The IL-1 system in HIV infection: Peripheral concentrations of IL-1 beta, IL-1 receptor antagonist and soluble IL-1 receptor type II

The proinflammatory cytokine IL-1 beta is thought to be involved in ongoing HIV disease. Furthermore, its naturally occurring inhibitors soluble IL-1 receptor type II (sIL-1RII) and 1L-1 receptor antagonist (IL-1Ra) may play a pivotal role in regulating its biological action. To investigate the involvement of the IL-1 system we determined serum levels of IL-1 beta, IL-1Ra and sIL-1RII in 90 HIV+ patients, The obtained values were compared with markers of disease progression such as CD4(+) count, 5'-neopterin. beta(2)-microglobulin and soluble tumour necrosis factor receptors (sTNF-R) p55 and p75 and then compared with C-reactive protein (CRP), granulocyte count, IL-6 and TNF-alpha. While IL-1Ra concentrations increased significantly with progressive CDC disease stages, sIL-1RII and IL-1 beta were not altered in our cohort. IL-1Ra showed statistical relation to decreasing CD4(+) lymphocytes and increasing 5'-neopterin, beta(2)-microglobulin, sTNF-R p55, sTNF-R p75. Furthermore, IL-1Ra correlated positively with serum IL-6, TNF-alpha, CRP and granulocytes. In contrast, sIL-1RII and IL-1 beta tended to show an inverse correlation or showed no significant relationship to all these parameters, IL-1 beta was measurable only in a limited number of samples. IL-1Ra showed a clear relationship to acute inflammatory events as well as to the different disease stages. Our data suggest a dissociation between IL-1Ra and sIL-1RII serum levels which may indicate that the two IL-1 binding proteins have different pathophysiological roles in HIV infection.