Pure Red Cell Aplasia PRCA

Pure Red Cell Aplasia

Pure Red Cell Aplasia (PRCA)

An uncommon disorder in which maturation arrest occurs in the formation of erythrocytes

A type of anemiaaffecting the precursors tored blood cellsbut not towhite blood cells Bone marrow ceases to produce red blood cells

In 1922Kaznelson recognized that this condition was a different entity fromaplastic anemia, which presents with pancytopenia

Etiology and MorphologyAutoimmune diseaseIdiopathicThymomaLymphoproliferativeViral infections: HIV, Herpes, Parvovirus B19 (fifth disease) or HepatitisCongenital: Diamond-Blackfan anemia (hereditary)Self-limited Transient erythroblastopenia of childhood Transient aplastic crisis of hemolysis (acute B19 parvovirus infection)Fetal red blood cell aplasia Nonimmune hydrops fetalis (in utero B19 parvovirus infection)Hereditary pure red cell aplasia Congenital pure red cell aplasia (Diamond-Blackfan syndrome)Acquired pure red cell aplasia Thymoma and malignancy Thymoma Lymphoid malignancies (and more rarely other hematologic diseases) Paraneoplastic to solid tumors Connective tissue disorders with immunologic abnormalities Systemic lupus erythematosus, juvenile rheumatoid arthritis, rheumatoid arthritis Multiple endocrine gland insufficiency Virus Persistent B19 parvovirus, hepatitis, adult T cell leukemia virus, Epstein- Barr virus Pregnancy Drugs4

Etiology and MorphologyBone Marrow

severe lack of erythroid precursorsmyeloid precursors megakaryocytic elementslymphocytes

Pure red cell aplasia is morphologically characterized by severe lack of erythroid precursors in the bone marrow whereas myeloid precursors and megakaryocytic elements are unaffected and are present in normal numbers. This bone marrow aspirate shows myeloid precursors and lymphocytes but not a single red cell precursor can be identified. The two arrows indicate two darkly stained lymphocytes that simulate late erythroid precursors but are not. Pure red aplasia is much more commonly acquired secondary to viral infections, drugs, autoimmune disorders, thymoma, and idiopathic but rare congenital syndromes also exist such as Diamond-Blackfan syndrome. This patient suffered from a self-limiting systemic viral syndrome with reversal of the anemia and reticulocytosis after resolution of the viral syndrome.5

PathogenesisHumoralCellularUnhealthy marrow environmentPlasma inhibitor of erythropoiesis

Signs and SymptomsBone marrow

Decrease in the number of RBCsdeficient in the number of precursors of RBCs(erythroblasts)Levels of the hormone erythropoietin that stimulates the bone marrow to produce RBCs are usually elevated.

Fatigue, lethargy or listlessness, pallor(abnormal paleness of skin) , poor appetite, congestive failure with breathlessness, hepatomegaly, and splenomegaly

Screening

Confirmatory

BONE MARROWPERIPHERAL BLOOD

Case StudyPure red cell aplasia associated with thymoma: clinical insights from a 50-year single-institution experience

By :Carrie A. Thompson and David P. SteensmaDivision of Hematology, Department of Medicine, Mayo Clinic, Rochester, MN, USA

Acquired pure red cell aplasia (PRCA) is a rare disorder of erythropoiesis that can develop in association with a thymoma. Optimal management of this subgroup is unclear, and there have been few series reporting long-term clinical outcomes. The median age at PRCA diagnosis was 65 years (range 3176 years) with no gender predilection (seven males and six females) and median haemoglobin concentration of 6.1 g/dl (range 4.89.1)http://onlinelibrary.wiley.com/doi/10.1111/j.1365-2141.2006.06295.x/pdf12

All but one patient underwent surgical excision of the thymoma. The patient who did not undergo resection had significant medical co-morbidities that precluded operative intervention13 patients treated for PRCA associated with thymoma over 50 years at our institution

Surgical resection of the thymoma was insufficient for normalisation of erythropoiesis in all casesT-cell gene rearrangement studies did not routinely demonstrate a clonal process, and ciclosporin and anti-thymocyte globulin were effective adjuvant treatments

However, treatment-related morbidity was high, with frequent infectious complications