Evaluation of antigen-positive toxin-negative enzyme immunoassay results for the diagnosis of toxigenic Clostridium difficile infection

Clostridium difficile (C. difficile)-associated diarrhea (CDAD) is a challenging nosocomial infectious disease. C. DIFF Quik Chek Complete assay is widely used to detect glutamate dehydrogenase (GDH) antigen and toxin A/B of C. difficile simultaneously. However, the interpretation of GDH positive/toxin negative results is problematic.We performed a retrospective study of patients with GDH positive/toxin negative results to determine the probability of detecting toxigenic C. difficile and its risk factors. Between April 2012 and March 2017, we investigated cultures of fecal specimens followed by toxin detection tests. The clinical histories of patients with and without toxigenic C. difficile were compared using univariate- and multivariate-analyses. In total, 2675 patients were examined using C. Diff Quik Chek Complete assay. Among 356 GDH positive/toxin negative patients, cultures were performed in 220 cases and toxigenic C. difficile was recovered from 139 (63.2%) specimens. Patients with toxigenic C. difficile had significantly lower body mass index than those without. Over half the GDH positive/toxin negative patients were infected with toxigenic C. difficile. Lower BMI was a CDAD risk factor in this patient population. These data can be utilized to initiate isolation and clinical interventions before confirmatory test results are available

Effects of changing the timing of warfarin administration in combination with fluconazole on prolongation of the PT-INR: a case report

Abstract Background Fluconazole (FLCZ) inhibits cytochrome P450 (CYP) 2C9, 2C19, and 3A4 and has a drug-drug interaction that potentiates the effects of warfarin and prolong the prothrombin time-international normalized ratio (PT-INR). Although a drug-drug interaction have been reported between FLCZ and warfarin, the effects of the timing of their administration on this interaction have not yet been investigated. Case presentation A female patient in her 30s with Marfan syndrome had undergone the Bentall procedure with a mechanical valve and total arch replacement for acute aortic dissection Stanford A type and rupture of the ascending aorta. Warfarin was administered to prevent thromboembolism. She was hospitalized 1 year ago for graft infection caused by Candida albicans, and treatment with FLCZ was initiated. She received FLCZ 200 mg once a day in the morning and warfarin 1.75 mg once a day in the evening, and the PT-INR remained stable at approximately 2.0 and within the therapeutic range. However, 42 days after changing the timing of administration of warfarin from evening to morning, the PT-INR was prolonged by approximately 3-fold to 6.25. The PT-INR then decreased to the previous level by changing the timing of administration of warfarin from morning to evening. Conclusions The timing of administration of FLCZ and warfarin may affect the magnitude of drug-drug interaction

Evaluation of antigen‐positive toxin‐negative enzyme immunoassay results for the diagnosis of toxigenic Clostridium difficile infection

Clostridium difficile (C. difficile)-associated diarrhea (CDAD) is a challenging nosocomial infectious disease. C. DIFF Quik Chek Complete assay is widely used to detect glutamate dehydrogenase (GDH) antigen and toxin A/B of C. difficile simultaneously. However, the interpretation of GDH positive/toxin negative results is problematic.We performed a retrospective study of patients with GDH positive/toxin negative results to determine the probability of detecting toxigenic C. difficile and its risk factors. Between April 2012 and March 2017, we investigated cultures of fecal specimens followed by toxin detection tests. The clinical histories of patients with and without toxigenic C. difficile were compared using univariate- and multivariate-analyses. In total, 2675 patients were examined using C. Diff Quik Chek Complete assay. Among 356 GDH positive/toxin negative patients, cultures were performed in 220 cases and toxigenic C. difficile was recovered from 139 (63.2%) specimens. Patients with toxigenic C. difficile had significantly lower body mass index than those without. Over half the GDH positive/toxin negative patients were infected with toxigenic C. difficile. Lower BMI was a CDAD risk factor in this patient population. These data can be utilized to initiate isolation and clinical interventions before confirmatory test results are available