Biphasic rate of CD4+ cell count decline during progression to AIDS correlates with HIV-1 phenotype.
OBJECTIVE
To determine the kinetics of decline of CD4+ lymphocytes in HIV-1-infected asymptomatic homosexual men.


METHODS
CD4+ lymphocytes were enumerated in a cohort of 187 HIV-1-infected initially asymptomatic homosexual men seen at 3-month intervals over 5 years. During follow-up, 45 men progressed to AIDS (excluding cases presenting with Kaposi's sarcoma). Correlation between rate of CD4+ cell decline and presence of a particular HIV-1 biological phenotype was analysed in 43 participants.


RESULTS
CD4+ cell counts declined slowly and continuously in HIV-1-seropositive men who remained asymptomatic during follow-up. A biphasic CD4+ cell count decline was observed in the group who developed AIDS: the decline was slow and steady (5.6 x 10(6)/l per month, similar to that observed in the asymptomatic group) until 18 months before AIDS diagnosis, but became three to five times faster thereafter. Rapid CD4+ cell decline was significantly related to syncytium-inducing, fast-replicating HIV-1 isolates; during the period of slow and steady CD4+ cell count decline, non-syncytium-inducing isolates were predominant.


CONCLUSIONS
At an average of 18 months preceding AIDS diagnosis, a three to fivefold increase in the rate of loss of CD4+ lymphocytes occurs, and may be related to the appearance of a more virulent HIV-1 phenotype.
Schellekens
P T
PT
Central Laboratory of The Netherlands Red Cross Blood Transfusion Service, Amsterdam.
Tersmette
M
M
Roos
M T
MT
Keet
R P
RP
de Wolf
F
F
Coutinho
R A
RA
Miedema
F
F
D000163:Acquired Immunodeficiency Syndrome / Q000382:microbiology / Q000473:pathology*; D015496:CD4-Positive T-Lymphocytes / Q000382:microbiology / Q000473:pathology*; D005500:Follow-Up Studies; D006679:HIV Seropositivity / Q000382:microbiology / Q000473:pathology; D015497:HIV-1 / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification; D006801:Humans; D007958:Leukocyte Count; D008297:Male; D010641:Phenotype; D011446:Prospective Studies