Congenital Cytomegalovirus Conference - Congenital CMV ...

O-19 Histological and virological diagnosis of symptomatic congenital CMV infection in fetuses.
Liliana Gabrielli, Stefania Lega, Maria Pia Foschini, Donatella Santini, Marcello Lanari, Brunella Guerra, Giulia
Piccirilli, Tiziana Lazzarotto. Operative Unit of Microbiology and Virology, University of Bologna and St.
Orsola Malpighi University Hospital, Bologna, Italy.
Background: Congenital CMV infection is a major cause of central nervous system damage leading to
sensorineural hearing loss, mental retardation and cerebral palsy.
Objectives. Due to the scarcity of information, we studied fetal CMV infection to describe the type of
organ involvement and histomorphological findings, and identify histological and virological markers for
an adverse outcome.
Methods: 30 cases of fetal congenital CMV infection documented by prenatal diagnosis (amniotic
fluid CMV culture positive and PCR positive) were studied. At the time of amniocentesis, abnormal
ultrasonographic findings had been recorded in 9 of the 30 fetuses (30%). Two fetuses died in utero.
The remaining pregnancies were electively terminated at 22 weeks gestation. Macroscopic and
histomorphological examinations were performed and CMV early (ppUL44) and late (major protein
55KD) antigen expression in the tissues of different organs were studied using immunohistochemical
staining procedures.
Results: Histological examination of all placentas showed varying degrees of chronic villitis and early
and late CMV antigens were detected by immunohistochemistry. Fetal organs positive for early CMV
antigens were as follows: pancreas (95%), lung (88%), kidney (83%), liver (68%), brain (52%) and heart
(27%). Severe inflammatory cell reaction suggestive of histological damage was found in only 33% of the
brains studied and in only 4% of each of the remaining organs. Severe inflammatory cell infiltration was
frequently associated with pathological findings at macroscopic observation (hydrocephalus, cerebellar
hypoplasia, etc.) and/or at ultrasonography (cerebral ventriculomegaly, hyperechogenic bowel, etc.). A
correlation was also found between the presence of late CMV antigens and organ damage, but the study
is still underway.
Conclusions: The presence of early CMV antigens in fetal organs is correlated with the dissemination
of infection, but does not indicate organ damage. Instead, the presence of a severe inflammatory cell
reaction is highly suggestive of CMV symptomatic infection, especially when it is associated with
abnormal macroscopic or ultrasonographic findings and probably also with the presence of late CMV
antigens. Using these parameters, the percentage of organ damage observed in fetuses is the same as
those observed in newborns with CMV congenital infection.
O-20 The Role of RhCMV ULb1ORF in the Dissemination of RhCMV to Sites of Viral Shedding.
Peter A. Barry, Lisa Strelow, William W.-L. Chang, Yujuan Yue, Kristie L. Oxford, Kimberli A. Schmidt, Kai-
Wen Yang, Kristina Abel. Center for Comparative Medicine/California National Primate Research Center/
Dept. of Pathology & Laboratory Medicine, UC Davis, Davis, CA.
Rhesus cytomegalovirus (RhCMV) is ubiquitous in both free-ranging and colony-reared populations
of rhesus macaques. Clinical signs of RhCMV infection are almost never observed in either population
following either natural exposure to wild-type virus (RhCMVWT) or experimental inoculation with
the 68-1 strain of virus (RhCMV68-1). A hallmark of natural infection with RhCMVWT is that a large
percentage of infected macaques (~75%) shed virus in bodily fluids for a sustained period of time. This
stands in contrast to our observations with RhCMV68-1 in which only low titer shedding in fluids such
as saliva or urine, is sporadically observed, or often not detected. These RhCMV strains are distinguished
by differences in the coding content of the ULb’ region, such that RhCMV68-1 lacks UL128, UL130,
and three alpha chemokine-like ORF found in RhCMVWT (Oxford et al, Virology, 373:181, 2008). To
determine whether these genetic differences account for the differences in shedding potential between
RhCMVWT and RhCMV68-1, an initial study was performed in which 2 macaques were inoculated with
RhCMV68-1 and two RhCMV variants containing the full-length ULb’ (RhCMV22659 and RhCMV21252).
Unlike previous inoculations with RhCMV68-1, sustained excretion of RhCMV was detected in urine
and saliva. Using differential PCR to distinguish between the three variants, only RhCMV22659 and
RhCMV21252 were detected in urine and/or saliva, or recovered from parotid gland explanted in
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