Expert panel consensus recommendations on the utilization of nebulized budesonide for managing asthma and COPD in both stable and exacerbation stages in Thailand.

OBJECTIVE: This study investigated the utilization of nebulized budesonide for acute asthma and COPD exacerbations as well as for maintenance therapy in adults. DATA SOURCES: We conducted a search on PubMed for nebulized budesonide treatment. SELECTED STUDIES: Selecting all English-language papers that utilize Mesh phrases "asthma," "COPD," "budesonide," "nebulized," "adult," "exacerbation," and "maintenance" without temporal restrictions, and narrowing down to clinical research such as RCTs, observational studies, and real-world studies. RESULTS: Analysis of 25 studies was conducted to assess the effectiveness of nebulized budesonide in asthma (n = 10) and COPD (n = 15). The panel in Thailand recommended incorporating nebulized budesonide as an additional or alternative treatment option to the standard of care and systemic corticosteroids (SCS) based on the findings. CONCLUSION: Nebulized budesonide is effective and well-tolerated in treating asthma and COPD, with less systemic adverse effects compared to systemic corticosteroids. High-dose nebulized budesonide can enhance clinical outcomes for severe and mild exacerbations with slow systemic corticosteroid response. Nebulized budesonide can substitute systemic corticosteroids in some situations.

Determination of latent tuberculosis infection from plasma samples via label-free SERS sensors and machine learning.

Effective diagnostic tools for screening of latent tuberculosis infection (LTBI) are lacking. We aim to investigate the performance of LTBI diagnostic approaches using label-free surface-enhanced Raman spectroscopy (SERS). We used 1000 plasma samples from Northeast Thailand. Fifty percent of the samples had tested positive in the interferon-gamma release assay (IGRA) and 50 % negative. The SERS investigations were performed on individually prepared protein specimens using the Raman-mapping technique over a 7 × 7 grid area under measurement conditions that took under 10 min to complete. The machine-learning analysis approaches were optimized for the best diagnostic performance. We found that the SERS sensors provide 81 % accuracy according to train-test split analysis and 75 % for LOOCV analysis from all samples, regardless of the batch-to-batch variation of the sample sets and SERS chip. The accuracy increased to 93 % when the logistic regression model was used to analyze the last three batches of samples, following optimization of the sample collection, SERS chips, and database. We demonstrated that SERS analysis with machine learning is a potential diagnostic tool for LTBI screening.

Serum proteomics analysis for differentiation among Mycobacterium tuberculosis infection categories.

Inhalation of Mycobacterium tuberculosis (Mtb) bacilli can lead to a range of TB categories including early clearance (EC), latent TB infection (LTBI) and active TB (ATB). There are few biomarkers available to differentiate among these TB categories: effective new biomarkers are badly needed. Here, we analyzed the serum proteins from 26 ATB cases, 20 LTBI cases, 34 EC cases and 38 healthy controls (HC) using label-free LC-MS/MS. The results were analyzed using MaxQuant software and matched to three different bacterial proteomics databases, including Mtb, Mycobacterium spp. and normal lung flora. PCA of protein candidates using the three proteomics databases revealed 44.5% differentiation power to differentiate among four TB categories. There were 289 proteins that showed potential for distinguishing between each pair of groups among TB categories. There were 50 candidate protein markers specifically found in ATB and LTBI but not in HC and EC groups. Decision trees using the top five candidate biomarkers (A0A1A2RWZ9, A0A1A3FMY8, A0A1A3KIY2, A0A5C7MJH5 and A0A1X0XYR3) had 92.31% accuracy to differentiate among TB categories and the accuracy was increased to 100% when using 10 candidate biomarkers. Our study shows that proteins expressed from Mycobacterium spp. have the potential to be used to differentiate among TB categories.

High clustering rate and genotypic drug-susceptibility screening for the newly recommended anti-tuberculosis drugs among global extensively drug-resistant Mycobacterium tuberculosis isolates.

Multidrug-resistant tuberculosis (MDR-TB) and extensively drug-resistant tuberculosis (XDR-TB) make TB difficult to control. Global susceptibility data for six newly recommended anti-TB drugs against M/XDR-TB are still limited. Using publicly available whole-genome sequences, we determined the proportion of 513 phenotypically XDR-TB isolates that carried mutations associated with resistance against these drugs (bedaquiline, clofazimine, linezolid, delamanid, pretomanid and cycloserine). Mutations of Rv0678 and Rv1979c were detected in 69/513 isolates (13.5%) for bedaquiline resistance and 79/513 isolates (15.4%) for clofazimine resistance with additional mmpL5 mutations. Mutations conferring resistance to delamanid were detected in fbiB and ddn genes for 11/513 isolates (2.1%). For pretomanid, a mutation was detected in the ddn gene for 3/513 isolates (0.6%). Nineteen mutations of pykA, cycA, ald, and alr genes, conferring resistance to cycloserine, were found in 153/513 isolates (29.8%). No known mutations associated with linezolid resistance were detected. Cluster analysis showed that 408/513 isolates fell within 99 clusters and that 354 of these isolates were possible primary drug-resistant TB (292 XDR-TB, 57 pre-XDR-TB and 5 MDR-TB). Clonal transmission of primary XDR isolates might contribute significantly to the high prevalence of DR-TB globally.

Presentations of chronic cavitary pulmonary histoplasmosis mimic infected cystic bronchiectasis in an immunocompetent host: A case report.

BACKGROUND: Chronic cavitary pulmonary disease and laryngeal involvement are unusual manifestations of Histoplasmosis capsulatum infection, particularly in patients who are not immunocompromised. The presence of fibro-cavitary lesions has been reported as a radiologic presentation of chronic histoplasmosis in patients with pre-existing lung disease. However, there have been few reports of extensive basal predominant cavitary lesions that mimic cystic-bronchiectasis. CASE PRESENTATION: A 65-year-old previously healthy Thai male presented with productive cough, hoarseness, low-grade fever, and weight loss for 6 months. There was no history of significant exposure to Histoplasmosis capsulatum. Tests for HIV and anti-IFN- γ antibody were negative. Chest CT revealed multifocal thick wall cavities, which were distributed in a peri-bronchial pattern, and some areas of consolidation in both basal lungs. Laryngoscopy revealed an ulcerative lesion of the false vocal cords. Histopathological study of false vocal cords and lung tissue showed granulomatous inflammation with mixed inflammatory cell infiltration and aggregation of histiocytes containing round intracytoplasmic organisms. GMS-staining was positive, but negative mucicarmine-staining was negative. A real-time PCR assay of the lung tissue was positive for Histoplasmosis capsulatum. The final diagnosis was chronic cavitary pulmonary histoplasmosis with laryngeal involvement. CONCLUSION: Chronic cavitary pulmonary histoplasmosis is rare, as is laryngeal involvement. However, there have been such cases in endemic areas, even in immunocompetent patients. Chronic histoplasmosis should be considered in patients who present with the extensive basal predominant cavitary-pulmonary lesions that mimic cystic bronchiectasis.

Whole-genome analysis of drug-resistant Mycobacterium tuberculosis reveals novel mutations associated with fluoroquinolone resistance.

Multidrug-resistant and extensively drug-resistant tuberculosis (M/XDR-TB) remains a global public-health challenge. Known mutations in quinolone resistance-determination regions cannot fully explain phenotypic fluoroquinolone (FQ) resistance in Mycobacterium tuberculosis (Mtb). The aim of this study was to look for novel mutations in Mtb associated with resistance to FQ drugs using whole-genome sequencing analysis. Whole-genome sequences of 659 Mtb strains, including 214 with phenotypic FQ resistance and 445 pan-susceptible isolates, were explored for mutations associated with FQ resistance overall and with resistance to individual FQ drugs (ofloxacin, levofloxacin, moxifloxacin and gatifloxacin). Three novel genes (recC, Rv2005c and PPE59) associated with FQ resistance were identified (P < 0.00001 based on screening analysis and absence of relevant mutations in a pan-susceptible validation set of 360 strains). Nine novel single nucleotide polymorphisms (SNPs), including in gyrB (G5383A and G6773A), gyrA (G7892A), recC (G725900C and G726857T/C), Rv2005c (C2251373G, G2251420C and C2251725T) and PPE59 (C3847269T), were used for diagnostic performance analysis. Enhancing the known SNP set with five of these novel SNPs, including gyrA [G7892A (Leu247Leu)], recC [G725900C (Leu893Leu) and G726857T/C (Arg484Arg)], Rv2005c [G2251420C (Pro205Arg)] and PPE59 [C3847269T (Asn35Asn)] increased the sensitivity of detection of FQ-resistant Mtb from 83.2% (178/214) to 86.9% (186/214) while maintaining 100% specificity (360/360). No specific mutation associated with resistance to only a single drug (ofloxacin, levofloxacin, moxifloxacin or gatifloxacin) was found. In conclusion, this study reports possible additional mutations associated with FQ resistance in Mtb.

Clusters of Drug-Resistant Mycobacterium tuberculosis Detected by Whole-Genome Sequence Analysis of Nationwide Sample, Thailand, 2014-2017.

Multidrug-resistant tuberculosis (MDR TB), pre-extensively drug-resistant tuberculosis (pre-XDR TB), and extensively drug-resistant tuberculosis (XDR TB) complicate disease control. We analyzed whole-genome sequence data for 579 phenotypically drug-resistant M. tuberculosis isolates (28% of available MDR/pre-XDR and all culturable XDR TB isolates collected in Thailand during 2014-2017). Most isolates were from lineage 2 (n = 482; 83.2%). Cluster analysis revealed that 281/579 isolates (48.5%) formed 89 clusters, including 205 MDR TB, 46 pre-XDR TB, 19 XDR TB, and 11 poly-drug-resistant TB isolates based on genotypic drug resistance. Members of most clusters had the same subset of drug resistance-associated mutations, supporting potential primary resistance in MDR TB (n = 176/205; 85.9%), pre-XDR TB (n = 29/46; 63.0%), and XDR TB (n = 14/19; 73.7%). Thirteen major clades were significantly associated with geography (p<0.001). Clusters of clonal origin contribute greatly to the high prevalence of drug-resistant TB in Thailand.

Microorganisms and clinical outcomes of early- and late-onset ventilator-associated pneumonia at Srinagarind Hospital, a tertiary center in Northeastern Thailand.

BACKGROUND: Ventilator-associated pneumonia (VAP) is a common nocosomial infection in intensive care unit (ICU). Local microbiological surveillance of pathogens and resistance patterns for early-onset VAP (EOVAP) and late-onset VAP (LOVAP) will help to choose appropriate empiric antibiotics. OBJECTIVE: To compare the multi-drug resistant (MDR) pathogens, treatment outcomes, and factors associated with hospital mortality of VAP. METHOD: A cross-sectional study between 1 January 2015 and 31 December 2017 at Srinagarind hospital, Khon Kaen University was conducted. The demographic data, causative pathogens, hospital length of stay (LOS), ICU LOS, mechanical ventilator (MV) days, and hospital mortality were retrospectively reviewed. RESULTS: One hundred and ninety patients were enrolled; 42 patients (22%) were EOVAP and 148 patients (78%) were LOVAP. Acinetobacter baumannii was the most common pathogen in both groups (50% EOVAP vs 52.7% LOVAP). MDR pathogens were significant greater in LOVAP (81.8%) than EOVAP (61.9%) (p = 0.007). The EOVAP had a significantly better ICU LOS [median (interquartile range, IQR) 20.0 (11.0, 30.0) vs. 26.5 (17.0, 43.0) days], hospital LOS [median (IQR) 26.5 (15.0, 44.0) vs. 35.5 (24.0, 56.0) days] shorter MV days [median (IQR) 14.0 (10.0, 29.0) vs. 23.0 (14.0, 35.5) days] and lower hospital mortality (16.7% vs 35.1%) than LOVAP (p < 0.05). The factor associated with hospital mortality was having simplified acute physiology (SAP) II score ≥ 40 with an adjusted odds ratio (aOR) of 2.22 [95% confidence interval (CI), 1.08-4.54, p = 0.02]. CONCLUSION: LOVAP had significantly higher MDR pathogens, MV days, ICU LOS, hospital LOS and hospital mortality than EOVAP. A broad-spectrum antibiotic to cover MDR pathogens should be considered in LOVAP. The factor associated with hospital mortality of VAP was a SAPII score ≥ 40.

Whole-genome sequence analysis and comparisons between drug-resistance mutations and minimum inhibitory concentrations of Mycobacterium tuberculosis isolates causing M/XDR-TB.

Drug resistance (DR) remains a major challenge for tuberculosis (TB) control. Whole-genome sequencing (WGS) provides the highest genetic resolution for genotypic drug-susceptibility tests (DST). We compared DST profiles of 60 Mycobacterium tuberculosis isolates which were drug resistant according to agar proportion tests (one poly DR-TB, 34 multidrug-resistant TB and 25 extensively drug-resistant TB). We additionally performed minimum inhibitory concentration (MIC) tests using Sensititre MYCOTBI plates (MYCOTB) and a WGS-based DST. Agreement between WGS-based DST and MYCOTB was high for all drugs except ethambutol (65%) and ethionamide (62%). Isolates harboring the -15 c/t inhA promoter mutation had a significantly lower MIC for isoniazid than did isolates with the katG Ser315Thr mutation (p < 0.001). Similar patterns were seen for ethambutol (embB Gly406Asp vs. embB Met306Ile), streptomycin (gid Gly73Ala vs. rpsL Lys43Arg), moxifloxacin (gyrA Ala90Val vs. gyrA Asp94Gly) and rifabutin (rpoB Asp435Phe/Tyr/Val vs. rpoB Ser450Leu). For genotypic heteroresistance, isolates with lower proportion of mapped read tended to has lower MIC of anti-TB drugs than those with higher proportion. These results emphasize the high applicability of WGS for determination of DR-TB and the association of particular mutations with MIC levels.

Proteomic analysis of infected primary human leucocytes revealed PSTK as potential treatment-monitoring marker for active and latent tuberculosis.

Markers for monitoring clearance of Mycobacterium tuberculosis (Mtb) infection during anti-TB drug treatment could facilitate management of tuberculosis (TB) treatment, but are lacking. We aimed to screen for Mtb clearance markers from in-vitro-infected leucocytes and to evaluate these markers in followed-up active TB (ATB) patients and latent TB (LTBI) cases after anti-TB drug treatment. Extracellular proteins from primary leucocytes infected with each of the Mtb lineages (East-Asian, Indo-Oceanic, Euro-American and the laboratory strain H37Rv) were screened as possible clearance markers. Leucocytes infected with Staphylococcus aureus acted as controls. The proteomic analysis was performed using GeLC-MS/MS. Several quantitative and qualitative candidate clearance markers were found. These proteins were suppressed during the infection stage of all Mtb lineages and re-expressed after bacillary clearance. PSTK, FKBP8 and MGMT were common clearance markers among the four Mtb lineages in our model. Only PSTK was a potential clearance marker based on western blot validation analysis from culture supernatants. The PSTK marker was further validated with western blot analysis using serum samples (n = 6) from ATB patients and LTBI cases during anti-TB drug treatment, and from healthy controls (n = 3). Time-dependent increase of PSTK was found both in ATB and LTBI patients during the course of anti-TB drug treatment, but not in healthy controls. We have demonstrated that PSTK is a potential treatment-monitoring marker for active and latent TB.

Diagnosis of active tuberculosis and latent tuberculosis infection based on Raman spectroscopy and surface-enhanced Raman spectroscopy.

Current tools for screening LTBI are limited due to the long turnaround time required, cross-reactivity of tuberculin skin test to BCG vaccine and the high cost of interferon gamma release assay (IGRA) tests. We evaluated Raman spectroscopy (RS) for serum-protein fingerprinting from 26 active TB (ATB) cases, 20 LTBI cases, 34 early clearance (EC; TB-exposed persons with undetected infection) and 38 healthy controls (HC). RS at 532 nm using candidate peaks provided 92.31% sensitivity and 90.0% to distinguish ATB from LTBI, 84.62% sensitivity and 89.47% specificity to distinguish ATB from HC and 87.10% sensitivity and 85.0% specificity to distinguish LTBI from EC. RS at 532 nm with the random forest model provided 86.84% sensitivity and 65.0% specificity to distinguish LTBI from HC and 94.74% sensitivity and 87.10% specificity to distinguish EC from HC. Using preliminary sample sets (n = 5 for each TB-infection category), surface-enhanced Raman spectroscopy (SERS) showed high potential diagnostic performance, distinguishing very clearly among all TB-infection categories with 100% sensitivity and specificity. With lower cost, shorter turnaround time and performance comparable to that of IGRAs, our study demonstrated RS and SERS to have high potential for ATB and LTBI diagnosis.

Multiple pulmonary nodules in granulomatous polyangiitis: A case series.

Granulomatous polyangiitis (GPA) is a multiple systemic necrotizing vasculitis. Diagnosis of pulmonary nodules in GPA is still challenging in clinical practice, however, other extrapulmonary manifestations, serology, and histopathology may help the diagnosis of GPA. This case series was of limed GPA with one of the largest pulmonary nodules which had a poor treatment response in contrast with previous literature.

Massive pleural effusion due to IgG-Kappa subtype multiple myeloma: A case report.

Multiple myeloma (MM) is a hematologic malignancy of plasma cell origin. Incidence of pleural effusion in multiple myeloma patients is approximately 6%. Myelomatous pleural effusions (MPE) are rare and occur in less than 1% of all MM cases. MPE is associated with advanced diseases, decreased survival time, and poor treatment response. In our case report, we describe a 59-year old man who presented with MPE at the initial diagnosis of MM. A diagnosis of MPE was reach through pleural fluid cytology and pleural tissue histology. The MPE had good response to initial dexamethasone without local therapy.

Dataset of serum proteomic spectra from tuberculosis patients detected by Raman spectroscopy and surface-enhanced Raman spectroscopy.

In this data article, we present Raman spectroscopy (RS) and surface-enhanced Raman spectroscopy (SERS) data obtained using an InVia Reflex confocal Raman microscope (Renishaw; Wotton-under-Edge, UK) and processed using WiRE™ 4.2 software. The data include RS and SERS spectra detected, after removal of albumin, from the serum proteome of tuberculosis (TB) patient categories and controls (active tuberculosis; ATB, latent tuberculosis; LTBI, TB-exposed persons with undetected infection; EC, healthy controls; HC) using 532 nm and 785 nm laser wavelengths for RS and 785 nm for SERS. The RS and SERS data had high reproducibility (SERS; R2 = 0.988, RS at 785 nm; R2 = 0.972, RS at 532 nm; R2 = 0.9150). This data can be used for analysis of proteomic spectra based on RS and SERS for TB diagnosis and can also be compared to other populations. The spectral dataset based on normal, healthy control groups might be used as the control data for analysis of other diseases using RS and SERS approaches.

The immediate effects of breathing with oscillated inspiratory and expiratory airflows on secretion clearance in intubated patients with cervical spinal cord injury.

STUDY DESIGN: A prospective, randomized crossover trial. OBJECTIVES: To evaluate the efficacy of the combination of incentive spirometry with oscillation (OIS) and positive expiratory pressure with oscillation (OPEP) to promote secretion clearance in intubated patients with cervical spinal cord injury. SETTING: Spinal cord unit, tertiary care hospital, North East Thailand. METHODS: Thirteen intubated patients (C4-7, AIS score C) with secretion retention performed three interventions randomly allocated on consecutive days, a Sham deep breathing, OPEP and OPEP + OIS breathing exercise. Secretions were collected by sterile suction for 3 h before, and 3 h after, each intervention and wet weight recorded. Cardiopulmonary parameters were measured before and after each intervention. RESULTS: The median (IQR) secretion wet weight pre-intervention was 2.61 g (2.21, 3.85) and in the 3 h after Sham there was an increase of 1.97 g (0.6, 3.6). The increase after OPEP was 2.67 g (1.7, 3.9) and after OPEP + OIS, 4.28 g (2.4, 6.7); all the increases being significant (p ≤ 0.007). The clearance after OPEP and OPEP + OIS were both greater than Sham while OPEP + OIS was greater than OPEP (p ≤ 0.019). There were no significant changes in cardiopulmonary measures following any intervention or when compared between interventions. CONCLUSIONS: Deep breathing with an oscillated and humidified air flow in a combination of OIS + OPEP more than doubled secretion clearance and was more effective than OPEP or Sham deep breathing. There were no adverse effects of the procedures which were well tolerated by the patients and may be used to complement existing methods for secretion clearance.

Differentiation between persistent infection/colonization and re-infection/re-colonization of Mycobacterium abscessus isolated from patients in Northeast Thailand.

Mycobacterium abscessus can cause true infection or be present in the host as a harmless colonist. The ability of M. abscessus to cause disease and develop drug resistance is known to have a genetic basis. We aimed to differentiate between persistent infection and reinfection using multilocus sequence typing (MLST) and to study the genetic diversity of M. abscessus relative to multi-organ infection and drug resistance in Northeast Thailand. DNA was extracted from 62 M. abscessus isolates (24 cases). The following genes were sequenced: argH, cya, glpK, gnd, murC, pta, purH and rpoB. Drug susceptibility tests were performed using broth microdilution. Subspecies classification and phylogeny were determined. Among the 24 cases (62 isolates), 19 cases (49 isolates) were of true NTM infection and 5 cases (13 isolates) examples of colonization. Two subspecies, M. abscessus subsp. massiliense (12 cases, 32 isolates) and M. abscessus subsp. abscessus (12 cases, 30 isolates) were identified. The major sequence type (ST) was ST227. Two clonal groups among patients were found; clonal cluster I (5 cases, 8 isolates) and clonal cluster II (2 cases, 4 isolates) but no epidemiological link was apparent. Reinfection (2 cases with different clones of M. abscessus strains; >9 SNPs different) and persistent infection (14 cases with the same clone; <6 SNPs) were distinguished based on a phylogeny. Based on these SNP cutoff values, 3 cases of persistent colonization (same strain through time) and 2 cases of re-colonization (different strains through time) were identified. M. abscessus subsp. abscessus was significantly associated with clarithromycin resistance (p < .001) and multi-organ infection (p = .03). Molecular epidemiology based on MLST can be used to differentiate between reinfection vs persistent infection, persistent colonization vs re-colonization. ST227 was the main epidemic strain in Northeast Thailand.

Analysis of drug-susceptibility patterns and gene sequences associated with clarithromycin and amikacin resistance in serial Mycobacterium abscessus isolates from clinical specimens from Northeast Thailand.

Mycobacterium abscessus is an important infectious agent highly associated with drug resistance and treatment failure. We investigated the drug resistance situation of M. abscessus in Northeast Thailand and the possible genetic basis for this. Sixty-eight M. abscessus clinical isolates were obtained from 26 patients at Srinagarind Hospital during 2012-2016. Drug susceptibility tests and sequencing of erm(41), rrl and rrs genes were performed. Mycobacterium abscessus was resistant to 11/15 antibiotics (nearly 100% resistance in each case). Partial susceptibility to four antibiotics was found (amikacin, tigecycline, clarithromycin and linezolid). Non-massiliense subspecies were significantly associated with clarithromycin resistance (p<0.0001) whereas massiliense subspecies were associated with tigecycline resistance (p = 0.028). Inducible clarithromycin resistance was seen in 22/68 (32.35%) isolates: 21 of these isolates (95.45%) belonged to non-massiliense subspecies and resistance was explicable by the T28C mutation in erm(41). Inducible clarithromycin resistance was found in one isolate of the massiliense subspecies. Acquired clarithromycin resistance explicable by the A2271G/C mutation of rrl was seen in only 7/16 (43.75%) of strains. Inducible and acquired resistance mechanisms can be interchangeable during the course of infection. Rrs mutations were not associated with amikacin resistance in our study. Antibiotic resistance in subspecies of M. abscessus was reported from Northeast Thailand. Known resistance-associated mutations cannot explain all of the resistance patterns observed.

Epidemiology of and risk factors for extrapulmonary nontuberculous mycobacterial infections in Northeast Thailand.

BACKGROUND: Nontuberculous mycobacterial (NTM) infection is increasing worldwide. Current epidemiological data and knowledge of risk factors for this disease are limited. We investigated the trends in and risk of NTM infection in Northeast Thailand during 2012-2016. METHODS: Patient demographics, infection site(s), and underlying disease or conditions from 530 suspected cases of NTM infections were retrieved from medical records, reviewed and analyzed. A diagnosis of true NTM infection was accepted in 150 cases. Risk factor analyses were done for extrapulmonary NTM infections compared to pulmonary NTM infections and for Mycobacterium abscessus compared to members of the Mycobacterium avium complex (MAC). Trend analysis among NTM species causing NTM infections was performed. RESULTS: The most common species of NTMs causing extrapulmonary (n = 114) and pulmonary (n = 36) NTM infections in Northeast Thailand were M. abscessus (25.4% of extrapulmonary infected cases and 27.8% of pulmonary cases) followed by MAC (14.9% of extrapulmonary and 13.9% of pulmonary cases). Presence of anti-IFN-γ autoantibodies was the major risk factor for extrapulmonary (odds ratio (OR) = 20.75, 95%CI [2.70-159.24]) compared to pulmonary NTM infection. M. abscessus infection was less likely (OR = 0.17; 95%CI [0.04-0.80]) to be found in patients with HIV infection than was MAC infection. The prevalence of NTM infection, especially M. abscessus, in Northeast Thailand has recently increased. Extrapulmonary NTM and complicated NTM infections have increased in concordance with the recent trend of increasing frequency of anti-IFN-γ autoantibodies in the population. CONCLUSIONS: M. abscessus was the commonest NTM pathogen followed by MAC. The prevalence of NTM infections and anti-IFN-γ are showing an upward trend. Autoimmune disease due to anti-IFN-γ is the major risk factor for extrapulmonary NTM infection in Northeast Thailand.

Chemokines additional to IFN-γ can be used to differentiate among Mycobacterium tuberculosis infection possibilities and provide evidence of an early clearance phenotype.

Current diagnostic tests for tuberculosis (TB) remain limited in their ability to discriminate between active TB (ATB) and latent TB infection (LTBI). Early clearance (EC) of TB by individuals exposed to Mycobacterium tuberculosis is a debated phenomenon for which evidence is lacking. We measured and compared secreted chemokines in the plasma fraction from 48 ATB, 38 LTBI, 162 presumed EC and 39 healthy controls (HC) using the QuantiFERON®-TB Gold In-Tube assay. Single chemokine markers were limited in their ability to discriminate between ATB and LTBI: IFN-γ showed 16.7% sensitivity; CCL2 showed moderate sensitivity (70.8%) and specificity (74.4%); CXCL10 showed high sensitivity (87.5%) and specificity (78.9%). Compared to IFN-γ alone, IFN-γ combined with CXCL10 significantly improved (p < 0.001) the sensitivity and specificity to discriminate between ATB and HC (97.9% sensitivity and 94.9% specificity) and between ATB and LTBI (89.6% sensitivity and 71.1% specificity). Levels of CCL2 were very significantly lower (p < 0.0001) in EC compared to HC groups and hence CCL2 is a useful marker for EC. This study demonstrated the potential application of profiling using multiple chemokines for differentiating among the various M. tuberculosis infection possibilities. We also present evidence to support the EC phenomenon based on the decrease of CCL2 levels.

COMPARISON OF GeneXpert MTB/RIF ASSAY WITH CONVENTIONAL AFB SMEAR FOR DIAGNOSIS OF PULMONARY TUBERCULOSIS IN NORTHEASTERN THAILAND.

Among infectious agents, Mycobacterium tuberculosis remains one of the most significant causes of death worldwide. Rapid and accurate diagnosis of pulmonary tuberculosis (TB) remains a great challenge. GeneXpert MTB/RIF assay is a novel integrated diagnostic system for rapid diagnosis of TB and particularly of rifampicin-resistant strains. A study was conducted between January 2010 and December 2014 to compare the performance of the sputum GeneXpert MTB/RIF assay with the conventional sputum AFB smear for diagnosis of active pulmonary TB in Thailand, a country with a high burden of this disease. Of the 125 patients who had cough and/or prolonged fever together with abnormal chest radiograph, 63 were diagnosed as having pulmonary TB by mycobacterium culture assay, while the remaining subjects were considered of having TB-like conditions, viz non-tuberculous mycobacterium infection (NTM), bacterial pneumonia or bronchogenic carcinoma. Two-thirds of the patients had underlying diseases, eg, diabetes mellitus (19 patients), autoimmune diseases (14), and HIV (6). Among patients with positive diagnosis of M. tuberculosis infection, 30 were AFB smear positive and 53 by sputum GeneXpert MTB/RIF method; among patients negative for M. tuberculosis infection, 4 were AFB smear positive and 5 by GeneXpert MTB/ RIF assay. Sensitivity and specificity of the sputum AFB smear and GeneXpertMTB/ RIF assay test were 48% (95% CI: 35-61) and 84% (95% CI: 73-92), and 94% (95% CI: 84-98) and 92% (95% CI: 82-97), respectively. Diagnostic performance of the GeneXpert MTB/RIF assay among AFB smear positive patients was higher than among AFB smear negative patients (adjusted OR 6.7; 95% CI: 2.3-19.9). Earlier diagnosis of pulmonary TB using GeneXpert MTB/RIF assay will lead to earlier appropriate treatment and provide opportunities to interrupt TB transmission.