If an HIV-infected patient has an initial negative antibody assay for HIV but demonstrates a positive polymerase chain reaction (PCR)result 10 days later,what is the most likely cause?

Question

Quizplus · Accepted Answer

Variables in HIV testing include the following:
General sensitivity of the Western blot test (WB)in detecting antibodies specific for various HIV-1 antigens (especially during the window period of seronegativity)
Frequent lack of specificity because of contamination of the viral reference preparation by histocompatibility and other antigens that electrophoretically migrate with p24 and gp41
Variation in band reactivity patterns in sera from an individual over the course of HIV-1 infection
Indeterminate test results account for 4% to 20% of WB assays with positive bands for HIV-1 proteins.Indeterminate WB results can be caused by a variety of conditions,including serologic tests in the process of seroconverting,end-stage HIV infection,cross-reacting nonspecific antibodies,infection with O strain or HIV-2,recipients of HIV vaccine,perinatally exposed infants who are seroconverting (losing maternal antibody),and technical or clerical error.
In addition,nonspecific reactions producing indeterminate results in uninfected persons have occurred more frequently in pregnant women or mothers than in persons in other groups characterized by low HIV seroprevalence.The incidence of indeterminate WB results is relatively low.Immunofluorescence assay can be used to resolve an EIA-positive,WB-indeterminate sample.

If an HIV-Infected Patient Has an Initial Negative Antibody Assay