Acid hydrolysis of serum samples to increase detection of HIV antigen

Sera from 32 HIV-infected patients and 20 controls were assayed for HIV antigen (HIV-Ag) and antibodies following acid hydrolysis. Acid hydrolysis, followed by neutralization immediately prior to the assay, was found to be a simple means to solubilize immune complexes and allowed recovery of 40-50% of complexed antigen. Following acid hydrolysis, HIV-Ag levels rose or became detectable in 22/32 patients and HIV IgG1-4 levels rose in 17/20 patients studied. The results show that complexed HIV-Ag may evade detection in HIV-infected patients.