Diagnostic role of MGIT culture of BAL samples in sputum smearnegative pulmonary tuberculosis.

Background: In view of the diagnostic difficulties associated with sputum- negative pulmonary TB (PTB), we aimed at exploring if bronchoalveolar lavage (BAL) samples can be subjected to smear- microscopy and rapid mycobacterial culture (by Mycobacterial Growth Indicator Tube (MGIT) method) to achieve improved diagnosis of this condition. Methods: Patients presenting with clinico-radiological features suggestive of pulmonary tuberculosis and whose sputum smears were negative for acid- fast bacilli (AFB) or who could not expectorate sputum were prospectively enrolled in this study. BAL samples collected from them were subjected to smear- microscopy for AFB and micro-MGIT culture. BAL samples were also inoculated on Lowenstein- Jensen (LJ) slants. Results: A total of 105 patients (74 males) were recruited in the study, with a mean (±SD) age of 51 (± 15) years. The diagnosis of PTB was made in 52 patients on the basis of clinico- radiological presentation, with or without microbiological confirmation. Thirty- four patients (65.4 %) had microbiologically confirmed PTB. Of them, AFB were detected in 12 BAL samples, while culture- positivity was noted in 24 and 27 patients by the LJ and MGIT methods respectively. Intertest agreement between the LJ and MGIT methods was found to be significant (ê= 0.655; p= <0.001). However, the mean time to positivity was significantly lower for the MGIT method than for the LJ method (p= <0.001). Conclusion: Examination of BAL samples by smear- microscopy and micro-MGIT culture can, therefore, provide a rapid and definitive diagnosis of PTB in sputum- negative patients.

Study of pulmonary mainfestations in systemic sclerosis

Pulmonary involvement is frequent in systemic sclerosis, which leads to reduction in lung volumes and gas transfer across the alveolocapillary barrier and alteration of the pulmonary functions. The aim of this work was to study the pulmonary [functional and structural] changes in patients with systemic sclerosis. Thirty subjects comprised the material of this study, twenty of them had systemic sclerosis and ten were normal healthy volunteers as a control group. They were subjected to thorough history taking, complete clinical examination, PFT, BAL, CXR, 2D Echocardiography and HRCT. It was found that the mean values of FVC and DLCO were significantly lower in sysiemic sclerosis patients than those in normal control group. Also the lymphocytes, granulocytes, IgG and albumin in BAL fluid of patients with systemic scterosis were significantly higher than that in the normal control. HRCT scores were significantly higher in systemic sclerosis patients than normal control and also were higher in patients with abnormal BAL than those with normal BAL. It was concluded that: 1. Patients with systemic sclerosis have an inflammatory aiveolitis with hypercellularity and increased percentage of granulocytes recovered from the lower respiratory tract by BAL. 2. The significant correlalion between the degree of alveolitis and the degree of decline in PFT in such patients, increases the value oi BAL in identification of high risk group. 3. HRCT is an excellent radiodiagnostic tool for quantification of lurig lesions in systemic sclerosis and also for predication of sequale of these lesions on pulmonary functions