Prognostic and predictive significance of soluble programmed death ligand 1 in bronchoalveolar lavage fluid in stage IV non-small cell lung cancer.

Background: Patients with non-small cell lung cancer (NSCLC) have been shown to exhibit elevated levels of soluble programmed death-ligand 1 (sPD-L1) in the blood, associated with poor survival in NSCLC. The bronchoalveolar lavage fluid (BALF) composition reflects the tumor microenvironment of lung cancer. In this study, we investigated sPD-L1 levels in BALF and its role as a prognostic and predictive marker in patients with stage IV NSCLC. Methods: We prospectively obtained BALF from lung cancer patients who underwent bronchoscopy between January 2020 and September 2022 at Chungnam National University Hospital (CNUH). Finally, 94 NSCLC stage IV patients were included in this study. Soluble PD-L1 levels in BALF were measured using a human PD-L1 Quantikine ELISA kit. Results: The correlation between PD-L1 expression in tumor cells and sPD-L1 in BALF was weakly positive (rho =0.314, P=0.002). The median overall survival (OS) of the low sPD-L1 in BALF group was 16.47 months [95% confidence interval (CI): 11.15-21.79 months], which is significantly longer than 8.87 months (95% CI: 0.0-19.88 months, P=0.001) in the high sPD-L1 in BALF group. In 64 patients treated with or without immune checkpoint inhibitors (ICIs), sPD-L1 in BALF was significantly associated with progression-free survival (PFS) and OS. In the subgroup analysis of 31 patients treated with ICI, the objective response rate (ORR) in the low sPD-L1 BALF group was significantly higher than in high sPD-L1 in BALF group (ORR: 60.9% vs. 12.5%, P=0.02). Conclusions: Soluble PD-L1 in BALF is a potential prognostic indicator for patients with stage IV NSCLC and a predictive marker for ICI treatment response.

Clinical Characteristics and Prognosis of Older Patients with Coronavirus Disease 2019 Requiring Mechanical Ventilation.

An older age is associated with severe progression and poor prognosis in coronavirus disease 2019 (COVID-19), and mechanical ventilation is often required. The specific characteristics of older patients undergoing mechanical ventilation and their prognostic factors are largely unknown. We aimed to identify potential prognostic factors in this group to inform treatment decisions. This retrospective cohort study collected data from patients with COVID-19 at 22 medical centers. Univariate and multivariate Cox regression analyses were performed to assess factors that influence mortality. We allocated 434 patients in geriatric (≥80 years) and elderly (65-79 years) groups. The former group scored significantly higher than the elderly group in the clinical frailty scale and sequential organ failure assessment, indicating more severe organ dysfunction. Significantly lower administration rates of tocilizumab and extracorporeal membrane oxygenation and higher intensive care unit (ICU) and in-hospital mortality were noted in the geriatric group. The factors associated with ICU and in-hospital mortality included high creatinine levels, the use of continuous renal replacement therapy, prone positioning, and the administration of life-sustaining treatments. These results highlight significant age-related differences in the management and prognosis of critically ill older patients with COVID-19. Increased mortality rates and organ dysfunction in geriatric patients undergoing mechanical ventilation necessitate age-appropriate treatment strategies to improve their prognoses.

Clinical characteristics and prognosis of patients with COVID-19 on mechanical ventilation undergoing continuous renal replacement therapy.

BACKGROUND: The coronavirus disease (COVID-19) pandemic has significantly strained global healthcare, particularly in the management of patients requiring mechanical ventilation (MV) and continuous renal replacement therapy (CRRT). This study investigated the characteristics and prognoses of these patients. METHODS: This multicenter retrospective cohort study gathered data from patients with COVID-19 across 26 medical centers. Logistic analysis was used to identify the factors associated with CRRT implementation. RESULTS: Of the 640 patients with COVID-19 who required MV, 123 (19.2%) underwent CRRT. Compared to the non-CRRT group, the CRRT group was older and exhibited higher sequential organ failure assessment scores. The incidence of hypertension, diabetes, cardiovascular disease, chronic neurological disease, and chronic kidney disease was also higher in the CRRT group. Moreover, the CRRT group had higher intensive care unit (ICU) (75.6% vs. 26.9%, p < 0.001) and in-hospital (79.7% vs. 29.6%, p < 0.001) mortality rates. CRRT implementation was identified as an independent risk factor for both ICU mortality (hazard ratio [HR]:1.833, 95% confidence interval [CI]:1.342-2.505, p < 0.001) and in-hospital mortality (HR: 2.228, 95% CI: 1.648-3.014, p < 0.001). Refractory respiratory failure (n = 99, 19.1%) was the most common cause of death in the non-CRRT death group, and shock with multi-organ failure (n = 50, 40.7%) was the most common cause of death in the CRRT death group. Shock with multi-organ failure and cardiac death were significantly more common in the CRRT death group, compared to non-CRRT death group. CONCLUSION: This study indicates that CRRT is associated with higher ICU and in-hospital mortality rates in patients with COVID-19 who require MV. Notably, the primary cause of death in the CRRT group was shock with multi-organ failure, emphasizing the severe clinical course for these patients, while refractory respiratory failure was most common in non-CRRT patients.

Risk Factors for the Mortality of Patients With Coronavirus Disease 2019 Requiring Extracorporeal Membrane Oxygenation in a Non-Centralized Setting: A Nationwide Study.

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 among patients with COVID-19 who received ECMO.

Characteristics and outcomes of patients with do-not-resuscitate and physician orders for life-sustaining treatment in a medical intensive care unit: a retrospective cohort study.

BACKGROUND: In the intensive care unit (ICU), we may encounter patients who have completed a Do-Not-Resuscitate (DNR) or a Physician Orders to Stop Life-Sustaining Treatment (POLST) document. However, the characteristics of ICU patients who choose DNR/POLST are not well understood. METHODS: We retrospectively analyzed the electronic medical records of 577 patients admitted to a medical ICU from October 2019 to November 2020, focusing on the characteristics of patients according to whether they completed DNR/POLST documents. Patients were categorized into DNR/POLST group and no DNR/POLST group according to whether they completed DNR/POLST documents, and logistic regression analysis was used to evaluate factors influencing DNR/POLST document completion. RESULTS: A total of 577 patients were admitted to the ICU. Of these, 211 patients (36.6%) had DNR or POLST records. DNR and/or POLST were completed prior to ICU admission in 48 (22.7%) patients. The DNR/POLST group was older (72.9 ± 13.5 vs. 67.6 ± 13.8 years, p < 0.001) and had higher Acute Physiology and Chronic Health Evaluation (APACHE) II score (26.1 ± 9.2 vs. 20.3 ± 7.7, p < 0.001) and clinical frailty scale (5.1 ± 1.4 vs. 4.4 ± 1.4, p < 0.001) than the other groups. Solid tumors, hematologic malignancies, and chronic lung disease were the most common comorbidities in the DNR/POLST groups. The DNR/POLST group had higher ICU and in-hospital mortality and more invasive treatments (arterial line, central line, renal replacement therapy, invasive mechanical ventilation) than the other groups. Body mass index, APAHCE II score, hematologic malignancy, DNR/POLST were factors associated with in-hospital mortality. CONCLUSIONS: Among ICU patients, 36.6% had DNR or POLST orders and received more invasive treatments. This is contrary to the common belief that DNR/POLST patients would receive less invasive treatment and underscores the need to better understand and include end-of-life care as an important ongoing aspect of patient care, along with communication with patients and families.

Clinical Manifestations and Outcomes of Older Patients with COVID-19: A Comprehensive Review.

The consequences of coronavirus disease 2019 (COVID-19) are particularly severe in older adults with a disproportionate number of severe and fatal outcomes. Therefore, this integrative review aimed to provide a comprehensive overview of the clinical characteristics, management approaches, and prognosis of older patients diagnosed with COVID-19. Common clinical presentations in older patients include fever, cough, and dyspnea. Additionally, preexisting comorbidities, especially diabetes and pulmonary and cardiovascular diseases, were frequently observed and associated with adverse outcomes. Management strategies varied, however, early diagnosis, vigilant monitoring, and multidisciplinary care were identified as key factors for enhancing patient outcomes. Nonetheless, the prognosis remains guarded for older patients, with increased rates of hospitalization, mechanical ventilation, and mortality. However, timely therapeutic interventions, especially antiviral and supportive treatments, have demonstrated some efficacy in mitigating the severe consequences in this age group. In conclusion, while older adults remain highly susceptible to severe outcomes from COVID-19, early intervention, rigorous monitoring, and comprehensive care can play a pivotal role in improving their clinical outcomes.

Age Distribution and Clinical Results of Critically Ill Patients above 65-Year-Old in an Aging Society: A Retrospective Cohort Study.

BACKGROUND: Increasing age has been observed among patients admitted to the intensive care unit (ICU). Age traditionally considered a risk factor for ICU mortality. We investigated how the epidemiology and clinical outcomes of older ICU patients have changed over a decade. METHODS: We analyzed patients admitted to the ICU at a university hospital in Seoul, South Korea. We defined patients aged 65 and older as older patients. Changes in age groups and mortality risk factors over the study period were analyzed. RESULTS: A total of 32,322 patients were enrolled who aged ≥65 years admitted to the ICUs between January 1, 2007, and December 31, 2017. Patients aged ≥65 years accounted for 35% and of these, the older (O, 65 to 74 years) comprised 19,630 (66.5%), very older (VO, 75 to 84 years) group 8,573 (29.1%), and very very older (VVO, ≥85 years) group 1,300 (4.4%). The mean age of ICU patients over the study period increased (71.9±5.6 years in 2007 vs. 73.2±6.1 years in 2017) and the proportions of the VO and VVO group both increased. Over the period, the proportion of female increased (37.9% in 2007 vs. 43.3% in 2017), and increased ICU admissions for medical reasons (39.7% in 2007 vs. 40.2% in 2017). In-hospital mortality declined across all older age groups, from 10.3% in 2007 to 7.6% in 2017. Hospital length of stay (LOS) decreased in all groups, but ICU LOS decreased only in the O and VO groups. CONCLUSION: The study indicates a changing demographic in ICUs with an increase in older patients, and suggests a need for customized ICU treatment strategies and resources.

Cathepsin C regulates tumor progression via the Yes-associated protein signaling pathway in non-small cell lung cancer.

Cathepsin C (CTSC), also known as dipeptidyl peptidase I, is a cathepsin with lysosomal exocysteine protease activity and a central coordinator for the activation of neutrophil-derived serine proteases in the lysosomes of neutrophils. Although the role of CTSC in various cancers, including liver and breast cancers, has recently been reported, its role in non-small cell lung cancer (NSCLC) is largely unknown. This study aimed to investigate the functional role of CTSC in NSCLC and the molecular mechanisms underlying CTSC involvement in disease progression. CTSC overexpression markedly enhanced the growth, motility, and invasiveness of NSCLC cells in vitro and in vivo. CTSC knockdown using shRNA in NSCLC cells reversed the migratory and invasive behavior of NSCLC cells. CTSC also induced epithelial-mesenchymal transition through the Yes-associated protein signaling pathway. In addition, our analyses of clinical samples confirmed that high CTSC expression was associated with lymph node metastasis and recurrence in lung adenocarcinoma. In conclusion, CTSC plays an important role in the progression of NSCLC. Thus, targeting CTSC may be a promising treatment option for patients with NSCLC.

The Matrix Stiffness Coordinates the Cell Proliferation and PD-L1 Expression via YAP in Lung Adenocarcinoma.

The extracellular matrix (ECM) exerts physiological activity, facilitates cell-to-cell communication, promotes cell proliferation and metastasis, and provides mechanical support for tumor cells. The development of solid tumors is often associated with increased stiffness. A stiff ECM promotes mechanotransduction, and the predominant transcription factors implicated in this phenomenon are YAP/TAZ, ß-catenin, and NF-κB. In this study, we aimed to investigate whether YAP is a critical mediator linking matrix stiffness and PD-L1 in lung adenocarcinoma. We confirmed that YAP, PD-L1, and Ki-67, a marker of cell proliferation, increase as the matrix stiffness increases in vitro using the lung adenocarcinoma cell lines PC9 and HCC827 cells. The knockdown of YAP decreased the expression of PD-L1 and Ki-67, and conversely, the overexpression of YAP increased the expression of PD-L1 and K-67 in a stiff-matrix environment (20.0 kPa). Additionally, lung cancer cells were cultured in a 3D environment, which provides a more physiologically relevant setting, and compared to the results obtained from 2D culture. Similar to the findings in 2D culture, it was confirmed that YAP influenced the expression of PD-L1 and K-67 in the 3D culture experiment. Our results suggest that matrix stiffness controls PD-L1 expression via YAP activation, ultimately contributing to cell proliferation.

Evolution and Spread of Highly Pathogenic Avian Influenza A(H5N1) Clade 2.3.4.4b Virus in Wild Birds, South Korea, 2022-2023.

During October 2022-March 2023, highly pathogenic avian influenza (HPAI) A(H5N1) clade 2.3.4.4b virus caused outbreaks in South Korea, including 174 cases in wild birds. To understand the origin and role of wild birds in the evolution and spread of HPAI viruses, we sequenced 113 HPAI isolates from wild birds and performed phylogenetic analysis. We identified 16 different genotypes, indicating extensive genetic reassortment with viruses in wild birds. Phylodynamic analysis showed that the viruses were most likely introduced to the southern Gyeonggi-do/northern Chungcheongnam-do area through whooper swans (Cygnus cygnus) and spread southward. Cross-species transmission occurred between various wild bird species, including waterfowl and raptors, resulting in the persistence of HPAI in wild bird populations and further geographic spread as these birds migrated throughout South Korea. Enhanced genomic surveillance was an integral part of the HPAI outbreak response, aiding in timely understanding of the origin, evolution, and spread of the virus.

Quantitative Computed Tomography Lung COVID Scores with Laboratory Markers: Utilization to Predict Rapid Progression and Monitor Longitudinal Changes in Patients with Coronavirus 2019 (COVID-19) Pneumonia.

Coronavirus disease 2019 (COVID-19), is an ongoing issue in certain populations, presenting rapidly worsening pneumonia and persistent symptoms. This study aimed to test the predictability of rapid progression using radiographic scores and laboratory markers and present longitudinal changes. This retrospective study included 218 COVID-19 pneumonia patients admitted at the Chungnam National University Hospital. Rapid progression was defined as respiratory failure requiring mechanical ventilation within one week of hospitalization. Quantitative COVID (QCOVID) scores were derived from high-resolution computed tomography (CT) analyses: (1) ground glass opacity (QGGO), (2) mixed diseases (QMD), and (3) consolidation (QCON), and the sum, quantitative total lung diseases (QTLD). Laboratory data, including inflammatory markers, were obtained from electronic medical records. Rapid progression was observed in 9.6% of patients. All QCOVID scores predicted rapid progression, with QMD showing the best predictability (AUC = 0.813). In multivariate analyses, the QMD score and interleukin(IL)-6 level were important predictors for rapid progression (AUC = 0.864). With >2 months follow-up CT, remained lung lesions were observed in 21 subjects, even after several weeks of negative reverse transcription polymerase chain reaction test. AI-driven quantitative CT scores in conjugation with laboratory markers can be useful in predicting the rapid progression and monitoring of COVID-19.

Spontaneous regression of recurrent pulmonary large cell neuroendocrine carcinoma with alteration of PD-L1 expression after surgical resection: A case report.

Pulmonary large cell neuroendocrine carcinoma (LCNEC) is a rare and aggressive subtype of non-small cell lung cancer with a poor prognosis. Spontaneous regression, that is, partial or complete disappearance of a malignancy without medical intervention, is extremely rare in LCNEC. Herein, we present a case of spontaneous complete regression in a 71-year-old male patient with recurrent LCNEC after surgical resection. The patient was diagnosed with stage IB LCNEC and underwent surgical resection. At 1-year follow-up, chest computed tomography revealed a recurrent lesion next to the stump site and enlargement of lymph nodes 4R and 7; recurrent LCNEC was confirmed. The patient declined chemoradiation therapy. One year after recurrence, the patient experienced severe multifocal necrotizing pneumonia and was treated with antibiotics, resulting in a gradual decrease in the size of the recurrent lesion. Five years after the initial diagnosis, positron emission tomography/computed tomography revealed no hypermetabolic lesions, indicating the spontaneous complete regression of LCNEC.

Evolution of the Stethoscope: Advances with the Adoption of Machine Learning and Development of Wearable Devices.

The stethoscope has long been used for the examination of patients, but the importance of auscultation has declined due to its several limitations and the development of other diagnostic tools. However, auscultation is still recognized as a primary diagnostic device because it is non-invasive and provides valuable information in real-time. To supplement the limitations of existing stethoscopes, digital stethoscopes with machine learning (ML) algorithms have been developed. Thus, now we can record and share respiratory sounds and artificial intelligence (AI)-assisted auscultation using ML algorithms distinguishes the type of sounds. Recently, the demands for remote care and non-face-to-face treatment diseases requiring isolation such as coronavirus disease 2019 (COVID-19) infection increased. To address these problems, wireless and wearable stethoscopes are being developed with the advances in battery technology and integrated sensors. This review provides the history of the stethoscope and classification of respiratory sounds, describes ML algorithms, and introduces new auscultation methods based on AI-assisted analysis and wireless or wearable stethoscopes.

Corticosteroid outcome may be dependent of duration of use in severe COVID-19.

BACKGROUND/AIMS: For patients hospitalized with coronavirus disease 2019 (COVID-19) who require supplemental oxygen, the evidence of the optimal duration of corticosteroid is limited. This study aims to identify whether long-term use of corticosteroids is associated with decreased mortality. METHODS: Between February 10, 2020 and October 31, 2021, we analyzed consecutive hospitalized patients with COVID-19 with severe hypoxemia. The patients were divided into short-term (≤ 14 days) and long-term (> 14 days) corticosteroid users. The primary outcome was 60-day mortality. We performed propensity score (PS) analysis to mitigate the effect of confounders and conducted Kaplan-Meier curve analysis. RESULTS: There were 141 (52%) short-term users and 130 (48%) long-term corticosteroid users. The median age was 68 years and the median PaO2/FiO2 at admission was 158. Of the patients, 40.6% required high-flow nasal cannula, 48.3% required mechanical ventilation, and 11.1% required extracorporeal membrane oxygenation. The overall 60-day mortality rate was 23.2%, and that of patients with hospital-acquired pneumonia (HAP) was 22.9%. The Kaplan-Meier curve for 60- day survival in the PS-matched cohort showed that corticosteroid for > 14 days was associated with decreased mortality (p = 0.0033). There were no significant differences in bacteremia and HAP between the groups. An adjusted odds ratio for the risk of 60-day mortality in short-term users was 5.53 (95% confidence interval, 1.90-18.26; p = 0.003). CONCLUSION: For patients with severe COVID-19, long-term use of corticosteroids was associated with decreased mortality, with no increase in nosocomial complications. Corticosteroid use for > 14 days can benefit patients with severe COVID-19.

The Influence of Sex on Characteristics and Outcomes of Coronavirus-19 Patients: A Retrospective Cohort Study.

BACKGROUND: The influence of sex on the clinical characteristics and prognosis of coronavirus disease (COVID-19) patients is variable. This study aimed to evaluate COVID-19 management based on sex differences. METHODS: We retrospectively reviewed COVID-19 patients who were admitted to the tertiary hospital between January 2020 and March 2021. Logistic regression analysis was used to evaluate the factors associated with in-hospital mortality. RESULTS: During the study period, 584 patients were admitted to our hospital. Among them, 305 patients (52.2%) were female, and 279 patients (47.8%) were male. Males were younger than females, and frailty scale was lower in males than in females. Fever was more common in males, and there was no difference in other initial symptoms. Among the underlying comorbidities, chronic obstructive disease was more common in males, and there were no significant differences in other comorbidities. Moreover, treatment, severity, and outcome did not significantly differ between the groups. The risk factors for in-hospital mortality were age, high white blood cell count, and c-reactive protein level. CONCLUSIONS: We found no definite sex differences in the clinical characteristics and outcomes of COVID-19 patients. However, a better understanding of sex-dependent differences in COVID-19 patients could help in understanding and treating patients.

Diagnostic and Prognostic Roles of C-Reactive Protein, Procalcitonin, and Presepsin in Acute Kidney Injury Patients Initiating Continuous Renal Replacement Therapy.

For reducing the high mortality rate of severe acute kidney injury (AKI) patients initiating continuous renal replacement therapy (CRRT), diagnosing sepsis and predicting prognosis are essential. However, with reduced renal function, biomarkers for diagnosing sepsis and predicting prognosis are unclear. This study aimed to assess whether C-reactive protein (CRP), procalcitonin, and presepsin could be used to diagnose sepsis and predict mortality in patients with impaired renal function initiating CRRT. This was a single-center, retrospective study involving 127 patients who initiated CRRT. Patients were divided into sepsis and non-sepsis groups according to the SEPSIS-3 criteria. Of the 127 patients, 90 were in the sepsis group and 37 were in the non-sepsis group. Cox regression analysis was performed to determine the association between the biomarkers (CRP, procalcitonin, and presepsin) and survival. CRP and procalcitonin were superior to presepsin for diagnosing sepsis. Presepsin was closely related to the estimated glomerular filtration rate (eGFR) (r = -0.251, p = 0.004). These biomarkers were also evaluated as prognostic markers. Procalcitonin levels ≥3 ng/mL and CRP levels ≥31 mg/L were associated with higher all-cause mortality using Kaplan-Meier curve analysis. (log-rank test p = 0.017 and p = 0.014, respectively). In addition, procalcitonin levels ≥3 ng/mL and CRP levels ≥31 mg/L were associated with higher mortality in univariate Cox proportional hazards model analysis. In conclusion, a higher lactic acid, sequential organ failure assessment score, eGFR, and a lower albumin level have prognostic value to predict mortality in patients with sepsis initiating CRRT. Moreover, among these biomarkers, procalcitonin and CRP are significant factors for predicting the survival of AKI patients with sepsis-initiating CRRT.

The first case report of Paragonimus westermani infection diagnosed by transbronchial lung cryobiopsy.

We report a case of pulmonary paragonimiasis diagnosed by transbronchial lung cryobiopsy (TBLC). TBLC is likely to be a superior method to transbronchial forceps biopsy because TBLC can get larger specimens, resulting in a higher chance of containing the eggs. A male patient aged 57 years presented with hemoptysis and dyspnea on exertion. His initial chest computed tomography scans showed a cavitary nodule with a peripheral ground-glass appearance, leading to a prescription of an oral antibiotic, with an initial assumption of pneumonia. A follow-up chest computed tomography, however, revealed an appearance of a new nodule adjacent to the original nodule. TBLC and transbronchial forceps biopsy were done to rule out lung cancer and eventually, the eggs of Paragonimus westermani were found using TBLC. Praziquantel was prescribed, showing improvements in symptoms and chest X-ray findings. TBLC has more potential to be utilized as a diagnostic method than transbronchial forceps biopsy because it has a better chance to confirm pulmonary paragonimiasis, which can be initially suspected as pulmonary tuberculosis or lung cancer.

Clinical outcomes of and risk factors for secondary infection in patients with severe COVID-19: a multicenter cohort study in South Korea.

BACKGROUND/AIMS: Secondary infection with influenza virus occurs in critically ill patients and is associated with substantial morbidity and mortality; however, there is limited information about it in patients with severe coronavirus disease 2019 (COVID-19). Thus, we investigated the clinical outcomes of and risk factors for secondary infections in patients with severe COVID-19. METHODS: This study included patients with severe COVID-19 who were admitted to seven hospitals in South Korea between February 2020 to February 2021. Multivariate logistic regression analyses were performed to assess factors associated with the risk of secondary infections. RESULTS: Of the 348 included patients, 104 (29.9%) had at least one infection. There was no statistically significant difference in the 28-day mortality (17.3% vs. 12.3%, p = 0.214), but in-hospital mortality was higher (29.8% vs. 15.2%, p = 0.002) in the infected group than in the non-infected group. The risk factors for secondary infection were a high frailty scale (odds ratio [OR], 1.314; 95% confidence interval [CI], 1.123 to 1.538; p = 0.001), steroid use (OR, 3.110; 95% CI, 1.164 to 8.309; p = 0.024), and the application of mechanical ventilation (OR, 4.653; 95% CI, 2.533 to 8.547; p < 0.001). CONCLUSION: In-hospital mortality was more than doubled in patients with severe COVID-19 and secondary infections. A high frailty scale, the use of steroids and application of mechanical ventilation were risk factors for secondary infection.

Plasma GDF15 levels associated with circulating immune cells predict the efficacy of PD-1/PD-L1 inhibitor treatment and prognosis in patients with advanced non-small cell lung cancer.

PURPOSE: Although increased plasma growth differentiation factor-15 (GDF15) levels have been reported in patients with various cancers, the predictive role of PD-1/PD-L1 inhibitors in advanced cancers remains unknown. This study aimed to investigate GDF15 levels as a predictive marker in advanced non-small cell lung cancer (NSCLC) treated with PD-1/PD-L1 inhibitors and analyze their association with immune cell populations. METHODS: This study included 87 patients with advanced NSCLC receiving anti-PD-1/PD-L1 inhibitors between March 2018 and May 2020. Blood samples were obtained immediately before and months after PD-1/PD-L1 inhibitor administration. RESULTS: The objective response rate (ORR) was significantly higher in the low GDF15 than in the high GDF15 group (39.2% vs. 15.3%, P = 0.013). The median progression-free survival (PFS) was significantly longer in the low GDF15 than in the high GDF15 group (13.2 [95% CI 7.6-18.9] vs. 7.2 [95% CI 4.8-9.6] months, P = 0.048). Moreover, plasma GDF15 levels negatively correlated with PD-1+/CD8+ T cells (r = - 0.399, P = 0.003) and positively with PD-1+/Treg cells (r = 0.507, P < 0.001) and PD-1+Treg/CD4+ T cells (r = 0.439, P < 0.001). The ORR was significantly higher in the group with decreased GDF15 from baseline than in the increased GDF15 group (37.2% vs. 10.0%, P = 0.026). The median PFS was significantly longer in the decreased GDF15 group (14.8 [95% CI 10.4-19.2] vs. 5.9 [95% CI 2.8-9.0] months, P = 0.002). Plasma GDF15 levels were associated with PD-1+CD8+ T cells and PD-1+ Treg cells. CONCLUSION: Plasma GDF15 could be a potential biomarker for predicting the efficacy and survival benefit of immunotherapy in advanced NSCLC.