Diagnostic Value of Enzyme Linked Immuno-sorbent Assay for Cytomegalovirus Disease

Background: Since interpretation of results of enzyme linked immuno-sorbent assay (ELISA) for diagnosis of Cytomegalovirus (CMV) infection in India is difficult, its diagnostic value required evaluation.

Aims: To evaluate the diagnostic value of ELISA against polymerase chain reaction (PCR) in CMV disease.

Settings And Design: Results of ELISA test for CMV antibodies in CMV-DNA PCR positive and negative patients and normal healthy blood donors were analysed.

Methods And Material: Anti-CMV antibodies were assayed by ELISA on the sera of 26 CMV PCR positive and 21 PCR negative patients and 35 normal healthy blood donors.

Statistical Analysis: Chi square and Fischer exact test were used for statistical analysis.

Results: Anti-CMV antibodies (IgG or IgG and IgM) were present in 20 (76.9%) of 26 PCR positive and 13 (61.9%) of 21 PCR negative patients. ELISA was negative in six (23.1%) of 26 PCR positive patients. Of the 28 paediatric patients, ELISA was positive in 14 (73.7%) of 19 PCR positive and three (33.3%) of nine PCR negative patients showing a statistically significant difference (Chi square test, P value 0.038). Among the 19 patients having complications after organ transplant, ELISA showed anti-CMV antibodies in six (85.7%) of seven PCR positive and 11 (91.7%) of 12 PCR negative patients showing no significant difference. CMV-DNA was not detected in the buffy coat of 35 sero-positive blood donors.

Conclusion: ELISA has no diagnostic value in the detection of CMV activation although it may help in the differential diagnosis of CMV infection in the paediatric age group.