Philadelphia Chromosome-Positive Myelodysplastic Syndrome With Single Lineage Dysplasia

Banaras Hindu University Vijai Tilak 
Banaras Hindu University Disha Arora 
Banaras Hindu University Marisha 
Banaras Hindu University Rahul 
Banaras Hindu University Akhtar Ali  ( [email protected] )
Banaras Hindu University
Posted Date: July 5th, 2022
DOI: https://doi.org/10.21203/rs.3.rs-1785114/v1
License: This work is licensed under a Creative Commons Attribution 4.0 International License.   Read Full License
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Abstract Myelodysplastic syndrome (MDS) is a group of acquired clonal disorders characterized by dysplastic and ineffective hematopoiesis in the bone marrow. Various specic karyotypic and molecular abnormalities associated with MDS further guide the prognosis. Although translocation t(9;22)(q34;q11) (Philadelphia positive [Ph+]) and corresponding BCR-ABL fusion transcript are classically dened to differentiate CML from non-CML myeloproliferative disorders, it is also associated with adult acute lymphoblastic leukemia (Ph + ALL), acute myeloid Leukemia (Ph + AML), myelodysplastic syndrome (Ph + MDS). The occurrence of Ph + MDS is very uncommon, and a review of literature has shown by far 40 cases so far in which the majority are seen on progression to Leukemia. Few had de novo presence of such chromosomal abnormality. Due to its rarity, this entity has not yet found its space in the current WHO classication. Also, the role of tyrosine kinase inhibitors in such a scenario is still debatable. We found two such cases of de novo Ph + MDS diagnosed at institute of medical sciences, Banaras Hindu university and a brief literature review.
Introduction The Philadelphia chromosome is a reciprocal translocation of some segment of chromosome 9 and chromosome 22 in a balanced manner, genes were involved in the BCR region (breakpoint cluster) for chromosome 22 and ABL (Abelson protooncogene) gene involved in chromosome 9. Chromosome 22 is smaller in size after translocation so clearly visible in the naked eye, whereas chromosome 9 is larger and cannot be seen the translocation well in nacked eye. It is associated with a particular human cancer, chronic myelogenous leukemia (CML), the BCR-ABL fusion transcript. It was rst identied in leukemia in 1960 as an abnormally small chromosome present in 95% of CML cases.1 There are three distinct clinical stages characterized by World health organization in chronic myeloid leukemia: chronic phase, accelerated phase, and blast crisis.
Myelodysplastic syndrome (MDS) is a clonal condition of bone marrow pluripotent stem cells and it is groups of myeloid diversify malignancies. MDS estimates the actual disease burden and its impact on the Indian and worldwide populations. Genetics plays pivotal role in diagnosis and prognostic of most malignancies. MDS is produce by a single cell's clonal growth that has acquired a somatic mutation in one allele of a normally functioning gene that regulates cellular maturation and division. Cytogenetic abnormalities are common in advanced cancers, and tumor-specic chromosomal translocations, like translocations and other genetic abnormalities, directly contribute to malignant transformation. Chromosomal anomalies known in MDS include del 11q, -Y, der (1;7), del (5q), del(12p), and del(20q) which forms transcriptionally active regions. Myelodysplastic syndrome symptoms include shortness of breath and fatigue. In myelodysplastic syndrome with single lineage dysplasia, they affect a single type of blood cell. These patient have low numbers of RBC, WBC, and platelets also called anemia, neutropenia, and thrombocytopenia. Specic mutations related with morphologic characteristics and MDS include the SF3B1 mutation, which is associated with ring sideroblasts, and mutations in ASXL1, RUNX1, TP53, and SRSF2.2 There is a reciprocal translocation involving chromosome 22 BCR region
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(breakpoint cluster) and chromosome 9 ABL1 gene (Abelson protooncogene) with results in the formation of fusion oncogene, which encodes chimeric protein BCR-ABL1. The molecular weight of this fusion protein varies from 185 to 210 kDa depending on the precise region of fusion (clinically signicant variants are p190, p210, and p230 isoforms) 3. p190 has been linked to B cell ALL, whereas p210 has been linked to CML. Still, both can occur in AML and ALL, while p230 is associated with CML with neutrophilia (CML-N)4. Ph + MDS is rarely reported in the literature, but its presence in prognosis and treatment is not yet dened. The myelodysplastic syndrome can develop after treatment or environmental exposure to radiation, toxins, or chemotherapeutic agents. Usually, the patient remains asymptomatic for a long time before diagnosis. Chromosome loss or deletion is a common cytogenetic abnormality like 5 or 7, del 20q, a gain of function of chromosome 8. Conventional karyotyping for the Philadelphia chromosome is not routinely done in such patients. Still, few case reports have shown its association with acute leukemia progression.5 here we reported two de novo Ph + MDS cases.
Case Reports And Results
CASE 1 A 66-year-old male, known hypertensive, presented with generalized body weakness and easy fatigability for two months. Physical examination showed no organomegaly or lymphadenopathy except for pallor. His pathological investigations showed that Megakaryocytes were adequate in number with signicant dysplasia is the form of monolobated & hypolobated forms. Pearl stains showed 4 + iron stores with no ringed sideroblast marrow spaces are normocellular was very high representation of granulopoiesis, with low hemoglobin 6gm/dl severe erythroblastopenia, monolobated and hypolobated megakaryocytes with signicant dysplasia observed. (Table 1. A and B).
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Parameter Patient value Normal range
Hemoglobin 6 gm/dl 13–17 g/dl
Mean corpuscular volume
88.8/ 80–100
Mean corpuscular hemoglobin
29.4 pg 27-32pg
Platelet 1,25,000/ul 150–410 x 103ul
Total leucocyte count
Differential leucocyte count
Lymphocyte 20–40%
Monocytes 2–10%
Eosinophil 1–6%
Basophils < 1–2%
Within normal limits  
Iron 207.57 58–158 mcg/dl
TIBC 216.87 250–425 mcg/dl
Ferritin 1272 80–270 ng/ml
General blood picture
 
ESR 46 ≤ 14 mm in Hrs
Vitamin B12 1400 190–950 pg/ml
Table 1 B. Bone marrow aspiration
CELLULARITY: Particulate variable cellularity ranging for hypercellular to normocellular
M: E Ratio M: E ratio cannot be determined due to severe erythroblastopenia (100 nucleated bone marrow cells were counted, and not a single erythroid cell was observed.
Erythropoiesis: Marked depressed normoblastic
Megakaryopoiesis: Megakaryocytes were adequate in number with signicant dysplasia is the form of monolobated & hypolobated forms.
Perl’s stain Pearl stains showed 4 + iron stores with no ringed sideroblast
Trephine biopsy Marrow spaces are normocellular Adequate representation of granulopoiesis, severe erythroblastopenia, monolobated and hypolobated megakaryocytes with signicant dysplasia observed.
Reticulin: MF 0
Myelodysplastic syndrome with single lineage dysplasia
Based on the above ndings, a provisional diagnosis of MDS with 5q deletion was suspected, and bone marrow aspirate for karyotyping and FISH for 5q deletion was advised. FISH for 5q deletion was not observed in any cell. Bone marrow biopsy report was suggestive of myelodysplastic syndrome with single lineage dysplasia. Conventional karyotyping showed presence of 46 XY, t(9;22) (q34;q11.2). Karyogram showed in Fig. 1 and bone marrow aspiration in Fig. 2.
CASE 2 A 60-year-old female with no comorbidities presented with generalized body weakness for 5 months. On examination, pallor was present with no organomegaly. She was investigated as follows. Details shown in Table 2. A and B.
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Parameter Patient value Normal range
Hemoglobin 9.6 gm/dl 13–17 g/dl
Mean corpuscular volume 91.3/ 80–100
Mean corpuscular hemoglobin
Platelet 110 x 103/microliter 150–410 x 103
Total leucocyte count 6.75 x 1000/microliter 4–10 x 103/ ul
Differential leucocyte count N72, L24, E02, M02
(neutrophil/lymphocyte/eosinophil/monocytes)
LDH 178 U/L 140–280 U/L
Iron 150 58–158 mcg/dl
TIBC 200 250–425 mcg/dl
Ferritin 980 80–270 ng/ml
General blood picture Microcytic hypochromic anemia
WBC: within normal limit
 
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CELLULARITY: Particulate variable cellularity ranging from hypercellular to normocellular
M: E Ratio 1.4:1
Megakaryopoiesis: Megakaryocytes were adequate in number with signicant dysplasiain the form of monolobated & hypolobated forms.
Other nding: Signicant adipocytosis seen
Perl’s stain 3 + iron stores with no ring sideroblast.
Trephine biopsy Marrow spaces are normocellular. Adequate representation of granulopoiesis, moderate erythroblastopenia, monolobated and hypolobated megakaryocytes with signicant dysplasias observed.
Reticulin: MF 0
Myelodysplastic syndrome with single lineage dysplasia
Based on the higher than ndings, a tentative designation of MDS with 5q deletion was suspected, and bone marrow aspirate for karyotyping and FISH for 5q deletion was advised. FISH for 5q deletion wasn't ascertained in any cell. Bone marrow diagnostic assay report was connotative myelodysplastic syndrome with single lineage dysplasia. Typical karyotyping showed presence of 46XX, t(9;22) (q34;q11.2). Karyogram showed in gure three and bone marrow aspiration in Fig. 4. Therefore, the present case is described as a Philadelphia positive myelodysplastic syndrome (MDS) with single lineage dysplasia.
In both cases, bone marrow examination was suggestive of myelodysplastic syndrome with single lineage dysplasia, and karyotyping showed the presence of t(9;22) with no other chromosomal abnormality. So, the nal diagnosis of Philadelphia chromosome-positive MDS with single lineage dysplasia was kept. Supportive therapy was started for both the patients (erythropoietin with anabolic steroids). Both Patients responded well with a rise of hemoglobin to 9.3 and 11.6 respectively in follow-up at two months. They are in close follow-up.
Discussion MDS is a clonal disorder in which chromosomal abnormalities occur in 50 percent of karyotyped cases and 80 percent of secondary and therapy-related MDS.6 International prognostic scoring system scores include cytopenias, bone marrow blast percentage, and karyotype7. However, 14% of the cytogenetic abnormalities seen in MDS have no prognostic signicance. It is well known that neither all the molecular genetic changes turn into cytogenetic abnormality nor all cytogenetic abnormality is translated into well- dened molecular events5. Philadelphia positivity with MDS is an association whose prognostic signicance is yet to be determined. However, Table 2 of the literature review points towards poor
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outcomes of such patients. Keung et al.,8 reported that all three cases progressed to granulocytic sarcoma or AML.
Similarly, Dutta et al.9 showed despite imatinib therapy transformation to blast crisis occurred. Manabe et al.10 showed similar outcomes. The likely explanation behind such outcome is increased proliferation in marrow due to increased tyrosine kinase activity due to BCR ABL translocation, which further activates signaling pathways like Myc, Ras, c-Raf, NFKB, MAPK/ERK, SAPK/JNK, STAT, c-JUN, PI-3 kinase. But paradoxically, peripheral cytopenias are seen in MDS Ph + cases as seen in our case. Whether Ph + acute leukemias are a distinct entity or just a blast phase of undiagnosed CML is a matter of question; however, most experts consider these two as separate entities. t(8;21) associated with MDS transforms into AML in around three months, so current WHO guidelines consider t(8,21) MDS to be treated as AML11. A review of the literature reveals that determine average time of Ph + MDS to transform into leukemia is around 13 months. But, whether this recommendation can be extrapolated to Philadelphia positive MDS cases is not yet certain. Current NCCN guidelines also don’t recommend routine use of conventional karyotyping in every MDS case.
Also, the role of using tyrosine kinase inhibitors in de-novo Ph + MDS without pre-existing CML is a matter of debate due to the rarity of such an entity. In patients with Ph + ALL, imatinib induces complete cytologic and hematologic responses like in CML in blastic phases.12 At present, Ph + MDS is being treated as ordinary MDS until progression to AML, however, more studies are required to justify this rationale.
Declarations Ethical approval was obtained from the institutional ethical committee (Ref. No: I.Sc./ECM-XII/2021-22) Institute of Science, Banaras Hindu University, and written informed consent was obtained from the patient/participant for publication.
CONFLICTS OF INTEREST- The authors have declared that no conict of interest exists.
ACKNOWLEDGEMENTS- Fellowship support was provided by CSIR-UGC NET JRF.
References 1. Kang, Z. J., Liu, Y. F., Xu, L. Z., Long, Z. J., Huang, D., Yang, Y., … Liu, Q. (2016). The Philadelphia
chromosome in leukemogenesis. Chinese journal of cancer, 35(1), 1–15.
2. Caponetti, G. C., & Bagg, A. (2020). Mutations in myelodysplastic syndromes: Core abnormalities and CHIPping away at the edges. International Journal of Laboratory Hematology, 42(6), 671–684.
3. Advani, A. S.; Pendergast, A. M. (2002). "Bcr-Abl variants: Biological and clinical aspects". Leukemia Research. 26 (8): 713–720.
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4. Zahid, M. F., Malik, U. A., Sohail, M., Hassan, I. N., Ali, S., & Shaukat, M. H. S. (2017). Cytogenetic abnormalities in myelodysplastic syndromes: an overview. International journal of hematology- oncology and stem cell research, 11(3), 231.
5. Pakakasama, S.; Kajanachumpol, S.; Kanjanapongkul, S.; Sirachainan, N.; Meekaewkunchorn, A.; Ningsanond, V.; Hongeng, S. (2008). "Simple multiplex RT-PCR for identifying common fusion transcripts in childhood acute leukemia". International Journal of Laboratory Hematology. 30 (4): 286–291.
. Chen G, Zeng W, Miyazato A, Billings E, Maciejewski JP, Kajigaya S, et al. Distinctive gene expression proles of CD34 cells from patients with myelodysplastic syndrome characterized by specic chromosomal abnormalities. Blood 2004;104:42108.
7. www.lls.org/myelodysplastic-syndromes/diagnosis/international-prognostic-scoring-system
. Keung YK, Beaty M, Powell BL, Molnar I, Buss D, Pettenati M. Philadelphia chromosome positive myelodysplastic syndrome and acute myeloid leukemiaretrospective study and review of literature. Leuk Res 2004;28:57986.
9. Dutta S, Kumari P, Natraj KS, Mandal PK, Saha S, Bagchi B, et al. Philadelphia chromosomepositive myelodysplastic syndrome: Is it a distinct entity? Acta Haematol 2013;129:215
10. Manabe M, Yoshii Y, Mukai S, Sakamoto E, Kanashima H, Nakao T, et al. Late appearing Philadelphia chromosome as another clone in a patient with myelodysplastic syndrome harboring der(5;12) (q10;q10) at diagnosis. Rinsho Ketsueki 2012;53:61822.
11. Brunning RD, Matutes E, Flandrin G, Vardiman J, Bennett JM, Head D, et al. Acute myelogenous leukemia with recurrent cytogenetic abnormalities. In: Jaffe ES, Harris NLSH, Vardiman JW, editors. Pathology and genetics of tumours of haematopoietic and lymphoid tissues. Lyon: IARC Press; 2001. p. 81–7
12. Druker BJ, Sawyers CL, Kantarjian H, Resta DJ, Reese SF, Ford JM, et al. Activity of a specic inhibitor of the BCR-ABL tyrosine kinase in the blast crisis of chronic myeloid leukemia and acute lymphoblastic leukemia with the Philadelphia chromosome. N Engl J Med 2001;344:1038–42.
Figures
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Figure 1
A. Metaphase shown in MDS patient chromosome. B.  Karyogram of MDS patient shown Philadelphia chromosome.
Figure 2
A & B Bone marrow aspiration (40X) shown Dysplastic monolobated megakaryocytes C. Interphase FISH with a probe shows LSI 5q EGRF1 spectrum Orange D5S23 spectrum Green DC DNA probe. Monosomy 5 or deletion of 5q was not observed in any cells.
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Figure 3
A. Metaphase shown in MDS patient chromosome. B.  Karyogram of Female MDS patient shown Philadelphia chromosome.
Figure 4