Expanded T gamma cell populations with the morphology of large granular lymphocytes -- I. Immunological, clinical and morphological characterization.

Lymphocytes from two patients with T gamma cell proliferations displaying the morphology of large granular lymphocytes (LGL) were characterized in terms of cell marker phenotyping and immunologic functions. In both patients, the lymphocytes were positive for E-R, HuTLA, OKT5, OKT8, OKT11, OKM1, VEP13, Leu1, Leu2a, Lyt2 and Lyt3 and were negative for Tmu, Tar, SIg, BA1, BA2, EM-R, C3d-R, C3b-R, OKT6, OKT9, Leu3a, OKIa1 and TdT. In addition, investigations for T411, T811 and M522 in patient 1 yielded positive results. There were differences in the phenotype of the two patients with regard to the reactions with OKT3, OKT10 and VEP10. While, in patient 1, OKT3 was very pronounced and OKT10 and VEP10 were completely negative, OKT10 and VEP10 were very pronounced in patient 2, whereas OKT3 was positive only in a very small percentage of cells. Though the lymphocytes in both patients were potent effectors of NK and K functions (patient 2 more strongly than patient 1) and a noticeably reduced mitogen response was shown to PHA, Con A and zinc, patient 1 showed a distinct suppression of allogenic and autologous B cell response to transformation into ISC, coinciding with the clinical observation of a hypogammaglobulinemia; neither B cell suppression nor dysgammaglobulinemia was seen in patient 2. The results are discussed with regard to other comparable T gamma proliferations reported in the literature.