MM-098: A Case Report: Acquired Pure Red Cell Aplasia Associated with Monoclonal Gammopathy of Undetermined Significance

Abstract

Background: Pure Red Cell Aplasia (PRCA) is a rare disorder characterized by profound anemia and absence of erythroid precursor in the bone marrow, and it can be genetic or acquired; the acquired form can be idiopathic or secondary and one of these causes is monoclonal gammopathy (MG). In review of the literature, we found a few cases that were treated in different ways. Case Presentation: We will report a case of pure red cell aplasia associated with monoclonal gammopathy of undetermined significance; the patient admitted for severe anemia with hemoglobin 5.4 g/dl, MCV 120 fl, and white blood count (WBC) was 3750/mm3 with 67% neutrophils and a normal platelet count. The workup was done and showed a reticulocyte count of 0.03%, negative coombs (direct and indirect), negative ANA, and anti-double stranded DNA (dsDNA). Vitamin B12 was 900 pg/ml and folate 7.66 ng/ml; serology for HIV, HBV, and HCV found to be negative. TSH, LDH, liver function tests were all normal. Erythropoietin level was 11.79 IU/L. Bone marrow aspirate revealed a cellular bone marrow (60-70%) with less than 5% plasma cells expressing excess lambda light chain. Immunohistochemistry using CD138 confirmed the result and flow cytometry revealed a small population of plasma cells with aberrant phenotype. Serum protein electrophoresis showed a monoclonal gamma peak and immunofixation showed high light lambda chains. Total body MRI showed diffuse infiltrative marrow disorder. Patient was treated with Lenalidomide 25 mg daily on days 1-21 of repeated 28-day cycles and Dexamethaxone 8 mg twice weekly with excellent response. After 6 months of treatment and follow-up, patient had normal bone marrow cytology, normal hemoglobin, and normal reticulocyte count.