferation
[13], and has been proven to block the development of
autoimmune diseases such as systematic lupus erythe-
matosus [14]. It has also been applied to autoimmune
cytopenia in recent years [7,15], but the numbers of
patients in these studies were limited, especially
patients with primary AIHA, ES, or ITP. In addition,
the majority of studies focused on children with auto-
immune cytopenia, except that of Li et al. [16], which
comprised only adult ITP patients. Our study reports
the experience of two institutions with sirolimus in the
treatment of primary relapsed/refractory AIHA, ES,
and ITP, adults and children included. As far as we
know, this is the largest cohort study focused on siroli-
mus treatment for these three diseases. We also com-
pared the efficacy between different diseases and
evaluated other risk factors that could affect CR or.
In our study, sirolimus was effective for patients
with primary AIHA, ES, and ITP with a CR rate of
46.7% and an OR rate of 75.6%, which was in line
with most of the previous reports [7,15,16]. The CR
and OR rates of ITP patients at the end of follow-up in
our study was higher than those in Feng et al. [17],
which could be explained by the longer course of treat-
ment received by our patients. It was noticeable that
the CR rate of ES patients was 25.0%, which was rela-
tively low compared with those of the pediatric patients
studied by Miano et al. [15] and Jasinski et al. [9].
Nevertheless, an OR rate of 83.3% at the end of fol-
low-up was still satisfactory. There was a gap between
CR and OR rates of ES patients because 3 ES patients
shifted from CR to PR during treatment, but for these
patients only one hematological parameter (hemoglobin
or platelet count) dropped below normal at the end of
follow-up. Therefore, although it might be more diffi-
cult for adult ES patients to attain a long-term normali-
zation of all hematological parameters, the efficacy of
sirolimus in adult ES patients is still promising and
durable. The lower CR…
cytopenia: a multicenter study
Hongmin Lia, Jiang Jia, Yali Dua, Yuzhou Huanga, Hao Gub, Miao Chena, RunHui Wub, and Bing Hana
aDepartment of Hematology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College,
Beijing, China; bHematology−Oncology Center, Beijing Children’s Hospital, Capital Medical University, National Center for Children’s Health,
Beijing, China
(Received 7 April 2020; revised 31 July 2020; accepted 2 August 2020)
HL and JJ contr
Autoimmune cytopenia includes autoimmune hemolytic anemia (AIHA), immune thrombocy-
topenia (ITP), and Evans syndrome (ES) caused by abnormal activation of autoimmunity
and has a considerable refractory/relapse rate. To evaluate the efficacy and toxicity of siroli-
mus of primary relapsed/refractory autoimmune cytopenia, records of 45 patients with pri-
mary relapsed/refractory AIHA, ES, or ITP from October 2016 to January 2019 in two
institutions, were collected; there were 3 pediatric patients and 42 adult patients. The
median age at diagnosis was 31 (1−84) years. Patients were treated for a median of 14
(6−39) months and followed-up for a median of 18 (10−40) months. Thirty-eight patients
responded to sirolimus, with 28 complete responses (CRs) and a median of 2 (2−5) months
to response. Five patients had mucositis; the incidences of other adverse events were all less
than 5%. Four patients relapsed, making the CR and overall response rate 46.7% and
75.6% at the end of follow-up. There were no differences in patient age, sex, time from diag-
nosis to sirolimus, serum sirolimus concentration, and disease distribution between CR and
non-CR patients, or between responders and nonresponders, though AIHA patients were
likely to relapse less and respond better. In conclusion, sirolimus is effective for patients
with primary relapsed/refractory autoimmune cytopenia with a low relapse rate and good
tolerance. © 2020 ISEH – Society for Hematology and Stem Cells. Published by Elsevier Inc.
All rights reserved.
ders characterized by immune-mediated destruction of
hematologic cell lineages [1] and results in single- or multi-
lineage cytopenia. Immune-mediated destruction can be sec-
ondary to other illnesses such as autoimmune disease,
immune deficiency, and lymphoproliferative disorders [2,3],
but are mostly idiopathic. Immune thrombocytopenia (ITP),
ibuted equally to this work. HL, JJ, and BH
and wrote the article. HL and JJ collected and
l data. YD, YH, HG, and RW helped to collect
ed critical suggestions. All authors reviewed the
all authors approved the final submission of the
to: Bing Han, Peking Union Medical College
aiFuYuan, Dongcheng District, Beijing 100730,
[email protected]
6/j.exphem.2020.08.001
drome (ES) are common autoimmune cytopenias, with con-
siderable proportions of child patients. Glucocorticoid is the
first-line therapy and can induce remission in 80%−90% of
patients [4,5]. However, the relapse rate of glucocorticoid
therapy is high, especially after dose decrement, and
some patients are refractory to glucocorticoids at the
very beginning. Second-line therapies include rituximab
and immunosuppressants such as cyclosporine A (CsA),
cyclophosphamide (CTX), and azathioprine. Unfortu-
nately, the response rate is limited, and some patients
are intolerant to the aforementioned treatments [4].
Sirolimus is a product of Streptomyces hygroscopi-
cus and has been reported to have an immunosuppres-
sive effect in preventing acute graft rejection in
by Elsevier Inc. All rights reserved.
different transplantations [6]. In a prospective multi-
institutional trial, sirolimus was effective in relapsed/
refractory autoimmune cytopenia, particularly autoim-
mune lymphoproliferative syndrome (ALPS) [7]. Other
studies have also reported its efficacy in AIHA, ES or
ITP [8,9]. However, previous studies included only
limited numbers of patients, and few studies have
included and compared the data for AIHA, ES, and
ITP for the same period. In this study, we pooled the
data from two institutions to evaluate the effects of
sirolimus on primary AIHA, ES, and ITP in both adults
and children, and compared risk factors that possibly
affect the complete response (CR) or overall response
(OR) rate.
from October 2016 to January 2019 at Peking Union Medical
College Hospital and Beijing Children’s Hospital, National
Center for Children’s Health, and treated with sirolimus were
analyzed retrospectively; patients with secondary autoim-
mune cytopenia were excluded from this study. Refractori-
ness was defined as lack of response after receiving a
sufficient number of courses of standard therapy. Clinical
data including sex, age, previous therapies, clinical symp-
toms, hematological parameters, and biochemical parameters,
were collected before and after sirolimus treatment.
This study was performed in accordance with the 1964
Declaration of Helsinki and its later amendments or compara-
ble ethics standards and was approved by the ethics commit-
tee of Peking Union Medical College Hospital and Beijing
Children’s Hospital, National Center for Children’s Health.
Informed consent was obtained from each patient before data
collection.
Treatment
Sirolimus was given at a dose of 1−3 mg/d for adults and
1−2.5 mg/d for children, and dose was adjusted if necessary
to maintain the serum concentration of sirolimus at 4−15 ng/mL
during the treatment period. All patients were treated with siroli-
mus for at least 6 months, and those who responded continued the
treatment for at least 1.5 years and tapered gradually afterward.
Evaluation of response and toxicity
Response to sirolimus and adverse events were evaluated
every month after therapy initiation and then every 2 months
when the serum concentration of sirolimus could be main-
tained at a steady level. The response criteria for AIHA, ITP,
and ES were in accordance with the consensus of an interna-
tional group [10,11]: CR = complete response or normaliza-
tion of all cytopenias (anemia and/or thrombocytopenia),
lasting longer than 2 months; PR = partial response, an increase
of 20 g/L in hemoglobin or 30£ 109/L in thrombocytes and at
least a twofold increase in the baseline count of thrombocytes,
lasting longer than 2 months, without bleeding or significant
anemia-related symptoms; OR = overall response, achievement of
CR or PR; NR = no response, a failure to achieve CR or PR;
relapse = shift from CR/PR to NR. For the evaluation of toxicity,
patients were asked about known adverse effects of sirolimus,
and their blood lipid, liver function, and kidney function were
examined. Adverse events were evaluated according to the
National Cancer Institute Common Toxicity Criteria for Adverse
Events (version 4.0) [7].
Evaluation of risk factors
responding (CR + PR) and non-responding (NR) patients.
Examination of regulatory T cells
Regulatory T (Treg) cells were defined as CD4+CD25+foxP3
+ co-expression and expressed as a percentage of the total
CD4+ T-cell population. Peripheral blood samples were taken
immediately before sirolimus and after 6 months of treat-
ment, and were determined by cytometry. Treg cells were
stained with the markers CD4-fluorescein isothiocyanate
(FITC), CD25-phycoerythrin (PE), and foxP3-allophycocya-
nin (APC) and subsequently analyzed with a Beckman Coul-
ter (Brea CA) FC500 flow cytometer. Anti-CD4 conjugated
to FITC, anti-foxP3 conjugated to APC, and anti-CD25 con-
jugated to PE antibodies were obtained from BD Biosciences
(Franklin Lakes, NJ). Total events of 50,000 were gated based
on forward- and side-scatter characteristics, and dotplots for Treg
cells were gated on CD4+ cells.
Statistical analysis
Qualitative data were expressed as the frequency (percent-
age), and continuous data as the median or mean (range) or
mean § SD. One-way analysis of variance (ANOVA) and
the Kruskal−Wallis test were used to compare quantitative
data. The x2 test or Fisher’s exact test was used to compare
categorical variables in risk factor analysis. Comparison of
laboratory values before and after sirolimus treatment was
performed using the Wilcoxon matched-pairs signed rank test
or paired t test. All tests were two-tailed, and a p value < 0.05
was considered to indicate statistical significance. Kaplan−Meier
curves were generated using GraphPad (San Diego, CA) Prism
Software. SPSS Statistics (version 25; IBM, Armonk, NY) and
GraphPad Prism software (version 5.00) were used.
Results
The 45 patients included 8 males and 37 females; there
were 3 children (<14 years old) and 42 adults, and
their baseline characteristics are summarized in Table 1.
Among them, 14 (31.1%) patients were diagnosed with
AIHA, 12 (26.7%) with ES, and 19 (42.2%) with ITP.
The median age at the time of diagnosis was 31 years
(range: 1−84 years) for all patients. All patients had
been treated with glucocorticoids as first-line therapy
before sirolimus; 30 had achieved a response but
relapsed during steroid weaning, 14 had no response,
Table 1. Patient baseline characteristics
Patient characteristics Total (n = 45) AIHA (n = 14) ES (n = 12) ITP (n = 19) p value
Male sex 8 (17.8) 2 (14.3) 2 (16.7) 4 (21.1) 1.000
Age at diagnosis, y 31 (1−84) 33 (1−84) 28 (8−50) 28 (17−68) 0.317
Previous therapies
Glucocorticoid 45 (100) 14 (100) 12 (100) 19 (100) — Cyclosporine A 11 (24.4) 2 (14.3) 3 (25.0) 6 (31.6) — Cyclophosphamide 4 (8.9) 1 (7.1) 1 (8.3) 2 (10.5) — Danazol 13 (29.9) 0 1 (8.3) 12 (63.2) — Intravenous immunoglobin 4 (8.9) 0 0 4 (21.1) — rhTPO 5 (11.1) 0 0 5 (26.3) — Azathioprine 2 (4.4) 0 1 (8.3) 1 (5.3) — Rituximab 1 (2.2) 0 1 (8.3) 0 —
Time on previous therapies, mo 21 (1−600) 19 (2−600) 34 (4−84) 21 (1−120) 0.705
Time on sirolimus, mo 14 (6−39) 12 (6−35) 16 (7−39) 12 (6−33) 0.139
Patient trough level of sirolimus, ng/mL 6.7 (2.7−19.5) 6.1 (2.7−10.7) 6.0 (3.6−10.8) 7.2 (2.9−19.5) 0.403
Follow-up time, mo 18 (10−40) 12 (12−40) 18 (10−39) 18 (10−33) 0.241
Results are expressed as the number (%) or median (range).
AIHA=Autoimmune hemolytic anemia; ES=Evans syndrome; ITP=immune thrombocytopenia; rhTPO=recombinant human thrombopoietin.
H. Li et al. / Experimental Hematology 2020;89:87−95 89
and 1 was intolerant to glucocorticoids. Second-line
therapies such as CsA, CTX, danazol, intravenous
immunoglobulin (IVIG), and recombinant human
thrombopoietin (rhTPO) were given solely or in combi-
nation to some patients as well, and the majority did
not respond to these therapies; 2 patients had a tran-
sient response to CsA, but relapsed when weaned off
the drug, and 1 patient had a response to danazol but
stopped taking the medication because of side effects
including menopause and severe acne. All patients had
stopped second-line therapy for at least 6 months and
glucocorticoids were stopped or tapered as previously
scheduled when sirolimus started. The median follow-
up time was 18 months (range: 10−40 months) after
sirolimus. The median time on previous therapies was
21 months (range: 1 month−50 years), and the median
time on sirolimus was 14 months (range: 6−39 months).
No significant difference was detected in the proportion of
males (p = 1.000), patient age distribution (p = 0.317), time
on previous therapy (p = 0.705), time on sirolimus
(p = 0.139), median trough level of sirolimus (p = 0.403),
and follow-up time (p = 0.241) between patients with
AIHA, ES, and ITP (Table 1).
Efficacy
Patient responses at 3, 6, and 12 months and at the end
of follow-up are reported in Table 2. Thirty-eight
(84.4%) of the 45 patients responded to sirolimus,
among whom 28 (62.2%) achieved an optimal response
(CR) and the remaining 10 (22.2%) had a PR. The
median time to response was 2 months (range: 2−5
months), and the time to optimal efficacy was 2 months
(range: 2−18 months). Twenty-one (75.0%) of the 28
CR patients reached optimal efficacy within 6 months
of sirolimus treatment (Figure 1A,B). The majority of OR
patients had been on sirolimus for at least 12 months;
patients who stopped sirolimus treatment within 1 year did
so mainly because of no response (Figure 1C). Three
patients were lost to follow-up as they terminated hospital
visits and could not be reached by telephone. CR and OR
rates peaked at 12 and 6 months of follow-up, respec-
tively, for the entire cohort, at 16 and 6 months of follow-
up for AIHA patients, at 6 and 6 months of follow-up for
ES patients, and at 12 and 3 months of follow-up for ITP
patients (Table 2). Of the 3 pediatric patients, 1 achieved
a CR and 1 a PR at the end of follow-up. Most patients
achieved a durable response; 1 ES patient and 3 ITP
patients relapsed at the end of follow-up. The cumulative
relapse rates at the end of follow-up for patients with
AIHA, ES, and ITP were 0, 25.0%, and 25.3%, respec-
tively (p = 0.139, Figure 1D). Consequently, the CR and
OR rates at the end of follow-up were 46.7% and 75.6%
for the whole cohort, and the CR/OR rate was 57.1%/
85.7% for AIHA patients, 25.0%/83.3% for ES patients,
and 52.6%/63.2% for ITP patients. For patients with
AIHA and ES, the level of bilirubin generally decreased
during sirolimus treatment, and the bilirubin level 3
months after treatment was significantly lower than the
baseline level before treatment (p = 0.005) and remained
stable thereafter (p = 0.022, Figure 1E). There were no
differences in patient characteristics such as age, sex,
time from diagnosis to sirolimus, serum concentration of
sirolimus, and type of disease between responders and non-
responders, or between CR and non-CR patients (Table 3).
Treg cell levels before and after treatment
Only 11 adult patients (1 AIHA, 2 ES, and 8 ITP
patients) gave their consent to test Treg cells before
and after sirolimus treatment (Table 4); a significant
increase in Treg cell levels was observed after 6 months
of treatment in tested patients (Treg/CD4+ T cells: 4.66 § 1.73% vs. 6.10 § 1.73%, p = 0.000; Figure 2).
Patient no. Disease Response during follow-up (mo) Trough sirolimus
(ng/mL)
1 AIHA PR PR CR CR 6.7 (4.1−8.8)
2 AIHA PR PR PR PR 4.2 (2.5−8.1)
3 AIHA CR CR CR CR 4.9 (3.0−5.7)
4 AIHA PR PR PR PR 7.3 (6.0−8.4)
5 AIHA CR CR CR CR 5.2 (5.0−7.9)
6 AIHA CR CR CR CR 4.2 (2.3−6.1)
7 AIHA PR PR PR CR 4.5 (3.4−6.1)
8 AIHA CR CR CR CR 2.7 (0.3−4.8)
9 AIHA CR CR CR CR 10.7 (7.3−13.1)
10 AIHA NR NR NR NR 6.3 (1.7−9.4)
11 AIHA PR CR CR CR 8.9 (5.6−11.3) Mucositis 1 Recovery without
medication
12 AIHA NR NR NR NR 7.4 (4.3−9.2)
13 AIHA NR PR PR PR 9.7 (6.8−10.5) Mucositis 1 Recovery without
medication
14 AIHA PR PR PR PR 5.8 (4.6−7.2) Upper respiratory
infection
15 ES CR CR PR PR 4.6 (2.9−9.9)
16 ES PR PR CR NR 4.7 (2.7−13.5) Headache 1 Recovery without
medication
17 ES PR PR PR CR 5.0 (2.6−6.6) Gastrointestinal
disorder
18 ES PR PR PR PR 3.6 (2.5−5.3)
19 ES CR CR PR PR 4.5 (4.1−5.8)
20 ES CR CR CR PR 4.8 (3.6−10.6)
21 ES PR PR PR PR 8.2 (5.8−10.7)
22 ES CR CR CR CR 6.9 (5.8−9.1) Urethral infection 2 Recovery with symp-
tomatic treatment
23 ES PR PR PR PR 10.8 (5.2−14.2)
24 ES PR PR PR PR 7.0 (5.9−9.6)
25 ES NR CR CR CR 8.4 (6.0−12.8) Mucositis 1 Recovery without
medication
CR rate (%) of ES 33.3 41.7 33.3 25.0
OR rate (%) of ES 83.3 91.7 91.7 83.3
27 ITP NR PR PR CR 6.2 (4.8−7.9) Rash 1 Recovery with symp-
tomatic treatment
28 ITP PR PR CR CR 5.0 (3.2−6.4)
29 ITP CR CR CR CR 9.2 (7.6−10.8)
30 ITP PR NR NR NR 4.3 (3.6−5.6)
31 ITP NR NR LTF NR 19.5 (11.5−23.3)
32 ITP PR CR CR CR 5.2 (4.0−26.7)
33 ITP PR PR PR PR 5.9 (0.3−8)
34 ITP CR CR CR NR 2.9 (2.2−20.2) Fatigue 2 Stable
Mucositis 1 Recovery without
36 ITP NR NR NR NR 4.5 (4.2−6.3) Irregular
menstruation
tomatic treatment
37 ITP NR NR LTF NR 6.5 (5.0−11.4) Hyperlipidemia 2 Recovery with symp-
tomatic treatment
38 ITP PR PR PR PR 10.2 (8.6−14.4)
39 ITP CR CR CR CR 8.9 (5.3−13.5) Mucositis 1 Recovery without
medication
40 ITP CR CR CR CR 8.7 (5.9−12.4)
41 ITP CR CR CR CR 7.7 (1.8−13.6) Hyperlipidemia 2 Recovery with symp-
tomatic treatment
(ng/mL)
42 ITP CR PR PR NR 8.9 (3.0−15.4)
43 ITP CR CR CR CR 6.9 (1.3−14.4)
44 ITP CR CR CR CR 9.4 (3.9−14)
45 ITP CR CR CR CR 7.2 (4.7−8.1)
CR rate (%) of ITP 47.4 47.4 52.6 52.6
OR rate (%) of ITP 73.7 73.7 73.7 63.2
p value for CR ratea 0.741 1.000 0.551 0.207
p value for OR rateb 0.903 0.552 0.552 0.338
AIHA=Autoimmune hemolytic anemia; CR=complete response; ES=Evans syndrome; ITP=immune thrombocytopenia; LTF=lost to follow-up;
OR=overall response; PR=partial response. aComparison of CR rate between patients with AIHA, ES, and ITP. bComparison of OR rate between patients with AIHA, ES, and ITP.
H. Li et al. / Experimental Hematology 2020;89:87−95 91
Toxicity
cohort are recorded in Table 2. Mucositis was the most
common AE with an incidence of 11.1%; the inciden-
ces of other AEs were less than 5%. Generally, only
one type of AE was observed in a single patient,
except for one patient who presented with both mucosi-
tis and fatigue. Among the 3 children, 1 presented with
mucositis and recovered without medication. The
majority of AEs occurred within the first 3 months of
treatment and resolved with or without medication.
Pharmacokinetics
reached the ideal range within the first month of treat-
ment. There were 12 patients whose sirolimus concen-
trations were out of range in the first month of
treatment and 10 patients whose sirolimus concentra-
tion was ideal in the beginning yet fell out of range
afterward (Table 2). For all of these patients, usually
one dose adjustment was enough. Only 1 patient with
AIHA, 2 with ES, and 1 with ITP experienced stepwise
sirolimus dose adjustments to raise the sirolimus con-
centration to >4 ng/mL.
nia remains a challenge, as patients’ responses to cur-
rent therapies are often unsatisfactory [12]. Sirolimus
has with the ability to inhibit the mammalian target of
rapamycin (mTOR) and regulate T-cell proliferation
[13], and has been proven to block the development of
autoimmune diseases such as systematic lupus erythe-
matosus [14]. It has also been applied to autoimmune
cytopenia in recent years [7,15], but the numbers of
patients in these studies were limited, especially
patients with primary AIHA, ES, or ITP. In addition,
the majority of studies focused on children with auto-
immune cytopenia, except that of Li et al. [16], which
comprised only adult ITP patients. Our study reports
the experience of two institutions with sirolimus in the
treatment of primary relapsed/refractory AIHA, ES,
and ITP, adults and children included. As far as we
know, this is the largest cohort study focused on siroli-
mus treatment for these three diseases. We also com-
pared the efficacy between different diseases and
evaluated other risk factors that could affect CR or.
In our study, sirolimus was effective for patients
with primary AIHA, ES, and ITP with a CR rate of
46.7% and an OR rate of 75.6%, which was in line
with most of the previous reports [7,15,16]. The CR
and OR rates of ITP patients at the end of follow-up in
our study was higher than those in Feng et al. [17],
which could be explained by the longer course of treat-
ment received by our patients. It was noticeable that
the CR rate of ES patients was 25.0%, which was rela-
tively low compared with those of the pediatric patients
studied by Miano et al. [15] and Jasinski et al. [9].
Nevertheless, an OR rate of 83.3% at the end of fol-
low-up was still satisfactory. There was a gap between
CR and OR rates of ES patients because 3 ES patients
shifted from CR to PR during treatment, but for these
patients only one hematological parameter (hemoglobin
or platelet count) dropped below normal at the end of
follow-up. Therefore, although it might be more diffi-
cult for adult ES patients to attain a long-term normali-
zation of all hematological parameters, the efficacy of
sirolimus in adult ES patients is still promising and
durable. The lower CR…
Related Documents
