MEFV gene variants in children with Henoch-Schönlein purpura and association with clinical manifestations: a single-center Mediterranean experience

Associations of MEFV gene variants, IL-33, and sST2 with the risk of Henoch-Schönlein purpura in children

Objective

Henoch-Schönlein purpura (HSP) is the most common systemic vasculitis in children. HSP is a multifactorial inflammatory disease, but its pathogenesis is still unclear. The pathogenicity of familial Mediterranean fever gene (MEFV) variants in HSP remains controversial. The objective of this study was to evaluate relationships between MEFV variants and susceptibility to HSP and their associations with clinical outcomes. We also investigated levels of IL-33 and soluble suppression of tumorigenicity 2 (sST2) in children with HSP and their clinical significance.

Methods

We selected 100 children with HSP as the case group. The control group consisted of 50 children who visited the hospital for physical health examinations. All subjects were screened for MEFV gene exon mutations, and levels of IL-33 and sST2 were measured.

Results

The frequency of MEFV variants was significantly greater in HSP patients than in healthy controls. The variant with the highest frequency was E148Q. The frequency of the C allele of the MEFV variant E148Q was 32 % in HSP patients and 18 % in controls (P-adjust = 0.04). Patients with the MEFV E148Q variant had more frequent joint involvement and recurrent purpura and higher levels of IL-33 and C-reactive protein (CRP). Levels of IL-33 and sST2 in children with HSP were significantly higher than those in the control group, and the sST2/IL-33 ratio in children with HSP was unbalanced (P-adjust <0.05). Logistic regression analysis revealed the presence of E148Q and an unbalanced sST2/IL-33 ratio to be independent risk factors for HSP.

Conclusion

The results of this study suggest that the MEFV variant E148Q is associated with HSP susceptibility in Chinese children and that carriers of the variant may have more severe clinical manifestations and greater inflammatory responses. E148Q and the sST2/IL-33 ratio may play important roles in the pathogenesis of HSP.

IgA vasculitis update: Epidemiology, pathogenesis, and biomarkers

Immunoglobulin A vasculitis (IgAV), formerly known as Henoch-Schönlein purpura, is the most common systemic vasculitis in children, characterized by diverse clinical manifestations with a wide spectrum ranging from isolated cutaneous vasculitis to systemic involvement. The incidence of IgAV is geographically and ethnically variable, with a prevalence in autumn and winter, suggesting a driving role that genetic and environmental factors play in the disease. Although IgAV has a certain degree of natural remission, it varies widely among individuals. Some patients can suffer from severe renal involvement and even progress to end-stage renal disease. Its pathogenesis is complex and has not been fully elucidated. The formation of galactose-deficient IgA1 (Gd-IgA1) and related immune complexes plays a vital role in promoting the occurrence and development of IgAV nephritis. In addition, neutrophil activation is stimulated through the binding of IgA to the Fc alpha receptor I expressed on its surface, resulting in systemic vascular inflammation and tissue damage. Starting from the epidemiological characteristics, this article will review the role of immunological factors such as Gd-IgA1, autoantibodies, circulating immune complexes, complement system, cellular immunization, and the contributions of environmental and genetic factors in the pathogenesis of IgAV, and conclude with the major biomarkers for IgAV.

A Review of the Mechanism of Vascular Endothelial Injury in Immunoglobulin A Vasculitis

Immunoglobulin A (IgA) vasculitis (IgAV), also known as Henoch-Schönlein purpura, is the most common form of childhood vasculitis. It is characterized by cutaneous hemorrhage, resulting from red blood cell leakage into the skin or mucosae, possibly caused by damage to small blood vessels. These acute symptoms usually disappear without treatment. Endothelial cells are distributed on the inner surfaces of blood vessels and lymphatic vessels, and have important functions in metabolism and endocrine function, as well as being the primary targets of external stimuli and endogenous immune activity. Injury to endothelial cells is a feature of IgA vasculitis. Endothelial cell damage may be related to the deposition of immune complexes, the activation of complement, inflammatory factors, and chemokines, oxidative stress, hemodynamics, and coagulation factors. Both epigenetic mechanisms and genetic diversity provide a genetic background for endothelial cell injury. Here, research on the role of endothelial cells in allergic IgA vasculitis is reviewed.

Pathogenesis of IgA Vasculitis: An Up-To-Date Review

Immunoglobin A (IgA) vasculitis (IgAV), formerly called the Henoch-Schönlein purpura (HSP), is a small vessel vasculitis, characterized by IgA1-dominant immune deposition at diseased vessel walls. IgAV is the most common form of vasculitis in children; typical symptoms include palpable purpura, arthritis or arthralgia, abdominal pain, and hematuria or proteinuria. Galactose-deficient IgA1 is detected in the tissues of the kidney and skin in patients with IgAV; it forms immune complexes leading to subsequent immune reactions and injuries. This report provides the recent advances in the understanding of environmental factors, genetics, abnormal innate and acquired immunity, and the role of galactose-deficient IgA1 immunocomplexes in the pathogenesis of IgAV.

Immunoglobulin A Vasculitis in a Japanese Patient with Complete Familial Mediterranean Fever Carrying MEFV Exon 10 Mutation

Immunoglobulin A (IgA) vasculitis is a systemic small-vessel vasculitis involving the skin, kidney, joints, and gastrointestinal tract. Familial Mediterranean fever (FMF) is the most common autoinflammatory disease characterized by periodic fever, peritonitis, pleuritis, or arthritis. It is well known that FMF may coexist with vasculitis, especially small and medium vessel vasculitis. Here we present a Japanese male patient with FMF who later developed IgA vasculitis and a relapsing disease course. A 51-year-old Japanese male was referred because of upper abdominal pain, arthralgia, and bilateral purpura of the lower limbs. He fulfilled the criteria for IgA vasculitis, which was successfully treated by corticosteroid and immunosuppressive therapy. He had a medical history of periodic fever since the age of 10 years old. The Mediterranean fever (MEFV) gene analysis revealed that he was heterozygous for M694I and E148Q mutations. Colchicine therapy resolved his periodic febrile attacks. To our knowledge, coexistence of FMF with IgA vasculitis has not been reported in East Asia, including Japan. Our case suggests that MEFV gene exon 10 mutations could be related to the development of IgA vasculitis and affects its clinical course.

Inflammasomes and Childhood Autoimmune Diseases: A Review of Current Knowledge

Inflammasomes are multiprotein complexes capable of sensing pathogen-associated molecular patterns (PAMPs), danger-associated molecular patterns (DAMPs), and cellular perturbations. Upon stimulation, the inflammasomes activate the production of the pro-inflammatory cytokines IL-1β and IL-18 and induce gasdermin D-mediated pyroptosis. Dysregulated inflammasome signaling could lead to hyperinflammation in response to environmental triggers, thus contributing to the pathogenesis of childhood autoimmune/autoinflammatory diseases. In this review, we group childhood rheumatic diseases into the autoinflammation to autoimmunity spectrum and discuss about the involvement of inflammasomes in disease mechanisms. Genetic mutations in inflammasome components cause monogenic autoinflammatory diseases, while inflammasome-related genetic variants have been implicated in polygenic childhood rheumatic diseases. We highlight the reported associations of inflammasome signaling-related genetic polymorphisms/protein levels with pediatric autoimmune disease susceptibility and disease course. Furthermore, we discuss about the use of IL-1 receptor antagonist as an adjunctive therapy in several childhood autoimmune diseases, including macrophage activation syndrome (MAS) and multisystem inflammatory syndrome in children (MIS-C) related to COVID-19. A comprehensive multi-cohort comparison on inflammasome gene expression profile in different pediatric rheumatic diseases is needed to identify patient subsets that might benefit from the adjunctive therapy of IL-1β inhibitors.

Clinical manifestations and outcomes of 420 children with Henoch Schönlein Purpura from a single referral center from Turkey: A three-year experience

Objectives: Henoch Schönlein Purpura (HSP) is the most common systemic vasculitis in childhood. We aimed to evaluate the clinical features, seasonal variation, treatment outcomes and the possible predicting factors related to outcome among a large cohort of pediatric HSP patients.Methods: We conducted a medical record review study between July 2016 and January 2019 and evaluated the clinical manifestations and potential risk factors for severe gastrointestinal (GI) involvement, biopsy-proven nephritis and relapses.Results: The study included 420 HSP patients, of which the mean age at diagnosis was 7.68 ± 3.15 years. Clinical manifestations were arthralgia and/or arthritis (n = 244, 58.1%), abdominal pain (n = 235, 56%), subcutaneous edema (n = 163, 38.8%), and renal involvement (n = 125, 29.8%). Disease recurred for at least once, in 69 (16.4%) patients and colchicine treatment yielded a favorable response in 11 of 12 relapsing patients, who did not respond to ibuprofen or steroids. Frequencies of renal involvement and biopsy-proven nephritis were higher in patients with severe GI involvement. Besides, patients with biopsy-proven nephritis had higher rates of abdominal pain, intussusception, severe GI involvement, and systemic steroid administration.Conclusion: We speculate that renal involvement, biopsy-proven nephritis and severe GI involvement can be related to each other. Colchicine may be effective in patients with relapsing disease.

Serum neopterin and ischemia modified albumin levels are associated with the disease activity of adult immunoglobulin A vasculitis (Henoch-Schönlein purpura)

AIM

The aims of the study are to investigate serum neopterin and ischemia modified albumin (IMA) levels in patients with immunoglobulin A vasculitis (IgAV) and evaluate the association of these markers with disease activity and relapse.

METHOD

Thirty-four consecutive adult patients (24 male and 10 female) admitted to the rheumatology clinic and met the IgAV American College of Rheumatology (ACR) criteria were enrolled in this cross-sectional study. Demographic and clinical features of IgAV and a control group were recorded into a predefined protocol. Disease activity was categorized as "remission" or "active" according to Birmingham Vasculitis Activity Score (BVAS). BVAS ≥ 1 was accepted as "active". Serum neopterin levels, high-sensitivity C-reactive protein (hsCRP) and IMA were evaluated according to BVAS and compared to the healthy control group.

RESULTS

Serum median (interquartile range) neopterin, IMA levels and hsCRP were higher in the study group than in control group (2.01 [12.5] ng/mL vs 1.77 [1.37] ng/mL, 0.67 [0.2] ng/mL vs. 0.43 [0.17] ng/mL, 5.6 [17.1] mg/L vs. 1.55 [1.6] mg/L, P = .095, P < .001 and P = .002, respectively). When evaluated according to BVAS, IMA and hsCRP levels were significantly higher in the group with active disease (0.77 [0.12] vs 0.61 [0.13] and 14.85 [4.6], P = .009 and P = .03, respectively). Serum neopterin levels were significantly higher in the active group compared to BVAS (18.95 [32.36] vs 1.63 [1.48], P < .001).

CONCLUSION

Oxidative stress is important in IgAV pathogenesis. Roles of hsCRP, neopterin and IMA as potential markers of diagnosis and disease activity seem to be worth studying in future studies with larger study groups.