Development of a rapid quantitative assay for HIV-1 plasma infectious viraemia-culture-PCR (CPID)

A simple and rapid assay for the quantification of infectious HIV-1 in plasma was developed using short-term culture and DNA PCR. This method, called culture PCR, allows detection and quantification of infectious HIV-1 viraemia within 48 hours, and measures the number of infectious cell-free HIV-1 particles, expressed as culture PCR infectious doses (CPID/ml). 42 HIV infected subjects were assessed by this method. The titres obtained by CPID closely correlated with CD4+ count and clinical status. CPID titres had significant correlation with infectious virus titre determined by conventional limiting dilution tissue-culture methods. This culture-PCR technique permits rapid assessment of infectious plasma viraemia, and is comparable to longer culture based assay methods.