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

We report a patient with clonal proliferation of CD3(+)8(+)TCR alpha beta() large granular lymphocytes (LGL) presenting multiple episodes of autoimmu ne cytopenia, including autoimmune neutropenia, idiopathic thrombocytopenic purpura, autoimmune haemolytic anaemia, and pure red cell aplasia. Each di sorder appeared separately or as a combination during an 11-year clinical c ourse. The increase of blood CD3(+)8(+)TCR alpha beta(+) LGL was detected 6 years after the initial diagnosis of cptopenia, but the absolute number of LGL cells was always <1.0x10(9)/l. LGL cells were of monoclonal origin and had a chromosomal abnormality. LGL cells transiently responded to cyclospo rine A therapy, which was also effective on all of these autoimmune cytopen ias. Accordingly, an undetectable level of proliferation of a clonal LGL po pulation could cause various autoimmune haemopoietic disorders.