Pure red cell aplasia of the bone marrow in combination with thymoma. A literature review and own data

Eight patients were observed with a rare combination of thymoma and pure red cell aplasia of bone marrow (PRCA), of which seven women were between 44 to 68 years old. The diagnosis of PRCA was established before the detection of thymoma in 1 patient, simultaneously in 3, after - in 4. Seven patients underwent timomectomy. The weight of removed thymomas was from 200 to 780 grams. Morphological type A thymoma variant (spindle cell) was installed in 2 patients, type B1 - in 2, type B2 - in 2, type B3 - in 2. Complete remissions were obtained using cyclophosphamide and cyclosporin in 5 patients, lasting from 6 months to 7 years. The results of immunological studies with the identification of non - hemolytic antibodies to the proteolytic antigen (Pr1d) on the erythrocyte membrane in 4 patients are presented. Of these, two studied patients simultaneously detected antibodies to the Pr1d antigen and the interspecific antigen of mammalian erythroblasts (IAME). It is shown that the lifespan of red blood cells are not changed. The direct Coombs test was negative in 5 patients, but with the help of aggregate hemaglutination test and enzyme immunoassay, antibodies were detected on the surface of erythrocytes. The pathogenesis of this combination of diseases remains unclear and needs to be elucidated.