Cell-mediated and humoral immune responses to human cytomegalovirus in pregnant women with vertically transmitted infection following primary infection: A case report

Abstract

Human cytomegalovirus (HCMV) is the major cause of neurological sequelae in infants. Immune control of primary HCMV infection appears to depend on the interaction between humoral and cell-mediated immune responses. We report the case of an HCMV-transmitter mother observed with dissociation between humoral and cell-mediated immune responses. The patient had immunoglobulin (Ig) G and M positivity at 11 weeks of gestation and showed fetal hyperechoic bowel and minimal ascites at 21 weeks of gestation. At 25 weeks of gestation, the polymerase chain reaction result for HCMV using amniotic fluid was positive. The numbers of spots in the enzyme-linked immunosorbent spot (ELISPOT) assay at 25, 36, and 39 weeks of gestation were three, five, and six spots/2 × 10⁵ peripheral blood mononuclear cells, respectively. Furthermore, IgG avidity indexes (AIs) at 21, 25, 36, and 39 weeks of gestation were 37.6, 49.7, 72.5, and 74.3, respectively. At 40⁺¹ weeks of gestation, the patient delivered a symptomatic infected newborn with a weight of 2,384 g (-2.6 SD) and a head circumference of 30 cm (-2.6 SD). The neonate had a petechial rash and bilateral hearing loss although did not show liver dysfunction or thrombocytopenia. Cranial magnetic resonance imaging revealed mild ventriculomegaly, left lateral/parietal polymicrogyria, and a punctate white matter lesion. This case showed that IgG AI increased with increasing gestational age, whereas the numbers of spots in the ELISPOT assay had no change. The dissociation between humoral and cell-mediated immune responses may be characteristic of the immune response of a transmitter mother.

Keywords: Cell-mediated immunity; Congenital infection; Cytomegalovirus; Enzyme-linked immunosorbent spot assay; Pregnancy.