Virologic and immunologic response to HAART, by age and regimen class.
OBJECTIVE
To determine the impact of age and initial HAART regimen class on virologic and immunologic response within 24 months after initiation.


METHODS
Pooled analysis of data from 19 prospective cohort studies in the North American AIDS Cohort Collaboration on Research and Design (NA-ACCORD).


METHODS
Twelve thousand, one hundred and ninety-six antiretroviral-naive adults who initiated HAART between 1998 and 2008 using a boosted protease inhibitor-based regimen or a nonnucleoside reverse transcriptase inhibitor (NNRTI)-based regimen were included in our study. Discrete time-to-event models estimated adjusted hazard odds ratios (aHOR) and 95% confidence intervals (CIs) for suppressed viral load (≤500 copies/ml) and, separately, at least 100 cells/μl increase in CD4 cell count. Truncated, stabilized inverse probability weights accounted for selection biases from discontinuation of initial regimen class.


RESULTS
Among 12 196 eligible participants (mean age = 42 years), 50% changed regimen classes after initiation (57 and 48% of whom initiated protease inhibitor and NNRTI-based regimens, respectively). Mean CD4 cell count at initiation was similar by age. Virologic response to treatment was less likely in those initiating using a boosted protease inhibitor [aHOR = 0.77 (0.73, 0.82)], regardless of age. Immunologic response decreased with increasing age [18-<30: ref; 30-<40: aHOR = 0.92 (0.85, 1.00); 40-<50: aHOR = 0.85 (0.78, 0.92); 50-<60: aHOR = 0.82 (0.74, 0.90); ≥60: aHOR = 0.74 (0.65, 0.85)], regardless of initial regimen.


CONCLUSIONS
We found no evidence of an interaction between age and initial antiretroviral regimen on virologic or immunologic response to HAART; however, decreased immunologic response with increasing age may have implications for age-specific when-to-start guidelines.
Althoff
Keri N
KN
Johns Hopkins University, Baltimore, Maryland 21287, USA.
Justice
Amy C
AC
Gange
Stephen J
SJ
Deeks
Steven G
SG
Saag
Michael S
MS
Silverberg
Michael J
MJ
Gill
M John
MJ
Lau
Bryan
B
Napravnik
Sonia
S
Tedaldi
Ellen
E
Klein
Marina B
MB
Gebo
Kelly A
KA
D000293:Adolescent; D000328:Adult; D017677:Age Distribution; D023241:Antiretroviral Therapy, Highly Active; D018791:CD4 Lymphocyte Count; D005260:Female; D015658:HIV Infections / Q000188:drug therapy* / Q000276:immunology / Q000821:virology; D015497:HIV-1; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D012367:RNA, Viral / Q000276:immunology*; D019562:Viral Load; D055815:Young Adult
D012367:RNA, Viral