HIV-1 viral subtype differences in the rate of CD4+ T-cell decline among HIV seroincident antiretroviral naive persons in Rakai district, Uganda.
BACKGROUND
Data on the effect of HIV-1 viral subtype on CD4 T-cell decline are limited.


METHODS
We assessed the rate of CD4 T-cell decline per year among 312 HIV seroincident persons infected with different HIV-1 subtypes. Rates of CD4 decline by HIV-1 subtype were determined by linear mixed effects models, using an unstructured convariance structure.


RESULTS
A total of 59.6% had D, 15.7% A, 18.9% recombinant viruses (R), and 5.8% multiple subtypes (M). For all subtypes combined, the overall rate of CD4 T-cell decline was -34.5 [95% confidence interval (CI), -47.1, -22.0] cells/ microL per yr, adjusted for age, sex, baseline CD4 counts, and viral load. Compared with subtype A, the adjusted rate of CD4 cell loss was -73.7/microL/yr (95% CI, -113.5, -33.8, P < 0.001) for subtype D, -43.2/microL/yr (95% CI, -90.2, 3.8, P = 0.072) for recombinants, and -63.9/microL/yr (95% CI, -132.3, 4.4, P = 0.067) for infection with multiple HIV subtypes. Square-root transformation of CD4 cell counts did not change the results.


CONCLUSIONS
Infection with subtype D is associated with significantly faster rates of CD4 T-cell loss than subtype A. This may explain the more rapid disease progression for subtype D compared with subtype A.
Kiwanuka
Noah
N
Department of Epidemiology and Biostatistics, School of Public Health, Makerere University College of Health Sciences, Kampala, Uganda. nkiwanuka@rhsp.org
Robb
Merlin
M
Laeyendecker
Oliver
O
Kigozi
Godfrey
G
Wabwire-Mangen
Fred
F
Makumbi
Fredrick E
FE
Nalugoda
Fred
F
Kagaayi
Joseph
J
Eller
Michael
M
Eller
Leigh Anne
LA
Serwadda
David
D
Sewankambo
Nelson K
NK
Reynolds
Steven J
SJ
Quinn
Thomas C
TC
Gray
Ronald H
RH
Wawer
Maria J
MJ
Whalen
Christopher C
CC
D000293:Adolescent; D000328:Adult; D000367:Age Factors; D018791:CD4 Lymphocyte Count; D018450:Disease Progression; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D015658:HIV Infections / Q000276:immunology / Q000821:virology*; D015497:HIV-1 / Q000235:genetics* / Q000472:pathogenicity; D006801:Humans; D008297:Male; D008875:Middle Aged; D012737:Sex Factors; D014454:Uganda; D019562:Viral Load; D055815:Young Adult