340   Effectiveness of Antiretroviral Therapy in the Elderly Compared to a Younger Cohort.

A. Chakroborty, V. Waring, and I. E. Salit*.
Toronto Gen. Hosp., Ontario, Canada.

Background:5—11% of those with HIV are >50 years old. The elderly have more rapid progression to AIDS. In the HAART era, it is not known if elderly patients receive therapy as frequently as younger patients and if they respond similarly.

Methods:Retrospective case-control study in a tertiary-care HIV clinic. The elderly cohort consisted of all patients in this clinic with age >55 years. Each older patient (case) was matched to a younger patient age <40 years (control). Matching was done on baseline CD4, baseline viral load and year of HIV diagnosis, and comparisons were done using the paired T-test. There were 90 case-control pairs followed >12 months.

Results:The elderly patients comprised 7.5% (90/1200) of the clinic population. The median age of the cases was 59 years, and that of the controls was 36 years. The groups also differed in race: more of the elderly patients were white (91% vs. 56%), P < 0.001. The elderly and younger patients did not differ in risk category, gender, median duration of infection or antiretroviral use: antiretroviral naïve, 10% vs. 9%; ever used a PI, 69% vs. 79%; current PI use, 62% vs. 67%; and currently on no antiretrovirals, 17% vs. 19%. The two groups were well matched for baseline CD4 (cases vs. control, 336 vs. 347; CD4 >450, 22% vs. 25%; and CD4 <50, 10% vs. 9%) as well as baseline viral load (median viral load was 4.64 vs. 4.12) (P = N.S.). The change in CD4 counts from baseline to current CD4 (+74 vs. +69 CD4 cells) (P = 0.88) or from baseline to peak CD4 did not differ between the two groups. There was also no significant difference in the response of the viral load to antiretroviral therapy in the elderly vs. the younger cohort: 73% vs. 69% had a >1 log decrease, 63% vs. 70% ever had an undetectable (<50) viral load (UDVL), and 40% vs. 36% currently have an UDVL. The durability of the UDVL was similar in

the elderly and younger patients (at 3 months, 47/90 (52%) vs. 57/89 (64%), and at 6 months, 39/90 (43%) vs. 47/89 (53%) (P = N.S.)) Opportunistic infections occurred at any time in 21% vs. 24%, and the mortality was 0% over 12 months.

Conclusions:In our clinic setting, elderly patients compared to younger patients received similar antiretroviral therapies and had similar immunologic recovery and suppression of plasma viral load.