Thrombosis following acute cytomegalovirus infection: a community prospective study.

Infection might be associated with increased risk of venous thromboembolism (VTE) and arterial thrombosis. Specific hypotheses have been raised regarding the procoagulant response induced by acute cytomegalovirus (CMV) infection. Accordingly, we investigated the 6-month incidence of VTE and/or arterial thrombosis in patients that had been tested positive for CMV-IgM antibodies in a large health maintenance organization. Logistic regression analysis was used to identify independent risk factors for VTE and arterial thrombosis. Among 90,515 patients eligible for the VTE analysis and 90,805 patients eligible for the arterial thrombosis analysis, 6,205 (6.9%) and 6,222 (6.9%) patients were tested positive for CMV-IgM antibodies, respectively. During 6 months of follow-up from index date, the incidence rates per 1,000 capita of VTE among CMV-IgM seropositive and CMV-IgM seronegative patients were 3.06 (19 patients) and 1.36 (115 patients), respectively (odds ratio (OR) 2.25; 95% confidence intervals (95% CI) 1.38-3.66; p = 0.003). CMV-IgM seropositivity was independently associated with VTE appearance (OR 2.49; 95% CI 1.53-4.06; p < 0.0001) following adjustment for age, sex, and other confounders. The incidence rates per 1,000 capita of arterial thrombosis among CMV-IgM seropositive and CMV-IgM seronegative patients were 1.12 (7 patients) and 1.06 (90 patients), respectively (OR 1.06; 95% CI 0.49-2.28; p = 0.840). CMV-IgM seropositivity was not associated with arterial thrombosis. We conclude that acute CMV infection might be associated with an increased short-term VTE risk. To the best of our knowledge, this is the largest study ever to confirm this association.