• Poster 543: ILSTIM (ANRS 082): A Randomized Comparative Open-Label Study of Interleukin (IL2) in Patients with CD4 <200/mm³ Despite Effective HAART (Authored by C. Katlama, C. Duvivier, C. Chouquet, B. Autran, G. Carcelain, M. De Sa, L. Zagury, D. Cotagliola, and R. Tubiana. Hopital Pitie-Salpetriere; SC4 INSERM Paris, France)
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Poster 543 presented data from the ILSTIM study (ANRS 082) which looked at the effect of adding interleukin-2 (IL-2) therapy to a HAART regimen in patients with <200 CD4 cells. Patients were required to have been on HAART for >6 months and have a viral load of <1,000/ml. Patients were randomized to either continue HAART treatment alone (36 patients), or to have self administered subcutaneous IL-2 added to their regimen (34 patients). Patients received 4.5 million units (MU) twice daily for 5 days. This was repeated every six weeks four times (total time 24 weeks). After week 24, IL-2 was given to both groups at nine MU/d for five days every eight weeks for at least an additional 24 weeks. Baseline median CD4 prior to HAART was <70 in both arms. Baseline CD4 prior to IL-2 was <150 in both groups. Median increase in CD4 count in the IL-2 arm was 65 compared to 18 in the HAART alone arm. >80% of patients in the IL-2 arm had a CD4 count >200 at 24 weeks. After 48 weeks of IL-2, the median CD4 count had increased to 330. The HAART group that added IL-2 at week 34 now had a CD4 of 276 at week 48. Almost all patients experienced fever, fatigue, and muscle pain. About half the patients had nausea, sweats and rash. One patient discontinued and five required a dose reduction secondary to side effects. Eight patients had small (1-2,000/ml) transient increases in viral load. Improvement in immune function was also seen in the IL-2 arm. Lymphocyte proliferation against tuberculosis and cytomegalovirus antigens was significantly increased at week 24 and 48 in the IL-2 arm. This study demonstrates that IL-2 can be of benefit in patients with <200 CD4 cells. This is contrary to what prior studies showed. Namely that a CD4 count of >300 was required to demonstrate significant increases in CD4 count. Therefore IL-2 might be an important addition to HAART in patients with very low CD4 counts. IL-2 appears to increase CD4 counts significantly over and above what HAART alone can do.