Isoniazid use, effectiveness, and safety for treatment of latent tuberculosis infection: a systematic review

ABSTRACT Background: The treatment strategy for latent tuberculosis infection is to reduce the number of tuberculosis cases and consequently reduce the transmission of pathogenic bacteria. This study aimed to determine the safety, effectiveness, and adherence of isoniazid use for latent tuberculosis infection treatment. Methods: To identify studies on isoniazid use for latent tuberculosis infection, five electronic databases were searched. The methods and results are presented in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Results: Most studies (53) used isoniazid for 9 months. The prevalence of use and adherence to treatment varied considerably (18% to 100%), and were evaluated by participant completion of isoniazid treatment for latent tuberculosis infection. The adverse events most frequently reported were hepatotoxicity, gastric intolerance, and neuropathy; the rates of occurrence ranged from < 1% to 48%. In the studies that evaluated the effectiveness of isoniazid for latent tuberculosis infection, the rate varied from 0 to 19.7% for patients who did not have active tuberculosis after the follow-up period. Conclusions: The importance of maintaining follow up for patients using isoniazid should be emphasized due to the risk of developing adverse events. Despite the treatment challenges, the rates of patients who used isoniazid and developed active tuberculosis during the follow-up period were low. We believe that isoniazid continues to contribute to tuberculosis control worldwide, and better care strategies are required.

Latent tuberculosis infection and preventive treatment among in-school students: a review / 预防医学

@#School is a densely populated place, which can easily lead to tuberculosis clusters, then affect the physical and mental health of students and the normal teaching order of school. Tuberculosis latent infection (LTBI) screening for new students and close contacts of tuberculosis patients has become important parts of school tuberculosis prevention and control strategies. Previous studies have shown that the LTBI rate of Chinese in-school students is about 5.74% to 11.67%, and there are differences in gender, studying phase and urban-rural distributions. Preventive treatment is an effective measure to prevent LTBI from developing into active tuberculosis, but the proportion of LTBI preventive treatment for students in most areas is low. The difficulties in implementing preventive treatment may be attributed to concerns about adverse reactions to medication and sense of shame towards illness among students, and lack of awareness about preventive treatment among medical staff. This review searches the research literature published from 2016 to 2023, and summarizes the prevalence of LTBI in Chinese students and progress on preventive treatment, so as to provide insights into prevention and control of tuberculosis among students.

The prevalence of tuberculosis infection in India: A systematic review and meta-analysis

Background & objectives: The National Prevalence Survey of India (2019-2021) estimated 31 per cent tuberculosis infection (TBI) burden among individuals above 15 years of age. However, so far little is known about the TBI burden among the different risk groups in India. Thus, this systematic review and meta-analysis, aimed to estimate the prevalence of TBI in India based on geographies, sociodemographic profile, and risk groups. Methods: To identify the prevalence of TBI in India, data sources such as MEDLINE, EMBASE, CINAHL, and Scopus were searched for articles reporting data between 2013-2022, irrespective of the language and study setting. TBI data were extracted from 77 publications and pooled prevalence was estimated from the 15 community-based cohort studies. Articles were reviewed in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines and were sourced using a predefined search strategy from different databases. Results: Out of 10,521 records, 77 studies (46 cross-sectional and 31 cohort studies) were included. The pooled TBI prevalence for India based on the community-based cohort studies was estimated as 41 per cent [95% confidence interval (CI) 29.5-52.6%] irrespective of the risk of acquiring it, while the estimation was 36 per cent (95% CI 28-45%) prevalence observed among the general population excluding high-risk groups. Regions with high active TB burden were found to have a high TBI prevalence such as Delhi and Tamil Nadu. An increasing trend of TBI was observed with increasing age in India. Interpretation & conclusions: This review demonstrated a high prevalence of TBI in India. The burden of TBI was commensurate with active TB prevalence suggesting possible conversion of TBI to active TB. A high burden was recorded among people residing in the northern and southern regions of the country. Such local epidemiologic variation need to be considered to reprioritize and implement-tailored strategies for managing TBI in India.

Evaluation of screening methods for the students who had close contact with pulmonary tuberculosis patients in Shanghai / 上海预防医学

ObjectiveTo evaluate the current screening methods for the students who were in close contact with tuberculosis patients， that could accurately identify the preventive treatment subjects， and to improve the tuberculosis prevention and control in Shanghai schools. MethodsThe freshman/sophomore who were in close contact with active tuberculosis patients in the colleges in 2019 were recruited. All the subjects underwent both tuberculin skin test （TST） and QuantiFERON-TB gold in-tube （QFT） test at the enrollment. After signed the informed consent， all of the participants filled in a questionnaire and determined their baseline tuberculosis infection status. They were followed up for 2 years to monitor the conversion of infection status and the incidence of tuberculosis. ResultsFour of 9 （44.4%） positive participants had conversion to negative results， and 5 of 300 （1.7%） negative participants had conversion to positive during the 2-year follow-up， one of which was diagnosed with active tuberculosis. We assessed diagnostic agreement between QFT and TST at different cut-off values. The highest coincidence rate was 94.0% when choosing 15 mm as the cut-off value， with Kappa coefficient of 0.45 （95%CI： 0.32‒0.59）. ConclusionAlthough stricter than the national work requirements， the prevention and control of tuberculosis in Shanghai schools still need to be carried out meticulously. It's necessary to strengthen daily prevention and control measures， and improve the ability of management.

Latent tuberculosis infection status and its risk factors among tuberculosis-related health-care workers in Shanghai / 上海预防医学

ObjectiveTo obtain the status of latent tuberculosis infection （LTBI） among tuberculosis （TB）-related health-care workers （HCWs） in Shanghai， and to explore the risk factors related to TB infection. MethodsA multi-center cross-sectional study was conducted by recruiting medical workers from multiple designated TB hospitals， centers for disease control and prevention， and community health service centers in Shanghai. Each subject was required to complete a questionnaire and to provide a blood sample for TB infection test. Univariate and multivariate analysis ware made in order to find risk factors relating to TB infection. ResultsA total of 165 medical workers were recruited， and the proportion of TB infection was 16.36% （95%CI： 11.49%‒22.76%）. Multivariate logistic analysis showed that clinical doctors and nurses （adjusted OR=9.756， 95%CI： 1.790‒53.188）， laboratory staffs （adjusted OR=78.975， 95%CI： 8.749‒712.918）， and nursing and cleaning workers （adjusted OR=89.920， 95%CI： 3.111‒2 598.930） had higher risk of TB infection. ConclusionThe overall LTBI prevalence among TB-related HCWs is low. However， working as doctors， nurses， laboratory staffs， nursing workers and cleaning workers are risk factors of TB infection. TB-related HCWs who work at hospitals are at risk of TB infection comparing to medical staffs who work outside hospitals.

Strengthening management of latent tuberculosis infection and accelerating the elimination of the tuberculosis epidemic / 上海预防医学

Screening and preventive treatment for latent tuberculosis infection （LTBI） are important measures to reduce the incidence of active tuberculosis （TB） and its global burden. This paper discusses the current status of LTBI prevalence and preventive treatment， risk of incidence in high-risk groups， screening methods， and other interventions， emphasizing the importance of prevention and control as early as possible in a scientific strategy， so as to lay a solid foundation for eliminating TB by 2030.

Application of the “TST-IGRA” two-step method in screening close contacts of active tuberculosis patients among three high schools / 公共卫生与预防医学

Objective To explore the application of the TST-IGRA two-step method in the screening of close contacts of active tuberculosis patients among three high schools in Jinshan District in 2020-2021，and to provide evidence for improving the prevention and control of tuberculosis in schools. Methods Three school tuberculosis outbreaks in Jingshan District from 2020 to 2021 were included in the present study. After excluding active tuberculosis, tuberculin skin test and γ-interferon release assay (IGRA) were conducted to screen latent infection of Mycobacterium tuberculosis in close contacts, and the necessity of the two-step method was analyzed. Results A total of 362 close contacts were screened in the three outbreaks, and 350 people were tested by TST. Comparing the results of TST and IGRA among different types of close contacts, it was found that the positive rate of TST in teachers was higher than that in students（54.84% vs 20.38%，P<0.05）. The positive rate of TST among students from high-burden areas of pulmonary tuberculosis in Shanghai was higher than that of local students（24.71% vs 18.80%，P<0.05). IGRA detection was performed on those with moderate and strong positive TST results, and the results showed that the positive rate of IGRA in those with strong positive TST results was only 17.7%, with Kappa value of 0.3. Conclusion The prevention and control of tuberculosis in school should strengthen the annual health examination of teachers and staff, promote timely medical treatment for suspected tuberculosis symptoms, reasonably increase the screening frequency of students in high-burden areas of tuberculosis in Shanghai, and collect students’ previous history of tuberculosis exposure. When screening close contacts, after excluding active tuberculosis, it is recommended that TST and IGRA should be combined to determine latent Mycobacterium tuberculosis infection and achieve accurate intervention.

Novel biomarkers combination in the application of discriminating active tuberculosis and latent tuberculosis infection / 中华传染病杂志

Objective:To evaluate the expressions of three biomarkers combination of CD27, CD38 and human leucocyte antigen (HLA)-DR in the application of discrminating active tuberculosis (ATB) and latent tuberculosis infection (LTBI).Methods:Sixty cases of ATB and 44 cases of LTBI were enrolled from March 2021 to February 2022 in Huashan Hospital, Fudan University and Wuxi Fifth People′s Hospital. Freshly isolated peripheral blood mononuclear cells (PBMC) from patients were stimulated with 6 kDa early secretory antigenic target/culture filtrate protein 10 peptide pools. The expressions of CD27, CD38 and HLA-DR on Mycobacterium tuberculosis-specific CD4 + T lymphocytes were evaluated by polychromatic flow cytometry. Mann-Whitney U test was used for statistical analysis. The area under the receiver operator characteristic curve (AUROC) was used to evaluate the diagnostic value of biomarkers in discriminating ATB and LTBI. Results:The frequencies of CD27 -, CD38 +, HLA-DR +, CD27 -CD38 +, CD27 -HLA-DR + and CD38 + HLA-DR + in ATB group were all higher than those in LTBI group, and the differences were all statistically significant ( U=26.00, 451.00, 384.00, 8.00, 7.00 and 184.00, respectively, all P<0.001). The AUROC of CD27 -CD4 + interferon-γ(IFN-γ) + T lymphocytes was 0.71 with a cut-off value of 52.31%, with the sensitivity of 50.00% and specificity of 87.20%. The AUROC of CD38 + CD4 + IFN-γ + T lymphocytes was 0.82 with a cut-off value of 30.25%, with the sensitivity of 73.40% and specificity of 89.70%. The AUROC of HLA-DR + CD4 + IFN-γ + T lymphocytes was 0.85 with a cut-off value of 36.60%, with the sensitivity of 66.00% and specificity of 94.90%. The AUROC of CD27 -CD38 + CD4 + IFN-γ + T lymphocytes was 0.80 with a cut-off value of 8.82%, with the sensitivity of 90.60% and specificity of 61.50%. The AUROC of CD27 -HLA-DR + CD4 + IFN-γ + T lymphocytes was 0.83 with a cut-off value of 18.62%, with the sensitivity of 75.00% and specificity of 79.50%. The AUROC of CD38 + HLA-DR + CD4 + IFN-γ + T lymphocytes was 0.93 with a cut-off value of 22.35%, with the sensitivity of 79.70% and specificity of 100.00%. Conclusions:The expressions of CD27 -, CD38 + and HLA-DR + in Mycobacterium tuberculosis-specific CD4 + T lymphocytes are higher in ATB group compared to LTBI group. ATB and LTBI could be well discriminated by detecting the expressions of CD27, CD38 and HLA-DR on CD4 + IFN-γ + T lymphocytes with flow cytometry.

Health communication issues related to latent tuberculosis infection treatment support for the foreign-born in Japan / 国際保健医療

Objective  To identify issues in health communication regarding treatment support for foreign-born who are diagnosed as latent tuberculosis infection (LTBI) in Japan, from the perspective of public health centers (PHCs).Methods  A self-administered survey was sent to 469 PHC, between June and July 2020. The survey asked closed and open-ended questions to tuberculosis (TB) program personnel on (1) their experiences of foreign-born patients who were eligible for LTBI treatment but did not start their treatment, and who started treatment but were lost to follow-up, and (2) health communication issues with foreign-born patients. Responses were summarized descriptively for close-ended questions, and analyzed qualitatively for open-ended question.Results  We obtained response from 307 PHCs, regarding 315 foreign-born patients. Twenty-five patients did not initiate, and 52 were lost to follow-up after initiating LTBI treatment. Of the 77 patients who either did not start treatment or were lost to follow-up, 45 apparently could hold everyday conversation in Japanese but had difficulties understanding technical terms, and 19 could not even exchange basic conversation, with PHC staff. Barriers to LTBI treatment initiation and completement, as perceived by PHC staff, included “lack of correct knowledge about TB and LTBI”, “different attitudes to health” and “economic difficulties”. Conclusion  Issues in health communication between PHC staff and foreign-born patients included not only a language barrier, but also the unconscious mind among PHC staff, which sought reasons for refusal or termination of LTBI treatment in patients. We argue that this mind is based on positivism, whereby health personnel consider themselves as the provider of “scientific knowledge” and that “lay persons” can act rationally once enlightened. However, PHC staff may need to reflect upon such position as the provider of scientific knowledge, but instead, learn from foreign-born patients about how they perceive health, TB or LTBI, to conduct better communication.

Latent tuberculosis infection and screening method among close contacts in schools in Xuhui District，Shanghai from 2020 to 2022 / 上海预防医学

ObjectiveTo investigate the latent tuberculosis infection （LTBI） of close contacts in schools of Xuhui District， and to explore the tuberculin skin test （TST）- interferon-γ release assay （IGRA） two-step method in order to discover the screening strategy of tuberculosis in Xuhui District. MethodsClose contacts of tuberculosis in schools of Xuhui District from 2020 to 2022 were selected as research subjects. Screening was conducted using symptom questionnaire， TST， chest X-rays， IGRA， and the information including the etiological results and grade of the index cases， as well as gender， age， and relationship with the index cases of the research subjects were collected. ResultsTotally 615 close contacts of 32 tuberculosis cases occurred in the schools were finally included. Of the 609 close contacts who completed tuberculosis infection screening and underwent TST testing， 153 TST（+） individuals underwent IGRA testing. The final LTBI rate was 4.6%， and the pulmonary tuberculosis detection rate was 163 per 100 000. The relationship with the index cases was an influencing factor for LTBI. The IGRA positivity rate was higher among close contacts with TST ≥15 mm than among those with 10 mm≤ TST <15 mm （χ2=14.41， P<0.05）. ConclusionThe latent tuberculosis infection among close contacts of school tuberculosis cases in Xuhui District remains serious. TST-IGRA two-step method can assist in the accurate diagnosis of LTBI and pulmonary tuberculosis cases.

Progress on diagnosis and treatment of latent tuberculosis infection / 浙江大学学报·医学版

One fourth of the global population has been infected with Mycobacterium tuberculosis, and about 5%-10% of the infected individuals with latent tuberculosis infection (LTBI) will convert to active tuberculosis (ATB). Correct diagnosis and treatment of LTBI are important in ending the tuberculosis epidemic. Current methods for diagnosing LTBI, such as tuberculin skin test (TST) and interferon-γ release assay (IGRA), have limitations. Some novel biomarkers, such as transcriptome derived host genes in peripheral blood cells, will help to distinguish LTBI from ATB. More emphasis should be placed on surveillance in high-risk groups, including patients with HIV infection, those using biological agents, organ transplant recipients and those in close contact with ATB patients. For those with LTBI, treatment should be based on the risk of progression to ATB and the potential benefit. Prophylactic LTBI regimens include isoniazid monotherapy for 6 or 9 months, rifampicin monotherapy for 4 months, weekly rifapentine plus isoniazid for 3 months (3HP regimen) and daily rifampicin plus isoniazid for 3 months (3HR regimen). The success of the one month rifapentine plus isoniazid daily regimen (1HP regimen) suggests the feasibility of an ultra-short treatment strategy although its efficacy needs further assessment. Prophylactic treatment of LTBI in close contact with MDR-TB patients is another challenge, and the regimens include new anti-tuberculosis drugs such as bedaquiline, delamanid, fluoroquinolone and their combinations, which should be carefully evaluated. This article summarizes the current status of diagnosis and treatment of LTBI and its future development direction.

Tuberculosis latente: diagnóstico y tratamiento actual / Latent tuberculosis: current diagnosis and treatment

Resumen La infección tuberculosa latente (TL) afecta al 23% de la población y constituye un reservorio de tuberculosis (TBC) ya que 10% progresa hacia una TBC. La TL se reconoce por pruebas como la tuberculina (PPD o TST) y los ensayos de liberación de Interferón gama (IGRAs). La sensibilidad de IGRAs (versión Quantiferon TB Gold plus) es 94% y del PPD 77%. La especificidad del Quantiferon TB Gold Plus es 97% y del PPD 68%. El valor predictivo de progresión a TBC activa de estas pruebas es bajo (PPD: 1,5%, IGRAs: 2,7%) pero mejora en personas de alto riesgo de contraer TBC (PPD: 2,4%, IGRAs: 6,8%). Las personas con pruebas negativas que posteriormente presentan viraje (prueba positiva) tienen mayor riesgo de progresión a TBC activa. Estas pruebas son útiles en el seguimiento de contactos intradomiciliarios, extranjeros de países con altas tasas de TBC, inmunosuprimidos, enfermedad renal crónica, diabetes, silicosis y secuelas pulmonares de TBC no tratada. En la terapia de TL se utiliza isoniazida (H) auto-administrada por plazos de 6 a 12 meses con eficacia protectora de 60% y riesgo de toxicidad hepática de 2% pero con baja adherencia (50-70%). La asociación de H con rifapentina en dosis única semanal durante 12 semanas tiene eficacia de 81%, adherencia de 82% y baja toxicidad hepática (0,4%). Nuevos biomarcadores de TL y vacunas que mejoren la inmunidad en TL se encuentran en estudio. El tratamiento de la TL puede reducir la incidencia de TBC a largo plazo.

Latent tuberculosis infection (LT) affects 23% of the population and constitutes a reservoir of tuberculosis (TB) as 10% progresses to TB. LT is recognized by tests such as tuberculin (PPD or TST) and Interferon gamma release assays (IGRAs). The sensitivity of IGRAs (Quantiferon TB Gold plus version) is 94% and PPD 77%. The specificity of Quantiferon TB Gold Plus is 97% and PPD 68%. The predictive value of progression to active TB of these tests is low (PPD: 1.5%, IGRAs: 2.7%) but improves in people at high risk of contracting TB (PPD: 2.4%, IGRAs: 6.8%). People with negative tests who subsequently turn around (positive) have a higher risk of progression to active TB. These tests are useful in the follow-up of intra-household contacts, foreigners from countries with high rates of TB, immunosuppressed, chronic kidney disease, diabetes, silicosis and pulmonary sequelae of untreated TB. In LT therapy, self-administered isoniazid (H) is used for periods from 6 to 12 months with protective efficacy of 60% and risk of liver toxicity of 2%, but with low adherence (50-70%). The association of H with rifapentine in a single weekly dose for 12 weeks has efficacy of 81%, adherence of 82% and low liver toxicity (0.4%). New LT biomarkers and vaccines that improve immunity in LT are under study. Treatment of LT may reduce the incidence of TB in the long term.

To study the prevalence of latent tuberculosis infection among medical students

Background: Risk of developing latent tuberculosis infection increases in medical students with their higher exposure to TB care facilities. Objective: To study the prevalence of latent TB infection among students attending professional degrees MBBS, BDS, MD, MS, MDS at King George’s Medical University, India. Methods: This study was carried out with Tuberculin skin testing among students and active TB cases were excluded. A standard dose of 0.1?mL of purified protein derivative was slowly injected intra dermally into non-dominant forearm. After 48-72 hours, the reaction was estimated by measuring the transverse diameter of the induration. Results: Total 561 students had given consent to get enrolled. Prevalence of latent tuberculosis infection was significant with period of clinical exposure (p-value < 0.05), average size of induration (p-value < 0.001), and history of prior Tuberculin Skin Test (p-value < 0.001). However it was not significant with the age (p-value > 0.05), gender (p-value > 0.05), and history of contact with active cases of TB (p-value > 0.05). Conclusion: The prevalence of latent tuberculosis infection is higher in post graduate students followed by interns and final year students due to more exposure to patients in wards and clinics at King George’s Medical University, India.

Polymorphisms of the BCL2 gene associated with susceptibility to tuberculosis

ABSTRACT Although tuberculosis (TB) is a serious public health concern, we still don't understand why only 10% of people infected will develop the disease. Apoptosis plays a role in the interaction of Mycobacterium tuberculosis (Mtb) with the human host and it may be modified by subtle alterations in the B-cell lymphoma 2 (BCL2) gene, an anti-apoptotic regulatory element. Therefore, we investigated whether there is an association between BCL2 polymorphisms and susceptibility to TB by analyzing 130 TB cases, 108 subjects with latent TB infection (LTBI), and 163 healthy controls (HC). Logistic regression was used to calculate odds ratios (ORs) and 95% confidential intervals (95% CIs) for possible associations between single nucleotide polymorphisms (SNPs) in BCL2 and the risk of tuberculosis. We found that the G allele of rs80030866 (OR=0.62, 95%CI:0.42-0.91, P=0.015), and also the G allele of rs9955190 (OR=0.58, 95%CI:0.38-0.88, P=0.011) were less frequent in the TB group compared with the LTBI group. In addition, individuals with rs2551402 CC genotype were more likely to have LTBI than those with AA genotype (OR=2.166, 95%CI:1.046-4.484, P=0.037). Our study suggests that BCL2 gene polymorphisms may be correlated with susceptibility to both TB and LTBI.

Spotlight on latent tuberculosis infection screening for juvenile idiopathic arthritis in two countries, comparing high and low risk patients

Abstract Background: Rheumatic diseases are associated with an increase in overall risks of tuberculosis (TB). The aim of this study was to evaluate the frequency of TB and the frequency of latent TB infection (LTBI), in clinical practice, for juvenile idiopathic arthritis (JIA) patients from high and low risk of TB incidence endemic countries. Methods: This is an international, multicenter, cross-sectional, observational study of data collection from Brazil and Registry of Portugal at REUMA.PT. The inclusion criteria were patients with Juvenile Idiopathic Arthritis (JIA) with age ≤ 18 years who underwent screening for Mycobacterium tuberculosis infection [tuberculin skin test (TST) and/or interferon gamma release assay (IGRA)]. Chest X-rays and history of exposure to TB were also assessed. Results: 292 JIA patients were included; mean age 14.3 years, mean disease duration 7.5 years, 194 patients (66.4%) performed only TST, 14 (4.8%) only IGRA and 84 (28.8%) both. The frequency of LTBI (10.6%) and TB was similar between the two countries. The reasons for TB screening were different; in Brazil it was performed more often at JIA onset while in Portugal it was performed when starting Disease Modified Anti-Rheumatic Drugs (DMARD) treatment (p < 0.001). Isoniazid therapy was prescribed in 40 (13.7%) patients (31 with LTBI and 9 with epidemiologic risks and/or due to contact with sick people). Only three patients (1%) developed active TB. Conclusion: We found nearly 10% of patients with LTBI, a small percentage of patients with treatment due to epide-miologic risks and only 1% with active TB. Distinct reasons and screening methods for LTBI were observed between the two countries.

Prevalence of latent tuberculosis infection among patients with interstitial lung disease requiring immunosuppression / Prevalência de infecção latente por tuberculose em pacientes com doença pulmonar intersticial com necessidade de imunossupressão

ABSTRACT Objective To characterize the prevalence of latent tuberculosis infection (LTBI) in patients with interstitial lung diseases (ILDs) requiring immunosuppression. Only 5 to 10% of individuals infected with Mycobacterium tuberculosis develop tuberculosis, and certain groups of patients have an increased risk of illness, such as the immunocompromised. Patients with ILDs are frequently treated with immunosuppressants and, therefore, might have a higher risk of developing the disease. Methods Prospective study conducted at the ILD reference center of the Federal University of Paraná from January 2019 to December 2020. The screening of LTBI was performed with the use of the tuberculin skin test (TST). Results The sample consisted of 88 patients, of whom 64.8% were women, with a mean age of 61.4 years. The most frequent diagnoses were autoimmune rheumatic disease ILD (38.6%) and hypersensitivity pneumonitis (35.2%). The most common immunosuppressant in use at the time of the TST was prednisone, either in combination with mycophenolate (19.3%) or alone (17.1%). The majority of participants had fibrotic lung disease, characterized by a reticular interstitial pattern on chest computed tomography (79.5%) and moderate to severe functional impairment (mean FVC 69.2%). A prevalence of LTBI of 9.1% (CI 95%, 2.1%-15.1%) was found, with a TST median of 13. Conclusion Patients with ILD who are treated with immunosuppressants are not commonly screened for LTBI, despite being under a greater risk of progression to active disease. This study suggests the need for a more cautious approach to these patients.

RESUMO Objetivo Caracterizar a prevalência de Infecção Latente por Tuberculose (ILTB) em pacientes com Doenças Pulmonares Intersticiais (DPIs) que necessitam de imunossupressão. Apenas 5 a 10% dos indivíduos infectados pelo Mycobacterium tuberculosis desenvolvem tuberculose, sendo que certos grupos de pacientes apresentam maior risco de doença, tais como os imunocomprometidos. Pacientes com DPIs são frequentemente tratados com imunossupressores, portanto, podem apresentar maior risco de desenvolver a doença. Métodos Estudo prospectivo conduzido no Centro de Referência para DPI da Universidade Federal do Paraná (UFPR), entre Janeiro de 2019 e Dezembro de 2020. O rastreio de ILTB foi realizado por meio da Prova Tuberculínica (PT). Resultados A amostra foi composta por 88 pacientes, dos quais 64,8% eram mulheres, com, em média, 61,4 anos de idade. Os diagnósticos mais frequentes foram DPI associada a doença reumática autoimune (DRAI) (38,6%) e pneumonite de hipersensibilidade (35,2%). Prednisona foi o imunossupressor mais comumente utilizado à época da PT, em combinação com micofenolato (19,3%) ou isoladamente (17,1%). A maioria dos participantes tinha doença pulmonar fibrótica, caracterizada por infiltrado reticular em tomografia computadorizada de tórax (79,5%), bem como comprometimento funcional moderado a grave (Capacidade Vital Forçada (CVF) média de 69,2%). Observou-se uma prevalência de ILTB de 9,1% (Intervalo de Confiança (IC) 95%, 2,1%-15,1%), com mediana da PT de 13. Conclusão Não é comum que pacientes com DPI tratados com imunossupressores sejam avaliados quanto à presença de ILTB, apesar de estarem sob um maior risco de progressão para doença ativa. Este estudo sugeriu a necessidade de uma abordagem mais cuidadosa em relação a esses pacientes.

Meta-analysis of infection and disease among household contacts of patients with drug-resistant tuberculosis / 中国热带医学

@#Abstract: Objective　To analyze the association between drug resistance and the risk of latent tuberculosis infection and disease among household contacts of patients with pulmonary tuberculosis, and to explore whether the compensatory mutation of drug-resistant Mycobacterium tuberculosis will enhance its pathogenicity or transmission ability. Methods　The English and Chinese databases, including PubMed, web of science, EMBASE, Cochrane library database, CNKI and Wanfang database, were searched by computer from the time of establishment of the database to January 2022. Cohort studies on the risk of infection and disease among household contacts of patients with drug-resistant and sensitive pulmonary tuberculosis were searched and screened according to the inclusion and exclusion criteria. The data were extracted and evaluated by NOS scale, using stata16.0 software meta-analysis to calculate the combined effect of tuberculosis infection and disease risk of family contacts, and carry out heterogeneity test, subgroup analysis and sensitivity analysis. Results　A total of 7 cohort studies involving 9653 TB index cases and 29, 734 house contacts were included. The results of meta-analysis showed that compared with drug-sensitive pulmonary tuberculosis patients, the risk of tuberculosis infection in house contacts of drug-resistant pulmonary tuberculosis patients was increased (OR=1.56, 95%CI=1.25-1.96, P<0.001), but there was no difference in the risk of incidence (RR=1.06, 95%CI=0.80-1.41, P=0.67>0.05). Subgroup analysis showed that the risk of latent tuberculosis infection in house contacts was affected by the study area, and the size of family contacts had an impact on the risk of TB . Sensitivity analysis showed that the results of meta-analysis were robust. Conclusion　Compared with drug sensitive TB patients, household contacts with drug-resistant TB patients had a higher risk of tuberculosis, but there was no difference in the risk of TB among the two groups.

Correlation between ILC2 and Th17/Treg ratio in peripheral blood of patients at different stages of Mycobacterium tuberculosis infection / 中华微生物学和免疫学杂志

Objective:To study the correlation between type 2 innate lymphocyte (ILC2) and Treg/Th17 ratio in the peripheral blood of patients at different stages of Mycobacterium tuberculosis ( Mtb) infection. Methods:This study recruited 30 individuals with active tuberculosis (ATB group), 26 with treated tuberculosis (RTB group), 22 with latent tuberculosis infection (LTBI group) and 17 negative for tuberculin skin test (TST-negative group). Flow cytometry was used to detect the proportion of ILC2 in CD45 + cells, and that of Th17 and Treg cells in CD4 + T lymphocytes in the peripheral blood of patients in each group. Expression of Foxp3 and RORγt at mRNA level was detected by real-time fluorescence quantitative PCR. Pearson method was used to analyze the correlation between Th17 and Treg, and that between ILC2 and Treg/Th17 ratio in the peripheral blood of patients with ATB and RTB. Results:The proportions of ILC2 in RTB and ATB groups were significantly higher than those of LTBI and TST-negative groups, and the proportion of ILC2 in RTB group was significantly higher than that of ATB group ( P<0.05). The proportion of Th17 in RTB group was lower than that of ATB group ( P<0.05), and the proportions of Th17 in ATB and RTB groups were lower than those of LTBI and TST-negative groups. The proportion of Treg in RTB group was lower than that of ATB group ( P<0.05), and close to that of LTBI group and TST-negative group, but the Treg/Th17 ratios in ATB and RTB groups were higher than those of LTBI and TST-negative groups. There was no significant difference in Treg/Th17 ratio between ATB and RTB groups ( P>0.05). The expression of Foxp3 and RORγt at mRNA level and Foxp3/RORγt ratio changed accordingly. Meanwhile, there was no correlation between Th17 and Treg in ATB or RTB group ( r=0.023, P=0.444; r=0.428, P=0.150). There was a positive correlation between ILC2 and Treg/Th17 ratio in ATB group ( r=0.794, P=0.000), while no correlation was found between ILC2 and Treg/Th17 ratio in RTB group ( r=0.197, P=0.297). Conclusions:In this study, the proportion of ILC2 was increased in the peripheral blood of TB patients, and the proportion of ILC2 in RTB group was higher than that of ATB group. In RTB group, Th17 accounted for a low proportion in the peripheral blood and was involved in inflammatory reactions, while Tregs were not involved in inflammatory reactions, but might have a certain inhibitory effect in patients with ATB. Further studies found that Th17-involved inflammatory reactions were not regulated by Tregs. ILC2 was involved in Treg/Th17 imbalance in ATB patients, but not in RTB patients.

Expert consensus on diagnosis and treatment of latent tuberculosis infection in patients with rheumatic diseases / 中华内科杂志

Rheumatic diseases, a typical kind of autoimmune disease, are often treated with glucocorticoids, immunosuppressants, biological agents, and small-molecule targeted drugs, which often leads to immune dysfunction in patients and increases the risk of activation of latent tuberculosis infection. To regulate the screening, diagnosis, and prophylactic treatment of latent tuberculosis infection in patients with rheumatic diseases, reduce the risk of developing active tuberculosis and improve the prognosis, Peking University Shenzhen Hospital, Shenzhen Third People′s Hospital and Peking Union Medical College Hospital jointly organized domestic experts in the field of rheumatology and tuberculosis to establish the expert consensus on the diagnosis and treatment of latent tuberculosis infection in patients with rheumatic diseases. This consensus focuses on epidemiology, the importance of screening, screening methods, and prophylactic anti-tuberculosis treatment strategies for latent tuberculosis infection combined with rheumatic diseases.

Prevalence of latent tuberculosis infections among residents in Nanchuan District / 预防医学

Objective@#To investigate the current prevalence of latent tuberculosis infection (LTBI) among residents living in Nanchuan District, Chongqing Municipality, so as to provide the evidence for formulating LTBI control measures.@*Methods@#The residents living in one street and one township from Nanchuan District were randomly selected using the multistage cluster sampling method during the period between January and April, 2020, and their demographic information, smoking history, history of alcohol consumption, history of contacts with tuberculosis patients and Bacillus Calmette-Guérin ( BCG ) vaccination scars were collected. The infection of Mycobacterium tuberculosis was detected using interferon gamma release assay ( IGRA ), and a positive IGRA test and exclusion of active tuberculosis was defined as LTBI. The prevalence of LTBI was descriptively analyzed among the study subjects.@*Results@#Totally 1 000 residents were recruited, including 381 males and 619 females, with a male to female ratio of 0.62∶1. The mean age was ( 45.87±18.40 ) years. Among all participants, there were 222 smokers ( 22.20% ), 247 subjects consuming alcohol (24.70%), 62 subjects with a history of contacts with tuberculosis patients ( 6.20% ) and 904 subjects with BCG scars ( 90.40% ). A total of 198 residents were diagnosed with LTBI (19.80% prevalence), and a higher prevalence rate of LTBI was seen in men than in women ( 23.36% vs. 17.61%; χ2=4.911, P=0.027 ). The prevalence of LTBI was significantly higher in married/divorced/widowed residents than in unmarried residents ( 24.22% vs. 2.01%; χ2=49.514, P<0.001 ), and significantly greater prevalence was found in smokers than in non-smokers ( 27.93% vs. 17.48%; χ2=11.871, P=0.001 ). The prevalence of LTBI appeared a tendency towards a rise with age ( χ2trend=59.100, P<0.001 ) and body mass index ( χ2trend=9.479, P=0.002 ).@*Conclusions@#The prevalence of LTBI is high among residents living in Nanchuan District, notably among elder, male smokers with high body mass index. Risk monitoring and timely interventions are required.