Determination of specific cytomegalovirus IgM antibodies using infected air dried cells and isolated nuclei by immunoperoxidase assay

Anti-epithelial (anti-A549) antibodies: their nature, specificity and relevance to transplantation

Several studies have addressed the possible importance of anti-epithelial cell antibodies in kidney transplantation using the A549 cell line as an in vitro model. In this paper we report our results using for the first time an enzyme-linked immunosorbent assay (ELISA) to detect the anti-A549 cell antibodies. Sera from 129 kidney transplant patients were tested for IgM anti-epithelial cell antibodies directed against the A549 cell line prior to transplantation; only three sera were positive (2.3%). 101 of these patients were then followed-up post-transplantation; sera were collected routinely at 2, 6 and 12 weeks and at the time of rejection episodes. All samples were also tested for cytomegalovirus (CMV) IgM antibodies. Sixteen patients developed anti-A549 IgM antibodies, and there was no correlation with acute graft rejection. Anti-epithelial antibodies showed no binding to sections of normal kidney or biopsies of rejected kidneys. Eleven patients were positive for anti-CMV IgM antibodies. In nine cases both IgM anti-A549 and IgM anti-CMV antibodies were found, which was a highly significant association (p < 0.001). Analysis of A549 cellular proteins by immunoblotting gave evidence for the presence of CMV polypeptides in the cell lysate. Electron-microscopic examination of A549 cell preparations revealed intracellular particles which were compatible in size with CMV. Polymerase chain reaction analysis confirmed the presence of a specific CMV DNA sequence in A549 cells of several batches from different sources. Our data strongly suggest that the A549 cell line used in several published reports is infected with CMV and that in the majority of cases the anti-A549 'anti-epithelial' antibodies found in renal transplant patients are anti-CMV antibodies.

Virus-specific serum IgG, IgM, and IgA antibodies in cytomegalovirus mononucleosis patients as determined by immunoblotting technique

The immune response to individual human cytomegalovirus (CMV) structural polypeptides was studied in paired sera from 15 adult CMV mononucleosis (CMV-MN) patients and healthy controls by immunoblotting technique (IB). IgM and IgG antibodies to at least 11 structural polypeptides with molecular weights of 28K, 49K, 55K, 57K, 66-70K, 82K, 87K, 110K, 150K, 205K, and 235K were detected in the patients' sera in the serum sample obtained in the acute phase of the disease. IgA antibodies to polypeptides with molecular weights of 66-70K, 82K, 110K, and 150K were also detected in these sera. In healthy seropositive adults, IgG antibodies with the same molecular weight polypeptides, excluding the 205K and 235K polypeptides, were detected as in convalescent CMV-MN patients. A prominent reactivity of IgM and IgA antibodies to the 66-70K and 150K polypeptides was noted in the acute sera from all the CMV-MN patients examined, but not in a number of late convalescent sera. The potential implications of these findings in the development of specific serological tests are discussed.