1/2. False-positive mycobacterium tuberculosis culture revealed by restriction fragment length polymorphism analysis.BACKGROUND: The microbiological analysis of respiratory specimens is the most reliable approach to diagnose active pulmonary tuberculosis. PATIENT AND methods: We report a 60-year-old female patient (index patient) who underwent diagnostic bronchoscopy for chronic cough. No acid-fast bacilli were detected in bronchial washings. Although cough subsided with symptomatic treatment, mycobacterium tuberculosis grew on egg-based media after 12 weeks. A false-positive culture result was suspected. Chart review and dna fingerprinting were carried out. RESULTS: The bronchoscope used to examine the index patient was previously used for a 30-year-old patient (source patient) with smear- and culture-positive pulmonary tuberculosis. Restriction fragment length polymorphism (RFLP) analysis based on the IS 6110 element confirmed that the two strains were identical. CONCLUSION: Cross-contamination is a reason for false-positive cultures with M. tuberculosis and should be suspected in patients with a low clinical probability for active tuberculosis.- - - - - - - - - - ranking = 1keywords = probability (Clic here for more details about this article) |
2/2. Steroid therapy for a case of severe drug-induced cholestasis.OBJECTIVE: To report a severe case of cholestatic liver disease successfully treated with corticosteroids following combined therapy with clarithromycin and nimesulide. CASE SUMMARY: A 15-year-old girl was admitted with cholestasis probably related to treatment with clarithromycin and nimesulide for an upper respiratory tract infection. Other causes of liver disease (infections, metabolic liver disorders, genetic cholestatic syndromes, autoimmune diseases, primary biliary tract disorders) were excluded. Liver biopsy showed a severe canalicular cholestasis with bile plugs in dilated bile canaliculi, giant cell transformation, and portal and lobular infiltrate. An objective causality assessment suggested that cholestasis was probably related to clarithromycin and/or nimesulide use. No benefit was derived from a course of ursodeoxycholic acid therapy. Since the patient experienced a progressive worsening in cholestasis, prednisone was started after 20 days. This therapy was promptly followed by improvement in clinical and laboratory test results. After 2 months of prednisone treatment, the patient became symptom-free with normal liver function tests. DISCUSSION: The manifestations of drug-induced hepatotoxicity are highly variable, ranging from asymptomatic hypertransaminemia to fulminant hepatic failure. No specific treatment for drug-induced hepatotoxicity exists. Early recognition and drug withdrawal are the keys to management of hepatotoxicity, but in some cases, liver disease may persist despite discontinuation of the drug. Possible advantages of corticosteroid therapy have not been well demonstrated. CONCLUSIONS: Application of the Naranjo probability scale indicates a probable relationship between cholestasis and nimesulide plus clarithromycin use. This case draws attention to a possible therapeutic option for some cases of drug-induced hepatotoxicity that show a severe course without any sign of improvement.- - - - - - - - - - ranking = 1keywords = probability (Clic here for more details about this article) |