Comparison of Sputum Induction with Fiberoptic Bronchoscopy in the Diagnosis of Tuberculosis

Abstract

Many patients with suspected pulmonary tuberculosis (PTB) do not produce sputum spontaneously or are smear-negative for acid-fast bacilli (AFB). We prospectively compared the yield of sputum induction (SI) and fiberoptic bronchoscopy with bronchoalveolar lavage (BAL) for the diagnosis of PTB in a region with a high prevalence of tuberculosis and human immunodeficiency virus (HIV) infection. Fifty seven percent (143 of 251) of patients had diagnoses of PTB, of whom 17% (25 of 143) were HIV seropositive. There were no significant differences in the yields of AFB smears or cultures whether obtained via SI or BAL. Among 207 HIV-seronegative patients, the AFB smear and mycobacterial culture results from specimens obtained by SI and BAL were in agreement in 97% (202 of 207) (kappa test = 0.92) and 90% (186 of 207) (kappa test = 0.78), respectively. Among HIV-seropositive patients the agreements between AFB smear and culture results for SI and BAL specimens were 98% (43 of 44) (kappa test = 0.93) and 86% (38 of 44) (kappa test = 0.69), respectively. We conclude that SI is a safe procedure with a high diagnostic yield and high agreement with the results of fiberoptic bronchoscopy for the diagnosis of PTB in both HIV-seronegative and HIV-seropositive patients.

Comparative study on effect of various induction methods on sputum smear positivity

“…(p=0.02) Discussion: In the present study it was tried to investigate the diagnostic value of induced sputum and bronchial lavage specimens in patients with suspected pulmonary tuberculosis who had negative spontaneous sputum specimens. From 228 sputum negative subjects 92 were subjected to chest physiotherapy and Nebulisation to induce sputum of which 41.3% and 43.4% came out to be sputum positive in respective groups which was comparable to study done by L Saglam et al from January 2001-June 2003 at Turkey in which they reported 41.8% post induction sputum positivity for AFB and also by Marcus B Conde from 1996-98 at Brazil in which they reported 35% post induction sputum positivity for AFB 5,6 . In present study only 14 sputum negative subjects has given consent (it's being a invasive procedure) for broncho alveolar lavage to collect sputum sample and 50% came out positive for AFB which was comparable to observations by L Saglam et al (47.3%) and Marcus B. Conde (40%).…”

Bacteriological analysis of induced sputum for the diagnosis of pulmonary tuberculosis in the clinical practice of a general tertiary hospital

“…In accordance with the findings of previous studies, (10,11) we demonstrated that the yield of the culture is almost twice as high as the yield of AFB smear testing and confirmed the importance of culture in the diagnosis of pulmonary TB.…”

“…Therefore, in this specific population (bronchoscopy after IS with negative AFB smear results), we observed a low degree of concordance between the IS and BAL fluid findings for the diagnosis of pulmonary TB, which is in contrast with the findings of previous studies. (8,11,12) Bronchoscopy samples accounted for 25 (64.1%) of the 39 confirmed diagnoses of pulmonary TB.…”

“…(7,8,(10)(11)(12)(13)(14)23,24) Anderson et al (8) compared a single IS sample with BAL specimens in HIV-negative patients and also reported low sensitivity for AFB smear testing using both techniques (19% and 12%, respectively), although the sensitivity of culture was 73% in IS and 87% in BAL fluid. Another group of authors (11) demonstrated higher sensitivity for AFB smear testing, comparing 3 IS samples with BAL specimens, and found no difference between HIV-negative and HIV-positive patients (34% and 36% for IS, and 38% and 40% for BAL fluid, respectively). The authors reported culture sensitivity similar to that demonstrated by Anderson et al (8) for HIV-negative patients (67% for IS and 74.5% for BAL fluid); for HIV-positive patients, the sensitivity was slightly lower but not statistically different (60% for IS and BAL fluid).…”

“…However, the invasive nature of bronchoscopy, together with its higher cost, has motivated researchers to assess its yield in the diagnosis of pulmonary TB. (7)(8)(9)(10)(11)(12)(13)(14) The objective of our study was to assess the diagnostic sensitivity of the bacteriologic analysis of induced sputum (IS) for the diagnosis of pulmonary TB in a tertiary referral hospital in a region with a high prevalence of TB, as well as to identify the clinical characteristics associated with the confirmed diagnosis. In addition, we evaluated the diagnostic yield of bronchoscopy performed after IS samples have tested negative for AFB.…”