RESUMO
BACKGROUND: Reliable laboratory methods for detecting congenital CMV infection are valuable since CMV infections are asymptomatic and because early detection is important for correct management and counseling of expectant mothers. OBJECTIVES: Compare the Beckman Coulter Access(®) method for the Unicel(®) DxI 800 analyzer with the bioMérieux VIDAS(®) method for two serological markers: CMV IgG and CMV IgM. STUDY DESIGN: Precision was determined with CLSI EP5-A2 protocol. Linearity of the Access CMV IgG was evaluated using selected high positive samples. Performance was assessed by testing non-selected pregnant women, frozen negative and positive samples with recent and old infections. Kinetics of the anti-CMV antibodies response was studied using samples from pregnant women with a recent infection. In a prospective study, 3992 pregnant women were screened for determining prevalence of a primo-infection and CMV IgM non-specific rate. RESULTS: Total CV is lower than 10% and 12% for Access CMV IgG and CMV IgM. The IgG method is linear (R(2)=0.999) with recoveries between 85% and 108%. Correlation between Access and VIDAS CMV IgG is highly significant (P<0.001). Observed agreement was 97.4% for CMV IgG and 93.7% for CMV IgM. Relative sensitivity and specificity was 97.2% and 100% for IgG and 100% and 97.4% for IgM. Kinetics of the antibody response measured with Access methods is significantly higher (P<0.02) when compared with VIDAS and probably easier to interpret. Prevalence of a recent infection was 0.85% and CMV IgM non-specific rate was 2.9%. CONCLUSION: Good sensitivity and specificity and pronounced anti-CMV antibody response make the Access CMV IgG and IgM tests suitable for screening prenatal CMV infections.
