GRANULAR LYMPHOCYTE PROLIFERATIVE DISORDERS - A MULTICENTER STUDY OF 20 CASES

A series of 20 patients with granular lymphocyte proliferative disorde rs (GLPD) is reported. The criterion of inclusion was presence of pers istent (greater than or equal to 6 months) granular lymphocytosis in t he absence of any causative illness. Diagnoses made upon analytical co ntrol in half the patients of splenomegaly (25%) and hepatomegaly (25% ) were infrequent. Clinical course was nonprogressive in 17/20 patient s, but two developed high-grade NHL several years later and one showed progressive disease. Actuarial probability of survival at 5 years was 85%. Granular lymphocyte morphology was relatively homogeneous, and p eripheral blood counts were preserved in the most patients. Bone marro w lymphocytic infiltration was low, as assessed by bone marrow aspirat ion and/or biopsy. Eosinophilia was an outstanding feature in eight ca ses. Ultrastructurally, all cases showed parallel tubular arrays; cyto plasmic granules and numerous short microvilli were noticed. The lymph oid phenotype was heterogeneous, the most common being CD2+CD3+CD4-CDg +, but six patients (30%) were CD4+ with variable expression of natura l killer-associated antigens. Chromosomal analysis was abnormal in 4/1 0 patients [trisomy 19, t(5,6), inv(14) and inv(10)]. The study of bet a-chain of the T-cell receptor revealed clonal rearrangements in 14 (7 8%), restricted to CD3+ patients (92%). In vitro culture of myeloid pr ecursors showed decreased CFU-GM in 5/6 patients. Virological studies for HTLV-I and II were negative. In conclusion, the presence of a clon al proliferation was not correlated with the clinical course or an ass ociated disease.