Low total IgM values and high cytomegalovirus loads in the blood of newborns with symptomatic congenital cytomegalovirus infection

Aims: Neurological outcomes differ considerably between symptomatic and asymptomatic infants with congenital cytomegalovirus (CMV) infection. Our objective was to characterize laboratory markers in symptomatic newborns in comparison with asymptomatic newborns with congenital CMV infection. Methods: Ten newborns with symptomatic and 13 newborns with asymptomatic congenital CMV infection were included in this 3-year prospective cohort study. Total immunoglobulin M (IgM), CMV-IgM, CMV antigenemia, and CMV-DNA in blood and urine were measured and their positive rates and quantitative values compared between the symptomatic and asymptomatic groups. Results: Fifty percent of newborns in the symptomatic group were positive based on total IgM; this was significantly lower than in the asymptomatic group (100%). Quantitative total IgM values were significantly lower, and there were significantly more copies of CMV-DNA in the blood of symptomatic newborns than in -asymptomatic newborns (median values for total IgM: 14 vs. 43 mg/dL and blood CMV-DNA: 3.2 x 10(2) vs. 3.5 x 10(1) copies/10(6) white blood cells). CMV-IgM, CMV antigenemia, and urine CMV-DNA did not differ significantly between groups. Conclusion: Low total IgM values and high blood CMV loads were associated with the presence of symptoms in newborns with congenital CMV infection.