Progressive CD4 loss seen in long-term non-progressors with HIV

NEW YORK (Reuters Health) - In a small study of long-term non-progressors (LTNP) with HIV infection for at least 10 years, a substantial proportion showed progressive loss of CD4+ T cells during follow-up. This suggests that at least in some LTNP resistance to immunologic damage does not last indefinitely.

Numerous studies have looked at LTNP in an attempt to identify factors that are associated with delayed disease progression. However, it still remains unclear whether their resistance to immunologic damage lasts forever or simply represents the extreme of a bell curve.

The current findings, which are reported in the May 21st issue of AIDS, are based on a study of 19 LTNP who had viral loads and CD4+ cell counts measured two to three times each year from 1997 to 2003. At baseline, all of the subjects had serologically proven HIV infection for 10 years or longer.

During follow-up, seven patients showed progressive CD4+ T cell loss and were reclassified as slow progressors, senior author Dr. Vincent Soriano, from Hospital Carlos III in Madrid, Spain, and colleagues note. However, of these patients, only three experienced a significant drop in their count.

Detectable viral levels were present in all of the slow progressors. By contrast, 5 of the 12 LTNP had consistently undetectable levels (p = 0.017).

None of the patients had the homozygous CCR5 genotype. The heterozygous CCR5 genotype was only found in slow progressors, not in LTNP (p = 0.036). No other significant differences were identified between the groups.

"No unique viral or host factors" explained why some LTNP become slow progressors and others do not, the authors note. The results indicate that "even very low levels of HIV replication seem to result in progressive CD4 T-cell depletion, although in these patients it may take decades to become manifest."

AIDS 2004;18:1109-1116.