Journal of Clinical Microbiology vol:47 issue:11 pages:3682-3691
The HTLV proviral load remains the best surrogate marker for disease progression. Real-time PCR techniques have been developed for detection and quantification of cosmopolitan HTLV-1a and HTLV-2. As a growing diversity in subtypes and genotypes is observed, we developed a multiplex quantitative PCR for simultaneous detection, genotyping and quantification of proviral load of HTLV-1, 2 and 3. Our assay uses tax type-specific primers and dual-labelled probes and has a dynamic range between 10(5) and 10 HTLV copies. 163 samples were analysed, of which all of the different subtypes within each HTLV genotype could be detected. The performance on proviral load determination of our multiplex assay was compared with a previously published HTLV-1 singleplex quantitative PCR based on SYBR Green detection, developed at a different institute. Linear regression analysis showed a statistically significant (p < 0.0001) and strong correlation (r(2) = 0.87) between proviral load values measured with the two distinct real-time PCR assays. In conclusion, our novel assay offers an accurate molecular diagnosis and genotyping together with the determination of the proviral load of HTLV-infected individuals in a single amplification reaction. Moreover, our molecular assay could offer an alternative when current available serological assays are insufficient.