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5′ Nucleotidase (5′NT) is an ectoenzyme associated with the plasma membrane of most mammalian cells. Low 5′NT activity has been observed in peripheral blood lymphocytes from patients with immunodeficiency states. 5′NT activity was measured in null and T-enriched lymphocytes from asymptomatic homosexual men and from 20 men with various degrees of the acquired immune deficiency syndrome (AIDS). Asymptomatic homosexuals were self-referred because of their concern about AIDS and were not necessarily representative of homosexuals in the general population. Enzyme activity was significantly decreased in both null (7.0 ± 2.4 nmol/106cells/h) and T-enriched (12.0 ± 6.0 nmol/106cells/h) lymphocytes in homosexuals as compared to lymphocytes from aged-matched heterosexual male and female controls (null = 10.8 ± 6.5 and T = 22.3 ± 10.6, P< .0001 and .008, respectively). Decreased activity was present regardless of whether the patients were asymptomatic, had prodromal symptoms such as fever, lymph node enlargement, weight loss and diarrhea, or had opportunistic infections or Kaposi’s sarcoma. Homosexuals had a significantly higher fraction of lymphocytes expressing the activation antigens T10 (20% ± 3.3%) and la (13% ± 2.9%) than controls (11% ± 1.8% and 5% ± 0.8%, respectively, P< .05). They also had a significantly lower fraction of OKT4-positive helper lymphocytes than controls (22% ± 3.4% v35% ± 2.2%, P< .05). 5′NT activity in lymphocytes enriched for null cells from homosexuals correlated inversely with the percentage of Ia-positive lymphocytes (r= –.655; P< .02). There was no correlation between 5′NT activity and the percentage of T4- or T8-positive lymphocytes or the T4/T8 ratio. Moreover, 5′NT activity was significantly decreased in both OKT4 (P< .025) and OKT8 (P< .05) enriched lymphocytes in homosexuals compared to controls. The data suggest that decreases in 5′NT may be a generalized defect of the peripheral blood T lymphocytes from active homosexuals that is independent of increases or decreases in specific T subpopulations or clinical status. It may contribute to the pathogenesis of AIDS.

A quantitative immunomorphological analysis of actively responding B-(germinal centre) and T-lymphocyte (paracortical) areas in 187 patients with malignant melanoma recurrent in the regional lymph nodes has been made. The results show that tumour involved nodes have significantly increased germinal centre and decreased paracortical response in comparison with uninvolved lymph nodes. Patients treated with surgery alone whose uninvolved nodes had hyperplastic (defined as exceeding the median) germinal centre areas, had significantly shorter survival than those without germinal centre hyperplasia. No association was found between lymph node immunomorphology and survival in BCG treated patients.

The effects of repeated leukapheresis with the IBM Blood Cell Separator were assessed in 13 patients with chronic lymphocytic leukemia (CLL). Five patients had from 14 to 25 leukaphereses at intervals ranging from 7 to 33 days. The median total number of lymphocytes removed was 18.0 × 1011(range 11.9 × 10H-26.6 × 1011). Two of these patients had a decrease in lymphocyte count and in lymphadenopathy. One of the above and eight additional patients had intensive leukapheresis therapy consisting of five procedures per week for 1-4 wk. The median total number of lymphocytes removed from these patients was 11.34 × 1011(range 3.30 × 1011-47.4 × 1011). Eight of these patients had a decrease in lymphocyte count, five in spleen size, eight in lymph node size, seven in bone marrow infiltration, and one in liver size. Lymphocyte counts before beginning leukapheresis therapy ranged from 20,500 to 684,000 (median 70,900). The median lymphocyte count on completion of treatment was 19,200 (range 6,590-40,000). After leukapheresis therapy, the median doubling time of the lymphocyte count was 71 days (range 29-118 days). In addition to demonstrating a significant proliferative component in CLL, the objective regression of disease in ten of the 13 patients suggests that leukapheresis is a potentially useful treatment for CLL.