Complement factor B activation in patients with preeclampsia.

Preeclampsia is a leading cause of maternal and fetal morbidity and mortality. Bb, the active fragment of complement factor B (fB), has been reported to be a predictor of preeclampsia. However, conflicting results have been found by some investigators. We hypothesized that the disagreement in findings may be due to the racial/ethnic differences among various study groups, and that fB activation is significant in women of an ethnic minority with preeclampsia. We investigated the maternal and fetal levels of Bb (the activated fB fragment) in pregnant women of an ethnic minority with or without preeclampsia. We enrolled 291 pregnant women (96% of an ethnic minority, including 78% African-American). Thirteen percent of these were diagnosed with preeclampsia. Maternal venous blood was collected from all participants together with fetal umbilical cord blood samples from 154 deliveries in the 291 women. The results were analyzed using the Mann-Whitney U test and multivariate analyses. Maternal Bb levels were significantly higher in the preeclamptic group than in the nonpreeclamptic group. Levels of Bb in fetal cord blood were similar in both groups. Subgroup analyses of African-American patients' results confirmed the study hypothesis that there would be a significant increase in Bb in the maternal blood of the preeclamptic group and no increase in Bb in the fetal cord blood of this group. These results suggest that a maternal immune response through complement fB might play a role in the development of preeclampsia, particularly in African-American patients.

Investigation of critical care unit utilization and mortality in patients infected with Clostridium difficile.

BACKGROUND: A nationwide increase in the rate and severity of Clostridium difficile-associated disease may reflect infection with a virulent strain characterized by polymerase chain reaction as ribotype 027 (NAP1/B1). HYPOTHESIS: The high prevalence of ribotype 027 at our institution would allow investigation of the risk of mortality and admission to the intensive care unit (ICU) associated with C difficile infection. METHODS: In a retrospective cohort study, we identified 108 patients with positive enzyme-linked immunosorbant assay tests for C difficile toxins over a 6-month period and compared them to 108 patients who were suspected to have C difficile but with negative toxin assays. Proportions of all-cause mortality and ICU admission were compared using chi(2), and odds ratios (ORs) were estimated using logistic regression to adjust for potential confounders. Mean log lengths of stay were compared using t test. RESULTS: Comparing patients with C difficile to those without, mortality (20% vs 8%) and ICU admission (32% vs 17%) were significantly higher (P = .02 for both), whereas log length of stay was not (P = .29). Adjusting for potential confounders, the OR for mortality was 6.8 (95% confidence interval, 1.8-25.4; P = .01), whereas for ICU admission, the association was no longer observed (OR, 1.0; 95% confidence interval, 0.4-2.5; P = .97). CONCLUSION: C difficile infection was associated with increased all-cause mortality. An observed association with ICU admission and C difficile infection was identified through univariate analysis but was not significant in multivariate analysis. Although we did not strain-type isolates for patients infected with C difficile, the institutional prevalence of ribotype 027 C difficile infection was known to be high. These results document a strong association between ribotype 027 C difficile infection and mortality and underscore the need to identify effective C difficile preventive strategies.