Background The clinical and prognostic implications of asymptomatic tuberculosis remain poorly understood. Methods We conducted a multicentre prospective cohort study to evaluate the association between asymptomatic tuberculosis (TB) and treatment outcomes. Individuals with rifampicin-susceptible pulmonary TB were enrolled from the Cohort Study of Pulmonary Tuberculosis. Asymptomatic TB was defined as the absence of any TB-related symptoms at diagnosis. The primary outcome was a favourable outcome, defined as treatment success without recurrence. Multivariable logistic regression models were used to assess associations between asymptomatic TB and favourable outcomes. The Cox proportional hazards model was applied to evaluate effect of asymptomatic TB on failure to complete treatment within 1 year. Stratified analyses by symptom status and mode of detection were performed to examine stratum-specific effects. Results Of 1071 individuals with pulmonary TB, 32.7% were asymptomatic. Compared to symptomatic patients, asymptomatic individuals were younger, less likely to be underweight and more often diagnosed through population health screening rather than clinical presentation or opportunistic testing. Asymptomatic TB was associated with higher likelihood of favourable outcome in multivariable models (adjusted odds ratio (aOR) 1.50, 95% CI 1.04-2.20) and a reduced risk of failing to complete treatment within one year in survival analyses (adjusted hazard ratio 0.66, 95% CI 0.45-0.95). Asymptomatic TB detected through health screening had the most favourable outcomes (aOR 2.41, 95% CI 1.34-4.66). Conclusion Asymptomatic TB was significantly associated with treatment success without recurrence and particularly in patients identified through health screening. Our results support symptom-agnostic screening in TB control programmes.

Tuberculosis (TB) continues to be a primary cause of mortality from a singular infectious agent worldwide, with a significant number of patients still encountering unfavorable outcomes such as treatment failure, relapse, or death. Early identification of high-risk individuals is essential for optimizing clinical management, yet conventional statistical approaches often fail to capture the complex, nonlinear interactions among clinical predictors. Machine learning (ML) presents a promising alternative; however, previous ML-based prognostic studies in TB have been constrained by small sample sizes, retrospective designs, or insufficient external validation. We conducted a multicenter prospective cohort study in Korea using two prospective cohort databases (2016–2024). Adults with newly diagnosed drug-susceptible pulmonary tuberculosis were divided into training and external validation sets by institutions. Five machine learning models were created, and optimized decision thresholds to get the highest F2-score. We used the area under the receiver-operating characteristic curve (AUROC) and the area under the precision–recall curve to measure performance. Feature importance was assessed using SHapley Additive exPlanations (SHAP) values and compared with multivariate logistic regression. Among 1580 participants, 109 (6.9

The association between kidney function and tuberculosis treatment outcomes remains uncertain. We analyzed a multicenter prospective cohort of adults with rifampicin-susceptible pulmonary tuberculosis enrolled in Korea between 2019 and 2021. Kidney function was categorized using baseline estimated glomerular filtration rate (eGFR) calculated with the 2021 CKD-EPI creatinine equation and grouped as preserved (eGFR ≥ 60 mL/min/1.73 m²) and reduced (eGFR < 60 mL/min/1.73 m²) kidney function. An additional analysis evaluated severely reduced kidney function (eGFR < 30 mL/min/1.73 m²). The primary endpoint was unfavorable outcome, defined as loss-to-follow-up, treatment failure, death, still-on-treatment, transfer to another treatment unit, or recurrence, analyzed using multivariable logistic regression. The secondary endpoint was failure to complete treatment within 9 months of initiation, analyzed by Cox proportional hazards model. All models adjusted for prespecified covariates, with age and sex included in all models. Among 966 participants, 89 (9

Prospective real-world evidence on the effectiveness and safety of the World Health Organization-recommended 6-month fluoroquinolone-containing regimen (FqREZ) for isoniazid mono-resistant tuberculosis (Hr-TB) remain limited. We conducted a multicenter prospective observational cohort study within the Korean national TB program between 2016 and 2024. Adults with pulmonary Hr-TB received either a 6-month FqREZ or alternative non-FqREZ. The primary outcome was a favorable outcome, defined as treatment success without recurrence within 12 months after treatment completion. The secondary outcome was the occurrence of serious adverse events during treatment. Multivariable logistic regression was performed to assess factors associated with study outcomes. Among 99 participants with pulmonary Hr-TB, 55 (55.6

The standard treatment for drug-susceptible tuberculosis (TB) is a 6-month short-course regimen; however, extended courses are often used in clinical practice. We aimed to identify factors associated with extended treatment in patients with drug-susceptible TB. We conducted a prospective cohort study across 18 institutions in the Republic of Korea between July 2019 and June 2023 and enrolled patients with drug-susceptible TB who received the standard short-course regimen (isoniazid, rifampin, pyrazinamide, and ethambutol) and achieved treatment success at end of therapy. Patients were categorised by treatment duration: less than 200 days (standard treatment group) and more than 200 days (extended treatment group). Of 854 patients, 334 (39.1

This study aimed to evaluate whether plasma presepsin levels are a more reliable predictor of mortality than traditional infection biomarkers in patients with urinary tract infection (UTI)-related severe infection. This single-center retrospective study evaluated 69 patients with UTI-related severe infection admitted to the emergency department between May 2022 and August 2023. Data on vital signs, plasma presepsin levels, procalcitonin (PCT) levels, C-reactive protein (CRP) levels, white blood cell (WBC) count, and other laboratory values at admission were collected. The values of presepsin, PCT, CRP, and WBC count for predicting 28-day mortality were analyzed. Survivors and non-survivors were propensity score-matched in a 2:1 ratio based on age, sex, and estimated glomerular filtration rate. In the overall cohort, presepsin showed the highest area under the receiver operating characteristic curve (AUROC) of 0.716 for predicting 28-day mortality, surpassing that of PCT (0.641), CRP (0.488), and WBC count (0.433). Presepsin levels were independently associated with increased 28-day mortality risk (hazard ratio, 1.026; p = 0.008). In the matched cohort, presepsin levels showed the highest AUROC (0.660), followed by PCT (0.584), CRP (0.496), and WBC count (0.436). Presepsin levels were independently associated with increased 28-day mortality risk; this may be a valuable biomarker for identifying high-risk patients with UTI-related severe infection.

BACKGROUND:Isoniazid resistance is the most common type of ant-tuberculosis drug resistance, which is often neglected in clinical practice. This study aimed to evaluate the impact of isoniazid mono-resistant tuberculosis (Hr-TB) on the treatment outcomes of people with pulmonary tuberculosis. METHODS:People with pulmonary tuberculosis were enrolled from the Korea Tuberculosis Cohort (KTBC) registry and the multicenter prospective cohort study of pulmonary tuberculosis (COSMOTB). Isoniazid resistance was confirmed using drug susceptibility test results. The primary outcome was an unfavorable outcome, which defined as comprising death, failure, loss-to-follow-up, still-on-treatment, and not-evaluated. Logistic regression analysis was conducted to evaluate effect of isoniazid resistance on treatment outcomes. We also compared 2-month sputum negative culture conversion rate and incidence of adverse events between Hr-TB and drug-susceptible tuberculosis. RESULTS:From the KTBC and COSMOTB databases, 10,482 and 758 participants were included, respectively. Compared to drug-susceptible tuberculosis, Hr-TB had higher rates of unfavorable outcome in the KTBC (45.8% vs. 37.0%, P < 0.001) and COSMOTB (31.5% vs. 17.9%, P = 0.014). Multivariable logistic regression analysis showed significant association between isoniazid resistance and unfavorable outcome in the KTBC (adjusted odds ratio [aOR], 1.43; 95% confidence interval [CI], 1.24-1.65) and in the COSMOTB (aOR, 1.98; 95% CI, 1.02-3.85). Additional analyses on COSMOTB data showed that Hr-TB had more serious adverse drug reactions, while 2-month sputum culture conversion rates did not differ significantly. CONCLUSION:Isoniazid resistance is significantly associated with unfavorable clinical outcomes.

BACKGROUND:Understanding of the life-sustaining treatment (LST) decisions in critically ill coronavirus disease 2019 (COVID-19) patients remains limited. This study aimed to identify factors influencing LST decisions, and compare clinical outcomes between patients with, and without, LST. METHODS:This multicenter, retrospective cohort study analyzed data from 1,081 COVID-19 patients admitted to intensive care units (ICUs) across Korea from January 1, 2020, to August 31, 2021. Patients were divided into LST and non-LST groups. Demographic, clinical, and outcome data were collected and compared. RESULTS:Of 1,081 patients, 207 (19.2 %) received LST. LST patients were older (median age: 76 years vs. 67 years, p<0.001), and had more comorbidities (85.5% vs. 70.4%, p<0.001), especially cardiovascular and chronic lung disease. They showed higher blood urea nitrogen, lower albumin, and elevated D-dimer levels (all p<0.05). ICU interventions, including mechanical ventilation (82.6% vs. 50.9%, p<0.001) and extracorporeal membrane oxygenation (ECMO) (18.8% vs. 9.8%, p<0.001), were more common. ICU and hospital mortality rates were significantly higher in LST patients (82.6% and 94.2%, respectively, p<0.001). Logistic regression identified age (odds ratio [OR], 1.054 per year; p<0.001), mechanical ventilation (OR, 2.789; p=0.002), and ECMO use (OR, 3.580; p=0.002) as independent predictors of LST. CONCLUSION:Age, comorbidities, and ICU interventions significantly influence LST decisions, highlighting the need for ethical and evidence-based critical care guidelines.

While overweight has been associated with a reduced risk of developing tuberculosis and diabetes with an increased risk, it remains unclear how these conditions influence anti-tuberculosis treatment outcomes. We aimed to examine the association of overweight with anti-tuberculosis treatment outcomes, and to evaluate whether this association differs by diabetes status, using two Korean cohorts. Among patients with pulmonary tuberculosis enrolled in the multicenter prospective cohort study of pulmonary tuberculosis (COSMOTB) and the Korea Tuberculosis Cohort (KTBC) registry, we defined overweight as BMI ≥ 23 kg/m² according to national criteria and compared it with normal/underweight (BMI < 23 kg/m², per criteria). The primary and secondary outcomes were unfavorable outcomes and mortality. Multivariable regression analysis was conducted to evaluate the association of overweight with treatment outcomes, adjusting for potential confounders. Subgroup analyses were performed to assess the association in patients with and without diabetes. In the COSMOTB dataset, the proportion of overweight individuals was 34.4

Long noncoding RNA is also a molecule that is attracting attention these days. Only about 1.5% of the genome is protein-coding, while the other 98.5% consists of non-coding elements, which are transcribed by RNA polymerase II (polII) into non-coding RNA (ncRNA). Among them, ncRNAs with a size of 200nt or more are called long non-coding RNAs (lncRNAs). To date, lncRNA have been recognized to have regulatory roles in gene expression through various mechanisms. They are involved in diverse biological processes such as cell differentiation, apoptosis, development, inflammatory response, and immune response. Cancer stem cells (CSCs) identified in lung cancer exhibit resistance to chemotherapy, radiotherapy, and targeted therapy. Therefore, a technology for controlling CSCs is needed to overcome such resistance to cancer therapy. The authors planned this study to discover lncRNAs involved in cancer stemness. We analyzed TCGA data to search for lncRNAs that predict the prognosis of NSCLC and selected LINC01224 as a candidate lncRNA involved in cancer stemness. Treatment of LINC01224 with siRNA reduced colony formation ability in cell lines with stem cell characteristics. Next, we performed whole-genome expression in lung cancer cell line after siRNA treatment to identify gene controlled by LINC01224. This experiment revealed that lncRNA is involved in apoptosis, cell cycle, cell death, cell differentiation, cell migration, and DNA repair. LINC01224 is a prognostic factor and an attractive treatment target for non-small cell lung cancer. LINC01224 possibly regulates various biological phenomena and specific mechanism studies are needed. Ji Woong Son, Wan Jin Hwang, Minhyeok Lee, Daeun Kang, In Beom Jeong, Sun Jung Kwon. Long non coding RNA LINC01224 is prognostic marker and regulates cancer stemness in the NSCLC [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2025; Part 1 (Regular Abstracts); 2025 Apr 25-30; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2025;85(8_Suppl_1):Abstract nr 4651.

Background: The increasing incidence and mortality rates of tuberculosis among older individuals who suffer from multiple morbidities and are vulnerable to malnutrition are major obstacles to efforts to eradicate tuberculosis in the Republic of Korea. Herein, we identified the factors associated with mortality during anti-tuberculosis treatment in patients with pulmonary tuberculosis. Methods: We conducted a case-control study and extracted data from the database of a multi-center prospective observational cohort study in Korea. Among the participants with rifampicin-susceptible pulmonary tuberculosis, the survival group was defined as those who successfully completed treatment within one year, whereas the mortality group was defined as those who died during treatment. Univariable and multivariable logistic regression analyses were performed to identify factors associated with TB mortality. Results: Among 1,119 participants with pulmonary TB registered between 2019 and 2021, 799 and 59 were grouped in the survival and mortality groups, respectively. Age, positive smear results, alarming symptoms, nutrition risk score, Charlson comorbidity index score, and initial standard treatment regimen were significant based on univariable analysis and were selected for the multivariable logistic regression model. Nutrition risk score (adjusted odds ratio, 2.44; 95% confidence interval, 1.72-3.48) and Charlson comorbidity index score (adjusted odds ratio, 1.62; 95% confidence interval, 1.35-1.94) remained statistically significant in the multivariate analysis. Conclusion: Nutritional status and comorbidities at baseline were identified as important factors associated with mortality in patients with pulmonary tuberculosis.

Lung cancer remains one of the most common and lethal malignancies worldwide, with poor prognosis largely due to late-stage diagnosis and resistance to therapy. Emerging evidence indicates that long non-coding RNAs (lncRNAs) play critical roles in cancer development, metastasis, and treatment resistance. Particulate matter (PM), a major environmental pollutant and recognized Group 1 carcinogen, has been linked to lung cancer through mechanisms that may involve dysregulation of lncRNA expression. This study aimed to identify PM-responsive lncRNAs in lung cancer, and investigate their potential functional roles. Microarray analysis of lung cancer cell lines A549, H358, H292, and HCC827, exposed to PM10, revealed significant up-regulation of lnc-MTPAP-1. TUNEL staining confirmed that silencing of lnc-MTPAP-1 via siRNA resulted in increased apoptosis across all tested lines. Transcriptome analysis using next-generation sequencing showed that knockdown of lnc-MTPAP-1 altered the expression of apoptosis-related genes, with up-regulation of TNS4, MyD88, and IL6R, and down-regulation of CLPTM1L and EI24. These findings suggest that lnc-MTPAP-1 may exert anti-apoptotic effects in lung cancer cells, and be involved in pollution-induced cancer progression. Further research should explore the therapeutic potential of targeting lnc-MTPAP-1, and better understand the molecular impact of PM exposure on lung cancer pathogenesis.

BACKGROUND AND OBJECTIVE:Patients with tuberculosis and diabetes have a higher risk of unfavourable anti-tuberculosis treatment outcomes. In the present study, we aimed to evaluate the effects of various diabetes statuses on the outcomes of patients with pulmonary tuberculosis. METHODS:Among the patients with pulmonary tuberculosis enrolled in the Korea Tuberculosis Cohort (KTBC) registry and the multicentre prospective cohort study of pulmonary tuberculosis (COSMOTB), those with diabetes and complicated diabetes were identified. The primary and secondary outcomes were unfavourable outcomes and mortality, respectively. The effect of diabetes and complicated diabetes on the outcomes was assessed using multivariable logistic regression analysis. Using COSMOTB, subgroup analyses were performed to assess the association between various diabetes statuses and outcomes. RESULTS:In the KTBC, diabetes (adjusted odds ratio [aOR] = 1.93, 95% CI = 1.64-2.26) and complicated diabetes (aOR = 1.96, 95% CI = 1.67-2.30) were significantly associated with unfavourable outcomes, consistent with the COSMOTB data analysis. Based on subgroup analysis, untreated diabetes at baseline was an independent risk factor for unfavourable outcomes (aOR = 2.72, 95% CI = 1.26-5.61). Prediabetes and uncontrolled diabetes increased unfavourable outcomes and mortality without statistical significance. CONCLUSION:Untreated and complicated diabetes at the time of tuberculosis diagnosis increases the risk of unfavourable outcomes and mortality.

BACKGROUND:When suspicious lesions are observed on computer-tomography (CT), invasive tests are needed to confirm lung cancer. Compared with other procedures, bronchoscopy has fewer complications. However, the sensitivity of peripheral lesion through bronchoscopy including washing cytology is low. A new test with higher sensitivity through bronchoscopy is needed. In our previous study, DNA methylation of PCDHGA12 in bronchial washing cytology has a diagnostic value for lung cancer. In this study, combination of PCDHGA12 and CDO1 methylation obtained through bronchial washing cytology was evaluated as a diagnostic tool for lung cancer.METHODS:A total of 187 patients who had suspicious lesions in CT were enrolled. PCDHGA12 methylation test, CDO1 methylation test, and cytological examination were performed using 3-plex LTE-qMSP test.RESULTS:Sixty-two patients were diagnosed with benign diseases and 125 patients were diagnosed with lung cancer. The sensitivity of PCDHGA12 was 74.4% and the specificity of PCDHGA12 was 91.9% respectively. CDO1 methylation test had a sensitivity of 57.6% and a specificity of 96.8%. The combination of both PCDHGA12 methylation test and CDO1 methylation test showed a sensitivity of 77.6% and a specificity of 90.3%. The sensitivity of lung cancer diagnosis was increased by combining both PCDHGA12 and CDO1 methylation tests.CONCLUSION:Checking DNA methylation of both PCDHGA12 and CDO1 genes using bronchial washing fluid can reduce the invasive procedure to diagnose lung cancer.

Background: An evaluation of the persistence of symptoms following COVID-19 in economically active young and middle-aged adults is crucial due to its significant socioeconomic impact resulting from compromised work performance. Methods: A prospective, multicenter study at 12 South Korean hospitals from January to December 2022 involved telephone interviews along with validated questionnaires. Results: Among 696 participants with a median age of 32 and no prior diagnoses, 30% of participants experienced persistent fatigue, while 21.4% suffered from sleep disturbance at 6 months following infection. Additionally, approximately 25% of the participants exhibited depression that endured for up to 6 months. Symptomatic individuals at 3 months exhibited a significantly higher prevalence of persistent fatigue, sleep disturbances, and depression at 6 months compared to those who remained asymptomatic. Notably, sleep disturbance and persistent fatigue at 3 months emerged as significant independent predictors of the presence of depression at 6 months. Conclusions: Even among young and middle-aged healthy adults, prolonged fatigue, sleep disturbance, and depression exhibit a significant prevalence and persisted for up to 6 months. Therefore, implementing a workplace management protocol for these symptoms is essential to mitigate the socioeconomic burden caused by the impairment of work efficiency.

Background: Limited data are available on the mortality rates of patients receiving extracorporeal membrane oxygenation (ECMO) support for coronavirus disease 2019 (COVID-19). We aimed to analyze the relationship between COVID-19 and clinical outcomes for patients receiving ECMO. Methods: We retrospectively investigated patients with COVID-19 pneumonia requiring ECMO in 19 hospitals across Korea from January 1, 2020 to August 31, 2021. The primary outcome was the 90 -day mortality after ECMO initiation. We performed multivariate analysis using a logistic regression model to estimate the odds ratio (OR) of 90 -day mortality. Survival differences were analyzed using the Kaplan-Meier (KM) method. Results: Of 127 patients with COVID-19 pneumonia who received ECMO, 70 patients (55.1%) died within 90 days of ECMO initiation. The median age was 64 years, and 63% of patients were male. The incidence of ECMO was increased with age but was decreased after 70 years of age. However, the survival rate was decreased linearly with age. In multivariate analysis, age (OR, 1.048; 95% confidence interval [CI], 1.010-1.089; P = 0.014) and receipt of continuous renal replacement therapy (CRRT) (OR, 3.069; 95% CI, 1.312-7.180; P = 0.010) were significantly associated with an increased risk of 90 -day mortality. KM curves showed significant differences in survival between groups according to age (65 years) (log -rank P = 0.021) and receipt of CRRT (log -rank P = 0.004). Conclusion: Older age and receipt of CRRT were associated with higher mortality rates with COVID-19 who received ECMO.

Purpose:Isoniazid-monoresistant tuberculosis (Hr-TB) has emerged as a global challenge, necessitating detailed guidelines for its diagnosis and treatment. We aim to consolidate the Korean guidelines for Hr-TB management by gathering expert opinions and reaching a consensus.Patients and Methods:A conventional Delphi method involving two rounds of surveys was conducted with 96 experts selected based on their clinical and research experience and involvement in nationwide tuberculosis studies and development of the Korean guidelines on tuberculosis. The survey consisted of three sections of questionnaires on diagnosis, treatment, and general opinions on Hr-TB.Results:Among the 96 experts, 72 (75%) participated in the two rounds of the survey. A majority of experts (96%) strongly agreed on the necessity of molecular drug susceptibility testing (DST) for isoniazid and rifampin resistance in all tuberculosis patients and emphasized the importance of interpreting mutation types (inhA or katG) and additional molecular DST for fluoroquinolones for confirmed isoniazid-resistant cases. Over 95.8% of experts recommended treating Hr-TB with a combination of rifampin, ethambutol, pyrazinamide, and levofloxacin for six months, without exceeding 12 months unless necessary. They also acknowledged the drawbacks of long-term pyrazinamide use due to its side effects and agreed on shortening its duration by extending the duration of the rest of the treatment with a modified combination of choice.Conclusion:This Delphi survey enabled Korean tuberculosis experts to reach a consensus on diagnosing and treating Hr-TB. These findings will be valuable for developing the upcoming revised Korean guidelines for Hr-TB management.

Disparities exist between sexes regarding tuberculosis (TB) incidence, as well as disease severity and outcome. Using a nationwide TB registry database, we explored the impact of sex and age on extrapulmonary TB (EPTB) among all enrolled patients by (1) calculating the female proportion for every age category according to TB-affected locations, (2) calculating the proportions of EPTB stratified by sex according to age, (3) conducting multivariable analysis to examine the impact of sex and age on EPTB likelihood, and (4) assessing the odds of EPTB for female compared to male as reference in every age category. Further, we explored the impact of sex and age on disease severity among pulmonary TB (PTB) patients. Of all the TB patients, 40.1% were female, with a male-to-female ratio of 1.49. The proportion of females was lowest in their fifties, resembling a U-shape. The male-to-female ratios in PTB and EPTB were 1.67 and 1.03, respectively. Compared to men, women were significantly associated with EPTB in their forties, fifties, and sixties. Female patients with PTB had significantly lower odds of having cavitation and positive smear test results in their fifties. Significant differences were found concerning TB location and severity between sexes, especially during reproductive age.

Background. Drug-induced liver injury (DILI) may lead to the discontinuation of antituberculosis (anti-TB) treatment (ATT). Some studies have suggested that metabolic disorders increase the risk of DILI during ATT. This study aimed to identify risk factors for DILI, particularly metabolic disorders, during ATT. Methods. A multicenter prospective observational cohort study to evaluate adverse events during ATT was conducted in Korea from 2019 to 2021. Drug-susceptible patients with TB who had been treated with standard ATT for 6 months were included. The patients were divided into 2 groups depending on the presence of 1 or more metabolic conditions, such as insulin resistance, hypertension, obesity, and dyslipidemia. We monitored ATT-related adverse events, including DILI, and treatment outcomes. The incidence of DILI was compared between individuals with and without metabolic disorders, and related factors were evaluated. Results. Of 684 patients, 52 (7.6%) experienced DILI, and 92.9% of them had metabolic disorders. In the multivariable analyses, underlying metabolic disorders (adjusted hazard ratio [aHR], 2.85; 95% CI, 1.01-8.07) and serum albumin <3.5g/dL (aHR, 2.26; 95% CI, 1.29-3.96) were risk factors for DILI during ATT. In the 1-month landmark analyses, metabolic disorders were linked to an elevated risk of DILI, especially significant alanine aminotransferase elevation. The treatment outcome was not affected by the presence of metabolic disorders. Conclusions. Patients with metabolic disorders have an increased risk of ATT-induced liver injury compared with controls. The presence of metabolic disorders and hypoalbuminemia adversely affects the liver in patients with ATT.

Rationale: The use of bronchoscopy is key to the diagnosis of lung cancer. However, the sensitivity of bronchoscopy is low. In addition, bronchial washing cytology, a routine auxiliary test, does not significantly improve the performance of bronchoscopy due to its low sensitivity. To improve the diagnostic performance of bronchoscopy, protocadherin GA12 (PCDHGA12) and Cysteine ​​Dioxygenase Type 1 (CDO1) methylation biomarkers in bronchial washing fluid have been introduced as novel adjunctive diagnostic tests. Methods: A total of 161 patients with suspected lung cancer who underwent bronchoscopy were analyzed. Cytological examination of bronchial washing fluid and testing for PCDHGA12 and CDO1 methylation biomarkers were performed. Results: The final diagnosis was lung cancer in 114 patients, and benign disease in 49 patients. PCDHGA12 methylation biomarker showed sensitivity of 80.4% and specificity of 87.8%. CDO1 methylation biomarker showed sensitivity of 66.1% and specificity of 98.0%, whereas cytological evaluation showed sensitivity of 43.8% and specificity of 100%. The combined analysis of PCDHGA12 and CDO1 methylation showed sensitivity of 84.8% and specificity of 85.7%. The combined analysis of the methylation biomarkers and cytology tests resulted in a slightly increased sensitivity of 86.6% and specificity of 85.7%. The specificity and sensitivity of the methylation biomarkers were also high in peripheral lung cancer. Conclusion: The results of this study demonstrated that PCDHGA12 and CDO1 methylation as lung cancer biomarkers of bronchial washing may be used as adjunctive tests for bronchoscopy. Keywords: biomarker; bronchoscopy; lung cancer; protocadherin GA12: CDO1, methylation Citation Format: Ji Woong Son, Minhyeok Lee, In Beom Jeong, Sun Jung Kwon, Daeun Kang, Moon Jun Na. Usefulness of protocadherin GA12 and cysteine ​​dioxygenase type 1 methylation biomarkers in the diagnosis of lung cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 3299.