SEVERITY OF TB CLASSIFIED BY MODIFIED BANDIM TB SCORING ASSOCIATES WITH THE SPECIFIC SEQUENCE OF ESXA GENES IN MDR-TB PATIENTS

A novel hematological score (HS) and its related nomogram model to predict nontuberculous mycobacterial pulmonary disease in patients with suspected multidrug-resistant pulmonary tuberculosis

BACKGROUND

Nontuberculous mycobacteria pulmonary disease (NTM-PD) exhibits clinical and radiological characteristics similar to those of pulmonary tuberculosis (PTB). This study aimed to develop a novel hematological score (HS) and its related nomogram model to identify NTM-PD in patients with suspected multidrug-resistant pulmonary tuberculosis (SMDR-PTB) due to lack of response to first-line anti-TB treatment (ATT).

METHODS

We retrospectively recruited patients with SMDR-PTB from Wuhan Jinyintan Hospital between January 2014 and January 2022. These patients were divided into NTM-PD and MDR-PTB groups based on pathogen test results. Participants were randomly allocated to training and validation set in a 7:3 ratio. The ROC and LASSO regression were employed to select variables. Multivariate logistic analysis was conducted on the training set to develop the HS and its related nomogram models, followed by internal validation on the validation set.

RESULTS

The HS was constructed and developed on CKMB, ADA, GGT, LDL, and UHR, demonstrating good predictive value with AUCs of 0.900 and 0.867 in the training and validation sets, respectively. The HS-based nomogram model consists of Age, Gender, DM, HIV infection, ILD and HS, and exhibited strong discriminative ability, accuracy, and clinical utility in two sets. The AUCs were 0.930 and 0.948 in the training set and validation set, respectively.

CONCLUSION

HS may be a useful biomarker for identifying NTM-PD in patients with SMDR-PTB. The HS-based nomogram model serves as a convenient and efficient tool for guiding the treatment of SMDR-PTB patients.

Utility of a Clinical Scoring System (Bandim TB Score and Karnofsky Performance Score) to Assess Mycobacterial Burden in Terms of Cartridge-Based Nucleic Acid Amplification Test (CBNAAT) Cycle Threshold Values Among Pulmonary TB Patients

AIM

Tuberculosis (TB) continues to be a global public health problem. Physicians fail to clearly interpret cycle threshold (Ct) values as a measure of mycobacterial burden due to the paucity of literature correlating Ct values with the clinical scoring. This study aims to correlate the clinical scoring parameters (Bandim TB score and Karnofsky Performance score (KPS)) with Ct values obtained by Cartridge-Based Nucleic Acid Amplification Test (CBNAAT).

MATERIALS AND METHODS

The study spanned from November 2019 to October 2021, during which a total of 40 cases were recruited. These cases were identified as pulmonary TB patients based on Ziehl-Neelsen staining for acid-fast bacilli and/or the GeneXpert MTB/RIF assay. Bandim TB scores and KPSs were recorded using standardized questionnaires.

RESULTS

There was a strong negative correlation between Bandim TB score and Ct value (mean), and this correlation was statistically significant (rho = -0.82, p < 0.001). There was a moderate positive correlation between KPS and Ct value (mean), and this correlation was statistically significant (rho = 0.57, p < 0.001).

CONCLUSION

No literature has compared Bandim TB score and KPS with the Ct values obtained by CBNAAT for pulmonary TB. Thus, the knowledge on the proper utilization of CBNAAT cycle threshold values and its correlation with clinical scoring parameters will help clinicians in the early identification and prompt initiation of appropriate treatment.

Antibodies against native proteins of Mycobacterium tuberculosis can detect pulmonary tuberculosis patients

Accurate point-of-care testing (POCT) is critical for managing tuberculosis (TB). However, current antibody-based diagnosis shows low specificity and sensitivity. To find proper antigen candidates for TB diagnosis by antibodies, we assessed IgGs responsiveness to Mycobacterium tuberculosis proteins in pulmonary TB (PTB) patients. We employed major secreted proteins, such as Rv1860, Ag85C, PstS1, Rv2878c, Ag85B, and Rv1926c that were directly purified from M. tuberculosis. In the first screening, we found that IgG levels were significantly elevated in PTB patients only against Rv1860, PstS1, and Ag85B among tested antigens. However, recombinant PstS1 and Ag85B from Escherichia coli (E. coli) couldn't distinguish PTB patients and healthy controls (HC). Recombinant Rv1860 was not checked due to its little expression. Then, the 59 confirmed PTB patients from Soetomo General Academic Hospital, Surabaya, Indonesia, and 102 HC were tested to Rv1860 and Ag85B only due to the low yield of the PstS1 from M. tuberculosis. The ROC analysis using native Ag85B and Rv1860 showed an acceptable area under curve for diagnosis, which is 0.812 (95% CI 0.734-0.890, p < 0.0001) and 0.821 (95% CI 0.752-0.890, p < 0.0001). This study indicates that taking consideration of native protein structure is key in developing TB's POCT by antibody-based diagnosis.

Assessing Pulmonary Tuberculosis Using Bandim Tuberculosis and Karnofsky Performance Scale Scores with Serum Adenosine Deaminase Levels

BACKGROUND

Elevated pulmonary serum adenosine deaminase (ADA) levels signify lung tissue damage and severe tuberculosis (TB). Serum ADA assays can be used as an additional criterion for assessing TB treatment response and as a prognostic marker in patients with pulmonary TB. The Bandim TB and Karnofsky Performance Scale (KPS) scores were developed based on available clinical data and investigations to allow physicians to evaluate disease treatment and response. This study examined the use of a clinical scoring system (Bandim TB and KPS scores) in the context of serum ADA activity.

METHODS

Forty adults (aged >18 years) diagnosed with pulmonary TB by Ziehl-Neelsen staining for acid-fast bacilli and/or cartridge-based nucleic acid amplification test were recruited. Standardized questionnaires were used to record Bandim TB and KPS scores. Serum ADA levels were estimated using a commercial kit.

RESULTS

The Bandim TB score was positively associated (ρ=0.74, P≤0.001) and the KPS score was negatively associated (ρ=-0.69, P≤0.001) with serum ADA levels.

CONCLUSION

Subjective and objective clinical scores of pulmonary TB were strongly correlated with serum ADA levels. Knowledge of clinical scores corresponding to serum ADA levels could help physicians understand stage and progression of the disease which may aid in early detection and better management, and reduce disease transmission in a TB-endemic country.

CT Imaging Characteristics of Nontuberculous Mycobacteria Lung Disease, Active Tuberculosis and Multi-Drug Resistant Tuberculosis

Background

The differential diagnosis of nontuberculous mycobacteria (NTM) lung disease, active tuberculosis (ATB) and multi-drug resistant tuberculosis (MDR-TB) remains difficult.

Objectives

To explore the CT imaging characteristics of NTM lung disease, ATB and MDR-TB for differential diagnosis.

Methods

Patients with NTM lung disease (n=200), ATB (n=200) and MDR-TB (n=200) who were examined and treated from August 2013 to May 2021 were included. Their chest CT imaging results were retrospectively analyzed, and the imaging characteristics were compared.

Results

The proportion of cases complicated with underlying lung disease, cough and hemoptysis was significantly higher in NTM group than those in ATB and MDR-TB groups (P<0.05). Compared with ATB and MDR-TB groups, NTM group had significantly more cases of nodule-bronchus dilation type, but significantly fewer cases of nodule-mass type and other types (P<0.05). In NTM group, the cases of thin-wall cavity, bronchiectasis and centrilobular nodules increased, but the detection rate of thick-wall cavity, lung consolidation, atelectasis, lung damage, lung volume reduction, intrapulmonary calcification, hilar and mediastinal lymph node calcification, acinar nodules, pleural thickening and pleural effusion declined compared with ATB and MDR-TB groups (P<0.05). The detection rates of lesions, cavities and bronchiectasis in the lingual lobe of left lung and middle lobe of right lung were significantly higher in NTM group than those in ATB and MDR-TB groups (P<0.05).

Conclusions

The imaging characteristics of NTM lung disease are quite similar to those of ATB and MDR-TB, but they can be differentially diagnosed through the types of cavities and nodules, incidence rate of bronchiectasis, and differences in lung consolidation, lung damage, calcification, pleural thickening and pleural effusion.

Rifampicin exposure reveals within-host Mycobacterium tuberculosis diversity in patients with delayed culture conversion

Mycobacterium tuberculosis (Mtb) genetic micro-diversity in clinical isolates may underline mycobacterial adaptation to tuberculosis (TB) infection and provide insights to anti-TB treatment response and emergence of resistance. Herein we followed within-host evolution of Mtb clinical isolates in two cohorts of TB patients, either with delayed Mtb culture conversion (> 2 months), or with fast culture conversion (< 2 months). We captured the genetic diversity of Mtb isolates obtained in each patient, by focusing on minor variants detected as unfixed single nucleotide polymorphisms (SNPs). To unmask antibiotic tolerant sub-populations, we exposed these isolates to rifampicin (RIF) prior to whole genome sequencing (WGS) analysis. Thanks to WGS, we detected at least 1 unfixed SNP within the Mtb isolates for 9/15 patients with delayed culture conversion, and non-synonymous (ns) SNPs for 8/15 patients. Furthermore, RIF exposure revealed 9 additional unfixed nsSNP from 6/15 isolates unlinked to drug resistance. By contrast, in the fast culture conversion cohort, RIF exposure only revealed 2 unfixed nsSNP from 2/20 patients. To better understand the dynamics of Mtb micro-diversity, we investigated the variant composition of a persistent Mtb clinical isolate before and after controlled stress experiments mimicking the course of TB disease. A minor variant, featuring a particular mycocerosates profile, became enriched during both RIF exposure and macrophage infection. The variant was associated with drug tolerance and intracellular persistence, consistent with the pharmacological modeling predicting increased risk of treatment failure. A thorough study of such variants not necessarily linked to canonical drug-resistance, but which are prone to promote anti-TB drug tolerance, may be crucial to prevent the subsequent emergence of resistance. Taken together, the present findings support the further exploration of Mtb micro-diversity as a promising tool to detect patients at risk of poorly responding to anti-TB treatment, ultimately allowing improved and personalized TB management.

Tuberculosis (TB) is caused by Mycobacterium tuberculosis (Mtb), bacteria that are able to persist inside the patient for many months or years, thus requiring long antibiotic treatments. Here we focused on TB patients with delayed response to treatment and we performed genetic characterization of Mtb isolates to search for sub-populations that may tolerate anti-TB drugs. We found that Mtb cultured from 9/15 patients contained different sub-populations, and in vitro drug exposure revealed Mtb sub-populations in 6/15 isolates, none related to known drug-resistance mechanisms. By contrast, drug exposure revealed Mtb sup-populations in 2/20 isolates in the control cohort of patients with fast culture conversion. Furthermore, we characterized a Mtb variant isolated from a sub-population growing in the presence of rifampicin (RIF), a major anti-TB drug. We found that this variant featured a modified lipidic envelope, and that it was able to develop in the presence of RIF and inside human macrophage cells. We performed pharmacological modelling and found that this kind of variant may be related to a poor response to treatment. In conclusion, searching for particular Mtb sub-populations may help to detect patients at risk of treatment failure and provide additional guidance for TB management.