T-gamma lymphocytes in a case of congenital hypoplastic anemia (Diamond-Blackfan syndrome)

We analyzed surface markers on lymphocytes from Bone Marrow (BM) and Peripheral Blood (PB) obtained from a patient with Diamond-Blackfan Syndrome (CHA). The percentage of T lymphocytes which carry the receptor for the Fc of IgG (T-gamma cells) was significantly increased in both PB and BM at onset of the disease. The serum of the patient fcontained a factor capable of drastically inhibition CFU-E and BFU-E, but not CFU-C ('blocking factor'). T-gamma cells returned to normal percentage after prednisone treatment. However, prednisone therapy did not alter the inhibitory activity of the serum 'blocking factor'. The possible roles of T-gamma cells and serum blocking factor in the pathogenesis of CHA are discussed. Our studies suggest an immunological mechanism in the disease process.