Familial pulmonary alveolar proteinosis caused by mutations in CSF2RA

Primary pulmonary alveolar proteinosis (PAP) is a rare syndrome characterized by accumulation of surfactant in the lungs that is presumed to be mediated by disruption of granulocyte/macrophage colony-stimulating factor (GM-CSF) signaling based on studies in genetically modified mice. The effects of GM-CSF are mediated by heterologous receptors composed of GM-CSF binding (GM-CSF-Rα) and nonbinding affinity-enhancing (GM-CSF-Rβ) subunits. We describe PAP, failure to thrive, and increased GM-CSF levels in two sisters aged 6 and 8 yr with abnormalities of both GM-CSF-Rα–encoding alleles (CSF2RA). One was a 1.6-Mb deletion in the pseudoautosomal region of one maternal X chromosome encompassing CSF2RA. The other, a point mutation in the paternal X chromosome allele encoding a G174R substitution, altered an N-linked glycosylation site within the cytokine binding domain and glycosylation of GM-CSF-Rα, severely reducing GM-CSF binding, receptor signaling, and GM-CSF–dependent functions in primary myeloid cells. Transfection of cloned cDNAs faithfully reproduced the signaling defect at physiological GM-CSF concentrations. Interestingly, at high GM-CSF concentrations similar to those observed in the index patient, signaling was partially rescued, thereby providing a molecular explanation for the slow progression of disease in these children. These results establish that GM-CSF signaling is critical for surfactant homeostasis in humans and demonstrate that mutations in CSF2RA cause familial PAP

DOCK2 is involved in the host genetics and biology of severe COVID-19

「コロナ制圧タスクフォース」COVID-19疾患感受性遺伝子DOCK2の重症化機序を解明 --アジア最大のバイオレポジトリーでCOVID-19の治療標的を発見--. 京都大学プレスリリース. 2022-08-10.Identifying the host genetic factors underlying severe COVID-19 is an emerging challenge. Here we conducted a genome-wide association study (GWAS) involving 2, 393 cases of COVID-19 in a cohort of Japanese individuals collected during the initial waves of the pandemic, with 3, 289 unaffected controls. We identified a variant on chromosome 5 at 5q35 (rs60200309-A), close to the dedicator of cytokinesis 2 gene (DOCK2), which was associated with severe COVID-19 in patients less than 65 years of age. This risk allele was prevalent in East Asian individuals but rare in Europeans, highlighting the value of genome-wide association studies in non-European populations. RNA-sequencing analysis of 473 bulk peripheral blood samples identified decreased expression of DOCK2 associated with the risk allele in these younger patients. DOCK2 expression was suppressed in patients with severe cases of COVID-19. Single-cell RNA-sequencing analysis (n = 61 individuals) identified cell-type-specific downregulation of DOCK2 and a COVID-19-specific decreasing effect of the risk allele on DOCK2 expression in non-classical monocytes. Immunohistochemistry of lung specimens from patients with severe COVID-19 pneumonia showed suppressed DOCK2 expression. Moreover, inhibition of DOCK2 function with CPYPP increased the severity of pneumonia in a Syrian hamster model of SARS-CoV-2 infection, characterized by weight loss, lung oedema, enhanced viral loads, impaired macrophage recruitment and dysregulated type I interferon responses. We conclude that DOCK2 has an important role in the host immune response to SARS-CoV-2 infection and the development of severe COVID-19, and could be further explored as a potential biomarker and/or therapeutic target

Disseminated Mycobacterium genavense Infection in Patient with Adult-Onset Immunodeficiency

We report a case of disseminated Mycobacterium genavense infection resulting from neutralizing anti–interferon-γ autoantibodies in the patient. We identified M. genavense targeting the hsp65 gene in an aspiration specimen of the lymph node. Adult-onset immunodeficiency caused by neutralizing anti–interferon-γ autoantibodies, in addition to HIV infection, can lead to disseminated nontuberculous mycobacterial infection

The ROX index (Index combining the respiratory rate with oxygenation) is a prognostic factor for acute respiratory distress syndrome.

BackgroundThere is no existing reliable and practical method for predicting the prognosis of acute respiratory distress syndrome (ARDS).ObjectiveWe aimed to clarify the association between the ROX index, which is calculated as the ratio of peripheral oxygen saturation divided by the fraction of inspired oxygen to the respiratory rate, and the prognosis of patients with ARDS under ventilator support.MethodsIn this single-center retrospective cohort study from prospectively collected database, eligible patients were categorized into three groups based on ROX tertiles. The primary outcome was the 28-day survival, and the secondary outcome was 28-day liberation from ventilator support. We performed multivariable analysis using the Cox proportional hazards model.ResultsAmong 93 eligible patients, 24 (26%) patients died. The patients were divided into three groups according to the ROX index (ConclusionsThe ROX index at 24 h after initiating ventilator support is a predictor of outcomes in patients with ARDS and might inform initiation of more advanced treatments

Incidence of autoimmune pulmonary alveolar proteinosis estimated using Poisson distribution

The incidence and prevalence of autoimmune pulmonary alveolar proteinosis in Japan were previously estimated to be 0.49 and 6.2 per million, respectively. Thereafter, an increase in serological diagnosis forced a re-estimation of the incidence based on more contemporaneous data using more robust methods. Sera of 702 patients were positive for granulocyte-macrophage colony-stimulating factor autoantibody during the 2006–2016 period (group A). Of these patients, 43 were actively surveyed in Niigata prefecture (group B) for estimation of the incidence. To estimate the survival period, 103 patients (group C) were investigated retrospectively for the 1999–2017 period using restricted mean survival time. In group A, the number of patients diagnosed in each prefecture was closely correlated with the corresponding population, indicating no regional integration of onset. In group B, a total of 43 patients were diagnosed, the annual number followed a Poisson distribution and the incidence was thus estimated to be 1.65 per million. In group C, the retrospective cohort study revealed the mean survival period to be 16.1 years. Taken together, the prevalence was estimated to be 26.6 per million, indicating that the previous data for incidence and prevalence was an underestimation

Aging-associated and CD4 T-cell–dependent ectopic CXCL13 activation predisposes to anti–PD-1 therapy-induced adverse events

がん免疫療法の副反応による臓器傷害の原因解明に新たな一歩 --がんに対する免疫応答と、有害事象に関わる免疫応答の違い--. 京都大学プレスリリース. 2022-07-13.Clinical success of immune-checkpoint blockade (ICB) cancer immunotherapy is compromised by increased risk of immune-related adverse events (irAEs). However, mechanistic action(s) of immune responses underlying development of irAE remain not fully explored. Here, we found that in tumor-bearing aged, but not young, mice, antiprogrammed death receptor (PD)-1 therapy elicited irAE-like multiorgan dysfunctions with ectopic accumulation of T and B cells in damaged organs. In this preclinical model, the organ toxicities were mediated by immunoglobulin G (IgG) deposition because administration of IG from ICB-treated aged mice induced the pathogenicity specifically in naïve aged hosts. Mechanistically, CD4 T-cell–derived interleukin (IL)-21 upregulated B-cell–homing chemokine, CXCL13, preferentially in irAE organs from aged mice treated with anti–PD-1 therapy. The ICB-induced pathogenicity was alleviated by B-cell depletion or by blockade of IL-21 or CXCL13 activity. These results suggest that age-associated immune regulatory milieu contributes to the formation of tertiary lymphoid structure-like lymphocytic aggregates in irAE organs and irAE-related toxicity employing IL-21-CXCL13-auto-antibody axis. Supporting this, a systemic increase in CXCL13 and Il21 expression in CD4 T cells correlated with irAE incidence in ICB-treated patients. These findings provide rationale for therapeutic usefulness of CXCL13 in irAE management

The impact of factor Xa inhibitors on bleeding risk in patients with respiratory diseases

Abstract It is unclear which factor Xa (FXa) inhibitors are associated with higher bleeding risk in patients with respiratory diseases, and there are no studies on the association between prothrombin time–international normalized ratio (PT–INR) and bleeding risk. We conducted a retrospective cohort study comparing 1-year-outcomes and PT–INR between patients with respiratory diseases treated with rivaroxaban (R group, n = 82) or edoxaban (E group, n = 138) for atrial fibrillation or venous thromboembolism from 2013 to 2021. The most frequent event of all bleeding discontinuations was respiratory bleeding in both groups (7.3 and 4.3%, respectively). The cumulative incidence of bleeding discontinuation was significantly higher in the R group (25.6%) than in the E group (14.4%) (hazard ratio [HR], 2.29; 95% confidence interval [CI] 1.13–4.64; P = 0.023). PT–INR after initiation of therapy significantly increased and was higher in the R group than in the E group (median value, 1.4 and 1.2, respectively; P < 0.001). Multivariate analysis using Cox proportional hazards and Fine-Gray models revealed that PT–INR after initiation of therapy was an independent risk factor of bleeding discontinuation events (HR = 4.37, 95% CI 2.57–7.41: P < 0.001). Respiratory bleeding occasionally occurs in patients receiving FXa inhibitors, and monitoring the PT–INR may need to ensure safety

Analysis of Perimenstrual Asthma Based on Questionnaire Surveys in Japan

Background: Perimenstrual asthma (PMA) has been documented in 30% to 40% of asthmatic women; the characteristics of PMA have also been well described. However, there have been few epidemiological investigations of PMA in practice. In this study, we analyzed PMA based on a questionnaire survey carried out in Japan and compared the results with those of studies reported previously. Methods: For 8 weeks from September through October 2004, a questionnaire survey was administered to patients with bronchial asthma and their attending physicians. The questionnaire surveyed asthma control, asthma-related emergencies and satisfaction in daily life. The attending physicians were questioned about patient profiles and medications. All female patients who were menstruating during the survey period and who were known to have asthma exacerbation related to menstruation were allocated to the PMA group; those who were not were allocated to the non-PMA group. Results: The rate of PMA in female patients who were menstruating during the survey period was 11.3% in this study. Characteristic features of the PMA group (n = 54) included more severe disease, worsened disease control and more aggressive patient management, including increased oral corticosteroid use compared with the non-PMA group. The rates of emergency episodes in the PMA group were higher than in the non-PMA group. There was a significant increase in aspirin intolerant asthma (AIA, 25.5%) in the PMA group compared with the non-PMA group (8.4%). Conclusions: Attention should be paid to the lack of knowledge regarding PMA in patients with asthma in actual clinical settings. The low rate of PMA reported in this study may be due to the study method using self- reports of PMA by patients without sufficient knowledge, and may not be an accurate representation of the actual incidence of the disease. The clinical similarity of PMA to AIA in this study may also provide a new insight into the mechanism of PMA