Therapeutic effects of various initial combinations of chemotherapy including clarithromycin against Mycobacterium avium complex pulmonary disease.

BACKGROUND: The objective of this study was to find an optimal initial combination chemotherapy that includes clarithromycin (CAM) for treatment-naive patients with Mycobacterium avium complex (MAC) pulmonary disease, as assessed by microbiological conversion using a Mycobacterium growth indicator tube (MGIT). METHODS: Thirty-four patients with treatment-naive MAC pulmonary disease (determined using 1997 American Thoracic Society criteria) were evaluated retrospectively. They demonstrated a nodular and bronchiectatic pattern without cavity on high-resolution CT (HRCT) scans. The following three regimens were administered: regimen A (n = 9) consisted of CAM (400 mg/d), ethambutol (EB) [750 mg/d], and rifampicin (RFP) [450 mg/d]; regimen B (n = 12) consisted of CAM (800 mg/d), EB (750 mg/d), and RFP (450 mg/d); and regimen C (n = 13) consisted of CAM (800 mg/d), EB (1,000 mg/d), and RFP (600 mg/d) during the first 2 months followed by a reduction of the dosage of EB from 1,000 to 750 mg/d. Gender, age, BMI, and HRCT scan finding scores were not significantly different among the three groups. Chemotherapy was continued for 18 months. Sputum culture was periodically assessed by MGIT. RESULTS: Culture conversion at 18 months in regimen A (55.6%), which included a daily dosage of 400 mg of CAM (9.5 mg/kg), was significantly inferior to that in regimen B (91.7%), which included daily 800 mg of CAM (17.6 mg/kg; p < 0.05), but regimen B and C (92.3%) showed no between-group difference after > 18 months of chemotherapy. CONCLUSIONS: The higher dose of CAM allowed for better culture conversion. Daily combination chemotherapy that includes CAM (800 mg) seems appropriate as an initial treatment against treatment-naive patients with nodular and bronchiectatic MAC pulmonary disease.

New simple and rapid test for culture confirmation of Mycobacterium tuberculosis complex: a multicenter study.

Mycobacterial antigen MPB64 has been identified as a Mycobacterium tuberculoisis complex-specific secretory protein since 1984. Recently, a simple culture confirmation test for M. tuberculosis complex has been developed by using lateral flow immunochromatographic assay (ICA) to detect MPB64 with anti-MPB64 monoclonal antibody. The current multicenter study evaluated the performance of an ICA slide test for MPB64 antigen in the clinical setting. Primary positive cultures from clinical specimens, as well as stock cultures, were tested. Approximately 100 microl of positive liquid culture medium or suspension made from colonies on solid medium was placed into the test well of the plastic slide devise, and the test was read after 15 min. No processing or instrumentation was required. A total of 304 mycobacterial isolates consisting of M. tuberculosis complex (171 isolates) and mycobacteria other than M. tuberculosis (MOTT) complex (133 isolates) belonging to 18 different species were tested. Growth in liquid media (Mycobacteria Growth Indicator Tube [MGIT] and Radiometric 12B), as well as in solid (Löwenstein-Jensen and Middlebrook 7H10 agar) media, was evaluated. Results were compared with those obtained with nucleic acid-based and/or high-pressure liquid chromatography identification. All MOTT were found to be negative on the ICA slide with no cross-reaction. All M. tuberculosis and M. africanum cultures were found to be positive, whereas the results of M. bovis and M. bovis BCG cultures were variable since some of the BCG strains are known to lack MPB64 antigen production. The results did not change with prolonged storage of cultures. This low-tech rapid test with high sensitivity and specificity could provide an alternative to currently available identification methods, particularly for recently introduced nonradiometric liquid culture systems such as MGIT.