ELEVATED SERUM CALPROTECTIN LEVELS IN HIV-INFECTED PATIENTS - THE CALPROTECTIN RESPONSE DURING ZDV TREATMENT IS ASSOCIATED WITH CLINICAL EVENTS

The calcium-binding myelomonocytic protein calprotectin (L1 protein) w as quantified in serum from 51 patients with HIV infection and in 20 H IV-seronegative blood donors. Significantly elevated levels were found both in asymptomatic patients and in people with AIDS compared with c ontrols. The calprotectin level was not related to ongoing or recent o pportunistic infections. For patients with CD4(+) counts above 50 x 10 (6)/L, a significant negative correlation was found between serum calp rotectin levels and the CD4(+) counts. Serial samples from 24 patients during their first year of zidovudine (ZDV) treatment showed a furthe r elevation of serum calprotectin during the first months of ZDV treat ment, with a subsequent decline to pretreatment levels. A low calprote ctin response during the first 6 months, determined as area under the curve, was associated with the occurrence of at least one AIDS-definin g infection during the first year of antiviral treatment. Also, a low calprotectin maximal response during ZDV therapy was associated with s hort survival. Similar associations were not found for neopterin, beta (2)-microglobulin, HIV p24 antigen, or CD4(+) or CD8(+) lymphocytes in blood. Our findings in a limited number of patients suggest that calp rotectin levels may reflect immune activation and other immune mechani sms correlated with enhanced antimicrobial defense induced at least tr ansiently by antiviral treatment.