AEGiS-15IAC: Predictors of the CD4 count response during the first 8 months of follow up in the IL-2 arm of ESPRIT.

15th International AIDS Conference

Bangkok, Thailand - July 11-16, 2004

Predictors of the CD4 count response during the first 8 months of follow up in the IL-2 arm of ESPRIT.

Int Conf AIDS 2004 Jul 11-16; 15:(abstract no. WeOrB1288)

Ruxrungtham K, Fox ZV, Antunes F, Bebchuk JD, Davey RT, Gazzard B, Klimas NG, Labriola AM, Losso MH, Neaton JD, Staszewski S, Weiss L, Phillips AN, Lundgren JD
Chulalongkorn Hospital, Bangkok, Thailand

BACKGROUND: ESPRIT is an international, phase III, open-labelled randomised trial to evaluate the clinical benefit of subcutaneous IL-2 in subjects with baseline CD4 ≥300/muL. We set out to identify factors related to a CD4 count increase in 8 months of follow-up in those assigned IL-2. Three cycles of IL-2 were to be given by month 8.

METHODS: Linear regression was used to identify predictors of change in CD4 count between baseline and month 8.

RESULTS: Of 4150 subjects enrolled, 2090 were assigned IL-2 and 1804 had a CD4 count at month 8 without a cycle in the 29 days prior to the 8-month visit. At baseline, the median (IQR) CD4 count was 469 (377 - 596), prior nadir CD4 count 204 (98 - 312) and mean CD4 count in the year preceding baseline 439 (350 - 576)/muL; 1371 (77%) subjects had HIV-RNA<500 c/ml. The median CD4 count at month 8 was 714 (532 - 968) with a median change of 230 (78 - 416)/muL. In multivariable analysis baseline predictors of the change in CD4 count were HIV-RNA (52.7/muL higher rise in CD4 count over 8 months for<500 c/ml), age (18.3/muL lower rise for every 5 years older), mean CD4 count the year before baseline (38.1/muL higher rise for each 100/muL higher), CD4 nadir (20.2/muL higher rise for each 100/muL higher), time from HIV diagnosis (22.9/muL lower rise for every 5 years longer) and race (62.5/muL lower rise for white subjects). A linear relations hip between total IL-2 dose in the 1st cycle and CD4 count change existed (52.1/muL higher rise for every 15 MIU higher). Gender and hepatitis B/C co-infection were not predictors of the change in CD4 count. Further analyses relating dose and number of cycles to CD4 outcome will be investigated.

CONCLUSIONS: This is the largest study to date of the impact of IL-2 on CD4 count. An increase was observed in 8 months and baseline factors and dose in first IL-2 cycle predicted CD4 response. Maintenance of this response is being achieved with additional cycling. Assessment of clinical benefit requires several more years of follow-up.

Keywords: AEGIS, CD4 Lymphocyte Count, Interleukin-2, Acquired Immunodeficiency Syndrome, Fatty Acids, Omega-3, HIV Seropositivity, Antigens, CD4, Esapent, immunology, organization & administration

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WeOrB1288