IMMUNOLOGICAL ABNORMALITIES OF CHRONIC LARGE GRANULAR LYMPHOCYTOSIS

Chronic large granular lymphocytosis is a relatively common condition and comprises a clinically heterogenous group of patients. Phenotypica lly these can be divided into CD3+ (T cell) and CD3- (NK cell) expansi ons. They are characterized by a benign clinical course and a mild lym phocytosis, though a specific subgroup have a history of auto-immune d isease and cytopenias. In order to develop a better understanding of t he immunological abnormalities associated with this condition we exami ned systematically serum samples from 92 such patients for the presenc e of auto-antibodies, acute phase proteins and immunoglobulin levels. Auto-antibodies were found in 34% of patients and rheumatoid factor in 26%, though only half of these had active arthritis. Anti-neutrophil antibodies were negative in all cases. Quantitative immunoglobulin abn ormalities were frequent with a distinct paraprotein present in three patients. The high incidence of multiple immunological abnormalities i n these patients ranged from polyclonal hypergammaglobulinaemia and au toantibodies through to monoclonal gammopathy. The aetiology of these abnormalities was unclear and undoubtedly complex, and should necessar ily form part of the diagnostic investigations for all patients with p ersistent large granular lymphocyte expansions.