Comparative study of tissue culture and ELISA methods for cytomegalovirus infection diagnosis in abortions

Primary infection of cytomegalovirus especially in first and second trimester of pregnancy causes severe tissue injury and congenital abnormalities. Infection in third trimester of pregnancy has a higher chance of transmission but less tissue injury. Elisa method is a simple test for diagnosis of serum antibody but blood lymphocytes culture is a better and more specific diagnostic method than Elisa. In this study we compared Elisa and tissue culture methods for the diagnosis of congenital cytomegalovirus infections. In this study 5 ml of blood obtained from mothers who aborted their fetuses. Then serum antibody was titrated by ELISA method. Moreover, 5ml of citrated blood with 2 ml of Ficohl hypaque centrifuged in 3000 g and buffy coat layer of leukocytes was separated. These cells cultured in MRC5 fibroblast cell line and were assessed for intracellular inclusion bodies after 72 hours. Positive samples were selected and tested for nucleic acids of cytomegalovirus with PCR method. In this study, 118 cases of abortion were included. In tissue culture method, 6 samples (7.2%) had intracellular inclusion body. Of these samples only 4 had cytomegalovirus nucleic acid by PCR method. Two cases showed increasing anti-cytomegalovirus IgM with ELISA but they were negative by tissue culture method. In general, 6 cases (7.2%) of cytomegalovirus infection were diagnosed. ELISA and tissue culture methods should be performed together. Cytomegalovirus infection has not likely any relation with habitual abortion and is seen in first time abortions preferably.