title: Day zero quantitative mRNA analysis as a prognostic marker in pulmonary tuberculosis category II patients on treatment.
abstract: Mycobacterium tuberculosis m-RNA quantitation in sputum of pulmonary tuberculosis patients before starting supervised treatment was evaluated as a surrogate for response. Sputum specimens were collected from 50 patients (DOTS category II treatment; 303 specimens, day 0 to fourth month) and 16 controls (non-tubercular lung disorders). Microscopy, reverse-transcriptase PCR and DNA-PCR were compared with culture using the BACTEC 460 system. TaqMan real-time RT-PCR quantitated the mRNA levels. RT-PCR (sensitivity, 10 organisms/mL) and culture results were concordant. mRNA declined with time and correlated with culture clearance. Thirty-nine (78%) patients were smear, culture and RT-PCR negative at 2 months of treatment. Day 0 mRNA levels had statistically significant correlation with time to culture conversion and drug resistance (p 0.041). Of seven patients with sensitive isolates but high m-RNA levels, four presented with re-infection/mixed infection later, while three presented with relapse (ninth to twentieth month). The control group specimens were negative for the above tests. M. tuberculosis mRNA in the sputum is a useful prognostic marker and its quantitation an early and reliable indicator for monitoring response, prediction of culture conversion, drug resistance, re-infection and relapse. mRNA quantitation may prove to be of great value for evaluating the response to new drugs under trial.
authors.affiliation: Department of Microbiology, All India Institute of Medical Sciences, New Delhi, India. drurvashi@gmail.com
authors.forename: U B
authors.initials: UB
authors.lastname: Singh
authors.forename: T
authors.initials: T
authors.lastname: Rana
authors.forename: A
authors.initials: A
authors.lastname: Kaushik
authors.forename: C
authors.initials: C
authors.lastname: Porwal
authors.forename: N
authors.initials: N
authors.lastname: Makkar
mesh_terms: D000293:Adolescent; D000328:Adult; D000995:Antitubercular Agents / Q000008:administration & dosage*; D005260:Female; D006801:Humans; D008297:Male; D008853:Microscopy; D008875:Middle Aged; D009169:Mycobacterium tuberculosis / Q000235:genetics* / Q000302:isolation & purification; D011379:Prognosis; D012333:RNA, Messenger / Q000032:analysis* / Q000235:genetics; D060888:Real-Time Polymerase Chain Reaction; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013183:Sputum / Q000382:microbiology; D014397:Tuberculosis, Pulmonary / Q000175:diagnosis* / Q000188:drug therapy*; D055815:Young Adult
chemical_list: D000995:Antitubercular Agents; D012333:RNA, Messenger