Influence of the factor V Leiden mutation on infectious disease susceptibility and outcome: A population-based study

Background. The effect of the coagulation factor V Leiden mutation on infectious disease susceptibility and outcome is controversial. Methods. We genotyped 9253 individuals from the Copenhagen City Heart Study for the factor V Leiden mutation. The risk of hospitalization for any infectious disease during a follow-up period of 7.2 years and subsequent risk of disease progression to death were estimated by Cox proportional-hazards regression analysis. Results. During 66,789 person-years of follow-up, 1093 persons were hospitalized because of infection. The risk of urinary-tract infection was decreased in factor V Leiden heterozygotes, compared with that in noncarriers (adjusted relative risk [aRR], 0.55 [95% confidence interval {CI}, 0.31-0.99]), whereas the risk of skin infection was increased (aRR, 1.68 [95% CI, 1.07-2.66]). No associations between carrier status and risk of diarrheal disease, other viral infections, parasitic infections, pneumonia, sepsis, or upper respiratory-tract infection were detected. However, in subjects hospitalized for sepsis, factor V Leiden carriers were at an increased risk of mortality 28 days after admission, compared with noncarriers (aRR, 4.41; 95% CI, 1.42-13.67]). Conclusion. In the Danish general population, the factor V Leiden mutation may be associated with infectious disease susceptibility and an increased risk of mortality from sepsis.