HIV neutralizing antibodies: development and association with HIV related disease

Serum neutralization was measured in 72 sera collected during a 5.5-year period from 10 HIV infected individuals. Neutralizing antibodies (NA) were present in all sera. NA titers ranging from greater than 40 to greater than 640 were detected in sera from 4 patients, who all remained healthy and further an increase with time of NA was observed in these 4 patients. Progression to disease was observed in 3 persons with NA titers less than or equal to 40 who also lacked or lost anti-gag antibodies. Two of these patients were HIV antigenaemic prior to development of disease, whereas antigen was not detected in the remaining 7 healthy persons. A weak positive correlation (R(S) = +0.643, p less than 0.001) was found between titers of NA and whole virus antibody (WVA), with the ratios between titers (NA titer/WVA titer) varying a 100-fold. The results suggest that the presence of NA in some cases might be related to a healthy carrier state and that a combination of low titer NA with decline of anti-gag antibodies and/or HIV antigenaemia is associated with progression to clinical disease.