Differences in pulmonary nodular consolidation features among drug-sensitive pulmonary tuberculosis and multidrug/extensively-resistant pulmonary tuberculosis: a multi-national multi-center study.

Background: Pulmonary nodular consolidation (PN) may represent an imaging sign potentially useful in differentiating multidrug-resistant (MDR) pulmonary tuberculosis (PTB) from drug-sensitive (DS) tuberculosis (TB) on chest computed tomography (CT). This study aims to confirm the difference in PN features between DS and MDR patients. Methods: Eastern European (Belarus, Moldova, Romania, Azerbaijan, and Georgia) patient data were obtained from the NIAID TB (National Institute of Allergy & Infectious Diseases Tuberculosis) Portals Program registered before January 2019. Chinese patients were obtained from Shenzhen, China, treated between April 2017 and February 2019. There were in total 244 DS cases (222 new patients and 22 previously treated patients), 344 MDR cases (188 new patients and 156 previously treated patients), 155 extensively drug-resistant (XDR) TB cases (36 new patients and 119 previously treated patients). The first CT scan's images were used. A PN was defined as rounded or oval with a relatively clear boundary measuring between 6 and 30 mm in diameter. Calcified lesions in the lungs, as a sign of chronicity, were also recorded. Results: In new patients, there was no difference in lung lesion calcification prevalence among DS (16.1%) and MDR (15.0%). In previously treated patients, lung calcification prevalence was 38.5% for DS, 48.3% for MDR, and 52.8% for XDR. For new patients, the PN prevalence was higher for MDR/XDR cases than for DS cases (around 70% vs. around 39%). PN prevalence increased for DS cases from around 39% for new patients to 59% for treated patients, but the increases for MDR/XDR cases were minimal. For new patients, the mean PN number for positive cases was DS: 2.38, MDR: 2.89, XDR: 2.72. For treated cases, the mean PN number for positive cases was DS: 2.54, MDR: 3.91, XDR: 4.99. For both new patients and treated patients, PN No. ≥3 had a specificity of around 85% suggesting the diagnosis of XDR/XDR. The number of lung fields with PN lesion was higher for MDR cases than for DS cases. PN lesions were even more widely spread in XDR cases than in MDR cases. Additional analysis of recent literature suggests that a trend may exist in the frequency of lung lesions: DS < RR (rifampicin-resistant) < MDR < XDR. Conclusions: MDR/XDR patients exhibit significantly higher PN prevalence and more extensive pulmonary involvement compared to DS patients and which is not totally determined by disease history length, suggesting that PN characteristics could serve as imaging biomarkers for drug resistance assessment.