This article is more than 5 years old. Information may no longer be current.
CMV-specific T-cell response may indicate congenital infection
High maternal cytomegalovirus-specific T-cell response may be a useful biomarker in determining the likelihood of congenital transmission, according to recent data.
Researchers in Italy evaluated 80 pregnant women referred to Padua Reference Center for Infections in Pregnancy for suspected cytomegalovirus (CMV) infection and at risk for maternal-fetal transmission. The women were classified as having primary CMV infection (n = 57) or nonprimary CMV infection (reinfection or relapse, n = 23) after undergoing testing by CMV immunoglobulin G (IgG) avidity and CMV-ELISPOT assays.
Primary maternal CMV was defined as seroconversion in previously seronegative pregnant women or identification of maternal CMV immunoglobulin M (IgM) and coexisting low CMV immunoglobulin G avidity (< 25%). Nonprimary CMV infection was characterized by CMV viruria in positive pregnant women and identification of CMV IgG avidity less than 45% within 14 weeks of pregnancy.
Active fetal or newborn CMV infection by CMV-DNA detection was evaluated by qualitative real-time PCR in amniotic fluid. Logistic regression and receiving operator characteristic curve methods were used to ascertain correlations between CMV IgG avidity and CMV-ELISPOT assays and congenital infection.
The researchers found that CMV IgG avidity alone was predictive of congenital transmission, with 25% avidity associated with an 18.2% (95% CI, 7.7%-28.8%) probability of congenital transmission. This probability decreased by avidity increment.
When evaluating only the use of CMV-ELISPOT testing, the investigators said the likelihood of congenital transmission rose as the CMV-ELISPOT yield increased. When CMV-ELISPOT and low CMV IgG avidity were used in combination, however, a greater degree of correlation with fetal transmission rate was observed compared with either assay alone.
“This study highlights the relevance of the cell-mediated immunity to CMV and the consequences for congenital transmission and could also provide crucial insights in view of the CMV vaccine development,” the researchers wrote. “Moreover, this study shows that the detection of CMV specific cell-mediated immunity may be useful for the diagnosis of congenital CMV infection: the CMV-ELISPOT is a noninvasive procedure performed on blood isolated [peripheral blood mononuclear cells], thus much less invasive and risky compared to the amniocentesis at the present required to assess congenital CMV transmission” — by Jen Byrne
Disclosure: The researchers report no relevant financial disclosures.