Intestinal Permeability and IgA Provoke Immune Vasculitis Linked to Cardiovascular Inflammation.

Recent experimental data and clinical, genetic, and transcriptome evidence from patients converge to suggest a key role of interleukin-1ß (IL-1ß) in the pathogenesis of Kawasaki disease (KD). However, the molecular mechanisms involved in the development of cardiovascular lesions during KD vasculitis are still unknown. Here, we investigated intestinal barrier function in KD vasculitis and observed evidence of intestinal permeability and elevated circulating secretory immunoglobulin A (sIgA) in KD patients, as well as elevated sIgA and IgA deposition in vascular tissues in a mouse model of KD vasculitis. Targeting intestinal permeability corrected gut permeability, prevented IgA deposition and ameliorated cardiovascular pathology in the mouse model. Using genetic and pharmacologic inhibition of IL-1ß signaling, we demonstrate that IL-1ß lies upstream of disrupted intestinal barrier function, subsequent IgA vasculitis development, and cardiac inflammation. Targeting mucosal barrier dysfunction and the IL-1ß pathway may also be applicable to other IgA-related diseases, including IgA vasculitis and IgA nephropathy.

MRP1-Dependent Extracellular Release of Glutathione Induces Cardiomyocyte Ferroptosis After Ischemia-Reperfusion.

BACKGROUND: The membrane components of cardiomyocytes are rich in polyunsaturated fatty acids, which are easily oxidized. Thus, an efficient glutathione-based lipid redox system is essential for maintaining cellular functions. However, the relationship between disruption of the redox system during ischemia-reperfusion (IR), oxidized lipid production, and consequent cell death (ferroptosis) remains unclear. We investigated the mechanisms underlying the disruption of the glutathione-mediated reduction system related to ferroptosis during IR and developed intervention strategies to suppress ferroptosis. METHODS: In vivo fluctuations of both intra- and extracellular metabolite levels during IR were explored via microdialysis and tissue metabolome analysis. Oxidized phosphatidylcholines were assessed using liquid chromatography high-resolution mass spectrometry. The areas at risk following IR were assessed using triphenyl-tetrazolium chloride/Evans blue stain. RESULTS: Metabolomic analysis combined with microdialysis revealed a significant release of glutathione from the ischemic region into extracellular spaces during ischemia and after reperfusion. The release of glutathione into extracellular spaces and a concomitant decrease in intracellular glutathione concentrations were also observed during anoxia-reperfusion in an in vitro cardiomyocyte model. This extracellular glutathione release was prevented by chemical inhibition or genetic suppression of glutathione transporters, mainly MRP1 (multidrug resistance protein 1). Treatment with MRP1 inhibitor reduced the intracellular reactive oxygen species levels and lipid peroxidation, thereby inhibiting cell death. Subsequent in vivo evaluation of endogenously oxidized phospholipids following IR demonstrated the involvement of ferroptosis, as levels of multiple oxidized phosphatidylcholines were significantly elevated in the ischemic region 12 hours after reperfusion. Inhibition of the MRP1 transporter also alleviated intracellular glutathione depletion in vivo and significantly reduced the generation of oxidized phosphatidylcholines. Administration of MRP1 inhibitors significantly attenuated infarct size after IR injury. CONCLUSIONS: Glutathione was released continuously during IR, primarily in an MRP1-dependent manner, and induced ferroptosis. Suppression of glutathione release attenuated ferroptosis and reduced myocardial infarct size following IR.

Sortilin acts as an endocytic receptor for α-synuclein fibril.

Cell-to-cell spreading of misfolded α-synuclein (αSYN) is supposed to play a key role in the pathological progression of Parkinson's disease (PD) and other synucleinopathies. Receptor-mediated endocytosis has been shown to contributes to the uptake of αSYN in both neuronal and glial cells. To determine the receptor involved in αSYN endocytosis on the cell surface, we performed unbiased, and comprehensive screening using a membrane protein library of the mouse whole brain combined with affinity chromatography and mass spectrometry. The candidate molecules hit in the initial screening were validated by co-immunoprecipitation using cultured cells; sortilin, a vacuolar protein sorting 10 protein family sorting receptor, exhibited the strongest binding to αSYN fibrils. Notably, the intracellular uptake of fibrillar αSYN was slightly but significantly altered, depending on the expression level of sortilin on the cell surface, and time-lapse image analyses revealed the concomitant internalization and endosomal sorting of αSYN fibrils and sortilin. Domain deletion in the extracellular portion of sortilin revealed that the ten conserved cysteines (10CC) segment of sortilin was involved in the binding and endocytosis of fibrillar αSYN; importantly, pretreatment with a 10CC domain-specific antibody significantly hindered αSYN fibril uptake. The presence of sortilin in the core structure of Lewy bodies and glial cytoplasmic inclusions in the brain of synucleinopathy patients was confirmed via immunohistochemistry, and the expression level of sortilin in mesencephalic dopaminergic neurons may be altered with disease progression. These results provide compelling evidence that sortilin acts as an endocytic receptor for pathogenic form of αSYN, and yields important insight for the development of disease-modifying targets for synucleinopathies.

Epigenome editing reveals core DNA methylation for imprinting control in the Dlk1-Dio3 imprinted domain.

The Dlk1-Dio3 imprinted domain is controlled by an imprinting control region (ICR) called IG-DMR that is hypomethylated on the maternal allele and hypermethylated on the paternal allele. Although several genetic mutation experiments have shown that IG-DMR is essential for imprinting control of the domain, how DNA methylation itself functions has not been elucidated. Here, we performed both gain and loss of DNA methylation experiments targeting IG-DMR by transiently introducing CRISPR/Cas9 based-targeted DNA methylation editing tools along with one guide RNA into mouse ES cells. Altered DNA methylation, particularly at IG-DMR-Rep, which is a tandem repeat containing ZFP57 methylated DNA-binding protein binding motifs, affected the imprinting state of the whole domain, including DNA methylation, imprinted gene expression, and histone modifications. Moreover, the altered imprinting states were persistent through neuronal differentiation. Our results suggest that the DNA methylation state at IG-DMR-Rep, but not other sites in IG-DMR, is a master element to determine whether the allele behaves as the intrinsic maternal or paternal allele. Meanwhile, this study provides a robust strategy and methodology to study core DNA methylation in cis-regulatory elements, such as ICRs and enhancers.

DNAM-1 regulates Foxp3 expression in regulatory T cells by interfering with TIGIT under inflammatory conditions.

Regulatory T (Treg) cells that express forkhead box P3 (Foxp3) are pivotal for immune tolerance. Although inflammatory mediators cause Foxp3 instability and Treg cell dysfunction, their regulatory mechanisms remain incompletely understood. Here, we show that the transfer of Treg cells deficient in the activating immunoreceptor DNAM-1 ameliorated the development of graft-versus-host disease better than did wild-type Treg cells. We found that DNAM-1 competes with T cell immunoreceptor with Ig and ITIM domains (TIGIT) in binding to their common ligand CD155 and therefore regulates TIGIT signaling to down-regulate Treg cell function without DNAM-1-mediated intracellular signaling. DNAM-1 deficiency augments TIGIT signaling; this subsequently inhibits activation of the protein kinase B-mammalian target of rapamycin complex 1 pathway, resulting in the maintenance of Foxp3 expression and Treg cell function under inflammatory conditions. These findings demonstrate that DNAM-1 regulates Treg cell function via TIGIT signaling and thus, it is a potential molecular target for augmenting Treg function in inflammatory diseases.

Point of care ultrasound combined with CTS-6 to diagnose idiopathic carpal tunnel syndrome.

BACKGROUND: This study aimed to demonstrate the effectiveness of our new diagnostic chart using point of care ultrasound combined with CTS-6 for diagnosing idiopathic carpal tunnel syndrome. METHODS: We conducted a retrospective analysis of the data of patients who visited our department and received point of care ultrasound combined with CTS-6 from 2020 to 2023. Data regarding age, sex, initial and final diagnosis, cross-sectional area of the median nerve, CTS-6 score, and electrodiagnostic severity were obtained and statistically analyzed. RESULTS: Of the 177 wrists included in our study, 138 (78 %) were diagnosed with carpal tunnel syndrome, while 39 (22 %) were not (non-carpal tunnel syndrome). With our diagnostic method, 127 wrists (72 %) were diagnosed initially with carpal tunnel syndrome, 23 wrists (13 %) with non-carpal tunnel syndrome, and the rest 27 wrists (15 %) as borderline. Our initial diagnoses of carpal tunnel syndrome and non-carpal tunnel syndrome were maintained in all cases except for two. Cross-sectional area, CTS-6 score, and electrodiagnostic severity showed a positive correlation. A post hoc analysis showed that the new scoring system (CTS-6 score + 2 × cross-sectional area) with a cutoff value of 31.25 points showed a sensitivity as high as 95 % and a specificity of 100 %. CONCLUSIONS: Our findings suggest that most suspected idiopathic carpal tunnel syndrome cases can be diagnosed correctly using the diagnostic chart. Although additional tools, including electrodiagnostic studies, may be needed for borderline cases, the use of point of care ultrasound combined with CTS-6 may be a recommendable first-line confirmatory test because point of care ultrasound and CTS-6 could be complementary tools, and this chart may be especially beneficial for atypical or outlier cases. LEVEL OF EVIDENCE: Diagnostic III.

Webplasty using an external fixator for complex syndactyly caused by Apert syndrome.

BACKGROUND: Webplasty can be conducted for complex syndactyly caused by Apert syndrome (also referred to as Apert hand) by extending the soft tissue in the lateral direction using an external fixator. This study aimed to verify the usefulness of webplasty without skin grafting. METHODS: Webplasty with lateral extension was conducted at a single institution from 2015 to 2023. The patients were four children with Apert hand aged 1-3 years. A custom-made small external fixator was used for all of the soft tissue extension. RESULTS: Webplasty without skin grafting was completed by the time all five patients were 5-6 years of age. CONCLUSION: Webplasty without skin grafting was possible with lateral extension of the soft tissue using a simple external fixator.

DNAM-1 promotes inflammation-driven tumor development via enhancing IFN-γ production.

DNAM-1 is an activating immunoreceptor on T cells and natural killer (NK) cells. Expression levels of its ligands, CD155 and CD112, are up-regulated on tumor cells. The interaction of DNAM-1 on CD8+ T cells and NK cells with the ligands on tumor cells plays an important role in tumor immunity. We previously reported that mice deficient in DNAM-1 showed accelerated growth of tumors induced by the chemical carcinogen 7,12-dimethylbenz[a]anthracene (DMBA). Contrary to those results, we show here that tumor development induced by 12-O-tetradecanoylphorbol-13-acetate (TPA) together with DMBA was suppressed in DNAM-1-deficient mice. In this model, DNAM-1 enhanced IFN-γ secretion from conventional CD4+ T cells to promote inflammation-related tumor development. These findings suggest that, under inflammatory conditions, DNAM-1 contributes to tumor development via conventional CD4+ T cells.

Synthesis of P-Modified DNA from Boranophosphate DNA as a Precursor via Acyl Phosphite Intermediates.

In this study, we successfully synthesized several kinds of P-modified nucleic acids from boranophosphate DNAs via an acyl phosphite intermediate in solution and on a solid support. In the solution-phase synthesis, phosphorothioate diester, phosphotriester, and phosphoramidate diester were synthesized in a one-pot reaction from boranophosphodiester via the conversion of an acyl phosphite as a key intermediate. In addition, doubly P-modified nucleic acid derivatives which were difficult to synthesize by the phosphoramidite and H-phosphonate methods were also obtained by the conversion reaction. In the solid-phase synthesis, a boranophosphate derivative was synthesized on a solid support using the H-boranophosphonate method. Then, an acyl phosphite intermediate was formed by treatment with pivaloyl chloride in pyridine, followed by appropriate transformations to obtain the P-modified derivatives such as phosphotriester and phosphorothioate diester. Notably, it was suggested that the conversion reaction of a boranophosphate to a phosphorothioate diester proceeded with retention of the stereochemistry of the phosphorous center. In addition, a phosphorothioate/phosphate chimeric dodecamer was successfully synthesized from a boranophosphate/phosphate chimeric dodecamer using the same strategy. Therefore, boranophosphate derivatives are versatile precursors for the synthesis of P-modified DNA, including chimeric derivatives.

Low energy availability reduces bone mass and gonadal function in male mice.

INTRODUCTION: In women, the female athlete triad, marked by low energy availability, functional hypothalamic amenorrhea and osteoporosis, is a recognized risk for stress fractures. Stress injuries also occur in men, but by contrast risks and mechanisms underlying them are less characterized. MATERIALS AND METHODS: 5 week-old wild-type male mice were fed ad libitum (ad) or subjected to 60% food restriction (FR) for five weeks. In both groups, some mice were allowed access to an exercise wheel in cages to allow voluntary wheel running (ex) and/or treated with active vitamin D analogues. Mice were sacrificed and analyzed at 10 weeks of age. RESULT: Male FR mice exhibited significantly reduced testicle weight, serum testosterone levels and bone mass. Such bone losses in FR male mice were enhanced by exercise. Histological analysis revealed that both bone-resorbing and -forming activities were significantly reduced in FR or FR plus exercise (FR + ex) mice, mimicking a state of low bone turnover. Significantly reduced bone mass in FR or FR + ex male mice was significantly rescued by treatment with active vitamin D analogues, with significant restoration of osteoblastic activities. Serum levels of insulin-like growth factor I (IGF-I), which is critical for bone remodeling, were significantly lower in FR versus control male mice. CONCLUSIONS: Low energy availability puts men at risk for stress injuries as well, and low energy availability is upstream of gonadal dysfunction and osteoporosis in males. Active vitamin D analogues could serve as therapeutic or preventive options for stress injuries in men.

Development of a new synthetic method for oligodeoxynucleotides using 3'-H-phosphonamidate derivatives.

In this study, we developed a new approach for the solution-phase synthesis of oligodeoxynucleotides (ODNs) using nucleoside 3'-H-phosphonamidate derivatives as monomers. The H-phosphonamidate monomers having a heterocyclic amino group as the leaving group reacted with an alcohol to form an internucleotidic H-phosphonate diester under mild basic conditions without using additives. The resultant internucleotidic linkage was converted into a more stable linkage, such as an S-cyanoethyl phosphorothioate diester. Moreover, under the conditions for detritylation, the unreacted H-phosphonamidate monomer was converted into a water-soluble compound, which was easily removed by extraction. Thus, only simple extractions were required to purify intermediates, and the solution-phase synthesis of trithymidine diphosphorothioate from the monomer was achieved with only one silica gel column chromatography purification. This method was applied to deoxyadenosine, deoxycytidine, and deoxyguanosine derivatives. This strategy enables us to reduce the number of reagents and simplify the purification process.

Solid-phase synthesis of oligodeoxynucleotides using nucleobase N-unprotected oxazaphospholidine derivatives bearing a long alkyl chain.

In this study, we developed a new approach for the solid-phase synthesis of oligodeoxynucleotides (ODNs) using nucleobase-unprotected oxazaphospholidine derivatives. We tackled the problem of the difficult purification of N-unprotected monomers due to their high affinity to silica gel by introducing a tetrahydrogeranyl group into the oxazaphospholidine monomers, thereby enhancing the lipophilicity and facilitating the isolation. In addition, the cyclic structure of oxazaphospholidine enabled a hydroxy-group-selective condensation with sufficient efficiency. Unmodified and boranophosphate/phosphate chimeric ODNs were successfully synthesized using this strategy. This synthetic method can be expected to afford ODNs containing base-labile functional groups.

Care needs of Japanese men for sexual dysfunction associated with prostate cancer treatment.

PURPOSE: Prostate cancer (PC) treatment causes sexual dysfunction (SD) and alters fertility, male identity, and intimate relationships with partners. In Japan, little attention has been paid to the importance of providing care for SD associated with PC treatment. This study is aimed at clarifying the care needs of Japanese men regarding SD associated with PC treatment. METHODS: One-to-one semi-structured interviews were conducted with 44 PC patients to identify their care needs. Data were analyzed using thematic analysis. RESULTS: Four core categories emerged from the analysis. (1) "Need for empathy from medical staff regarding fear of SD": patients had difficulty confiding in others about their sexual problems, and medical staff involvement in their SD issues was lacking. (2) "Need for information that provides an accurate understanding of SD and coping strategies before deciding on treatment": lack of information about SD in daily life and difficulty understanding information from medical institutions, caused men to regret their treatment. (3) "Need for professional care for individuals and couples affected by SD": men faced loss of intimacy because of their partners' unwillingness to understand their SD issues or tolerate non-sexual relationships. (4) "Need for an environment that facilitates interaction among men to resolve SD issues": men felt lonely and wanted to interact with other patients about their SD concerns. CONCLUSION: These findings may help form care strategies tailored to these needs and applicable to other societies with strong traditional gender norms.

The effect of palliative care team intervention and symptom improvement using patient-reported outcomes: a multicenter prospective observational study.

PURPOSE: Hospital-based palliative care teams (HPCTs) are widespread internationally, but multicenter studies about their effectiveness, using patient-reported outcomes (PROs), are limited to Australia and a few other countries. We conducted a multicenter, prospective observational study in Japan to explore the effectiveness of the HPCTs using PROs. METHODS: Nationwide, eight hospitals participated in the study. We included newly referred patients for one month in 2021 and followed them for one month. We asked the patients to complete the Integrated Palliative Care Outcome Scale or the Edmonton Symptom Assessment System as PROs at the time of the intervention, three days later, and weekly after the intervention. RESULTS: A total of 318 participants were enrolled, of whom 86% were patients with cancer, 56% were undergoing cancer treatment, and 20% received the Best Supportive Care. After one week, the following 12 symptoms showed more than a 60% improvement from severe to moderate or less: vomiting (100%), shortness of breath (86%), nausea (83%), practical problems (80%), drowsiness (76%), pain (72%), poor sharing of feelings with family or friends (72%), weakness (71%), constipation (69%), not feeling at peace (64%), lack of information (63%), and sore or dry mouth (61%). Symptoms with improvement from severe/moderate to mild or less were vomiting (71%) and practical problems (68%). CONCLUSION: This multicenter study showed that HPCTs effectively improved symptoms in several severe conditions, as assessed by PROs. This study also demonstrated the difficulty of relieving symptoms in patients in palliative care and the need for improved care.

Web-Based Post-Bereavement Survey System in Specialized Palliative Care: A Feasibility Pilot Study.

Web-based post-bereavement survey systems for specialized palliative care will enable obtaining timely results on the care quality from more participants at a lower cost. The primary aim of the study was to develop a web-based post-bereavement survey system and to compare response rates for different number of items. The secondary aim was to examine response bias between web-based and mail survey in post-bereavement surveys. Between January and April 2019, two cross-sectional web-based questionnaire surveys were conducted among the bereaved families from six inpatient palliative care units in Japan. Measurements included structure and process of end-of-life (EOL) care, overall care satisfaction, achievement of a good death, depression, grief status, web survey usability, and participant and bereaved family member characteristics. The long survey included 34 items, and the short survey included 16 items. There were no significant differences in the response rates between the long and short surveys (24% and 27%, respectively, p = 0.376). Compared with a previous nationwide post-bereavement mail survey, more children responded; however, the quality rating scores was unchanged. Despite low response rate, no apparent response bias was observed, indicating its feasibility. This survey method is low-cost, less burdensome to the institution, and allows for ongoing quality assurance.

Analysis of Acetylated Hyaluronic Acid in Moisturizing Lotion and Milk Lotion by HPLC with Fluorescence Detection.

We developed a simple and sensitive analytical HPLC method for the determination of acetylated hyaluronic acid (AcHA) in moisturizing and milk lotions. AcHA with different molecular weights was separated as a single peak using a C4 column and detected through post-column derivatization using 2-cyanoacetamide. The limits of detection and quantification were 60 and 200 ng, respectively. We found that AcHA in water was successfully extracted into a strong anion exchange (SAX) spin column with a recovery rate of AcHA was 63.8 ± 1.8%. Although the supernatant from acetone precipitation of lotions could pass through the spin column, the recovery rate (%) and accuracy of AcHA were affected by the viscous properties of cosmetics and acidic and acetone-soluble ingredients. Upon conducting analytical methods in this study, the concentration of AcHA in nine lotions was found to have ranged from 7.50 to 83.3 µg/mL. These values are comparable to the concentration range of AcHA in emulsions that have been previously evaluated for their superior effects. We believe that the analytical and extraction method is useful for the qualitative analysis of AcHA in moisturizing and milk lotions.

Excision of the hook of hamate in athletes using the carpal tunnel approach.

BACKGROUND: Hook of the hamate fractures can be managed conservatively or fixed using a screw, but excision is recommended for prompt return to activities. Although various approaches have been described, there is no gold standard. Herein, the authors have described their clinical experiences in excising the hook of the hamate using the carpal tunnel approach, in athletes. METHODS: A total of 36 athletes underwent excision of the hamate hook using the carpal tunnel approach. The mean age of the patients was 23 years, and most of them were baseball players (n = 31). RESULTS: The mean operation time was 33 min. None of the patients presented with any complications aside from transient pillar pain in five cases. All of them returned to their sports activities within an average of 27 days. CONCLUSIONS: In our study, excision of the hook of the hamate was performed safely via the carpal tunnel. The carpal tunnel approach reportedly provides superior benefits over other approaches.

Japanese version of the Patient-rated elbow evaluation score correlates with physician-rated Japanese orthopaedic association-Japan elbow society elbow function score.

BACKGROUND: The association between Patient-Rated Elbow Evaluation: Japanese version (PREE-J) and Japanese Orthopaedic Association-Japan Elbow Society Elbow Function score (JOA-JES score) is unclear. This study evaluated the association between PREE-J and JOA-JES scores. METHODS: The patients with elbow disorders were divided into two groups: Group A (conservative treatment, n = 97) and Group B (surgical treatment, n = 156). The patients were also divided into four disease subgroups according to the JOA-JES classification (rheumatoid arthritis, trauma, sports, and epicondylitis groups), and the association between PREE-J and JOA-JES scores in each disease category was examined. In group B, associations between PREE-J and JOA-JES scores were examined pre-and postoperatively. RESULTS: In group A, there were significant associations between PREE-J and JOA-JES scores. In group B, a strong association between preoperative PREE-J and JOA-JES scores was observed in all disease categories. There was also a significant association between postoperative PREE-J and JOA-JES scores. Additionally, group B showed significant postoperative improvements in PREE-J and JOA-JES scores. CONCLUSIONS: The PREE-J score correlates well with the JOA-JES score and reflects treatment response before and after treatment.

Combination therapy with remdesivir and immunomodulators improves respiratory status in COVID-19: A retrospective study.

Immunomodulators (tocilizumab/baricitinib) improve outcomes of coronavirus disease 2019 (COVID-19) patients, but the synergistic effect of remdesivir is unknown. The effect of combination therapy with remdesivir, immunomodulators, and standard treatment in COVID-19 patients was investigated. This retrospective, single-center study included COVID-19 patients who were treated with tocilizumab or baricitinib. The severity of respiratory status in the two groups on Days 14 and 28 and the duration to respiratory recovery in both groups were compared, and the effect of remdesivir use on respiratory status was examined in a multivariate analysis. Ninety-eight patients received tocilizumab or baricitinib; among them, 72 used remdesivir (remdesivir group) and 26 did not (control group). The remdesivir group achieved faster respiratory recovery than the control group (median 11 vs. 21 days, p = 0.033), faster weaning from supplemental oxygen (hazard ratio [HR]: 2.54, 95% confidence interval [CI]: 1.14-5.66, p = 0.021). Age, body mass index, diabetes mellitus, and time from onset to oxygen administration were independent prognostic factors. The remdesivir group achieved better severity level at Days 14 and 28 (p = 0.033 and 0.003, respectively) and greater improvement from baseline severity (p = 0.047 and 0.018, respectively). Remdesivir combination therapy did not prolong survival (HR: 0.31, 95% CI: 0.04-2.16, p = 0.23). Among severely ill COVID-19 patients who received immunomodulator, remdesivir contributed to a shorter respiratory recovery time and better respiratory status at Days 14 and 28. Concomitant remdesivir with immunomodulators and standard treatment may provide additional benefit in improving respiratory status of COVID-19 patients.

Impact of end-of-life respiratory modalities on quality of dying and death and symptom relief in patients with interstitial lung disease: a multicenter descriptive cross-sectional study.

BACKGROUND: Respiratory modalities applied at the end of life may affect the burden of distressing symptoms and quality of dying and death (QODD) among patients with end-stage interstitial lung disease (ILD); however, there have been few studies into respiratory modalities applied to these patients near death. We hypothesized that high-flow nasal cannula (HFNC) might contribute to improved QODD and symptom relief in patients with end-stage ILD. OBJECTIVES: This multicenter study examined the proportion of end-of-life respiratory modalities in a hospital setting and explored its impact on QODD and symptom relief among patients dying with ILD. METHODS: Consecutive patients with ILD who died in four participating hospitals in Japan from 2015 to 2019 were identified and divided into four groups according to end-of-life respiratory modality: conventional oxygen therapy (COT), HFNC, non-invasive ventilation (NIV), and invasive mechanical ventilation (IMV). In addition, a mail survey was performed to quantify the QODD and symptom relief at their end of life from a bereaved family's perspective. QODD and symptom relief were quantified using the Good Death Inventory (GDI) for patients with a completed bereavement survey. The impact of end-of-life respiratory modalities on QODD and symptom relief was measured by multivariable linear regression using COT as a reference. RESULTS: Among 177 patients analyzed for end-of-life respiratory modalities, 80 had a completed bereavement survey. The most common end-of-life respiratory modality was HFNC (n = 76, 42.9%), followed by COT (n = 62, 35.0%), NIV (n = 27, 15.3%), and IMV (n = 12, 6.8%). Regarding the place of death, 98.7% of patients treated with HFNC died outside the intensive care unit. Multivariable regression analyses revealed patients treated with HFNC had a higher GDI score for QODD [partial regression coefficient (B) = 0.46, 95% CI 0.07-0.86] and domain score related to symptom relief (B = 1.37, 95% CI 0.54-2.20) than those treated with COT. CONCLUSION: HFNC was commonly used in patients with end-stage ILD who died in the hospital and was associated with higher bereaved family ratings of QODD and symptom relief. HFNC might contribute to improved QODD and symptom relief in these patients who die in a hospital setting.