Cytokine profile in human immunodeficiency virus positive patients with and without tuberculosis

Human immunodeficiency virus (HIV) infection is associated with a profound dysregulation of the immune system and alterations in the cytokine profile. Tuberculosis, a common opportunistic infection in HIV positive patients, leads to further immune suppression and a faster progression of the disease. This study was conducted to assess and compare the cytokine profiles in HIV positive subjects with and without pulmonary tuberculosis.

Twenty HIV positive patients and 20 controls were evaluated after being divided into four groups of 10 each--group 1--HIV positive patients without tuberculosis, group 2--HIV positive patients with pulmonary tuberculosis, group 3--healthy adults and group 4--HIV negative patients with pulmonary tuberculosis. After clinical evaluation, the CD4 cell counts and the cytokine profiles--interleukins (IL)-2, 4, 6, 10, 12, interferon gamma (IFN gamma) and tumour necrosis factor alpha (TNF alpha) were studied in all the subjects at the start and after three months of antituberculosis therapy.

the CD4 cell counts were significantly lower in groups 1 and 2 compared to groups 3 (p < 0.01) and the counts in group 2 were significantly lower than in group 1 in both at baseline (p = 0.0076) and at three months (p = 0.089). The levels of the type 1 cytokines (IL-2, IL-12 and IFN gamma were significantly lower in patients in groups 1 and 2 compared to group 3 (p < 0.001 for both). The levels in group 2 were lower than in group 1 (p < 0.001). The type 2 cytokines (IL-4, IL-6, IL-10 and TNF alpha) were higher in group 1 and 2 compared to group 3, though statistically significant for IL-6 in group 1 (p < 0.05) and for IL-4, IL-6 and TNF alpha in group 2. A highly significant (p < 0.0001) positive correlation between CD4 cell counts and type 1 cytokines and a highly significant (p < 0.0001) negative correlation between CD4 cell counts and type 2 cytokines was observed.

A decline in the type 1 and a rise in type 2 cytokines was observed in HIV infection. Patients in group 2 had the lowest CD4 cell counts, lowest levels of type 1 cytokines and highest levels of type 2 cytokines denoting maximum immunosuppression.