Association of IL-7 with disease progression in Chinese HIV-1 seropositive individuals

Background Elevated levels of interleukin-7 (IL-7) have been correlated with CD4(+) T cell depletion and the emergence of syncytium-inducing (SI) variants in human immunodeficiency virus type-1 (HIV-1) infection, and suggested as an indicator of acquired immunodeficiency syndrome (AIDS) disease progression. Therefore, we investigated the effects of IL-7 on disease progression and virus phenotype in Chinese HIV/AIDS patients. Methods In a cross-sectional study of 71 untreated HIV-1 seropositive individuals and 12 healthy donors, plasma IL-7 levels were determined by an ultra sensitive enzyme-linked immunosorbent assay (ELISA), and its relations to CD4+ T cells, CD8(+) T cells, plasma viral loads and HIV phenotypes were analyzed. Results Significant higher IL-7 levels were found in Chinese HIV/AIDS patients [(3.33 +/- 3.60) pg/ml] than those of health controls [(1.2 +/- 0.81) pg/ml] (P<0.05), and IL-7 levels were inversely associated with CD4(+) T cell counts (r=-0.497, P<0.01). Furthermore, IL-7 levels were significant higher in patients with SI variants [(9.12 +/- 4.55) pg/ml] than those with non-syncytium-inducing variants [(1.50 2.69) pg/ml] (P<0.01). Conclusions Increased IL-7 levels were found in Chinese HIV/AIDS patients and significantly associated with disease progression, thus increased IL-7 plasma levels may indicate disease progression.