European Society of Clinical Microbiology and Infectious Diseases
Abstract
Background: Human cytomegalovirus (HCMV) is an important opportunistic pathogen leading to
severe diseases in “at-risk” categories of individuals upon the symptomatic reactivation of the virus
belonging to specific genotypes. In this respect, it has been postulated that envelope glycoproteins (g)
N and O could have a key role as virulence factors, most likely in combined patterns. Several data is
accumulating about HCMV reactivations in non-immunocompromised adults with critical illness that
may impair clinical outcomes. The interplay between HCMV and immune surveillance is also
supposed to become more vulnerable in advanced age; here, subclinical reactivations may drive
expanded anti-HCMV immune responses. Accordingly, it is reasonable to expect cases of HCMV
reactivation in elderly patients facing an acute life-threatening disease such as ischemic stroke.
Materials/methods: We have performed an observational prospective study in a cohort of 105 elderly
patients admitted to the Stroke Care Units of Parma University-Hospital for major acute ischemic
stroke. Plasma samples from patients tested positive for anti-HCMV IgG, collected at 10±2 days from
hospital admission, were analyzed for the presence of viral DNA by Real-Time PCR; gN and gO
genotyping was performed by RFLP in case of positive DNAemia.
Results: HCMV DNA was detected in the range of few hundred copies/mL in 11.7% of the analyzed
samples. The gN and gO genotypes were characterized in 77.7% of the positive samples for HCMVDNAemia.
In particular, the gN3 genotype was found to predominate (57.1%); with regard to gO, the
recurrent genotypes were gO1 (57.1%) and gO2 (42.9%). Furthermore, these data suggest that
combined gN3-gO1 and gN3-gO2 genotypes could be the recurring virulence factor patterns
associated with viral DNAemia.
Conclusions: This study focused for the first time on the role of HCMV infection in acute ischemic
stroke. Overall, the results suggest that HCMV tends to escape immune surveillance in some elderly
patients in this clinical setting. The quite low viral genome copies could be associated with localized,
rather systemic, viral reactivations and involved specific HCMV envelope genotype combinations.
The impact of these data will be evaluated with respect to clinical outcomes and HCMV-specific T cell
responses of the studied population