Lee, James

Abstract Inflammatory bowel diseases (IBD), principally Crohn’s disease (CD) and ulcerative colitis (UC), are common chronic disorders involving inflammation and often progressive tissue damage. Genome-wide association studies have mapped many risk signals, but the causal variants, effector genes and relevant cellular contexts remain difficult to resolve, limiting mechanistic interpretation and therapeutic translation. Here we performed a multi-ancestry GWAS meta-analysis of 125,992 individuals with IBD and more than 1.2 million controls, identifying 619 independent association signals (374 novel) at 420 IBD regions that account for 77–80% of SNP-based heritability. Fine-mapping resolved 81 high-confidence variants, 41 not previously reported. Although most signals were shared between CD and UC, 39% showed IBD subtype specificity, with UC signals showing stronger enrichment in functional annotations from intestinal epithelial, secretory and enteroendocrine cells, and CD showing stronger genetic correlations with circulating inflammatory biomarkers, including C-reactive protein and glycoprotein acetylation. Latent causal modelling supported a causal effect of decreased high-density lipoprotein on CD risk. By integrating bulk and single-cell eQTL and pQTL resources using colocalisation and Mendelian randomisation, together with coding-variant evidence from exome sequencing, we prioritised 664 candidate effector genes across 341 signals, including 390 newly implicated IBD genes, revealing new biological mechanisms and candidate therapeutic targets supported by human genetics.

Abstract INTRODUCTION: Pulmonary veno-occlusive disease/pulmonary capillary hemangiomatosis (PVOD/PCH) is a rare subgroup of pulmonary arterial hypertension (PAH). Unfortunately, there is significant overlap between PVOD and PAH, making differentiation difficult. Thus, a constellation of investigations is necessary to suggest such a diagnosis. CASE PRESENTATION: A 65-year-old female with a history of smoking was diagnosed with idiopathic PAH following 2 months of worsening dyspnea. Right heart catheterization (RHC) revealed a mean PA pressure (mPAP) 58mmHg, pulmonary artery wedge pressure (PAWP) 14mmHg, cardiac output/index (CO/CI) 5.5/2.6, and pulmonary vascular resistance (PVR) 8 Wood units. Further workup excluded other causes of pulmonary hypertension (Table 1). Tadalafil was initially started followed by macitentan, which were associated with worsening hypoxemia and dyspnea. Computed tomography (CT) scan of the chest revealed mediastinal lymphadenopathy and small bilateral pleural effusions. This development in relation to the initiation of PAH-directed therapies raised concern for possible PVOD. Medical therapy was downtitrated, but worsening hypoxemia in the setting of worsening edema led to the cessation of all therapies. Due to clinical concern, the patient was admitted for a repeat RHC and close supervision during a trial of epoprostenol. RHC revealed a mPAP of 57mmHg, PAWP 5mmHg, CO/CI 3.4/1.6 and PVR 15 Wood units. She had been on metoprolol for hypertension which was discontinued. Low-dose epoprostenol was started at 1ng/kg/min. Her oxygen requirements increased slightly which improved with diuresis. Epoprostenol was slowly titrated with improvements in CI. Repeat chest CT showed mild diffuse centrilobular nodular opacities more prominent compared to prior scans, and adenopathy. After a steady dose of epoprostenol (4ng/kg/min), the patient improved with lower oxygen requirements. She was discharged with plans to continue low dose outpatient epoprostenol and start sotatercept. Lung transplant evaluation is on hold pending response to this approach. Genetic testing is pending. DISCUSSION: Despite challenges of definitive diagnosis where lung biopsy is risky, a diagnosis of PVOD can be supported from a spectrum of strongly suggestive clinical, hemodynamic and radiographic features. Though genetic testing for the EIF2AK4 mutation may confirm the presence of heritable PVOD, its absence does not exclude its possibility as most cases do not have an identifiable genetic cause. Management is challenging given ineffective or potentially harmful responses to PAH-directed therapies, though some do respond to a variable extent. As suggested here, close supervision during epoprostenol infusion adds to the limited body of evidence supporting such endeavors when initiating vasodilatory therapies in patients with suspected PVOD.

Objective Perianal Crohn’s disease (pCD) occurs in up to 40% of patients with CD and is associated with poor quality of life, limited treatment responses and poorly understood aetiology. We performed a genetic association study comparing CD subjects with and without perianal disease and subsequently performed functional follow-up studies for a pCD associated SNP in Complement Factor B ( CFB ). Design Immunochip-based meta-analysis on 4056 pCD and 11 088 patients with CD from three independent cohorts was performed. Serological and clinical variables were analysed by regression analyses. Risk allele of rs4151651 was introduced into human CFB plasmid by site-directed mutagenesis. Binding of recombinant G252 or S252 CFB to C3b and its cleavage was determined in cell-free assays. Macrophage phagocytosis in presence of recombinant CFB or serum from CFB risk, or protective CD or healthy subjects was assessed by flow cytometry. Results Perianal complications were associated with colonic involvement, OmpC and ASCA serology, and serology quartile sum score. We identified a genetic association for pCD (rs4151651), a non-synonymous SNP (G252S) in CFB , in all three cohorts. Recombinant S252 CFB had reduced binding to C3b, its cleavage was impaired, and complement-driven phagocytosis and cytokine secretion were reduced compared with G252 CFB. Serine 252 generates a de novo glycosylation site in CFB. Serum from homozygous risk patients displayed significantly decreased macrophage phagocytosis compared with non-risk serum. Conclusion pCD-associated rs4151651 in CFB is a loss-of-function mutation that impairs its cleavage, activation of alternative complement pathway, and pathogen phagocytosis thus implicating the alternative complement pathway and CFB in pCD aetiology.

Abstract Chronic asthma is characterized by pulmonary remodeling and sustained lung dysfunction. The expression of IL-13 has been demonstrated as sufficient and necessary to induce these pathologies. Despite the common assumption that T cells are the primary source of IL-13 in the lung following allergen provocation, the mechanistic events leading to IL-13 expression are unclear, including the potential importance of other cells (i.e., non-T cells). Methods: Co-expression of IL-5 and eotaxin-2 induces pulmonary histopathologies and lung dysfunction that are eosinophil-dependent (i.e., they are absent in triple transgenic I5/hE2/PHIL) animals. IL-13 knockout and CD4 knockout mice were crossed with I5/hE2 mice to assess the effects of these deficiencies on the induced pathologies occurring in this double transgenic model. Conclusions: The Th2 pulmonary pathologies associated with I5/hE2 mice included recruitment of pulmonary effector T cells and increased brochoalveolar Th2 cytokine levels. Conversely, I5/hE2/CD4-/- had only a ~50% reduction in IL-13 levels as compared to I5/hE2 mice, suggesting that a significant portion of IL-13 is non-T cell derived in these mice. I5/hE2/IL-13-/- mice are improved in lung dysfunction and mucus production as compared to I5/hE2 mice. All mice had similar levels of eosinophil degranulation. These results demonstrate a role for non-T cell derived IL-13 that contributes to mucus production and lung dysfunction in a mouse model of chronic severe asthma.

Abstract Eosinophil infiltration into tumors has been associated with positive and negative growth human cancers and in mouse models of tumorigenesis. Our previous studies have shown that eosinophils infiltrate tumors and differentially accumulate in the necrotic and capsule regions of tumors. Using various eosinophil-deficient mouse models, we demonstrate that in the absence of eosinophils tumor growth is attenuated. Methods: Tumor growth kinetics were assessed using a B16F10 melanoma subcutaneous cell injection model. Eosinophil chemotaxis was assessed using an ex vivo transwell insert assay system. We compared tumor growth in wild type animals vs. various eosinophil-deficient mouse models that are transgenic line of mice (PHIL) and MBP-/-/EPO-/- double knockout mice that are deficient in eosinophil-specific proteins (major basic protein (MBP) and eosinophil peroxide (EPO)) resulting in a blockade of eosinophilpoiesis. Conclusions: The migration of eosinophils was inhibited through blocking the sphingosine-1-phosphate pathway, suggesting recruitment and accumulation is primarily an inflammatory response. Tumor growth was decreased by ~40-60% in PHIL and in MBP-/-/EPO-/- double knockout mice relative to tumors in wild type animals. In addition, EPO-/- mice, and not MBP-/-mice, replicate this ~40% reduction in tumor size implicating a significant role for EPO in tumor growth kinetics. These data suggest eosinophils respond to inflammatory mediators and mediate augment tumor growth.

Abstract Atopic dermatitis and allergic contact dermatitis are two of the most common skin diseases. In both diseases, eosinophils have been suggested as potential contributors of the pathologies linked with these skin conditions. Our goal was to establish a causative relationship between the inflammatory response of chemically induced contact hypersensitivity and eosinophil-mediated activities. Wild type and eosinophil-less PHIL mice were sensitized and challenged with 2,4-dinitrochlorobenzene (DNFB) or alternatively trimellitic anhydride (TMA). Time lapsed videography was used to capture the number of itching events associated with treatment. Immunohistochemistry for eosinophils and nerves was performed to correlate the effect of dermatitis on innervation and eosinophil accumulation in these mice. Our studies showed that in both the DNFB and TMA models a robust eosinophil infiltrate occurred that was accompanied by copious levels of eosinophil degranulation. More importantly, these studies demonstrated that metrics of inflammation (e.g., induced ear swelling (i.e., thickness)) was reduced in PHIL mice relative to wild type. Our observations were also directly correlative with a loss of nerve growth and branching in PHIL mice. These data implicate eosinophils as contributors to the pathologies linked with chemically-induced contact hypersensitivity, including the induced itch responses associated with these models.

Abstract Eosinophil recruitment and accumulation in the lungs of asthmatics is a hallmark feature of asthma. The causative relationship between eosinophils and induced Th2 pulmonary pathologies remains unclear. Our data suggest a novel role for eosinophils as immune modulators that drive Th2-mediated pulmonary pathologies through modulation of dendritic cell function leading to the suppression of Th1/Th17 immune responses. Methods: Eosinophils and ovalbumin (OVA)-pulsed myeloid dendritic cells were adoptively transferred into IL-5-/- (eosinophil-low) or PHIL mice (eosinophil-null) at the time of allergen challenge using an established acute OVA protocol. Allergen-induced pulmonary changes were assessed as changes in lung and lung draining lymph node (LDLN) cells, activation/polarization of T cells, and induced lung histopathologies. Conclusions: We demonstrate that a threshold level of eosinophils must migrate to the lung draining lymph node to promote dendritic cell recruitment and thus activation of antigen-specific memory T cells. Expression of MHC II or CCR7 on eosinophils is not necessary for proliferation of T cells in the LDLN. These lymphatic eosinophils are necessary to suppress Th1/Th17 neutrophilic polarized immune responses initiated by OVA-pulsed dendritic cells during allergen challenge. These results imply an important function for eosinophils in modulating the balance between Th2 and Th1/Th17 pathways in the development of allergic respiratory inflammation.

AbstractObjectivesTo examine the safety of utilizing transapical access during structural interventions.BackgroundComplex interventions of the mitral or aortic region sometimes require coaxial forces to orient and deliver devices. Apical access can provide coaxial countertraction for either transseptal or retrograde aortic access. This manuscript describes the single center experience of small bore transapical access.MethodsRetrospective review of cases from 2013 to 2018 at Henry Ford Hospital was performed. Patient demographics and procedure characteristics were abstracted to describe the safety of transapical access using small bore sheaths.ResultsA total 21 cases were performed at Henry Ford, most of them for transcatheter mitral valve replacement (81%). The mean sheath size used was 4.7 ± 0.9 Fr and protamine was used at the end of 57% of cases. All patients received nitinol‐based plugs, 80.1% were from the Amplatz Duct Occluder II type. Four major complications related apical puncture occurred, two pericardial effusions, two hemothorax. Over a median follow time of 430 days (IQR 50–652) a total of five deaths occurred, two related to the procedure and three late deaths with a median time of 362 days (range 205–628 days). No deaths were associated with transapical access. Echocardiographic follow up did not detect any late structural complications from occluder devices.ConclusionsTransapical access and closure with nitinol‐based devices is feasible and facilitates complex interventions where coaxial forces are need for device delivery and alignment. The most common complication is bleeding and this should be kept in perspective when treating high‐risk patients.