Western blot technique in the serological evaluation of three LAV/HTLV III-infected Italian families

Abstract

In order to confirm suspected LAV/HTLV III infection, serological evaluation of patients is of utmost importance. ELISA is currently being employed on a large scale for screening, but like the immunofluorescence assay, it has a variable rate of possible non-specific positivity. On the other hand, the Western Blot (WB) technique can detect antibodies to different viral proteins. In this paper we are reporting the serological patterns of three LAV/HTLV III-infected families. In particular, their viral protein-specific antibody patterns are described. With the exception of one child, all the patients tested showed seropositivity in both ELISA and WB. In the one child mentioned above, ELISA and immunofluorescence positivity were due to non-specific binding. Two out of three children tested showed a close correlation between a severe clinical course and the absence of p25-specific IgM. In contrast, one child showing a switch from IgM to p25-specific IgG antibodies had a favorable clinical course. We observed a family in which vertical transmission of LAV/HTLV III from the mother to her neonate seems not to have happened; the child was seronegative and healthy at the age of one. At birth, this neonate had LAV/HTLV III-specific IgG corresponding to the mother's pattern, but it lacked viral-specific IgM. Its mother had transmitted the viral infection to her first child, who died of AIDS. Preliminary suggestions are made about the detection of different specific antibodies and clinical features; the utility of WB is emphasized.