Genetics, Pathophysiology, and Treatment of Dominant Autoinflammatory Diseases

在本报告所述期间，我们重点调查了三个领域： 1)化脓性关节炎、坏疽脓皮病、痤疮(PAPA)综合征的研究 在过去的二十年里，我们在我们的诊所跟踪观察了一组化脓性关节炎、坏疽脓皮病和痤疮患者。这些患者中的大多数都有PSTPIP1基因的突变，该基因编码一种已知与吡喃结合的蛋白质，这种蛋白质在家族性地中海热(FMF)中发生了突变。然而，这些患者中约有三分之一没有明显的PSTPIP1突变。PSTPIP1突变阳性患者的临床表现与突变阴性的PAPA样患者重叠，但突变阳性患者发病更早，关节炎更多。与费城儿童医院的Scott Canna合作，我们发现接受治疗的PAPA患者的血清总IL-18水平一致上升，几乎与NLRC4相关性自身炎症婴儿小肠结肠炎(AIFEC)患者的水平一样高，而大多数FMF患者的水平远远高于NLRC4相关性自身炎症患者。尽管疾病活动起伏不定，但PAPA患者血清中IL-18的水平仍持续升高。可溶性IL-18拮抗剂IL-18BP轻度升高，PAPA患者可检测到游离IL-18。PAPA综合征很少与CXCL9升高有关，CXCL9是干扰素-γ活性的指标，但没有PAPA患者有巨噬细胞激活综合征的病史。这些发现表明，吡咯炎症体激活、IL-18和自身炎症之间存在联系，而不是巨噬细胞激活综合征的易感性。 这项研究发表在《关节炎和风湿病》杂志上。 2)自体炎症性疾病过敏相关特征的协作性研究 NIAID的临床助理研究员Daniella Schwartz博士与我们团队合作，研究自体炎症疾病的过敏表现。施瓦茨博士对425名自体炎症性疾病患者进行了问卷调查和图表回顾。这些患者包括FMF、低温比林相关周期综合征(CAPS)、肿瘤坏死因子受体相关周期综合征(TRAPS)、高IGD综合征(HIDS)、PAPA综合征、ADA2缺乏(DADA2)、A20单倍体功能不全(HA20)、慢性非典型中性粒细胞皮肤病、脂肪营养不良和体温升高(蜡烛)，以及婴儿叮人相关血管病(SAVI)。对55例患者的外周血单个核细胞进行刺激，并检测其产生的CD4细胞因子。特别是，T辅助2型反应，这是典型的过敏性炎症，被评估。 FMF和Candle与T辅助细胞2型反应减少和临床变态反应发生率低相关。CAPS与嗜酸性粒细胞增多症、临床过敏和Th2细胞增殖有关。包括DADA2在内的几种自体炎症疾病与Th2反应减少有关，但医生诊断的过敏发生率很高，这表明自体炎症可以伪装成过敏性疾病。 数据表明，医生应该考虑将2型免疫作为CAPS的一个因素，但在将其他自体炎症疾病的过敏症状归因于2型免疫激活时应谨慎，因为这些特征可能是由于未经治疗的自体炎症造成的。了解天然免疫基因如何调节过敏表型将为天然免疫在变态反应相关疾病中的作用提供新的见解，并可能在针对2型免疫调节剂的治疗无效的患者中识别新的靶点。 这项研究发表在《风湿病年鉴》上。 3)一项合作研究，通过突变的ADGRE2研究肥大细胞机械激活中的信号 在早些时候的报道中，我们在家族性振荡性荨麻疹患者中发现了G蛋白偶联受体ADGRE2(EMR2)中的一个显性遗传的p.C492Y突变。在这些患者中，皮肤的摩擦通过p.C492Y-ADGRE2诱导肥大细胞过度脱颗粒，导致局限性麻疹、潮红和低血压。ADGRE2在中性粒细胞、单核细胞和肥大细胞中表达。在这项合作研究中，Andrea Naranjo博士、Dean Metcalfe博士和Anna Olivera博士研究了机械激活表达p.C492Y-ADGRE2并附着于ADGRE2配体硫酸皮肤素的人肥大细胞中的细胞内信号。他们发现，突变ADGRE2的存在降低了激活的阈值，增加了脱颗粒的程度，并增加了肥大细胞的反应百分比。振动引起磷脂酶C的激活，细胞内钙的一过性升高，以及磷脂酰肌醇3-激酶和细胞外信号调节蛋白激酶1和2的下游激活。振动引起的脱颗粒依赖于磷脂酶C途径，包括钙、蛋白激酶C和磷脂酰肌醇3-激酶，而不是细胞外信号相关蛋白1/2途径，以及百日咳毒素敏感信号。此外，肥大细胞的机械激活刺激了前列腺素D2的合成和释放，前列腺素D2是一种以前未见报道的振动性荨麻疹的中介物质，这种反应需要细胞外信号相关激酶1/2的激活，细胞外信号相关激酶1/2的激活与钙、蛋白激酶C以及一定程度上的磷脂酰肌醇3-激酶一起被激活。因此，这些研究确定了由机械力引发的关键分子事件和振动性荨麻疹患者的潜在治疗靶点。 这项研究发表在11月份的《皮肤病研究杂志》上。

During the current reporting period we focused on three areas of investigation: 1) Studies of pyogenic arthritis, pyoderma gangrenosum, and acne (PAPA) syndrome For the last two decades, we have followed a cohort of patients with pyogenic arthritis, pyoderma gangrenosum, and acne in our clinic. Most of these patients have mutations in the PSTPIP1 gene, which encodes a protein known to bind to pyrin, the protein mutated in familial Mediterranean fever (FMF). However, about one third of these patients have no demonstrable PSTPIP1 mutations. PSTPIP1 mutation-positive patients' clinical findings overlapped with mutation-negative PAPA-like patients, but mutation-positive patients had earlier onset and more arthritis. In collaboration with Scott Canna at the Childrens Hospital of Philadelphia, we found uniform elevation of total serum IL-18 in treated PAPA patients at levels nearly as high as NLRC4-associated autoinflammation with infantile enterocolitis (AIFEC) patients and well above levels in most FMF patients. IL-18 elevation in PAPA patients' serum persisted despite fluctuations in disease activity. The soluble IL-18 antagonist IL-18BP was modestly elevated, and PAPA patients had detectable free IL-18. PAPA syndrome was rarely associated with elevation of CXCL9, an indicator of interferon-gamma activity, but no PAPA patients had histories of macrophage activation syndrome. These findings suggest a link between pyrin inflammasome activation, IL-18, and autoinflammation without susceptibility to macrophage activation syndrome. This work is in press in Arthritis and Rheumatology. 2) A collaborative study of allergy-associated features in autoinflammatory disease Dr. Daniella Schwartz, an Assistant Clinical Investigator in the NIAID, collaborated with our group to study allergic manifestations in autoinflammatory disease. Dr. Schwartz studied 425 patients with autoinflammatory disease with questionnaires and chart reviews. These included patients with FMF, cryopyrin-associated periodic syndrome (CAPS), TNF receptor-associated periodic syndrome (TRAPS), hyper-IgD syndrome (HIDS), PAPA syndrome, deficiency of ADA2 (DADA2), haploinsufficiency of A20 (HA20), chronic atypical neutrophilic dermatosis, lipodystrophy, and elevated temperature (CANDLE), and STING-associated vasculopathy of infancy (SAVI). Peripheral blood mononuclear cells from 55 patients were stimulated and CD4 cytokine production assessed. In particular, T helper type 2 responses, which are typical of allergic inflammation, were assessed. FMF and CANDLE were associated with reduced T helper Type 2 responses and a low prevalence of clinical allergy. CAPS is associated with eosinophilia, clinical allergy, and Th2 expansion. Several autoinflammatory diseases, including DADA2, are associated with reduced Th2 responses but a high prevalence of physician-diagnosed allergy, suggesting that autoinflammation can masquerade as allergic disease. The data indicate that physicians should consider Type 2 immunity as a factor in CAPS but should be cautious in attributing allergic symptoms in other autoinflammatory diseases to type 2 immune activation, as these features could be due to untreated autoinflammation. Understanding how innate immune genes modulate allergic phenotypes will provide new insights into the role of innate immunity in allergy-associated diseases and may identify novel targets in patients refractory to treatments targeting type 2 immunomodulators. This work is in press in the Annals of the Rheumatic Diseases. 3) A collaborative study examining signaling in the mechanoactivation of human mast cells through mutant ADGRE2 In an earlier reporting period, we discovered a dominantly inherited p.C492Y mutation in the G-protein coupled receptor ADGRE2 (EMR2) in patients with familial vibratory urticaria. In these patients, friction of the skin induces mast cell hyper-degranulation through p.C492Y-ADGRE2, causing localized hives, flushing, and hypotension. ADGRE2 is expressed in neutrophils, monocytes, and mast cells. In this collaborative study, Drs. Andrea Naranjo, Dean Metcalfe, and Anna Olivera examined the intracellular signals elicited by mechanical activation in human mast cells expressing p.C492Y-ADGRE2 and attached to dermatan sulfate, a ligand for ADGRE2. They found that the presence of mutant ADGRE2 reduced the threshold to activation and increased the extent of degranulation along with the percentage of mast cells responding. Vibration caused phospholipase C activation, transient increases in cytosolic calcium, and downstream activation of phosphoinositide 3-kinase and extracellular signal-regulated kinases 1 and 2. Degranulation induced by vibration was dependent on phospholipase C pathways, including calcium, protein kinase C, and phosphoinositide 3-kinase but not extracellular signal-related kinases 1/2 pathways, along with pertussis toxin-sensitive signals. In addition, mechanoactivation of mast cells stimulated the synthesis and release of prostaglandin D2, a previously unreported mediator in vibratory urticaria, and extracellular signal-related kinases 1/2 activation was required for this response together with calcium, protein kinase C, and to some extent phosphoinositide 3-kinase. These studies thus identified critical molecular events initiated by mechanical forces and potential therapeutic targets for patients with vibratory urticaria. This work was published in November in the Journal of Investigative Dermatology.