Incidence of cytomegalovirus-associated thrombosis and its risk factors: a case-control study.

INTRODUCTION: Cytomegalovirus (CMV)-associated thrombosis has been reported sporadically in the medical literature until now. However, thrombosis incidence and its risk factors have never been studied in a cohort of patients with acute CMV infection.
MATERIALS AND METHODS: A retrospective case-control study. Medical charts and imaging study reports of all consecutive patients diagnosed with acute CMV infection during the years 2005-2006 in a tertiary medical center were reviewed for the presence of arterial and/or venous thromboses, and their acquired as well as inherited predispositions. The control group included age-matched and sex-matched consecutive patients, in whom acute CMV infection was excluded. Laboratory tests used for acute CMV infection diagnosis/exclusion were also matched, including serology, antigenemia, and PCR.
RESULTS: Included were 140 patients with acute CMV infection (study group) and 140 consecutive matched patients in whom acute CMV infection was excluded (control group). Among the control group, none of the patients had thrombosis, while among the study group, nine (6.4%; p=0.003) patients had thrombosis: five (3.6%; p=0.025) patients had arterial thrombosis and four (2.9%; p=0.045) patients had venous thrombosis. Binary logistic regression analysis showed that acute CMV infection was independently associated with thrombosis among the whole cohort (p=0.004), while use of oral contraceptives/hormones or pregnancy were independently associated with thrombosis among patients with acute CMV infection (p=0.043).
CONCLUSIONS: Thrombosis in patients with acute CMV infection is not rare. Acute CMV infection is associated with thrombosis independent of other risk factors for thrombosis. We hope to raise physician's awareness to the association between acute CMV infection and thrombosis.