Serological studies in asymptomatic congenital cytomegalovirus infection.

Immunological abnormalities have been described in patients with cytomegalovirus mononucleosis or with post-perfusion syndrome due to cytomegalovirus (CMV) (Wager et al., 1968; Klemola et al., 1969; Kantor et al., 1970). These abnormalities include the development of cryoglobulinaemia, elevation or depression of serum immunoglobulin levels, and the appearance of humoral autoantibodies, including rheumatoid factor, antinuclear antibody, anti-red cell antibodies, and cold agglutinins. The mechanism whereby the viral infection induces immunological abnormalities is unclear, though similar serological abnormalities may accompany other infectious diseases such as infectious mononucleosis (Wager et al., 1968). Cases of neonatal cytomegalic inclusion disease may show serious damage to the nervous system or liver (Stem and Tucker, 1965) and these patients have raised serum IgM and IgA levels (McCracken and Shinefield, 1965). However, it is now known that as many as 0 5 to 1% of babies are born excreting CMV after primary infection of the mother during pregnancy; the majority of these congenital infections are asymptomatic, though the infants may excrete the virus into the throat and urine for years after birth. The mothers may also excrete virus, without symptoms, during the pregnancy and may continue to do so for several months after term (Weller, 1971). It would be of interest to know whether these clinically silent CMV carrier states of pregnant women and neonates are characterized by the same serological alterations found in patients with overt CMV disease. We report such studies in asymptomatic mothers and babies who had serum anti-CMV antibodies, and most of whom were excreting the virus in their urine.