A comparative evaluation of prevalence of HTLV-1 antibodies in blood donors in Delhi India by PAT and LIA method.

ABSTRACT

An investigation to evaluate the prevalence of HTLV-1 antibodies among blood donors in Delhi, India was carried out. The study was initiated with an objective to evaluate the higher prevalence of the condition reported by various Indian authors. Most of the reports were based on the screening through particle agglutination test (PAT) which has been documented to be high sensitive but less specific. A pilot study was undertaken to compare the prevalence of HTLV-1 by using the PAT as well as Line Immunoassay (LIA). The study included 119 HIV positive and 114 HIV negative sera obtained from Zonal Blood Testing Centre (ZBTC), Institute of Pathology (ICMR), Safdarjung Hospital Campus, New Delhi. The PAT positive samples were evaluated through Line Immunoassay. The results indicated that (a) in contrast to the number of reports, none of the HIV seronegative blood donors had anti-HTLV-1 antibodies tested by PAT, (b) 12 out of 119 (10%) HIV positive sera showed PAT positivity (Titre 1 16). (c) None of the PAT positive sera showed antibodies to HTLV-I/II through LIA-(Line Immunoassay). The results of the study indicate that the reports on the higher prevalence of HTLV-1 in Indian blood donors may be due to adoption of highly sensitiv but less specific particle agglutination assay. The results also sugges that the status of HTLV-1 needs revalidation through the use of more specific assay like LIA in a larger number of samples.