A MULTICENTER QUALITY ASSESSMENT STUDY TO MONITOR THE PERFORMANCE OF HIV-1 PCR

Eleven German laboratories and one Swiss laboratory initiated a qualit y assessment study to evaluate the specificity and sensitivity of thei r polymerase chain reaction;(PCR) for detection of HIV-1 DNA. Followin g its own PCR protocols, each laboratory tested a panel of ten coded s amples consisting of cell pellets containing 0, 0.1, 1, 10, 10(2), 10( 3) and 10(4) ACH-2 cells per 1.5 x 10(5) uninfected peripheral blood m ononuclear cells. Of the twelve participating laboratories, three repo rted correct results for the dilution series as well as for uninfected specimens. One or more classification errors were recorded for 12% of the samples for which the diagnosis was expected to be positive or ne gative. Samples containing 10 copies of the target template were corre ctly reported by eleven of the twelve participants. The average sensit ivity was 97%. The results of the study revealed no significant differ ences between the Amplicor kit and in-house procedures. Most of the cl assification errors occurred in specimens from HIV-negative samples. O ut of 36 negative samples, 5 were reported false positive, showing tha t contamination remains a problem for some laboratories, regardless of the PCR test performed. Careful laboratory techniques and internal as well as external quality control procedures will help avoiding carryo ver contamination. (C) 1997 Elsevier Science B.V.