Multiple autoimmune haemopoietic disorders and insidious clonal proliferation of large granular lymphocytes.

We report a patient with clonal proliferation of CD3+8+TCRalphabeta+ large granular lymphocytes (LGL) presenting multiple episodes of autoimmune cytopenia, including autoimmune neutropenia, idiopathic thrombocytopenic purpura, autoimmune haemolytic anaemia, and pure red cell aplasia. Each disorder appeared separately or as a combination during an 11-year clinical course. The increase of blood CD3+8+TCRalphabeta+ LGL was detected 6 years after the initial diagnosis of cytopenia, but the absolute number of LGL cells was always < 1.0 x 109/l. LGL cells were of monoclonal origin and had a chromosomal abnormality. LGL cells transiently responded to cyclosporine A therapy, which was also effective on all of these autoimmune cytopenias. Accordingly, an undetectable level of proliferation of a clonal LGL population could cause various autoimmune haemopoietic disorders.