Revello MG, Baldanti F, Sarasini A, Zavattoni M, Torsellini M, Gerna G. Prenatal diagnosis of rubella virus infection by direct detection and semiquantitation of viral RNA in clinical samples by reverse transcription-PCR.
J Clin Microbiol 1997;
35:708-13. [PMID:
9041417 PMCID:
PMC229655 DOI:
10.1128/jcm.35.3.708-713.1997]
[Citation(s) in RCA: 46] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
A reverse transcription-nested PCR (RT-nPCR) method for prenatal diagnosis of rubella virus (RV) infection was developed. In the first step of RT-nPCR a synthetic RNA molecule (pRRV) differing from the RV target sequence by having a 21-nucleotide insertion was used as the internal control of amplification for the detection of PCR inhibitors. In addition, comparison of pRRV and RV-specific PCR signals allowed for the semiquantitation of RV input target sequences (range, 10 to > and = 1,000 RV genomes). In parallel, a complete RT-nPCR assay was performed with the same samples in the absence of the internal control to confirm the results of the first step and to detect RV RNA-positive samples containing < 10 RV genomes. Subsequently, the RT-nPCR method was used to examine retrospectively clinical samples (direct RT-nPCR) from eight congenitally infected and eight uninfected fetuses for RV RNA. RT-nPCR was also used to detect RV RNA in cell cultures (culture-RT-nPCR) 96 h after inoculation with the same specimens. With amniotic fluid (AF) samples, direct RT-nPCR identified eight of eight cases of RV transmission (sensitivity, 100%), whereas culture-RT-nPCR and virus isolation detected only six of eight cases (sensitivity, 75%). However, when the culture-RT-nPCR results were positive, culture-RT-nPCR confirmed the direct RT-nPCR results 3 days to 3 weeks earlier than virus isolation. The specificity of direct RT-nPCR was 100%, with eight of eight uninfected fetuses being negative. Semiquantitation showed only small amounts (< and = 100 copies) of viral RNA in clinical samples. In conclusion, direct RT-nPCR with AF samples (i) shows 100% sensitivity and specificity for prenatal diagnosis of RV infection and (ii) is a rapid technique, giving results in 24 to 48 h after sampling.
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