Serum concentrations of circulating endogenous granulocyte-macrophage colony-stimulating factor in HIV-1-seropositive injecting drug users.

OBJECTIVES

We compared serum concentrations cytokines in seronegative and seropositive HIV-I intravenous drug abusers.

METHODS

The cytokines granulocyte-macrophage colony-stimulating factor (GM-CSF), tumor necrosis factor alpha (TNF-alpha), interleukin-1 beta (IL-1 beta) and the immune activation markers soluble interleukin-2 receptor (sIL-2R) and neopterin were determined in sera of HIV-1-seropositive and HIV-1-seronegative injecting drug users (IDUs).

RESULTS

HIV-1-seropositive IDUs showed significantly lower serum concentrations of GM-CSF (p = 0.0064) and significantly higher concentrations of neopterin (p = 0.0005) than HIV-1-seronegative IDUs. All HIV-1-seropositive IDUs had neopterin levels above the normal range. Levels of TNF-alpha in HIV-1-seronegative IDUs did not differ from HIV-1-seropositive IDUs. Increased levels of IL-1 beta were found in 83.3% HIV-1-seronegative and in 94.4% HIV-1-seropositive IDUs with no significant difference between the two groups. An increase of serum levels of sIL-2R was found in 60% HIV-1-seronegative and in 63.6% HIV-1-seropositive IDUs. Again, no difference was found between the two groups. Neopterin concentrations correlated with TNF-alpha in HIV-1-seropositive as well as in HIV-1-seronegative IDUs, neopterin concentrations correlated with sIL-2R only in the HIV-1-seropositive IDUs. No correlations were found for GM-CSF.

CONCLUSIONS

An impaired production of GM-CSF may contribute to the loss of the myelopoetic progenitor cells and to the functional abnormalities of leukocytes associated with HIV-1 infection. Injecting drug use contributes to the levels of immune activation markers, therefore their use in HIV-1 infection may be limited in IDUs. However, neopterin remains a useful marker for HIV-1 infected IDUs.