Background:  Several previous studies suggest that HIV-infected persons over 50 may respond less well to HAART due to poorer immune response and other factors. We sought to compare response to HAART in patients ≥50 vs <50 years old.

Methods:  All patients who started their first HAART regimen at age ≥50 years were compared with adult patients <50 years in an cohort of HIV-infected patients in longitudinal HIV care at Johns Hopkins in Baltimore, Maryland. We compared achieving undetectable HIV-1 RNA (<400 copies/mL), durable undetectable HIV-1 RNA (defined as no more than 2 elevations >400 copies after first undetectable), CD4 change from baseline, development of AIDS-defining illness, and death. Bivariate (chi-square and ANOVA) and multivariate (logistic regression for undetectable HIV-1 RNA), MANOVA for CD4 change, Cox regression for AIDS-defining illness, and death)) comparisons were done.

Results:  We compared 256 patients >50 years (median 55, range 50 to 77), with 1322 patients 35 to 50 years and 895 patients 20 to 34 years old. There was no significant difference between age groups in race, sex, injecting drug user (IDU) status, baseline CD4 (median = 180 cells), or HIV-1 RNA (median = 65,000 copies), HAART backbone (NNRTI, PI, boosted-PI), nor follow-up time (median = 1200 days). The outcome comparisons are displayed in the table below.

*Significant compared to other groups

By multivariate analysis adjusting for race, sex, IDU history, use of NNRTI, boosted-PI, PI-based HAART, baseline CD4 and HIV-1 RNA, and past history of ART use prior to HAART, age ≥50 was associated with a higher rate of achieving an undetectable HIV-1 RNA (p = 0.01 ), and no difference in CD4 increase nor development of ADI. However, age ≥50 had a significantly higher mortality. Cause of death was not directly HIV-associated (no AIDS-defining illness and CD4 >200 at death) in 58% of age ≥50, compared to 29% in age 35 to 50 and 21% in age <35 (p <0.001).

Conclusions:  In our cohort, patients ≥50 years have a comparably good virologic and immunologic and clinical response to HAART. Mortality is higher, but appears to be due to causes other than HIV.

Keywords: aging; HAART; outcomes