CMV-specific polymeric and monomeric IgA antibodies in serum of renal transplant patients.

CMV-specific IgA, IgM and IgG antibodies were detected by ELISA in sera from 81 renal transplant patients. Twenty-seven patients were followed from transplantation; 6 patients who underwent on transplantation before the beginning of the study were followed during admissions for graft failure or acute illness; 48 outpatients were periodically monitored. One of the patient followed from transplantation experienced a primary CMV infection, serologically demonstrated by the appearance of specific IgM and IgG. Specific IgA appeared at the same time as IgM and lasted for about six months. A specific IgA response was observed in all but five recurrent CMV infections too, even when specific IgM were not present. In all outpatients periodically monitored for CMV serology specific IgA were not found. About specific IgA polimerization, a transient marked polymeric IgA (p-IgA) response was observed in only the primary infection whereas in all the other IgA positive patients, specific IgA were represented by monomers (m-IgA).