INCREASED PLASMA-LEVELS OF THE C-C CHEMOKINE RANTES IN PATIENTS WITH PRIMARY HIV-1 INFECTION

To investigate the role played by chemokines in the natural history of human immunodeficiency virus (HIV) infection, we measured the plasma levels of RANTES, MIP-1 alpha and MIP-1 beta in a cohort of patients w ith primary HIV-1 infection (PHI) followed longitudinally. The cohort included 17 patients with well-documented history of acute HIV syndrom e within two months of the first observation. This mean plasma concent ration of RANTES, but not that of MIP-1 alpha or MIP-1 beta, was signi ficantly higher in patients with PHI (192.3 ng/ml) than in five HIV-se ronegative controls (8.0 ng/ml) studied during the same time period. T reatment of blood with a cocktail of drugs preventing platelet activat ion, followed by high-speed centrifugation, reduced the levels of RANT ES by approximately 2 logs both in patients and in controls, indicatin g that the bulk of RANTES was released by platelets, which are known t o store this chemokine in their alpha-granules, in the immediate after math of blood drawing. No correlation was seen between the levels of R ANTES and the number of HIV genome equivalents in plasma. These data s uggest that large amounts of pre-formed RANTES are stored in platelets and, possibly, in other blood cells during the early phases of HIV in fection. The possible role of this HIV-suppressive chemokine in the co ntrol of viral replication during PHI remains to be established.