Clinical features in T-cell vs. natural killer-cell variants of large granular lymphocyte leukemia

Objective: Standard clinical and laboratory evaluations and novel laboratory techniques were used to identify patients with T-cell large granular lymphocyte leukemia (LGLL) and those with natural killer-cell variants of LGLL for comprehensive clinical evaluation. Methods: We used bone marrow histologic analysis, immunophenotypic markers of clonality, and T-cell-receptor gene rearrangement studies to identify patients. Results: The study identified 44 patients with T-cell LGLL and 14 with natural killer-cell LGLL. The two disorders were similar in sex and age distribution of patients; peripheral blood lymphocyte, neutrophil, and platelet counts; and incidence of rheumatoid arthritis. Among the two groups, patients with the T-cell LGLL presented with significantly lower hemoglobin concentrations (P < 0.04) and a higher frequency of palpable splenomegaly (P < 0.01). Conclusion: Overall disease progression and response to immunosuppressive therapy are similar between T-cell and natural killer-cell variants of LGLL.