Predicting Recurrent Clostridium difficile Infection

As physicians and scientists, we often forget how it feels to be a patient. I was acutely reminded of the patient perspective after the recent birth of my twins, when I became infected with Clostridium difficile —with multiple relapses. C. difficile infection (CDI) is a major cause of hospital-acquired diarrhea that is increasingly prevalent in the community-based setting. CDI is often associated with precedent antibiotic use, which is probably due to the eradication of competing bacteria. C. difficile , an anaerobic bacterium, secretes toxins that result in loss of cell-cell adhesion in the colon, as well as a robust inflammatory infiltrate that can lead to pseudomembranous colitis and toxic megacolon in a subset of cases. To date, prediction of which patients may develop symptomatic CDI and subsequent relapses has been challenging. A recent article by Garey et al. addresses the role of interleukin-8 (IL-8) gene polymorphisms in predicting recurrent CDI—defined as the return of watery diarrhea associated with a positive toxin assay within 3 months of initial diagnosis—in a prospective cohort of 96 hospitalized patients who developed disease. IL-8 represents one of a number of cytokines that appear to influence the immune response after infection, promoting increased inflammatory/neutrophil infiltrate during disease. The current study reveals that patients with the A/A genotype at –251 of the IL-8 promoter have a significantly increased likelihood of recurrent CDI and represents a novel finding of host genetic influence on recurrence of C. difficile . In a disease that can follow a protracted course with unpredictable recurrences—and with effects as psychological as much as physical—the finding of a predictor for recurrence provides some “rhyme and reason” to patients and offers a unique opportunity for further understanding and potential treatment of this disease. K. W. Garey et al ., A common polymorphism in the interleukin-8 gene promoter is sssociated with an increased risk for recurrent Clostridium difficile infection. Clin. Infect. Dis. 51 , 1406–1410 (2010). [[Abstract]][1] [1]: http://www.ncbi.nlm.nih.gov/pubmed/21058913