Reconstituted immunity against persistent parvovirus B19 infection in a patient with acquired immunodeficiency syndrome after highly active antiretroviral therapy

We discovered a patient with AIDS with persistent B19 infection who had slo w resolution of anemia after he commenced receiving HAART without intraveno us immunoglobulin. The patient's anemia recurred when the initial course of HAART failed, but it remitted slowly after salvage therapy was instituted. However, circulating B19 was still detectable by nested polymerase chain r eaction 1 year after commencement of salvage therapy. Immunoglobulin G and immunoglobulin M antibodies against B19 were not detected by means of enzym e-linked immunosorbent assay when the anemia initially resolved, but they w ere detected after the patient commenced receiving salvage therapy. The abs ence of antibody response after the initial remission of parvovirus B19 inf ection suggested that cellular immunity was an important component of recon stituted immune function against B19 after the patient received HAART. The humoral response that was restored later was abnormal; it had strong reacti vity to nonstructural protein NS-1 and poor generation of neutralizing anti bodies against linear epitopes unique to minor capsid protein VP1.