Severe neutropenia in a patient with large granular lymphocytosis: prolonged successful control with cyclosporin A.

A case of severe neutropenia associated with large granular lymphocytosis in a 40-year-old female is described. The patient, with no findings of an underlying systemic disorder, had suffered from recurrent life threatening, mainly pseudomonal, infections for about two years, despite the various regimes tried. During the last twelve months cyclosporin A treatment resulted in a significant increase in absolute neutrophil counts, concomitant with a remarkable decrease in bone marrow infiltration by GLs and almost normal counts of GLs in the peripheral blood. During this time she has remained completely free from infectious episodes. The mechanisms involved remain to be determined.