Comparison Of Human Cytomegalovirus Pp65 Antigen Test And HCMV-specific IgM Assay For Laboratory Diagnosis Of Cytomeglovirus Active Infection In The Stem Cell Transplantation Recipients

Objective To compare the diagnostic efficacy of the human cytomegalovirus(HCMV) pp65 antigenemia assay and the HCMV-specific IgM test in the diagnosis of active HCMV infection in the stem cell transplantation recipients.Methods Sequential blood specimens obtained from 30 stem cell transplantation recipients.The plasma and the ploy-morphonuclear cells were separated from the whole blood.The former was used for the IgG and IgM assay and the latter was used for the pp65 antigenemia test.Results 381 blood samples were obtained,the positive rate of pp65 antigenemia,IgG and IgM were 44.09%,100% and 23.36% respectively.The average number of positive leukocytes of CMV pp65 antigen was 7.40/5xl0⁴leukocytes,and the lever ranged from l⁶5/5X10⁴leukocytes.The positive agreement rate of IgM assay and CMV pp65 antigenemia assay was 49.87%.For prediction of active CMV infection,the sensitivity and specificity of IgM assay in comparison with pp65 antigernemia test,were 19.64% and 73.71% respectively.The positive and negative predictive value were 37.08% and 53.77% respectively.In our study,7 of 30 patients(23.3%) developed CMV disease at a median of 150.0 days after allogeneic stem cell transplant.When CMV disease developed,the averagenumber of positive leukocytes of pp65 antigenemia was 12.57/5x 10⁴ leukocytes,higher than they have no signs of CMV infection markedly (p<0.01) .There have no relation of CMV-specific IgM with symptom of CMV infection.Conclusion The pp65 antigenemia assay could reflect the level of CMV and predict active CMV infection in stem cell transplantation recipients. The CMV specific IgM assay had moderate specificity but often gave late positive results and was not sensitive enough for use as prediction tools for transplant patients.