Immunological abnormalities in myelodysplastic syndromes. I. Serum immunoglobulins and autoantibodies.

The immunoglobulin levels and autoantibody profiles of 104 patients with primary myelodysplastic syndromes (MDS), classified according to the FAB criteria, were analysed. Eight patients, four with coexistent non-Hodgkin's lymphomas, three with chronic lymphocytic leukaemia and one with a lymphoplasmacytoma, were excluded from the final analysis of immunoglobulin levels. Serum protein electrophoresis and immunoelectrophoresis revealed the presence of monoclonal gammopathy in 12 patients (12.5%). Of the remaining 84 patients, a polyclonal rise in serum immunoglobulins was present in 27 (32%) while a further 16 (19%) had low immunoglobulin levels. The direct antiglobulin test was positive in eight out of 98 patients tested (8.1%), and organ and non-organ specific autoantibodies were present in 15 out of 67 patients tested (22.3%). Two patients had associated pernicious anaemia (PA), two hypothyroidism, and one PA with hypothyroidism. Three patients had sero-negative rheumatoid arthritis. These results demonstrate that there is a high incidence of immunological abnormalities in MDS.