Impairment of circulating lactoferrin in HIV-1 infection.

Levels of plasma lactoferrin are decreased in HIV-1-infected patients in relation to the progression of the disease. Plasma lactoferrin concentrations were determined using a specific and sensitive enzyme immunoassay. 97 plasma were studied (22 asymptomatic, 45 symptomatic patients compared to 30 healthy controls) and the results showed a highly significant decrease (p < 0.001) of the level of lactoferrin in HIV-1-infected patients (respectively 2.79 +/- 1.2 and 0.68 +/- 0.22 micrograms/ml) compared to controls (4.37 +/- 0.83 micrograms/ml). Since it is well established that plasma lactoferrin level could be influenced by the number of neutrophils, the experiments were reproduced in neutropenic patients who represent 10% of recruitment (6 among 45 symptomatic patients). The plasma from neutropenic symptomatic patients (neutrophils < or = 1,300/mm3) showed their mean lactoferrin level at 0.36 micrograms/ml still far above the normal values. In view of the different reported biological effects of lactoferrin that are of great importance in the non-specific defences, the real biological place of the lack of such a molecule could be one important component of the multifactorial nature of HIV-1 infection.