ABSTRACT
A serological investigation for human T cell leukemia virus I (HTLV-I) infection was carried out at the University Hospital, Kuala Lumpur. A total of 626 sera from a non-patient population and 1,038 sera from unselected in-patients were screened for HTLV-I antibodies using an enzyme-linked immunosorbent assay (ELISA). 27/1664 (1.6%) were found to be reactive. However, on Western blotting, only 2 sera were confirmed positive, both showing reactions for the major core (p19 and p24) and the envelope (gp46) proteins. Both of the serum samples were from unselected hospital patients. Most of the remaining sera which were reactive on screening showed indeterminate results on Western blotting. These were further tested by radioimmunoprecipitation assay (RIPA) and none of these sera gave a positive reaction. Therefore, only 2/1038 (0.19%) unselected patients could be confirmed to have antibodies to HTLV-I. None of the normal individuals screened showed a positive Western blot result. Our data indicate that HTLV-I infection is present in our population, but at a low prevalence rate.
Subject(s)
HTLV-I Antibodies/blood , HTLV-I Infections/epidemiology , Adult , Blotting, Western/standards , Deltaretrovirus Antigens/blood , Enzyme-Linked Immunosorbent Assay/standards , Ethnicity , HTLV-I Infections/blood , HTLV-I Infections/immunology , Hospitals, University , Humans , Malaysia/epidemiology , Male , Mass Screening , Prevalence , Radioimmunoprecipitation Assay/standards , Sensitivity and Specificity , Seroepidemiologic StudiesSubject(s)
HIV-1 , HIV-2 , Animals , HIV/genetics , HIV-1/genetics , HIV-1/isolation & purification , HIV-2/genetics , HIV-2/isolation & purification , Humans , Immunoenzyme Techniques , MutationABSTRACT
The mechanism of the hook effect in a two site immunometric assay of hepatitis B surface antigen (HBsAg) was studied using a novel method. The results showed that HBsAg dissociated from immobilized anti-HBsAg at low as well as high doses of antigen (Ag). This probably was not due to lack of immobilized antibody (Ab) or dissociation of HBsAg non-specifically bound to the immobilized Ab. The dissociated Ag sequestered the labelled Ab in the second reaction and contributed to the decrease in percent binding (B%) of the assay and thus the hook effect. The dissociated Ag could contaminate the recovered pooled labelled Ab in recycled assay and give rise to high non-specific binding. Prolonged washing decreased the side reaction but also the B% of the assay.
