IL-18 receptor-α signalling pathway contributes to autoantibody-induced arthritis via neutrophil recruitment and mast cell activation.

OBJECTIVES: The interleukin (IL)-18 signalling pathway is involved in animal models of collagen-induced arthritis, but the role of this pathway in autoantibody-induced arthritis is poorly understood. An autoantibody-induced arthritis model, K/BxN serum transfer arthritis, reflects the effector phase of arthritis and is important in innate immunity including neutrophils and mast cells. This study aimed to investigate the role of the IL-18 signalling pathway in autoantibody-induced arthritis using IL-18 receptor (IL-18R) α-deficient mice. METHODS: K/BxN serum transfer arthritis was induced in IL-18Rα-/- and wild-type B6 (controls) mice. The severity of arthritis was graded, and histological and immunohistochemical examinations were performed on paraffin-embedded ankle sections. Total Ribonucleic acid (RNA) isolated from mouse ankle joints was analysed by real-time reverse transcriptase-polymerase chain reaction. RESULTS: IL-18 Rα-/- mice had significantly lower arthritis clinical scores, neutrophil infiltration, and numbers of activated, degranulated mast cells in the arthritic synovium than in controls. IL-1ß, which is indispensable for the progression of arthritis, was significantly downregulated in inflamed ankle tissue in IL-18 Rα-/- mice. CONCLUSIONS: IL-18/IL-18Rα signalling contributes to the development of autoantibody-induced arthritis by enhancing synovial tissue expression of IL-1ß and inducing neutrophil recruitment and mast cell activation. Therefore, inhibition of the IL-18Rα signalling pathway might be a new therapeutic strategy for rheumatoid arthritis.

Examination of Prognostic Factors in Anti-Melanoma Differentiation-Associated Gene 5 Antibody-Positive Dermatomyositis.

OBJECTIVE: This study investigated the prognostic factors of anti-melanoma differentiation-associated gene 5 antibody-positive dermatomyositis (MDA5-DM). METHODS: This study analysed 34 MDA5-DM cases (20 and 14 in the survival and death groups, respectively) encountered at Kurume University between 2008 and 2021. The clinical, physiological, and computed tomography findings, pulmonary function, and serological results were retrospectively evaluated for each MDA5-DM case during the first visit and throughout the next 12 weeks. RESULTS: In the death group, the mean age of patients was higher (47.6 vs. 61.8 years), while the duration from symptom onset to consultation was shorter (110 vs. 34.9 days). During the first visit, the death group demonstrated a significantly higher serum C-reactive protein (CRP) level (0.52 vs. 1.99) and a significantly lower albumin level (3.23 vs. 2.63) than the survival group; this persisted throughout the next 12 weeks. Poor prognosis was associated with CRP and albumin levels above 0.19 mg/dL and below 2.3 g/dL, respectively, 4 weeks after starting treatment. CONCLUSION: Four weeks after beginning treatment, serum CRP and albumin levels of patients with MDA5-DM can be used to evaluate treatment response and predict prognosis.

Enhanced immune complex formation in the lungs of patients with dermatomyositis.

BACKGROUND: Interstitial lung disease is frequently comorbid with dermatomyositis and has a poor prognosis, especially in patients with the anti-melanoma differentiation-associated gene 5 (MDA5) autoantibody. However, the pathogenesis of dermatomyositis-related interstitial lung disease remains unclear. METHODS: We examined 18 and 19 patients with dermatomyositis-related interstitial lung disease and idiopathic pulmonary fibrosis (control), respectively. Lung tissues obtained from these patients were semi-quantitatively evaluated by immunohistochemical staining with in-house anti-human MDA5 monoclonal antibodies, as well as anti-human immunoglobulin (Ig) G, IgM, IgA, and complement component 3(C3) antibodies. We established human MDA5 transgenic mice and treated them with rabbit anti-human MDA5 polyclonal antibodies, and evaluated lung injury and Ig and C3 expression. RESULTS: MDA5 was moderately or strongly expressed in the lungs of patients in both groups, with no significant differences between the groups. However, patients with dermatomyositis-related interstitial lung disease showed significantly stronger expression of C3 (p < 0.001), IgG (p < 0.001), and IgM (p = 0.001) in the lungs than control. Moreover, lung C3, but IgG, IgA, nor IgM expression was significantly stronger in MDA5 autoantibody-positive dermatomyositis-related interstitial lung disease (n = 9) than in MDA5 autoantibody-negative dermatomyositis-related interstitial lung disease (n = 9; p = 0.022). Treatment with anti-MDA5 antibodies induced lung injury in MDA5 transgenic mice, and strong immunoglobulin and C3 expression was observed in the lungs of the mice. CONCLUSION: Strong immunoglobulin and C3 expression in the lungs involve lung injury related to dermatomyositis-related interstitial lung disease. Enhanced immune complex formation in the lungs may contribute to the poor prognosis of MDA5 autoantibody-positive dermatomyositis-related interstitial lung disease.

Clinical significance of high monocyte counts for the continuous treatment with nintedanib.

BACKGROUND: Nintedanib is now widely used to treat interstitial lung disease (ILD). Adverse events, which occur in not a few patients, make it difficult to continue nintedanib treatment, but the risk factors for adverse events are not well understood. METHODS: In this retrospective cohort study, we enrolled 111 patients with ILDs treated with nintedanib and investigated the factors involved in starting dosage reduction, withdrawal, or discontinuation within 12 months, even with appropriate symptomatic treatment. We also examined the efficacy of nintedanib in reducing the frequency of acute exacerbations and the prevention of pulmonary function reduction. RESULTS: Patients with high monocyte counts (> 0.454 × 109/L) had a significantly higher frequency of treatment failure, such as dosage reduction, withdrawal, or discontinuation. High monocyte count was as significant a risk factor as body surface area (BSA). Regarding efficacy, there was no difference in the frequency of acute exacerbations or the amount of decline in pulmonary function within 12 months between the normal (300 mg) and reduced (200 mg) starting dosage groups. CONCLUSION: Our study results indicate that patients with higher monocyte counts (> 0.454 × 109/L) should very careful about side effects with regard to nintedanib administration. Like BSA, a higher monocyte count is considered a risk factor for nintedanib treatment failure. There was no difference in FVC decline and frequency of acute exacerbations between the starting doseage of nintedanib, 300 mg and 200 mg. Considering the risk of withdrawal periods and discontinuation, a reduced starting dosage may be acceptable in the patients with higher monocyte counts or small body sizes.

A Cluster of Paragonimiasis with Delayed Diagnosis Due to Difficulty Distinguishing Symptoms from Post-COVID-19 Respiratory Symptoms: A Report of Five Cases.

Paragonimiasis caused by trematodes belonging to the genus Paragonimus is often accompanied by chronic respiratory symptoms such as cough, the accumulation of sputum, hemoptysis, and chest pain. Prolonged symptoms, including respiratory symptoms, after coronavirus disease 2019 infection (COVID-19) are collectively called post-COVID-19 conditions. Paragonimiasis and COVID-19 may cause similar respiratory symptoms. We encountered five cases of paragonimiasis in patients in Japan for whom diagnoses were delayed due to the initial characterization of the respiratory symptoms as a post-COVID-19 condition. The patients had consumed homemade drunken freshwater crabs together. One to three weeks after consuming the crabs, four of the five patients were diagnosed with probable COVID-19. The major symptoms reported included cough, dyspnea, and chest pain. The major imaging findings were pleural effusion, pneumothorax, and nodular lesions of the lung. All the patients were diagnosed with paragonimiasis based on a serum antibody test and peripheral blood eosinophilia (560-15,610 cells/µL) and were treated successfully with 75 mg/kg/day praziquantel for 3 days. Before diagnosing a post-COVID-19 condition, it is necessary to consider whether other diseases, including paragonimiasis, may explain the symptoms. Further, chest radiographic or blood tests should be performed in patients with persistent respiratory symptoms after being infected with COVID-19 to avoid overlooking the possibility of infection.

Successful Treatment of a Patient with Drug-Refractory Rheumatoid Arthritis-Associated Interstitial Lung Disease with Upadacitinib: A Case Report.

Insufficient evidence exists regarding the efficacy of Janus kinase inhibitors (JAKis), a class of targeted synthetic disease-modifying anti-rheumatic drugs (tsDMARDs), in the treatment of rheumatoid arthritis (RA)-associated interstitial lung disease (ILD). Herein, we present a case of RA-ILD refractory to previous treatments that exhibited favorable response to upadacitinib. A 69-year-old man, former smoker, was diagnosed with RA-ILD based on persistent symmetric polyarthritis, elevated C-reactive protein levels and erythrocyte sedimentation rate, reduced diffusing capacity for carbon monoxide/alveolar volume (DLCO 69.9%), and bilateral ground-glass attenuation with traction bronchiectasis, predominantly in the lower lung lobe. Initial treatment with oral prednisolone and methotrexate was started; however, the patient showed worsening dyspnea, chest high-resolution computed tomography abnormalities, and decreased pulmonary function. The dose of prednisolone was increased, and methotrexate was shifted to tacrolimus; however, tacrolimus was eventually discontinued because of renal dysfunction. Subsequent treatment changes included abatacept followed by intravenous cyclophosphamide, but ILD activity continued to worsen and met the criteria of progressive pulmonary fibrosis. Approximately 4.5 years after the RA diagnosis, dyspnea, radiological abnormalities, and DLCO improved following treatment switch to upadacitinib, one of JAKis. JAKi therapy may have potential as a treatment option for refractory RA-ILD.

Cicatricial organising pneumonia associated with fibrosing interstitial pneumonia - a clinicopathological study.

AIMS: The recent recognition of cicatricial organising pneumonia (ciOP) indicates that the ciOP may resemble or simulate fibrotic interstitial pneumonia; however, there has been great uncertainty regarding the affected populations, pathogenesis, clinical relevance and characteristics. In this study, we compared the characteristics of fibrotic interstitial pneumonia with and without ciOP. METHODS AND RESULTS: We enrolled 121 patients from the consultation archive whose pathological findings were fibrotic interstitial pneumonia and for whom follow-up clinical data were available. We reviewed these cases histopathologically and classified them according to whether or not they showed ciOP. We compared the clinicopathological features between the two groups. CiOP, histopathologically characterised by deposition of dense collagenous fibres within the alveolar space without destruction of the lung structure, was found in 48 patients (39.7%). None of the cases with ciOP experienced acute exacerbation during 12 months' follow-up. The group with ciOP had more severe diffusion impairment but this, together with restrictive ventilatory impairment, improved significantly compared to the group without ciOP. CONCLUSION: CiOP is a histopathological finding commonly found in fibrotic interstitial pneumonia. It does not relate to acute exacerbation or decrease in pulmonary function.

Airway hyperresponsiveness and inflammation in Japanese patients with human immunodeficiency virus 1 infection.

INTRODUCTION: Despite the growing population of long-term survivors with human immunodeficiency virus 1 (HIV) exhibiting asthma-like features worldwide, the pathogenesis underlying airway hyperresponsiveness (AHR) and airway inflammation remains unclear. We aimed to investigate AHR and airway inflammation in an HIV-infected Japanese population. METHODS: Of 94 Japanese participants, 10 HIV-infected participants with asthma were excluded from the study. We compared the characteristics of HIV-infected (n = 34) and non-HIV-infected participants (n = 50). Eosinophilic, neutrophilic, mixed (eosinophilic and neutrophilic), and paucigranulocytic airway inflammatory phenotypes were classified based on induced sputum characteristics. RESULTS: The prevalence of AHR in HIV-infected participants (32.4%) was significantly higher than that in their non-HIV-infected counterparts (10.0%) (P = 0.0213). The multivariate nominal logistic regression analysis revealed HIV as an independent risk factor for AHR. HIV-infected participants were significantly more likely to have a neutrophilic airway inflammatory phenotype than non-HIV-infected participants (P = 0.0358). Furthermore, HIV-infected participants with AHR demonstrated a significant correlation between AHR levels and the percentage of sputum neutrophils (r = -0.65, P = 0.0316). The percentage of sputum neutrophils was negatively associated with the blood CD4 cell count (r = -0.66, P = 0.0266). CONCLUSIONS: We observed the high prevalence of AHR and neutrophilic airway inflammatory phenotype in Japanese participants with stable HIV infection. Our findings provide insight into the mechanisms of AHR and may facilitate the development of novel treatment for individuals with AHR and HIV infection.

The anti-inflammatory and protective role of interleukin-38 in inflammatory bowel disease.

Interleukin (IL)-38 exerts an anti-inflammatory function by binding to several cytokine receptors, including the IL-36 receptor. In this study, we evaluated IL-38 expression in the inflamed mucosa of patients with inflammatory bowel disease (IBD) and investigated its functions. IL-38 mRNA expression in endoscopic biopsy samples was evaluated using quantitative PCR. IL-38 protein expression was analyzed using immunohistochemical technique. Dextran sulfate sodium-induced colitis was induced in C57BL/6 background IL-38KO mice. The IL-38 mRNA and protein expression were enhanced in the active mucosa of ulcerative colitis, but not in Crohn's disease. The ratio of IL-36γ to IL-38 mRNA expression was significantly elevated in the active mucosa of UC patients. Immunofluorescence staining revealed that B cells are the major cellular source of IL-38 in the colonic mucosa. IL-38 dose-dependently suppressed the IL-36γ-induced mRNA expression of CXC chemokines (CXCL1, CXCL2, and CXCL8) in HT-29 and T84 cells. IL-38 inhibited the IL-36γ-induced activation of nuclear-factor kappa B (NF-κB) and mitogen-activated protein kinases in HT-29 cells. DSS-colitis was significantly exacerbated in IL-38KO mice compared to wild type mice. In conclusion, IL-38 may play an anti-inflammatory and protective role in the pathophysiology of IBD, in particular ulcerative colitis, through the suppression of IL-36-induced inflammatory responses.

Mast cells can produce transforming growth factor ß1 and promote tissue fibrosis during the development of Sjögren's syndrome-related sialadenitis.

OBJECTIVES: This study investigated the associations of mast cells with immune-mediated inflammation and fibrosis in patients with primary Sjögren's syndrome (pSS); it also explored the underlying pathophysiology of pSS-related sialadenitis. METHODS: Twenty-two patients with pSS and 10 patients with sicca (control individuals) underwent labial salivary gland biopsies. Sections were subjected to staining and immunofluorescence analyses. HMC-1 human mast cells were cocultured with fibroblasts in vitro; fibroblasts were also grown in HMC-1 conditioned medium. mRNA levels of collagen Type I (Col1a) and transforming growth factor (TGF)ß1 were analysed in cultured cells. RESULTS: Mast cell numbers in labial salivary glands were significantly greater in patients with pSS than in control individuals. In salivary glands from patients with pSS, mast cell number was significantly correlated with fibrosis extent; moreover, mast cells were located near fibrous tissue and expressed TGFß1. Col1a and TGFß1 mRNAs were upregulated in cocultured fibroblasts and HMC-1 cells, respectively. Fibroblasts cultured in HMC-1 conditioned medium exhibited upregulation of Col1a mRNA; this was abrogated by TGFß1 neutralizing antibodies. CONCLUSIONS: Mast cell numbers were elevated in patients with pSS-related sialadenitis; these cells were located near fibroblasts and expressed TGFß1. TGFß1 could induce collagen synthesis in fibroblasts, which might contribute to fibrosis.

Clinical significance of peripheral TCR and BCR repertoire diversity in EGFR/ALK wild-type NSCLC treated with anti-PD-1 antibody.

INTRODUCTION: TCR and BCR repertoire diversity plays a critical role in tumor immunity. Thus, analysis of TCR and BCR repertoires might help predict the clinical efficacy of anti-PD-1 treatment. METHODS: Blood samples from 30 patients with non-small cell lung cancer (NSCLC) treated with anti-PD-1 antibody were collected before and six weeks after treatment initiation. The clinical significance of TCR and BCR repertoire diversity in peripheral blood was evaluated in all the enrolled patients (n = 30) or in the subset with (n = 10) or without (n = 20) EGFR/ALK mutation. RESULTS: TCR and BCR diversity was significantly correlated at baseline (R = 0.65; P = 1.6 × 10-4) and on treatment (R = 0.72; P = 1.2 × 10-5). Compared to non-responders (SD or PD), responders (PR) showed significantly decreased TCR and BCR diversity after treatment in the EGFR/ALK wild-type subset (P = 0.0014 and P = 0.034, respectively), but not in all the enrolled patients. The post-treatment reduction in TCR and BCR repertoire diversity was also significantly associated with the occurrence of adverse events in the EGFR/ALK wild-type subset (P = 0.022 and P = 0.014, respectively). Patients with more reduced TCR diversity showed better progression-free survival (PFS) in the EGFR/ALK wild-type subset (P = 0.011) but not in the mutant subset. CONCLUSIONS: These findings suggest the clinical significance of changes in peripheral TCR and BCR repertoire diversity after anti-PD-1 treatment in patients with NSCLC without EGFR/ALK mutation. Monitoring of the peripheral TCR and BCR repertoires may serve as a surrogate marker for the early detection of EGFR/ALK wild-type NSCLC patients who would benefit from anti-PD-1 treatment.

Interleukin-38 promotes tumor growth through regulation of CD8+ tumor-infiltrating lymphocytes in lung cancer tumor microenvironment.

BACKGROUND: Interleukin (IL)-38 was discovered in 2001 and is a member of the IL-1 family of cytokines. IL-38 shows anti-inflammatory activity in several inflammatory diseases. In lung adenocarcinoma, we previously demonstrated that high IL-38 expression in tumor cells was associated with poor prognosis. However, the role of IL-38 in the tumor microenvironment has not been clarified. METHODS: IL-38-plasmid-transfected Lewis lung carcinoma cells (LLC-IL38) and empty vector-transfected LLC cells (LLC-vector) were established. Cell proliferation in vitro and tumor growth in vivo were examined, and immunohistochemical staining was used to assess tumor-infiltrating lymphocytes (TILs). A CD8+ lymphocyte depletion model was established to show the association between IL-38 and CD8+ lymphocytes. Moreover, we examined the association between IL-38 expression and CD8+ TILs in human samples, analyzing immunohistochemical staining in 226 patients with radically resected lung adenocarcinoma. RESULTS: Tumor growth of LLC-IL38 in vivo was significantly increased compared with that of LLC-vector, although cell proliferation of LLC-IL38 in vitro was lower than that of LLC-vector. CD8+ TILs were significantly decreased in LLC-IL38 tumor compared with LLC-vector tumor. The difference in tumor growth between LLC-IL38 and LLC-vector became insignificant after depletion of CD8+ lymphocytes. In immunohistochemical staining in tissues from patients with lung adenocarcinoma, multivariate analysis showed high IL-38 expression was an independent negative predicter of high density of CD8+ TILs. CONCLUSION: We demonstrated that high IL-38 expression in tumor cells was significantly associated with reduction of CD8+ TILs and tumor progression. These results suggest that IL-38 could be a therapeutic target for lung cancer.

Atezolizumab plus carboplatin and etoposide in small cell lung cancer patients previously treated with platinum-based chemotherapy.

Although immune checkpoint inhibitors have improved the survival of small cell lung cancer (SCLC) patients, their efficacy in SCLC patients who relapsed after systemic chemotherapy is unclear. This retrospective study aimed to investigate the utility of treatment with atezolizumab plus carboplatin and etoposide in SCLC patients previously treated with platinum-based chemotherapy. We retrospectively screened consecutive eight SCLC patients who received atezolizumab plus carboplatin and etoposide after platinum-based chemotherapy. We evaluated the efficacy of this treatment and its association with programmed cell death-ligand 1 (PD-L1) expression. Three and five patients had sensitive relapse and refractory relapse for first-line platinum-based chemotherapy, respectively. The overall response rate and disease control rate was 37.5% and 75.0%, respectively. Median progression-free survival was 4.0 months. Out of three patients who achieved clinical response, two patients had refractory relapse for first-line platinum-based chemotherapy. No patient exhibited PD-L1 expression. Atezolizumab plus carboplatin and etoposide therapy was effective in SCLC patients with sensitive and refractory relapse and might be a second-line treatment option for SCLC patients previously treated with platinum-based chemotherapy.

Comparative incidence of immune-related adverse events and hyperprogressive disease in patients with non-small cell lung cancer receiving immune checkpoint inhibitors with and without chemotherapy.

Immune-related adverse events (irAEs) and hyperprogressive disease (HPD) are serious problems arising in the early period of monotherapy (MT) with programmed cell death protein 1 (PD-1) and programmed cell death ligand1 (PD-L1) inhibitors. However, the frequency and clinical features of these problems in patients receiving combination therapy (CT) with cytotoxic chemotherapy in addition to these agents remain unclear. We retrospectively screened patients with pathologically confirmed advanced or recurrent non-small cell lung cancer (NSCLC) who had received PD-1/PD-L1 inhibitors at Kurume University Hospital between February 2016 and March 2020. We recruited 210 patients, of whom 172 (81.9%) had received PD-1/PD-L1 inhibitor MT and 38 (18.1%) had received CT. The incidence of irAE during the 3 months after treatment initiation was significantly higher in the MT group (57 of 172, 33.1%) than in the CT group (6 of 38, 15.8%) (p = 0.049). During the same period, the incidence of pneumonitis was also higher in the MT group (18 of 172, 10.9%) than in the CT group (0 of 38) (p = 0.049). A similar trend was observed in patients who had received these treatments on a first line basis. The HPD rate was significantly lower in the CT group (1 of 34, 2.9%) than in the MT group (25 of 142, 17.6%) (p = 0.031). The incidences of HPD and irAE, especially pneumonitis, during 3 months after treatment initiation were relatively lower in the CT group than in the MT group. The mechanisms underlying these differences warrant further study.

Overweight improves long-term survival in Japanese patients with asthma.

BACKGROUND: Obesity is a risk factor for severe and difficult-to-treat asthma. However, the impact of different physiques on long-term outcomes is poorly understood. We aimed to investigate the correlation between obesity and asthma-associated long-term mortality in Japanese adults. METHODS: From the data on 3146 individuals with air pollution-related respiratory diseases in the Omuta City Air Pollution-Related Health Damage Cohort Program, 697 adult patients with asthma were analyzed. Hazard ratios for long-term all-cause and respiratory disease -related mortality were compared in patients with different physiques using the Cox proportional hazard models. The classification of physiques was based on the WHO obesity criteria. RESULTS: Of the 697 patients, 439 died during the median observation period of 26.3 years. The number (% of total) of underweight, normal-weight, pre-obese, and obese class I-III individuals were 75 (10.8%), 459 (65.9%), 140 (20.1%), and 23 (3.3%), respectively. The Cox proportional hazard model (adjusted hazard ratio [95% confidence interval], P value) showed that pre-obese group had a significantly reduced risk for all-cause (0.65 [0.51 to 0.83], P < 0.05) and respiratory disease (0.55 [0.37 to 0.81], P < 0.05)-related mortality related to normal-weight group. CONCLUSIONS: Our cohort program demonstrated that being slightly overweight may reduce the risk of long-term mortality in patients with asthma. However, the influence of obesity on long-term outcomes remains unclear in asthma, because of the small number of obese patients included in our study. Our findings suggest that interventions, including nutrition and exercises, should be provided to Japanese patients with asthma.

MEFV E148Q variant is more associated with familial Mediterranean fever when combined with other non-exon 10 MEFV variants in Japanese patients with recurrent fever.

OBJECTIVE: To investigate the genetic characteristics of one of the MEFV gene variants, p.Glu148Gln (E148Q), in patients with familial Mediterranean fever (FMF) and examine its significance in Japanese patients with recurrent fever. METHODS: The clinical phenotype and genomic variants of systemic autoinflammatory diseases (SAIDs), including MEFV, were analyzed in 211 Japanese patients with recurrent fever. Genetic analysis was performed via next-generation sequencing of exons, including exon-intron boundaries. RESULTS: Twelve patients met the diagnostic criteria for SAIDs other than FMF. Considering 199 patients with recurrent fever, 137 cases (68.8%) were clinically diagnosed with FMF. Although Bonferroni-adjusted p-value did not reach significance level, the group containing heterozygous E148Q and other variants tended to be at higher risk of developing the FMF phenotype (nominal p = .036) than the group with heterozygous E148Q only. Comparison between the group with heterozygous E148Q and other variants and the heterozygous group containing non-E148Q showed no statistically significant difference in FMF phenotype expression (nominal p = 1.00). CONCLUSION: Patients with heterozygous E148Q and other variants exhibited higher expression of FMF phenotype than those with heterozygous E148Q only, and suggested that other variants than E148Q as well as exon 10 variants might contribute to the FMF phenotype.

Clinical phenotypes and genetic analyses for diagnosis of systemic autoinflammatory diseases in adult patients with unexplained fever.

OBJECTIVE: To make an accurate diagnosis of systemic autoinflammatory diseases (SAIDs), clinical and genetic analyses were performed in patients with unexplained fever. METHODS: The clinical phenotype and genomic variants of 11 genes responsible for SAIDs were analyzed in 179 Japanese patients with unexplained fever. Genetic analysis was performed by next generation sequencing (NGS) on exons including exon-intron boundaries. RESULTS: Three cases met the diagnostic criteria for SAIDs other than familial Mediterranean fever (FMF). Considering 176 patients with unexplained fever, 43 cases (24.0%) were clinically diagnosed as FMF. Gene variants were found in 53 cases (30.1%) when searching for variants in the 10 disease genes other than the MEFV gene. Among them, the most frequently-identified genes were NLRP3, NOD2, NLRP12, NLRC4, and PLCG2, which accounted for 14, 7, 17, 7, and 6 cases, respectively. These variants were less than 1% of healthy individuals or novel variants, but not regarded as pathogenic since the patients did not meet the diagnostic criteria of SAIDs caused by their identified variants clinically. CONCLUSION: Twenty four percent of Japanese patients with unexplained fever were clinically diagnosed as FMF in this study. Low frequency but not pathogenic variants in genes other than MEFV were identified in 30.1% of the cases. It is not clear how much these gene variants contribute to the inflammatory phenotypes; therefore, further analysis would uncover their autoinflammatory phenotypes that cause fever.

Interleukin-18 diagnostically distinguishes and pathogenically promotes human and murine macrophage activation syndrome.

Hemophagocytic lymphohistiocytosis (HLH) and macrophage activation syndrome (MAS) are life-threatening hyperferritinemic systemic inflammatory disorders. Although profound cytotoxic impairment causes familial HLH (fHLH), the mechanisms driving non-fHLH and MAS are largely unknown. MAS occurs in patients with suspected rheumatic disease, but the mechanistic basis for its distinction is unclear. Recently, a syndrome of recurrent MAS with infantile enterocolitis caused by NLRC4 inflammasome hyperactivity highlighted the potential importance of interleukin-18 (IL-18). We tested this association in hyperferritinemic and autoinflammatory patients and found a dramatic correlation of MAS risk with chronic (sometimes lifelong) elevation of mature IL-18, particularly with IL-18 unbound by IL-18 binding protein, or free IL-18. In a mouse engineered to carry a disease-causing germ line NLRC4T337S mutation, we observed inflammasome-dependent, chronic IL-18 elevation. Surprisingly, this NLRC4T337S-induced systemic IL-18 elevation derived entirely from intestinal epithelia. NLRC4T337S intestines were histologically normal but showed increased epithelial turnover and upregulation of interferon-γ-induced genes. Assessing cellular and tissue expression, classical inflammasome components such as Il1b, Nlrp3, and Mefv predominated in neutrophils, whereas Nlrc4 and Il18 were distinctly epithelial. Demonstrating the importance of free IL-18, Il18 transgenic mice exhibited free IL-18 elevation and more severe experimental MAS. NLRC4T337S mice, whose free IL-18 levels were normal, did not. Thus, we describe a unique connection between MAS risk and chronic IL-18, identify epithelial inflammasome hyperactivity as a potential source, and demonstrate the pathogenicity of free IL-18. These data suggest an IL-18-driven pathway, complementary to the cytotoxic impairment of fHLH, with potential as a distinguishing biomarker and therapeutic target in MAS.

Association between soluble immune mediators and tumor responses in patients with nonsmall cell lung cancer treated with anti-PD-1 inhibitor.

Although programmed death (PD)-1 immune checkpoint therapies target the immune system, the relationship between inflammatory factors and the clinical outcome of anti-PD-1 therapy for nonsmall cell lung cancer (NSCLC) is not fully understood. Here we examined the association between soluble immune mediators and the outcome of treatment with PD-1 inhibitors in patients with advanced/recurrent NSCLC. In two independent cohorts, we assessed the levels of 88 different soluble immune mediators in peripheral blood before and after anti-PD-1 treatment, and evaluated their associations with clinical outcomes. In the training cohort, the plasma levels of chitinase 3-like-1 and GM-CSF before treatment (p = 0.006 and p = 0.005, respectively) and changes in the plasma levels of CXCL2, VEGF, IFNα2, and MMP2 after treatment (p < 0.001, p = 0.019, p = 0.019, and p = 0.012, respectively) were significantly correlated with PFS. The change in the plasma CXCL2 level was also significantly associated with treatment-related AEs (p = 0.017). In the validation cohort, however, only the changes in the plasma levels of CXCL2 and MMP2 after treatment were associated with PFS (p = 0.003 and p = 0.006, respectively), and these changes were maintained during the course of anti-PD-1 therapy in patients who showed better clinical outcomes, even in those with tumor pseudoprogression. Since CXCL2 and MMP2 can be easily measured by minimally invasive blood sampling, they could be useful for monitoring of clinical outcomes in NSCLC patients receiving PD-1 inhibitor therapy.

Prognostic Impact of Programmed Death-Ligand 2 Expression in Primary Lung Adenocarcinoma Patients.

BACKGROUND: Programmed death-ligand 1 (PD-L1) expression on lung cancer cells is a prognostic marker and a predictive biomarker for response to immunotherapy. However, previous clinical trials have suggested that other programmed cell death 1 ligands, including programmed death-ligand 2 (PD-L2), might have clinical impacts. This study aimed to analyze the prognostic significance of PD-L2 expression in lung adenocarcinoma patients. METHODS: The study included 433 patients who underwent surgical resection for lung adenocarcinoma between 2003 and 2012 at Kyushu University Hospital. Both PD-L1 and PD-L2 expression were evaluated by immunohistochemistry. The cutoff value for PD-L2 positivity was set at 1% according to a time-dependent receiver operating characteristic curve for 5-year survival. RESULTS: Of the 433 patients, 306 (70.7%) were positive for PD-L2. No significant association between PD-L1 and PD-L2 expression was observed (P = 0.094). The multivariate analysis showed that the independent predictors of PD-L2 positivity were never-smoker status (P = 0.002), poor differentiation grade (P = 0.008), and advanced stage (P = 0.048). The PD-L2-positive patients had significantly shorter disease-free survival (DFS) (P = 0.018) and overall survival (OS) (P = 0.016). Both PD-L1 and PD-L2 positivity were independent predictors of OS (P < 0.001 and P = 0.027, respectively). In the subgroup analysis of the PD-L1-negative patients, PD-L2 positivity was significantly associated with shorter DFS (P = 0.018). CONCLUSIONS: The study demonstrated that the clinical characteristics of patients with PD-L1 expression may differ from those of patients with PD-L2 expression, and that both might contribute to poor prognoses. The potential role of PD-L2 expression as a predictive biomarker for response to immunotherapy should be investigated in future studies.