DETECTION OF HUMAN T-CELL LYMPHOTROPIC VIRUS TYPE-1 INFECTION BY THE POLYMERASE CHAIN-REACTION USING DRIED BLOOD SPECIMENS ON FILTER PAPERS

A simple method for detection of proviral DNA sequences of human T-cel l lymphotropic virus type 1 (HTLV-1) was developed using dried blood s pecimens on filter papers. The whole blood was blotted onto the Guthri e paper. After the blood has dried, the blotted paper was punched out into small discs. The discs were then boiled to prepare the template f or PCR (filter paper-PCR method). The filter paper-PCR method detected even a single HTLV-1-infected cell in three discs. The sensitivity of the filter paper-PCR method was equivalent to that of the method in w hich DNA was extracted with phenol and used as the template for PCR (D NA extraction-PCR method). In addition, DNA in the blotted filter pape r was still utilizable as the template after the storage at 25-degrees -C for at least 7 wk. A total of 53 clinical specimens from 30 seropos itive and 23 seronegative individuals who were screened by particle ag glutination (PA) test were analysed for HTLV-1 DNA by both PCR methods . Of 30 PA-positive specimens, 28 were also positive for HTLV-1 antibo dy by Western blot (WB) analysis, but two were indeterminate. The twen ty eight WB-positive and one of the two indeterminate specimens were p ositive for HTLV-1 proviral DNA by both PCR methods. Of 23 PA-negative specimens, 22 were negative for HTLV-1 proviral DNA by both PCR metho ds. However, one PA-negative specimen was positive by both PCR methods . This patient was a 16-mth-old infant who was born to an HTLV-1 carri er mother and fed thereafter without her breast milk. In comparison to DNA extraction-PCR method, the sensitivity and specificity of the fil ter paper-PCR method was 100%, respectively.