Clinical Phenotyping of Out-of-Hospital Cardiac Arrest Patients With Shockable Rhythm　- Machine Learning-Based Unsupervised Cluster Analysis.

BACKGROUND: The hypothesis of this study is that latent class analysis could identify the subphenotypes of out-of-hospital cardiac arrest (OHCA) patients associated with the outcomes and allow us to explore heterogeneity in the effects of extracorporeal cardiopulmonary resuscitation (ECPR).Methods and Results:This study was a retrospective analysis of a multicenter prospective observational study (CRITICAL study) of OHCA patients. It included adult OHCA patients with initial shockable rhythm. Patients from 2012 to 2016 (development dataset) were included in the latent class analysis, and those from 2017 (validation dataset) were included for evaluation. The association between subphenotypes and outcomes was investigated. Further, the heterogeneity of the association between ECPR implementation and outcomes was explored. In the study results, a total of 920 patients were included for latent class analysis. Three subphenotypes (Groups 1, 2, and 3) were identified, mainly characterized by the distribution of partial pressure of O2(PO2), partial pressure of CO2(PCO2) value of blood gas assessment, cardiac rhythm on hospital arrival, and estimated glomerular filtration rate. The 30-day survival outcomes were varied across the groups: 15.7% in Group 1; 30.7% in Group 2; and 85.9% in Group 3. Further, the association between ECPR and 30-day survival outcomes by subphenotype groups in the development dataset was as varied. These results were validated using the validation dataset. CONCLUSIONS: The latent class analysis identified 3 subphenotypes with different survival outcomes and potential heterogeneity in the effects of ECPR.

Early prognostic impact of serum sodium level among out-of-hospital cardiac arrest patients: a nationwide multicentre observational study in Japan (the JAAM-OHCA registry).

Dysnatremia is an electrolytic disorder commonly associated with mortality in various diseases. However, little is known about dysnatremia in out-of-hospital cardiac arrest (OHCA) cases. Here, we investigated the association between serum sodium level on hospital arrival and neurological outcomes after OHCA. This nationwide hospital-based observational study (The Japanese Association for Acute Medicine Out-of-Hospital Cardiac Arrest registry) enrolled patients with OHCA between 2014 and 2017. We included adult patients aged ≥ 18 years with non-traumatic OHCA who achieved return of spontaneous circulation (ROSC) and whose serum sodium level on hospital arrival was available. Based on the serum sodium level, patients were divided into three levels: hyponatremia (Na < 135 mEq/L), normal sodium level (Na ≥ 135 or ≤ 145 mEq/L), and hypernatremia (Na > 145 mEq/L). The primary outcome was 1-month survival with favourable neurological outcomes. Altogether, 34 754 patients with OHCA were documented, and 5160 patients with non-traumatic OHCA and who achieved ROSC were eligible for our analyses. The proportion of favourable neurological outcomes was highest in patients with normal sodium levels at 17.6% (677/3854), followed by patients with hyponatremia at 8.2% (57/696) and patients with hypernatremia at 5.7% (35/610). Moreover, hyponatremia and hypernatremia were associated with a decreased probability of favourable neurological outcomes compared with normal sodium level (vs. hyponatremia, adjusted odds ratio [AOR] 0.97, 95% confidence interval [CI] 0.95-0.99; vs. hypernatremia, AOR 0.96, 95% CI 0.94-0.98). Hypo- and hypernatremia on hospital arrival were associated with a decreased probability of favourable neurological outcomes in patients with non-traumatic OHCA who achieved ROSC.

Association between initial body temperature on hospital arrival and neurological outcome among patients with out-of-hospital cardiac arrest: a multicenter cohort study (the CRITICAL study in Osaka, Japan).

BACKGROUND: The association between spontaneous initial body temperature on hospital arrival and neurological outcomes has not been sufficiently studied in patients after out-of-hospital cardiac arrest (OHCA). METHODS: From the prospective database of the Comprehensive Registry of Intensive Care for OHCA Survival (CRITICAL) study in Osaka, Japan, we enrolled all patients with OHCA of medical origin aged > 18 years for whom resuscitation was attempted and who were transported to participating hospitals between 2012 and 2019. We excluded patients who were not witnessed by bystanders and treated by a doctor car or helicopter, which is a car/helicopter with a physician. The patients were categorized into three groups according to their temperature on hospital arrival: ≤35.9 °C, 36.0-36.9 °C (normothermia), and ≥ 37.0 °C. The primary outcome was 1-month survival, with a cerebral performance category of 1 or 2. Multivariable logistic regression analyses were performed to evaluate the association between temperature and outcomes (normothermia was used as the reference). We also assessed this association using cubic spline regression analysis. RESULTS: Of the 18,379 patients in our database, 5014 witnessed adult OHCA patients of medical origin from 16 hospitals were included. When analyzing 3318 patients, OHCA patients with an initial body temperature of ≥37.0 °C upon hospital arrival were associated with decreased favorable neurological outcomes (6.6% [19/286] odds ratio, 0.51; 95% confidence interval, 0.27-0.95) compared to patients with normothermia (16.4% [180/1100]), whereas those with an initial body temperature of ≤35.9 °C were not associated with decreased favorable neurological outcomes (11.1% [214/1932]; odds ratio, 0.78; 95% confidence interval, 0.56-1.07). The cubic regression splines demonstrated that a higher body temperature on arrival was associated with decreased favorable neurological outcomes, and a lower body temperature was not associated with decreased favorable neurological outcomes. CONCLUSIONS: In adult patients with OHCA of medical origin, a higher body temperature on arrival was associated with decreased favorable neurologic outcomes.

Trends in In-Hospital Advanced Management and Survival of Out-of-Hospital Cardiac Arrest Among Adults From 2013 to 2017　- A Multicenter, Prospective Registry in Osaka, Japan.

BACKGROUND: The aim of our study was to investigate in detail the temporal trends in in-hospital characteristics, actual management, and survival, including neurological status, among adult out-of-hospital cardiac arrest (OHCA) patients in recent years.Methods and Results:From the prospective database of the Comprehensive Registry of Intensive Care for OHCA Survival (CRITICAL) study in Osaka, Japan, we enrolled all OHCA patients aged ≥18 years for whom resuscitation was attempted, and who were transported to participating hospitals between the years 2013 and 2017. The primary outcome measure was 1-month survival with favorable neurological outcome after OHCA. Temporal trends in in-hospital management and favorable neurological outcome among adult OHCA patients were assessed. Of the 11,924 patients in the database, we included a total of 10,228 adult patients from 16 hospitals. As for in-hospital advanced treatments, extracorporeal cardiopulmonary resuscitation (ECPR) use increased from 2.4% in 2013 to 4.3% in 2017 (P for trend <0.001). However, the proportion of adult OHCA patients with favorable neurological outcome did not change during the study period (from 5.7% in 2013 to 4.4% in 2017, adjusted odds ratio (OR) for 1-year increment: 0.98 (95% confidence interval: 0.94-1.23)). CONCLUSIONS: In this target population, in-hospital management such as ECPR increased slightly between 2013 and 2017, but 1-month survival with favorable neurological outcome after adult OHCA did not improve significantly.

Poor Long-Term Survival of Out-of-Hospital Cardiac Arrest in Children.

The effect of post-cardiac arrest care in children with out-of-hospital cardiac arrest (OHCA) has not been adequately established, and the long-term outcome after pediatric OHCA has not been sufficiently investigated. We describe here detailed in-hospital characteristics, actual management, and survival, including neurological status, 90 days after OHCA occurrence in children with OHCA transported to critical care medical centers (CCMCs).We analyzed the database of the Comprehensive Registry of Intensive Care for OHCA Survival (CRITICAL) study, which is a multicenter, prospective observational data registry designed to accumulate both pre- and in-hospital data on OHCA treatments. We enrolled all consecutive pediatric patients aged <18 years who had an OHCA and for whom resuscitation was attempted and who were transported to CCMCs between 2012 and 2016.A total of 263 pediatric patients with OHCA were enrolled. The average age of the patients was 6.3 years, 38.0% were aged < 1 year, and 60.8% were male. After hospital arrival, 4.9% of these pediatric patients received defibrillation; 1.9%, extracorporeal life support; 6.5%, target temperature management; and 88.2% adrenaline administration. The proportions of patients with 90-day survival and a pediatric cerebral performance category (PCPC) score of 1 or 2 were 6.1% and 1.9%, respectively. The proportion of patients with a PCPC score of 1 or 2 at 90 days after OHCA occurrence did not significantly improve during the study period.The proportion of pediatric patients with a 90-day PCPC score of 1 or 2 transported to CCMCs was extremely low, and no significant improvements were observed during the study period.

Epidemiology of Out-of-Hospital Cardiac Arrest Due to Suffocation Focusing on Suffocation Due to Japanese Rice Cake: A Population-Based Observational Study From the Utstein Osaka Project.

BACKGROUND: Japanese rice cake ("mochi") is a major cause of food-choking accidents in Japan. However, the epidemiology of out-of-hospital cardiac arrests (OHCAs) due to suffocation caused by rice cakes is poorly understood. METHODS: OHCA data from 2005 to 2012 were obtained from the population-based OHCA registry in Osaka Prefecture. Patients aged ≥20 years who experienced OHCA caused by suffocation that occurred before the arrival of emergency-medical-service (EMS) personnel were included. Patient characteristics, prehospital interventions, and outcomes were compared based on the cause of suffocation (rice cake and non-rice-cake). The primary outcome was 1-month survival after OHCA. RESULTS: In total, 46 911 adult OHCAs were observed during the study period. Of the OHCAs, 7.0% (3,294/46,911) were due to suffocation, with choking due to rice cake as the cause in 9.5% of cases (314/3,294), and of these, 24.5% (77/314) occurred during the first 3 days of the New Year. In crude analysis, 1-month survival was 17.2% (54/314) in those with suffocation caused by rice cake and 13.4% (400/2,980) in those with suffocation due to other causes. In the multivariable analysis for all-cause suffocation, younger age, arrest witnessed by bystanders, and earlier EMS response time were significantly related to better 1-month survival. CONCLUSION: Approximately 10% of OHCAs due to suffocation were caused by rice-cake choking, and 25% of these occurred during the first 3 days of the New Year. Further efforts for establishing preventive measures as well as improving the early recognition of choking and encouraging bystanders to call EMS sooner are needed.

D-dimer predicts bleeding complication in out-of-hospital cardiac arrest resuscitated with ECMO.

PURPOSE: In out-of-hospital cardiac arrest (OHCA) patients resuscitated with veno-arterial extracorporeal membrane oxygenation (VA-ECMO), known as extracorporeal cardiopulmonary resuscitation (ECPR), bleeding is a common complication. The purpose of this study was to assess the risk factors for bleeding complications in ECPR patients. METHODS: We retrospectively analyzed the data for OHCA patients admitted to our hospital and resuscitated with ECPR between October 2009 and December 2016. We compared patients with and without major bleeding (i.e. the Bleeding Academic Research Consortium class≥3 bleeding) within 24h of hospital admission. Patients, whose bleeding complication was not evaluated, were excluded. RESULTS: During the study period, 133 OHCA patients were resuscitated with ECPR, of whom 102 (77%) were included. In total, 71 (70%) patients experienced major bleeding. There were significant differences in age (median 65 vs. 50years, P<0.001), prior antiplatelet therapy (25% vs. 3%, P=0.008), hemoglobin (median 11.6 vs. 12.6g/dL, P=0.003), platelet count (median 125 vs. 155×103/µL, P=0.001), and D-dimer levels on admission (median 18.8 vs. 6.7µg/mL, P<0.001) among patients with and those without major bleeding. Multivariate analysis showed significant associations between major bleeding and D-dimer levels (odds ratio, 1.066; 95% confidence interval, 1.018-1.116). Area under receiver-operating characteristic curve, which describes the accuracy of D-dimer levels in predicting major bleeding, was 0.76 (95% confidence interval, 0.66-0.87). CONCLUSION: D-dimer levels may predict major bleeding in ECPR patients, suggesting that hyperfibrinolysis may be related to bleeding.

Global Registry of Acute Coronary Events risk score predicts mortality and neurological outcome in out-of hospital cardiac arrest.

PURPOSE: The aim of this study was to assess the usefulness of the Global Registry of Acute Coronary Events (GRACE) risk score in predicting in-hospital mortality and neurological outcome of patients resuscitated after out-of-hospital cardiac arrest (OHCA). METHODS: We retrospectively analyzed the data of patients admitted to our hospital between October 2009 and October 2015 with OHCA and shockable initial cardiac rhythm who were resuscitated via conventional cardiopulmonary resuscitation. We calculated the GRACE risk score on admission and assessed its usefulness in predicting in-hospital mortality and neurological outcome. RESULTS: Among 91 patients, 42 (46%) had acute myocardial infarction (AMI), 19 (21%) died in-hospital, and 52 (57%) had favorable neurological outcome. Among all the study patients, GRACE risk score was lower in survivors than in non-survivors (median 211 [interquartile range 176-240] vs. 266 [219-301], p<0.001, respectively) and in favorable than in unfavorable neurological outcome group (202 [167-237] vs. 242 [219-275], p<0.001, respectively). Multivariate analysis showed significant association between GRACE risk score and favorable neurological outcome (odds ratio, 0.975; 95% confidence interval, 0.961-0.990). Areas under receiver-operating characteristic curves, that describe the accuracy of GRACE risk score in predicting in-hospital mortality and favorable neurological outcome, were both 0.79. CONCLUSION: GRACE risk score may predict the in-hospital mortality and neurological outcome associated with resuscitated patients with OHCA and shockable initial cardiac rhythm, regardless of the cause of arrest.

Clinical phenotypes of nontuberculous mycobacterial disease by cluster analysis based on pulmonary function.

BACKGROUND: Nontuberculous mycobacterial pulmonary disease (NTM-PD) often exhibits pulmonary function impairment, such as obstructive or restrictive pattern, with variation among patients according to the damaged lesions in the lung. METHODS: Patients with NTM-PD were consecutively enrolled between September 2019 and December 2020 at the Respiratory Infection Clinic of our hospital. Patients' data were comprehensively collected through laboratory examinations, PFT, chest computed tomography, and questionnaires for the assessment of subjective symptoms and health-related quality of life (HRQOL). Hierarchical cluster analysis was performed using PFT parameters to compare the clinical findings among clusters. RESULTS: Data of 104 patients were analyzed and classified into four clusters. The restrictive pattern with decreased forced expiratory volume in 1 s (FEV1) group showed high serum C-reactive protein and low albumin levels, severe radiological findings, and low HRQOL. In the restrictive pattern with preserved FEV1 group, HRQOL was as low as that in the restrictive pattern with decreased FEV1 group, and bacterial exacerbation was observed relatively frequently. HRQOL in the obstructive impairment group was maintained in comparison with that in the normal group. CONCLUSION: NTM-PD phenotypes were identified using cluster analysis based on PFT. Two different severe phenotypes were also observed. In the early stages of NTM-PD, PFT may be useful in recognizing disease progression.

Comparative Study of Immunodeficient Rat Strains in Engraftment of Human-Induced Pluripotent Stem Cell-Derived Airway Epithelia.

The airway epithelia (AE) play a role in the clearance of foreign substances through ciliary motility and mucus secreted. We developed an artificial trachea that is made of collagen sponges and polypropylene mesh for the regeneration of the tracheal defect, and it was used for a clinical study. Then, a model in which the luminal surface of an artificial trachea was covered with a human-induced pluripotent stem cell-derived AE (hiPSC-AE) was transplanted into the tracheal defect of nude rats to promote epithelialization. In the future, this model was expected to be applied to research on infectious diseases and drug discovery as a trachea-humanized rat model. However, at present, sufficient engraftment has not been achieved to evaluate functional recovery in transplanted cells. Therefore, this study focused on immunosuppression in recipient rats. Nude rats lack T cell function and are widely used for transplantation experiments; however, more severe immunosuppressed recipients are preferred for xenotransplantation. Several strains of immunodeficient rats were created as rats that exhibit more severe immunodeficiency until now. In this study, to establish a trachea-humanized rat model in which human AE function can be analyzed to improve engraftment efficiency, engraftment efficiency in nude rats and X-linked severe combined immunodeficiency (X-SCID) rats following hiPSC-AE transplantation was compared. In the analysis of the proportion of engrafted cells in total cells at the graft site, the engraftment efficiency of epithelial cells tended to be high in X-SCID rats, although no statistical difference was found between the two groups, whereas the engraftment efficiency of mesenchymal cells was higher in X-SCID rats. Furthermore, the number of immune cells that accumulated in the grafts showed that a pan T cell marker, that is, CD3-positive cells, did not differ between the two strains; however, CD45-positive cells and major histocompatibility complex (MHC) class II-positive cells significantly decreased in X-SCID rats. These results indicate that X-SCID rats are more useful for the transplantation of hiPSC-AE into the tracheae to generate trachea-humanized rat models.

Changes in the Proportion of Each Cell Type After hiPSC-Derived Airway Epithelia Transplantation.

No radical treatment is available for the regeneration of dysfunction and defects in airway epithelia. Artificial tracheae made of polypropylene and collagen sponge were used in clinical studies to reconstitute tracheae after resection. For early epithelialization of the luminal surface of the artificial trachea, a model was established, that is, an artificial trachea covered with human-induced pluripotent stem cell-derived airway epithelial cells (hiPSC-AECs) was transplanted into a tracheal defect in an immunodeficient rat. Unlike the cell types of hiPSC-derived cells that are currently used in clinical studies, AECs maintain tissues by proliferation and differentiation of basal cells into various cell types that constitute AECs constantly. Therefore, post-transplantation, the proportion of each cell type, such as ciliated and goblet cells, may change; however, no studies have examined this possibility. In this study, using our hiPSC-AEC-transplanted rat model, we investigated changes in the proportion of each cell type in hiPSC-AECs pre-transplantation and post-transplantation. As a result, the proportion of each cell type changed post-transplantation. The proportion of ciliated, basal, and club cells increased, and the proportion of goblet cells decreased post-transplantation. In addition, the proportion of each cell type in engrafted hiPSC-AECs is more similar to the proportion of each cell type in normal proximal airway tissue than the proportion of each cell type pre-transplantation. The results of this study are useful for the development of therapeutic techniques using hiPSC-AEC transplantation.

An Infection Model for SARS-CoV-2 Using Rat Transplanted with hiPSC-Airway Epithelial Cells.

Investigating the infection mechanism of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in the airway epithelium and developing effective defense strategies against infection are important. To achieve this, establishing appropriate infection models is crucial. Therefore, various in vitro models, such as cell lines and primary cultures, and in vivo models involving animals that exhibit SARS-CoV-2 infection and genetically humanized animals have been used as animal models. However, no animal model has been established that allows infection experiments with human cells under the physiological environment of airway epithelia. Therefore, we aimed to establish a novel animal model that enables infection experiments using human cells. Human induced pluripotent stem cell-derived airway epithelial cell-transplanted nude rats (hiPSC-AEC rats) were used, and infection studies were performed by spraying lentiviral pseudoviruses containing SARS-CoV-2 spike protein and the GFP gene on the tracheae. After infection, immunohistochemical analyses revealed the existence of GFP-positive-infected transplanted cells in the epithelial and submucosal layers. In this study, a SARS-CoV-2 infection animal model including human cells was established mimicking infection through respiration, and we demonstrated that the hiPSC-AEC rat could be used as an animal model for basic research and the development of therapeutic methods for human-specific respiratory infectious diseases.

Non-linear association between the time required to reaching temperature targets and the neurological outcome in patients undergoing targeted temperature management after out-of-hospital cardiac arrest: Observational multicentre cohort study.

Purpose: We evaluated associations between outcomes and time to achieving temperature targets during targeted temperature management of out-of-hospital cardiac arrest. Methods: Using Comprehensive Registry of Intensive Care for out-of-hospital cardiac arrest Survival (CRITICAL) study, we enrolled all patients transported to participating hospitals from 1 July 2012 through 31 December 2017 aged ≥ 18 years with out-of-hospital cardiac arrest of cardiac aetiology and who received targeted temperature management in Osaka, Japan. Primary outcome was Cerebral Performance Category scale of 1 or 2 one month after cardiac arrest, designated as "one-month favourable neurological outcome". Non-linear multivariable logistic regression analyses assessed the primary outcome based on time to reaching temperature targets. In patients subdivided into quintiles based on time to achieving temperature targets, multivariable logistic regression calculated adjusted odds ratios and 95% confidence intervals. Results: We analysed 473 patients. In non-linear multivariable logistic regression analysis, p value for non-linearity was < 0.01. In the first quintile (< 26.7 minutes), second quintile (26.8-89.9 minutes), third quintile (90.0-175.1 minutes), fourth quintile (175.2-352.1 minutes), and fifth quintile (≥ 352.2 minutes), one-month favourable neurological outcome was 32.6% (31/95), 40.0% (36/90), 53.5% (53/99), 57.4% (54/94), and 37.9% (36/95), respectively. Adjusted odds ratios with 95% confidence intervals for one-month favourable neurological outcome in the first, second, third, and fifth quintiles compared with the fourth quintile were 0.38 (0.20 to 0.72), 0.43 (0.23 to 0.81), 0.77 (0.41 to 1.44), and 0.46 (0.25 to 0.87), respectively. Conclusion: Non-linear multivariable logistic regression analysis could clearly describe the association between neurological outcome in patients with out-of-hospital cardiac arrest and the time from the introduction of targeted temperature management to reaching the temperature targets.

Association between atmospheric conditions and occurrence of out-of-hospital cardiac arrest- 10-year population-based survey in Osaka.

BACKGROUND: Weather conditions affect the occurrence of cardiovascular disease. The aim of this study was to investigate the associations between atmospheric conditions including temperature, pressure, and humidity, and the occurrence of out-of-hospital cardiac arrests (OHCAs) with cardiac etiology. METHODS AND RESULTS: This study was a cross-sectional analysis of a prospective cohort that included all persons aged ≥ 18 years with OHCA in Osaka, from 1998 through 2007. The association between the number of daily OHCA events with various atmospheric conditions was analyzed using Poisson regression. A total of 28,806 adult OHCAs were presumed to be of cardiac etiology. The number of OHCAs in 1 day was inversely correlated with the day's mean atmospheric temperature. The regression coefficient was greater on the days under 18°C (r=-0.317, P<0.001) than on days over 18°C (r=-0.088, P<0.001). A positive linear relation was found between the number of OHCAs in 1 day and the day's mean atmospheric pressure (r=0.321, P<0.001). Under 18°C, every 5°C decrease in the daily mean temperature was associated with an 11% (95% confidence interval [CI]: 8-13%) increase in OHCA occurrence in the non-elderly group, and a 16% increase in the elderly group (95% CI: 14-19%). CONCLUSIONS: The occurrence of adult OHCA with cardiac etiology increases with decreasing temperature of the day. Elderly people are more susceptible to severe weather conditions.

Transient asymptomatic pulmonary opacities in a patient with MET exon 14 skipping non-small cell lung cancer: A case report.

Mesenchymal epithelial transition factor receptor (MET) tyrosine kinase inhibitors (MET-TKIs) have been approved for the treatment of non-small cell lung cancers with MET exon 14 skipping mutations. Transient asymptomatic pulmonary opacities (TAPOs) associated with epidermal growth factor receptor (EGFR)-TKIs have been reported. Here, we report a case wherein ground-glass opacities (GGOs) appeared during the course of treatment with tepotinib, a MET-TKI, but spontaneously resolved with drug withdrawal, after which treatment was resumed with a reduced dose. Although there have been no reports of TAPOs with MET-TKIs, the clinical and imaging findings of this case were consistent with TAPOs. For TAPOs occurring because of MET-TKI, the drug can be continued under careful observation even if GGOs appear.

Physiologic 18F-FDG muscle uptake in severe COPD: Implications for accurate lung cancer staging.

Recognizing physiologic 18F-fluorodeoxyglucose (FDG) uptake in severe COPD is crucial to avoid mistaking it for lung cancer metastasis. Correlating 18F-FDG avid lesions with co-registered computed tomography is essential for accurate lung cancer staging and preventing unnecessary interventions.

Concurrent trastuzumab deruxtecan-induced interstitial lung disease and COVID-19 in the treatment of advanced breast cancer.

Patients with cancer are at an increased risk of developing coronavirus disease 2019 (COVID-19) infection. Trastuzumab deruxtecan (T-DXd) is an antibody-drug conjugate (ADC) against epidermal growth factor receptor 2 (HER2)-positive cancer, known to cause drug-induced interstitial lung disease (DILD), including drug-induced pneumonitis. A 60-year-old woman with breast cancer developed a fever during treatment with T-DXd and was diagnosed with COVID-19. The fever persisted for approximately 3 weeks, and chest computed tomography showed multiple consolidations with bilateral peripheral predominance. Since the clinical course was atypical for COVID-19 due to the long duration of the fever and the CT pattern was frequently seen in T-DXd-induced ILD, the patient was diagnosed with T-DXd-induced ILD, following which, prednisolone was started, leading to improvement in the symptoms and fading of shadows. Even in patients suspected of COVID-19 pneumonia, physicians should consider the possibility of DILD, particularly in patients undergoing cancer treatment.

Impact of methotrexate on humoral and cellular immune responses to SARS-CoV-2 mRNA vaccine in patients with rheumatoid arthritis.

The aim of this study was to longitudinally evaluate the undetermined impact of methotrexate (MTX) on the cumulative immunogenicity elicited by three doses of SARS-CoV-2 mRNA vaccination in patients with rheumatoid arthritis (RA). We prospectively evaluated vaccine-induced immune responses following the first dose, 1 and 6 months after the second dose, and 1 month after the third dose of BNT162b2 or mRNA-1273 in 144 SARS-CoV-2 naïve participants (70 patients with RA, 29 disease controls without immunosuppressive conditions, and 45 healthy controls). Humoral immune responses were assessed by quantifying anti-spike IgG antibody titers and the capacity of circulating antibodies to neutralize the ancestral SARS-CoV-2 strain and the Alpha, Delta, and Omicron variants. Vaccine-induced T-cell responses were measured using an interferon-gamma release assay. At 1 and 6 months after the second dose, anti-spike titers were highest in healthy controls, followed by disease controls and patients with RA. Multivariate analyses revealed that MTX treatment was significantly associated with a decrease in anti-spike titers, neutralizing activity, and SARS-CoV-2-specific interferon-gamma levels. Furthermore, MTX dose per body weight was negatively correlated with these two indices of humoral immune response. The third vaccine dose boosted anti-spike titers, especially in patients receiving MTX, while sera from these patients neutralized the Omicron variant far less robustly than those from healthy controls. In conclusion, MTX attenuated immunogenicity following two doses of SARS-CoV-2 mRNA vaccine in patients with RA, particularly resulting in dose-dependent suppression of the humoral immune response. Furthermore, MTX deteriorated the neutralizing activity against the Omicron variant, even after the third immunization.

Laryngeal Cartilage Regeneration of Nude Rats by Transplantation of Mesenchymal Stem Cells Derived from Human-Induced Pluripotent Stem Cells.

Previous studies transplanted human-induced pluripotent stem cells (hiPSCs)-derived mesenchymal stem cells (iMSCs) into thyroid cartilage defect of X-liked severe combined immunodeficiency (X-SCID) rats and confirmed transplanted cell survival and cartilage regeneration. Thus, this study aimed to investigate the contribution of iMSC transplantation to thyroid cartilage regeneration of nude rats. iMSCs were induced from hiPSCs via a neural crest cell lineage. Then, clumps formed from an iMSC/extracellular matrix complex were transplanted into thyroid cartilage defects in nude rats. The larynx was removed and histological and immunohistochemical analyses were performed 4 or 8 weeks after the transplantation. Human nuclear antigen (HNA)-positive cells were observed in 11 of 12 (91.7%) rats, which indicated that transplanted iMSCs survived in thyroid cartilage defects in nude rats. HNA-positive cells co-expressed SOX9, and type II collagen was identified around HNA-positive cells in 8 of 12 rats (66.7%), which indicated cartilage-like regeneration. Cartilage-like regeneration in nude rats in this study was comparable to the previous report on X-SCID rats (HNA-positive cells were observed in all 14 rats and cartilage-like regeneration was observed in 10 of 14 rats). This result suggests that nude rats could be an alternative to X-SCID rats in thyroid cartilage regeneration experiments using iMSCs, and this nude rat cartilage transplantation model may develop cartilage regeneration research concerning fewer problems such as infection due to immunosuppression.