Detection of virus-specific IgA antibodies in serum of kidney transplant patients with recurrent cytomegalovirus infection by enzymeimmuno and radioimmunoassay techniques

The feasibility of using human cytomegalovirus (CMV)-specific IgA antibody determinations as a signal for early detection of recurrent CMV infections in eight renal transplant recipients was analysed. Solid phase radioimmunoassay (RIA), enzyme-linked immunosorbent assay (ELISA) and immunoperoxidase assay (IPA) techniques were used for IgA antibody determinations. In parallel, IgG antibodies to CMV were studied by immunoperoxidase assay. A significant rise of CMV-specific IgG antibody titre was observed in all of these patients between 5 and 53 weeks post-transplantation. CMV-specific IgA antibody production was detected close to the time a rise in CMV IgG antibody was observed in seven out of eight patients studied by RIA and ELISA, and in six out of eight patients studied by IPA. In two patients specific CMV IgA antibodies were detected by all three methods before a significant rise of CMV IgG antibody titre was demonstrated. In these patients CMV IgA was detected by RIA earlier than by ELISA and IPA. The potential application of CMV-specific IgA antibody determination for early detection of recurrent CMV infection in renal transplant patients is discussed.