Chronic T cell lymphocytosis with large granular lymphocytes of helper (OKT4) phenotype.

A 54-year-old asymptomatic male patient was followed for more than 7 y and presented a constant T cell lymphocytosis without skin involvement or bone marrow depression. No clinical or haematological aggravation was noted during this follow-up. Morphologically, the cells were large granular lymphocytes strongly positive for beta-D-glucuronidase, negative for acid phosphatase and with features of T cells on transmission and scanning electron microscopy. The immunological studies of the lymphocytes showed the following parameters: E rosettes+, mouse rosettes-, SmIg-, OKT3+, OKT4+, OKT8-, OKT6-, Ia-, TdT-, NK-, HTLV-, decreased PHA and PWM stimulation, no interleukin 2 production and failure to enhance Ig synthesis in a PWM driven system. The karyotype was normal. This case of chronic T cell lymphocytosis with large granular lymphocytes helper profile and defect of helper function, not reported in the literature, may correspond to a distinct entity in the heterogeneous group of chronic T cell disorders.