Decreased 5' nucleotidase activity in lymphocytes from asymptomatic
sexually active homosexual men and patients with the acquired immune
deficiency syndrome
JL Murray, JM Reuben, CG Munn, PW Mansell, GR Newell and EM Hersh
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/10(6) cells/h) and T-enriched
(12.0 +/- 6.0 nmol/10(6) cells/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 less than .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 Ia
(13% +/- 2.9%) than controls (11% +/- 1.8% and 5% +/- 0.8%, respectively, P
less than .05). They also had a significantly lower fraction of
OKT4-positive helper lymphocytes than controls (22% +/- 3.4% v 35% +/-
2.2%, P less than .05). 5'NT activity in lymphocytes enriched for null
cells from homosexuals correlated inversely with the percentage of
Ia-positive lymphocytes (r = -.655; P less than .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 less than .025) and OKT8 (P less than .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.
Volume 64,
Issue 5,
pp. 1016-1021,
11/01/1984
Copyright © 1984 by The American Society of Hematology
