Abnormal proliferation of CD4- CD8+ γδ+ T cells with chromosome 6 anomaly: Role of fas ligand expression in spontaneous regression of the cells

We report a case of granular lymphocyte proliferative disorder accompanied with hemolytic anemia and neutropenia. Phenotypes of the cells were T cell receptor gamma delta(+) CD3(+) CD4(-)CD8(+) CD16(+) CD56(-) CD57(-), Southern blot analysis of T cell receptor beta and gamma chains demonstrated rearranged bands in both. Chromosomal analysis after IL-2 stimulation showed deletion of chromosome 6, Sorted gamma delta(+) T cells showed an increase in Pas ligand expression compared with the levels in sorted alpha beta(+) T cells, The expression of Pas ligand on these gamma delta(+) T cells increased after IL-2 stimulation, The patient's anemia improved along with a decrease in granular lymphocyte count and disappearance of the abnormal karyotype without treatment. The expression of Pas ligand may be involved in spontaneous regression of granular lymphocyte proliferation with hemolytic anemia, (C) 1999 Wiley-Liss, Inc.