Diagnostic utility of bronchoalveolar lavage in children with complicated intrathoracic tuberculosis

Abstract

Introduction: Bronchoscopy can be a useful tool in children with pulmonary tuberculosis (PTB) with severe disease potentially requiring intervention or in the face of diagnostic dilemmas. The aim of this study was to determine the value of Xpert MTB/RIF assay (Xpert) on bronchoalveolar lavage (BAL) samples in children with complicated PTB. Methods: Retrospective analysis of children with clinically diagnosed PTB, who underwent routine bronchoscopy over a 5-year period at a large referral hospital. BAL and other respiratory samples were tested by microscopy, culture, and Xpert. We explored whether clinical, radiographic and bronchoscopy findings, and duration of antituberculosis treatment were associated with bacteriological confirmation. Results: One hundred and twelve out of one hundred and forty-six (76.7%) children (median age 16 months) were on antituberculosis treatment for a median of 10 days at the time of bronchoscopy. Overall, bacteriological confirmation was achieved in 115 (78.7%), with 101 (69.2%) detected on BAL. Of those bacteriologically confirmed on BAL, 61.4% were positive by both Xpert and culture, 34.7% only by Xpert, and 3.9% only by culture. Sensitivity and specificity of Xpert compared with culture on BAL samples for children not on antituberculosis treatment were 94.1% (95% confidence interval [CI]: 71.3, 99.8) and 68.7% (95% CI: 41.3, 89.0), respectively. Conclusions: In children undergoing bronchoscopy for complicated PTB, Xpert testing of BAL had a high diagnostic yield in children already on antituberculosis treatment. Bronchoscopy should be considered if noninvasive respiratory specimens fail to confirm complicated TB.

Diagnostic Advances in Childhood Tuberculosis—Improving Specimen Collection and Yield of Microbiological Diagnosis for Intrathoracic Tuberculosis

“…An interim joint analysis of these two studies has shown similar sensitivity between the three methods, but lower sensitivity than the microbiological reference standard, and high specificity with less than 10% of combined invalid and error results [64]. Finally, bronchoalveolar lavage (BAL), which consists in aspirating normal saline instilled in a subsegment of the lung through flexible bronchoscopy, has a diagnostic performance equivalent to GA in children with presumptive TB, with no or little added value when both techniques are done [23]. It has a place in children with severe intrathoracic TB who cannot be confirmed on less invasive specimens.…”

“…The automated Mycobacterial Growth Indicator Tube (Bactec MGIT, Becton Dickinson Microbiology Systems, Cockeysville, MD, USA), has higher sensitivity, a shorter time to results, and improved reproducibility compared to culture on solid media such as Löwenstein-Jensen (LJ) [19]. Culture yield is usually low (30% to 40%) in children with intrathoracic TB, although certain disease manifestations are associated with much higher diagnostic yields [11,[20][21][22][23]. Classical decontamination methods used on samples prior to culture are known to kill up to 30% of the MTBc population and may be too harsh for paediatric paucibacillary specimens and result in a loss of viable organisms for culture [24].…”

The role of bronchoscopy in the diagnosis and management of pediatric pulmonary tuberculosis

“…Overall, bacteriological confirmation was achieved in 78.7% from all samples. 23 Bronchoscopy is unlikely to be; indeed, should not be, the first investigation used to identify the organism. This is especially true in the developing world, which is impacted by limited resources.…”

“…The median duration of treatment was significantly different for children with a positive culture compared with those with a negative culture (7 versus 14.5 days, p < 0.001); in contrast, there was no difference among children with a positive versus a negative Xpert (11 versus 8 days, p = 0.36). 23…”

“…The median duration of treatment was significantly different for children with a positive culture compared with those with a negative culture (7 versus 14.5 days, p < 0.001); in contrast, there was no difference among children with a positive versus a negative Xpert (11 versus 8 days, p = 0.36). 23 Most pediatric studies have shown that Xpert MTB/RIF has identified additional cases on BAL compared to culture and where other routine samples could not confirm the diagnosis. Except for confirming the diagnosis bacteriologically, bronchoscopy has the additional value of assessing the severity of airway obstruction, which can lead to the addition of corticosteroids to the TB treatment and to referral for surgical decompression.…”