Congenital rubella syndrome with rubella virus-associated generalized brownish macules, indurated erythemas, papules, and pigmentation

Persistent infection of human fetal endothelial cells with rubella virus

Cardiovascular abnormalities are the leading cause of neonatal death among patients with congenital rubella syndrome (CRS). Although persistence of rubella virus (RV) in fetal endothelium has been repeatedly suggested as a possible cause of cardiovascular birth defects, evidence of the permissiveness of fetal endothelial cells to RV is lacking. In this study we evaluated the ability of RV to infect and persist in primary fetal endothelial cells derived from human umbilical vein (HUVEC). We found that wild type (wt) low passage clinical RV productively infected HUVEC cultures without producing cytopathology or ultrastructural changes. RV did not inhibit host cell protein synthesis, cell proliferation, or interfere with the cell cycle. Persistently infected cultures were easily established at low and high multiplicities of infection (MOI) with both laboratory and wt clinical RV strains. However, synchronous infections of entire HUVEC monolayers were only observed with clinical RV strains. The release of infectious virions into media remained at consistently high levels for several subcultures of infected HUVEC. The results indicate that macrovascular fetal endothelial cells are highly permissive to RV and allow slow persistent RV replication. The findings provide more evidence for the suggestion that vascular pathologies in CRS are triggered by persistent rubella virus infection of the endothelium.

[Chronic exanthema in a child with congenital rubella]

BACKGROUND

Since congenital rubella has become extremely uncommon following the introduction of rubella vaccination, cutaneous signs are currently rarely reported.

PATIENTS AND METHODS

An infant, presenting congenital rubella (seroconversion of the mother for rubella at 11 weeks' amenorrhoea), presented diffuse exanthema between the ages of seven and 24 months. In a setting of congenital rubella syndrome, the infant presented psychomotor retardation, deafness, hypoplasia of the pulmonary artery and under-nourishment. Humoral and cell-mediated immunodeficiency was also noted.

DISCUSSION

The cutaneous signs of congenital rubella were first described in the 1960s and 1970s; they are rare and appear after a symptom-free period before resolving spontaneously several months later. Standard findings include chronic exanthema of the face and extremities associating reticulated erythema and pigmented macular papules. Exanthema indicates chronic and persistent viral infection, a common situation in newborn babies and infants following maternal-foetal infection. The persistence of viral infection in infants is attributed to immature cellular immunity, which would otherwise either eradicate the virus or ensure passage to the latency phase. In the present case, there was also relative humoral immunodeficiency resulting from foetal rubella infection. The symptom-free interval before the onset of rash and other clinical signs may be due to the relative transient protection afforded by the presence of maternal immunoglobulines G.