Inflammasome Adaptor ASC Suppresses Apoptosis of Gastric Cancer Cells by an IL18-Mediated Inflammation-Independent Mechanism.

Inflammasomes are key regulators of innate immunity in chronic inflammatory disorders and autoimmune diseases, but their role in inflammation-associated tumorigenesis remains ill-defined. Here we reveal a protumorigenic role in gastric cancer for the key inflammasome adaptor apoptosis-related speck-like protein containing a CARD (ASC) and its effector cytokine IL18. Genetic ablation of ASC in the gp130F/F spontaneous mouse model of intestinal-type gastric cancer suppressed tumorigenesis by augmenting caspase-8-like apoptosis in the gastric epithelium, independently from effects on myeloid cells and mucosal inflammation. This phenotype was characterized by reduced activation of caspase-1 and NF-κB activation and reduced expression of mature IL18, but not IL1ß, in gastric tumors. Genetic ablation of IL18 in the same model also suppressed gastric tumorigenesis, whereas blockade of IL1ß and IL1α activity upon genetic ablation of the IL1 receptor had no effect. The specific protumorigenic role for IL18 was associated with high IL18 gene expression in the gastric tumor epithelium compared with IL1ß, which was preferentially expressed in immune cells. Supporting an epithelial-specific role for IL18, we found it to be highly secreted from human gastric cancer cell lines. Moreover, IL18 blockade either by a neutralizing anti-IL18 antibody or by CRISPR/Cas9-driven deletion of ASC augmented apoptosis in human gastric cancer cells. In clinical specimens of human gastric cancer tumors, we observed a significant positive correlation between elevated mature IL18 protein and ASC mRNA levels. Collectively, our findings reveal the ASC/IL18 signaling axis as a candidate therapeutic target in gastric cancer.Significance: Inflammasome activation that elevates IL18 helps drive gastric cancer by protecting cancer cells against apoptosis, with potential implications for new therapeutic strategies in this setting. Cancer Res; 78(5); 1293-307. ©2017 AACR.

Elevated serum levels of free interleukin-18 in adult-onset Still's disease.

OBJECTIVE: IL-18 is a pro-inflammatory cytokine of the IL-1 family that is naturally inhibited by IL-18 binding protein (IL-18BP). High levels of IL-18 have been described in the serum of adult-onset Still's disease (AOSD) patients, but only total IL-18 levels (including inactive IL-18 bound to IL-18BP) have been measured. With a specific immunoassay, we aimed to measure free IL-18 serum levels in AOSD patients and other rheumatic diseases. METHODS: An ELISA was developed to measure free IL-18. Its sensitivity and specificity were tested by spiking recombinant IL-18 or IL-18BP in serum and PBS supplemented with 5% BSA. The binding affinity of IL-18 to IL-18BP was calculated by titration experiments using the ELISA and by Biacore analysis. Sera of 37 AOSD patients and 138 controls (40 healthy controls, 30 RA, 29 SLE, 21 AS and 18 PsA) were assayed for free IL-18, IL-18BP, total IL-18 and other cytokines. Correlations were performed between free IL-18 and markers of disease activity in AOSD patients. RESULTS: Free IL-18 serum levels were significantly higher in AOSD patients (median 8.89 pg/ml) than in healthy and disease controls (1.37 pg/ml; P < 0.01). Free IL-18 serum levels correlated with AOSD activity. The affinity of IL-18 to IL-18BP was found to be much higher than previously described, with a dissociation constant ranging from 30 to 50 pM. CONCLUSION: Free IL-18 levels are specifically elevated in AOSD compared with other inflammatory diseases, suggesting that IL-18 represents a potential target for the treatment of AOSD.

Tracheobronchial Stenoses in Granulomatosis With Polyangiitis (Wegener's): A Report on 26 Cases.

Tracheobronchial stenoses (TBSs) are potentially severe manifestations of granulomatosis with polyangiitis (Wegener's) (GPA) that usually respond poorly to corticosteroids and immunosuppressive agents. We describe 26 GPA patients with ≥1 tracheal (mainly subglottic, SGS) and/or bronchial stenosis(ses) (BS(s)).Sixteen patients had solitary SGS and 10 had ≥1 BS(s). The male/female sex ratio was 9:17, and the median age at GPA diagnosis was 32 years (3:13 and 28 years, respectively, for SGS patients). Antineutrophil cytoplasm antibodies were proteinase 3-positive in 65.5% of the patients (50% of those with SGS).Despite conventional GPA therapy, 62% patients experienced ≥1 stenosis relapse(s) (81% of SGS patients, for a total of 1-8 relapses per patient). None of the several systemic or endoscopic treatments prevented future relapses. Cyclophosphamide induction therapy was effective in 4/6 patients with BS(s) and in 1 patient with SGS among the 7 treated. After many relapses, rituximab achieved remission in 3/4 SGS patients. Endoscopic treatments (dilation, laser, corticosteroid injection, etc.) had only transient efficacy. Other GPA manifestations relapsed independently of TBSs. One SGS patient died of acute respiratory distress syndrome.Our findings confirmed that TBSs are severe GPA manifestations that evolve independently of other organ involvements and do not respond to conventional systemic regimens. As previously described, our population was younger and comprised more females than usual GPA patients, especially those with SGS.The small number of patients and the wide variety of local and systemic treatments prevent us from drawing definitive conclusions about the contribution of each procedure. However, cyclophosphamide seemed to effectively treat BSs, but not SGS, and rituximab may be of interest for SGS management.

Granulomatosis with polyangiitis: endoscopic management of tracheobronchial stenosis: results from a multicentre experience.

OBJECTIVES: Tracheobronchial stenosis (TBS) is noted in 12-23% of patients with granulomatosis with polyangiitis (GPA), and includes subglottic stenosis and bronchial stenosis. We aimed to analyse the endoscopic management of TBS in GPA and to identify factors associated with the efficacy of endoscopic interventions. METHODS: We conducted a French nationwide retrospective study that included 47 patients with GPA-related TBS. RESULTS: Compared with patients without TBS, those with TBS were younger, more frequently female and had less frequent kidney, ocular and gastrointestinal involvement and mononeuritis multiplex. Endoscopic procedures included 137 tracheal and 50 bronchial interventions, mainly endoscopic dilatation, local steroid injection and conservative laser surgery, and less frequently stenting. After the first endoscopic procedure, the cumulative incidence of endoscopic treatment failure was 49% at 1 year, 70% at 2 years and 80% at 5 years. Factors significantly associated with a higher cumulative incidence of treatment failure were a shorter time from GPA diagnosis to endoscopic procedure [hazard ratio (HR) 1.08 (95% CI 1.01, 1.14); P = 0.01] and a bronchial stenosis [HR 1.96 (95% CI 1.28, 3.00); P = 0.002]. A prednisone dose ≥30 mg/day at the time of the procedure was associated with a lower cumulative incidence of treatment failure [HR 0.53 (95% CI 0.31, 0.89); P = 0.02]. CONCLUSION: TBS represents severe and refractory manifestations with a high rate of restenosis. High-dose systemic CSs at the time of the procedure and increased time from GPA diagnosis to bronchoscopic intervention are associated with a better event-free survival. In contrast, bronchial stenoses are associated with a higher rate of restenosis than subglottic stenosis.

Bilateral angle-closure glaucoma and multifocal choroiditis as a first presentation in hodgkin lymphoma.

PURPOSE: To report atypical ocular manifestations in two patients with undiagnosed Hodgkin lymphoma. METHODS: Observational case report. RESULTS: The first patient, a 27-year-old man, presented with bilateral acute angle-closure glaucoma secondary to uveal effusion. Histopathology of chest lymph nodes obtained by mediastinoscopy revealed nodular sclerosing Hodgkin lymphoma. Ocular signs resolved after systemic chemotherapy. The second patient, a 56-year-old man, presented with bilateral multifocal choroiditis. Extensive biologic and microbiologic examinations were negative. Pathologic lymph nodes were detected in the anterior mediastinum. The histopathologic examination of the nodes after mediastinoscopy revealed nodular sclerosing Hodgkin lymphoma. Systemic chemotherapy was instituted. The patient encountered a major increase in the multifocal choroiditis within 3 days after the second chemotherapy injection. High-dose intravenous corticosteroid therapy was initiated. No recurrence of choroidal lesions was observed after the treatment completion. CONCLUSION: These two patients presented with bilateral paraneoplastic uveal tract involvement as initial presentation of Hodgkin lymphoma. Systemic corticosteroid therapy may be associated with systemic chemotherapy to obtain complete remission of the ocular inflammatory activity.

Yield of bone marrow examination in diagnosing the source of fever of unknown origin.

BACKGROUND: Fever of unknown origin (FUO) still remains a diagnostic challenge, while diagnosis may remain obscure for several weeks or months. The role of tissue biopsy is crucial in the diagnostic approach. We report a series of 130 consecutive patients with FUO who had undergone a bone marrow biopsy (BMB). METHODS: Among 280 consecutive nonimmunocompromised patients hospitalized between 1995 and 2005 for a febrile illness of uncertain cause, lasting at least 3 weeks, with no diagnosis after an appropriate minimal diagnostic workup, 130 underwent BMB. RESULTS: Overall, a specific diagnosis was achieved by BMB and histological examination in 31 cases (diagnostic yield, 23.7%). Three types of diseases were found: hematological malignant diseases in 25 cases, including 19 patients with malignant lymphoma, 4 with acute leukemia, 1 with hairy cell leukemia, and 1 with multiple myeloma; infectious diseases in 3 cases; systemic mastocytosis in 2 cases; and disseminated granulomatosis in 1 case. Thrombocytopenia (odds ratio, 4.9; 95% confidence interval, 1.04-9.30) and anemia (odds ratio, 3.24; 95% CI, 1.13-9.34) were the most reliable predictive factors regarding the usefulness of BMB. Bone marrow cultures had very limited value in our cohort. Finally, corticosteroid use did not seem to affect the yield of BMB. CONCLUSIONS: Bone marrow biopsy is a useful technique for the diagnosis of prolonged fever in immunocompetent patients. Thrombocytopenia and anemia seem to be correlated with the value of this test.