Childhood IgA Vasculitis (Henoch Schonlein Purpura)-Advances and Knowledge Gaps

Post-streptococcal small-vessel vasculitis in a 16-month-old with associated intussusception and hypertension: Henoch Schönlein purpura?

Henoch Schönlein purpura (HSP), also known as IgA vasculitis, is a systemic small-vessel vasculitis typically occurring in children 3-15 years of age, with peak incidence at 4-6 years. It is characterized by a constellation of symptoms including palpable purpura, arthralgias or arthritis, abdominal pain including intussusception, and renal involvement. We report a patient with these clinical findings whose IgA immunofluorescence was negative but with a presumptive diagnosis of HSP at 16 months of age, significantly younger than the classic population. This condition rarely affects this age group, and we highlight the importance of considering vasculitis in children of all ages, as a failure to diagnose could lead to insufficient long-term monitoring, particularly regarding renal function.

Common Seasonal Pathogens and Epidemiology of Henoch-Schönlein Purpura Among Children

Importance

Henoch-Schönlein purpura (HSP) is the most common type of vasculitis in children. The factors that trigger the disease are poorly understood. Although several viruses and seasonal bacterial infections have been associated with HSP, differentiating the specific associations of these pathogens with the onset of HSP remains a challenge due to their overlapping seasonal patterns.

Objective

To analyze the role of seasonal pathogens in the epidemiology of HSP.

Design, Setting, and Participants

This cohort study comprised an interrupted time-series analysis of patient records from a comprehensive national hospital-based surveillance system. Children younger than 18 years hospitalized for HSP in France between January 1, 2015, and March 31, 2023, were included.

Exposure

Implementation and relaxation of nonpharmaceutical interventions (NPIs) for the COVID-19 pandemic, such as social distancing and mask wearing.

Main Outcomes and Measures

The main outcomes were the monthly incidence of HSP per 100 000 children, analyzed via a quasi-Poisson regression model, and the estimated percentage of HSP incidence potentially associated with 14 selected common seasonal pathogens over the same period.

Results

The study included 9790 children with HSP (median age, 5 years [IQR, 4-8 years]; 5538 boys [56.4%]) and 757 110 children with the infectious diseases included in the study (median age, 0.7 years [IQR, 0.2-2 years]; 393 697 boys [52.0%]). The incidence of HSP decreased significantly after implementation of NPIs in March 2020 (-53.6%; 95% CI, -66.6% to -40.6%; P < .001) and increased significantly after the relaxation of NPIs in April 2021 (37.2%; 95% CI, 28.0%-46.3%; P < .001). The percentage of HSP incidence potentially associated with Streptococcus pneumoniae was 37.3% (95% CI, 22.3%-52.3%; P < .001), the percentage of cases associated with Streptococcus pyogenes was 25.6% (95% CI, 16.7%-34.4%; P < .001), and the percentage of cases associated with human rhino enterovirus was 17.1% (95% CI, 3.8%-30.4%; P = .01). Three sensitivity analyses found similar results.

Conclusions and Relevance

This study found that significant changes in the incidence of HSP simultaneously with major shifts in circulating pathogens after NPIs for the COVID-19 pandemic indicated that approximately 60% of HSP incidence was potentially associated with pneumococcus and group A streptococcus. This finding suggests that preventive measures against these pathogens could reduce the incidence of pediatric HSP.

Association between TRAF1/C5 Gene Polymorphisms and IgA Vasculitis in Chinese Children

OBJECTIVE

To investigate the association between loci rs3761847 and rs10818488 of tumor necrosis factor receptor-associated factor 1/complement C5 (TRAF1/C5) gene and the susceptibility to IgAV.

METHODS

100 blood samples of children with IgAV and 100 blood samples of healthy children were collected from the Third Xiangya Hospital of Central South University from June 2017 to June 2019. The target gene fragment was amplified by polymerase chain reaction (PCR), and the single nucleic acid gene polymorphism of the gene loci was detected by PCR sequencing based typing technique. The association between gene polymorphism of each locus and susceptibility to IgAV was analyzed.

RESULTS

There were significant differences in both genotype (P < .05) and allele frequencies （P < .05) of rs3761847 of TRAF1/C5 gene between the IgAV group and the control group.Besides, the risks of developing IgAV in children with the TT genotype was 0.495 times and in children with the C allele was 1.627 times of that in children with other genotypes and alleles, respectively (P < .05). For IgAV patients, renal involvement risk in children with CC genotype was 5.859 times of that in children with other genotypes (P < .05). There were no significant differences in genotype (P > .05) and allele frequencies (P > .05) of rs10818488 of TRAF1/C5 gene between the IgAV group and the control group. IgAV patients with TT genotype had a 3.2 times higher risk of renal involvement than those with other genotypes (P < .05).

CONCLUSIONS

There is an association between locus rs3761847 of TRAF1/C5 gene single nucleotide polymorphisms and susceptibility to IgAV. The T allele at locus rs3761847 of TRAF1/C5 gene may be a protective factor for IgAV. The C allele at locus rs3761847 and the T allele at locus rs10818488 of TRAF1/C5 gene may be associated with kidney injury in IgAV.

A Review of IgA Vasculitis (Henoch-Schönlein Purpura) Past, Present, and Future

The clinical association of purpura, arthralgia, and arthritis was first described in 1837 in a publication by Johann Lukas Schönlein, a German physician. In 1874, Eduard Henoch, a student of Schönlein, reported cases of children with purpura, abdominal pain, bloody diarrhea, and joint pain. IgA vasculitis, or Henoch-Schönlein purpura, is a systemic hypersensitivity vasculitis caused by the deposition of immune complexes in small blood vessels, including the renal glomeruli and mesangium. In the skin, the presentation is with non-thrombocytopenic purpura or urticaria. Worldwide, IgA nephropathy is the most common cause of primary glomerulonephritis. Detection of IgA deposition in small blood vessels and the renal glomeruli is diagnostic in most cases. This article aims to review the history, current classification, epidemiology, presentation, and diagnosis of IgA vasculitis and nephropathy, disease associations or trigger factors, including infections, vaccines, and therapeutic agents, and highlights some future approaches to improve diagnosis and clinical management.

Drusen and Other Retinal Findings in People With IgA Glomerulonephritis

PURPOSE

Retinal drusen have been described in people with IgA nephropathy. We examined the frequency of drusen in IgA nephropathy and compared their location and composition with those for drusen in age-related macular degeneration.

DESIGN

Immunohistological case series of eyes of patients with IgA nephropathy, and a comparison eye with age-related macular degeneration.

METHODS

Donor eyes from 4 individuals (3 male, 1 female, aged 40-80 years) with biopsy-proven IgA nephropathy and kidney failure were examined for the presence of drusen, and location and composition using antibodies for vitronectin, IgA, IgM, IgG, C3, and C1q. Results were compared with those for drusen in macular degeneration without IgA nephropathy.

RESULTS

All 4 donors had sparse, subretinal pigment epithelium drusen of 55-65 mm diameter that stained for vitronectin but not for IgA or complement. All donors had retinal capillaries and choriocapillaris staining for IgA. The youngest donor (female, 40) had rare deposits in the outer nuclear layer that stained for IgA, but not for vitronectin. The oldest donor (male, 82) had large cystlike spaces in the inner nuclear and plexiform layers, and smaller cysts in the outer nuclear layer, with no staining for IgA or complement.

CONCLUSIONS

Retinal drusen are uncommon in IgA nephropathy, even with kidney failure. Drusen in IgA nephropathy resemble drusen found in age-related macular degeneration. IgA-staining deposits in the outer nuclear layer were likely due to systemic deposition of IgA and complement activation. The nature of cystic spaces is unknown. Further analysis of the retinas of people with glomerulonephritis is recommended.

Urinary markers of the alternative and lectin complement pathway are increased in IgA vasculitis nephritis

Background

IgA vasculitis (IgAV) is the most common form of childhood vasculitis. Nephritis (IgAVN) occurs in 50% of patients and 1-2% progress to chronic kidney disease stage 5. The pathophysiology of nephritis remains largely unknown, but recent evidence suggests that the complement system may be involved. The aim of this cross-sectional study was to explore whether there is evidence of alternative and/or lectin complement pathway activation in children with IgAVN.

Methods

Children with IgAV were recruited and grouped according to proteinuria: IgAVN or IgAV without nephritis (IgAVwoN). Age and sex-matched healthy controls (HCs) were also recruited. Cross-sectional urine and plasma concentrations of complement factor D (CFD), factor B (CFB), and MBL-associated protease 1 (MASP-1) were performed using commercially available enzyme-linked immunoassays.

Results

A total of 50 children were included (IgAVN, n = 15; IgAVwoN, n = 20, HCs, n = 15). The mean age was 8.5 ± 3.7 years old, male:female ratio was 1:1. Urinary CFD and CFB concentrations were statistically significantly increased in children with IgAVN (3.5 ± 5.4 μg/mmol; 25.9 ± 26.5 μg/mmol, respectively) compared to both IgAVwoN (0.4 ± 0.4 μg/mmol, P = 0.002; 9.2 ± 11.5 μg/mmol, P = 0.004) and HCs (0.3 ± 0.2 μg/mmol, P < 0.001; 5.1 ± 6.0 μg/mmol, P < 0.001). No statistically significant difference was reported for the plasma concentrations of CFD and CFB. Urinary MASP-1 concentrations were statistically significantly increased in IgAVN (116.9 ± 116.7 ng/mmol) compared to HCs (41.4 ± 56.1 ng/mmol, P = 0.006) and plasma MASP-1 concentrations were increased in IgAVwoN (254.2 ± 23.3 ng/mL) compared to HCs (233.4 ± 6.6 ng/mL, P = 0.046).

Conclusion

There is evidence of complement pathway products in the urine of children with IgAVN that warrants further investigation.

A narrative review of potential drug treatments for nephritis in children with IgA vasculitis (HSP)

Immunoglobulin A (IgA) vasculitis (IgAV, also known as Henoch-Schoenlein purpura, HSP) is the most common vasculitis of childhood. It usually presents with a simple, self-limiting disease course; however, a small subset of patients may develop kidney involvement (IgAV-N) which occurs 4-12 weeks after disease onset and is the biggest contributor to long-term morbidity. Treatment currently targets patients with established kidney involvement; however; there is a desire to work towards early prevention of inflammation during the window of opportunity between disease presentation and onset of significant nephritis. There are no clinical trials evaluating drugs which may prevent or halt the progression of nephritis in children with IgAV apart from the early use of corticosteroids which have no benefit. This article summarises the latest scientific evidence and clinical trials that support potential therapeutic targets for IgAV-N that are currently being developed based on the evolving understanding of the pathophysiology of IgAV-N. These span the mucosal immunity, B-cell and T-cell modulation, RAAS inhibition, and regulation of complement pathways, amongst others. Novel drugs that may be considered for use in early nephritis include TRF-budesonide; B-cell inhibiting agents including belimumab, telitacicept, blisibimod, VIS649, and BION-1301; B-cell depleting agents such as rituximab, ofatumumab, and bortezomib; sparsentan; angiotensin converting enzyme inhibitors (ACE-Is); and complement pathway inhibitors including avacopan, iptacopan, and narsoplimab. Further clinical trials, as well as pre-clinical scientific studies, are needed to identify mechanistic pathways as there may be an opportunity to prevent nephritis in this condition. Key Points • Kidney involvement is the main cause of long-term morbidity and mortality in IgA vasculitis despite the current treatment recommendations. • The evolving understanding of the pathophysiology of IgA vasculitis is allowing exploration of novel treatment options which target underlying immune pathways. • Novel treatments currently being trialled in IgA nephropathy may have benefit in IgA vasculitis due to the similarities in the underlying pathophysiology, such as TRF-budesonide, B-cell modulators, and complement inhibitors. • Further studies, including clinical trials of novel drugs, are urgently needed to improve the long-term outcomes for children with IgA vasculitis nephritis.

Anti-Inflammatory and Immunomodulatory Effect of High-Dose Immunoglobulins in Children: From Approved Indications to Off-Label Use

BACKGROUND

The large-scale utilization of immunoglobulins in patients with inborn errors of immunity (IEIs) since 1952 prompted the discovery of their key role at high doses as immunomodulatory and anti-inflammatory therapy, in the treatment of IEI-related immune dysregulation disorders, according to labelled and off-label indications. Recent years have been dominated by a progressive imbalance between the gradual but constant increase in the use of immunoglobulins and their availability, exacerbated by the SARS-CoV-2 pandemic.

OBJECTIVES

To provide pragmatic indications for a need-based application of high-dose immunoglobulins in the pediatric context.

SOURCES

A literature search was performed using PubMed, from inception until 1st August 2023, including the following keywords: anti-inflammatory; children; high dose gammaglobulin; high dose immunoglobulin; immune dysregulation; immunomodulation; immunomodulatory; inflammation; intravenous gammaglobulin; intravenous immunoglobulin; off-label; pediatric; subcutaneous gammaglobulin; subcutaneous immunoglobulin. All article types were considered.

IMPLICATIONS

In the light of the current imbalance between gammaglobulins' demand and availability, this review advocates the urgency of a more conscious utilization of this medical product, giving indications about benefits, risks, cost-effectiveness, and administration routes of high-dose immunoglobulins in children with hematologic, neurologic, and inflammatory immune dysregulation disorders, prompting further research towards a responsible employment of gammaglobulins and improving the therapeutical decisional process.

Atypical Immunoglobulin A Vasculitis in a Pediatric Patient With Ulcerative Colitis

Rates of pediatric inflammatory bowel disease and biologic therapy use continue to rise. Consequently, specialists and generalists should recognize potential complications and side effects. We report the unique case of an adolescent with ulcerative colitis (UC) on vedolizumab presenting with severe abdominal pain, hematochezia, and subsequent purpura. After extensive investigation and a complex clinical course, diagnosis of atypical immunoglobulin A vasculitis was made. This is the first pediatric case of vasculitis in a patient with UC on vedolizumab and only the second reported case overall in UC. This case illustrates the emerging diagnostic challenge of distinguishing inflammatory bowel disease treatment complications from other common pediatric conditions.

Glomerulonephritis

Glomerulonephritis (GN) encompasses several disorders that cause glomerular inflammation and injury through an interplay of immune-mediated mechanisms, host characteristics, and environmental triggers, such as infections. GN can manifest solely in the kidney or in the setting of a systemic illness, and presentation can range from chronic and relatively asymptomatic hematuria to fulminant renal failure. Classic acute GN is characterized by hematuria, edema, and hypertension, the latter 2 of which are the consequence of sodium and water retention in the setting of renal impairment. Although presenting signs and symptoms and a compatible clinical history can suggest GN, serologic and urinary testing can further refine the differential diagnosis, and renal biopsy can be used for definitive diagnosis. Treatment of GN can include supportive care, renin-angiotensin-aldosterone system blockade, immunomodulatory therapy, and renal transplant. Prognosis is largely dependent on the underlying cause of GN and can vary from a self-limited course to chronic kidney disease. This review focuses on lupus nephritis, IgA nephropathy, IgA vasculitis, and postinfectious GN.

A case series on recurrent and persisting IgA vasculitis (Henoch Schonlein purpura) in children

BACKGROUND

IgA vasculitis (IgAV) is a small vessel vasculitis that is more common in childhood. Very limited evidence exists on patients who experience an atypical disease course. The aim of this study was to describe a cohort of children diagnosed with recurrent or persisting IgAV to identify any themes associated with their disease course and areas of unmet needs.

METHODS

A single centre retrospective study of children diagnosed with recurrent or persisting IgAV at Alder Hey Children's Hospital (Liverpool, UK). Clinical data, including features at presentation and during follow up, potential triggers, abnormal laboratory and histology results, treatment and outcome at last clinical review were retrospectively collected. Key themes were identified.

RESULTS

A total of 13 children met the inclusion criteria (recurrent disease, n = 4; persisting disease, n = 9). Median age at first presentation was 10.2 years [2.6-15.5], female:male ratio 1.2:1. Children in the atypical cohort were significantly older than a larger cohort of children who followed a non-complicated disease course (median age 5.5 years (range [0.6-16.7], p = 0.003)). All children re-presented with a purpuric rash (either recurring or persisting), accompanied by joint involvement in 92% of patients (12/13). Disease-modifying anti-rheumatic drugs (DMARDs) were used in 8/13 (62%) children. The median time from first presentation to diagnosis of atypical disease was 18.4 months [5.3-150.8] and the time from first presentation to treatment was 24.1 months [1.8-95.4]. Use of corticosteroids was significantly higher in children with renal involvement (p = 0.026). During follow up, 8/13 (62%) children were admitted at least once, whilst 10/13 (77%) had re-presented at least once to the emergency department. Five (38%) children were referred to psychology services and 7 (54%) children reported feelings of frustration.

CONCLUSIONS

This series describes some characteristics of a small cohort of children with atypical IgAV. It also identifies unmet needs in children with atypical IgAV, which includes delays in diagnosis and lengthy waits for treatment, lack of high-quality evidence regarding treatment choices and a high unrecognised disease burden. Further research is needed to study this subgroup of children as evidence is lacking.

Severe gastrointestinal involvement in pediatric IgA vasculitis: a retrospective single-center cohort study in China

Objectives

The study aimed to describe the characteristics of gastrointestinal (GI) involvement in a cohort of hospitalized children with IgA vasculitis (IgAV) in China.

Method

We reviewed the records of hospitalized IgAV patients from January 2014 to December 2020 at one tertiary medical center. The patients were divided into the severe GI group and the non-severe GI group according to the presence of massive GI bleeding and complications. The clinical manifestations, laboratory factors, and treatment were analyzed between the two groups.

Results

A total of 1,179 patients were hospitalized due to IgAV. GI involvement was noted in 50% (589) of the patients, of whom 288 (48.9%) had severe GI involvement. GI complications were observed in 34 patients with IgAV with GI involvement. Rare onset age (<3 years or within 13-17 years), purpura above the waist, vomiting, high neutrophil-to-lymphocyte ratio, and decreased serum albumin were factors associated with severe GI involvement. Frequencies of renal involvement and biopsy-proven nephritis were higher in the severe GI group. The most commonly used medications were corticosteroids (100.0%) in the severe GI group. The maximum corticosteroid dose was higher (2.9 vs. 2.0 mg/kg), and more second-line therapies were needed (30.9% vs. 16.94%) in the severe GI group.

Conclusions

Severe GI involvement in children is common in our center. Rare onset age, purpura above the waist, vomiting, high neutrophil-to-lymphocyte ratio, and decreased serum albumin are associated with severe GI involvement. Patients with severe GI involvement need higher doses of corticosteroids and second-line therapy.

Neutrophil extracellular traps involved in the pathogenesis of IgA vasculitis: Confirmed in two IgAV rat models

BACKGROUND

Neutrophil extracellular traps (NETs) have been found to play a role in the development of autoimmune diseases. In the past two years, studies have demonstrated a significantly increase of NETs in skin tissues during the early stages of IgAV, indicating their involvement in disease activity among children with IgAV. However, the presence of NETs in IgAV animal models has not yet been reported. The objective of this study is to investigate whether NETs are involved in the pathogenesis of IgA vasculitis (IgAV) rats.

METHODS

Twenty-four SD rats were randomly divided into three groups: the ovalbumin group, the gliadin group, and the control group. The IgAV rat models were established administering Indian ink with ovalbumin (ovalbumin group) or gliadin (gliadin group) with Freund's complete adjuvant. The cell-free DNA (cf-DNA) was quantified by using dsDNA quantification kit, while the levels of Immunoglobulins, complement C3 and myeloperoxidase-DNA (MPO-DNA) in serum were tested using enzyme linked immunosorbent assay (ELISA). The IgA, complement C3 and NETs in tissues were detected through multiple immunofluorescences.

RESULTS

Both the ovalbumin group and gliadin group showed IgA and C3 deposition in various tissues, including the glomerular mesangial region, skin, and digestive tract, while the control group showed no such deposition. The levels of circulatory cf-DNA and MPO-DNA, which are components of NETs, were significantly elevated in both ovalbumin and gliadin groups compared with the control group. Furthermore, the presence of NETs were found in gastrointestinal and renal tissues of the ovalbumin and gliadin groups, but not in the control group.

CONCLUSIONS

IgAV model rat can be established through the combination of ovalbumin and gliadin with Indian ink and Freund's complete adjuvant. This study provides the first confirmation that NETs are involved in the pathogenesis of IgAV rat.

A Rare Complication of Henoch-Schönlein Purpura/IgA Vasculitis in an Adult Woman After COVID-19 Infection

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection can affect multiple organs due to activation of an inflammatory response. One of the key components of this response is the activation of immunoglobulin A (IgA), thus causing endothelial injury and inflammation. Henoch-Schönlein purpura (HSP) has been rarely reported in adult patients as a complication of the coronavirus disease 2019 (COVID-19) infection. In this report, we present a case of HSP occurring one week after the diagnosis of COVID-19 in a 23-year-old woman. Her symptoms included nausea, vomiting, diffused abdominal pain, joint pain, hematuria, and palpable purpura of the lower extremities. She was treated with intravenous methylprednisolone sodium succinate, followed by oral prednisone therapy, which resulted in clinical improvement, including resolution of abdominal and joint pain as well as skin rashes, without remaining renal complication.

Adding Methylprednisolone and Cyclophosphamide Pulse Therapy Provides No Benefit in Pediatric IgAV Nephritis Grade III

Although immunoglobulin (Ig) A vasculitis (IgAV) nephritis is a common form of secondary pediatric glomerulonephritis, there is no consensus on an appropriate therapeutic regimen for moderate-to-severe pediatric IgAV nephritis grade III or the effectiveness of aggressive immunosuppressive therapy. The objective is to evaluate the efficacy and renal outcomes of methylprednisolone pulse therapy with or without cyclophosphamide pulse therapy for grade III IgAV nephritis in children. This retrospective, single-center study included 115 children with IgAV nephritis grade III. The primary endpoint was proteinuria reduction from moderate or severe levels to a normal level. The secondary endpoint was stable renal function, that is, an increase of less than 25% from the baseline creatinine level over the 4-month follow-up period. Among 115 children with IgAV nephritis grade III, 59 received methylprednisolone and cyclophosphamide double-pulse treatment; methylprednisolone and cyclophosphamide double-pulses did not significantly improve proteinuria remission. Proteinuria improvement did not show any difference with or without cyclophosphamide treatment. Furthermore, methylprednisolone pulse therapy showed no benefit over steroid therapy alone. The demographic and baseline disease characteristics among the treatment groups were well-balanced. The rates of complete remission in 24-hour proteinuria excretion over the 4-month follow-up period in the methylprednisolone and cyclophosphamide double-pulse, methylprednisolone plus oral prednisolone, and oral prednisolone-only groups were 91.52%, 92.31%, and 100%, respectively. Renal function remained stable in all the patients. Most patients with IgAV nephritis grade III showed a good prognosis. However, the addition of methylprednisolone and/or cyclophosphamide pulses did not offer benefits over steroid-only therapy.

Proanthocyanidins: A novel approach to Henoch‑Schonlein purpura through balancing immunity and arresting oxidative stress via TLR4/MyD88/NF‑κB signaling pathway (Review)

Henoch-Schonlein purpura (HSP), a recurrent and immunoglobulin (Ig)A-mediated vasculitis, presents not only as skin lesions but also as systemic involvement that can be life-threatening. Although the etiology of HSP remains unknown, immune imbalance and oxidative stress (OS) are primary contributors to its pathogenesis, alongside the abnormal activation of Toll-like receptor (TLR)/myeloid differentiation primary response gene 88 (MyD88)/nuclear factor-κB (NF-κB) pathway. TLRs, especially TLR4, stimulate downstream signaling molecules such as NF-κB and proinflammatory cytokines, which are released when TLRs combine with the key adapter molecule MyD88. This leads to the activation of T helper (Th) cell 2/Th17 and overproduction of reactive oxygen species (ROS). The function of regulatory T (Treg) cells is suppressed in the process. Th17/Treg imbalance then produces various inflammatory cytokines to promote proliferation and differentiation of B cells and the secretion of antibodies. IgA is secreted, and it binds to vascular endothelial surface receptors where the complex induces injury of the vascular endothelial cells. Additionally, excessive ROS creates OS that leads to an inflammatory response and vascular cell apoptosis or necrosis, thereby contributing to vascular endothelial damage and HSP occurrence. Proanthocyanidins are active compounds naturally enriched in fruits, vegetables and plants. Proanthocyanidins have diverse properties, including anti-inflammatory, antioxidant, antibacterial, immunoregulatory, anticarcinogenic and vascular protective effects. Proanthocyanidins are used in the management of various diseases. Proanthocyanidins regulate T cells, equilibrate immunity and arrest OS by inhibiting the TLR4/MyD88/NF-κB signaling pathway. Considering the pathogenesis of HSP and the properties of proanthocyanidins, the present study hypothesized that these compounds may potentially lead to HSP recovery through modulating the immune equilibrium and preventing OS by inhibiting the TLR4/MyD88/NF-κB pathway. To the best of our knowledge, however, little is known about the positive effects of proanthocyanidins against HSP. The present review summarizes the potential of proanthocyanidins to treat HSP.

Targeted Transcriptional Analysis of IgA Vasculitis, IgA Nephropathy, and IgA-Dominant Infection-Related Glomerulonephritis Reveals Both Distinct and Overlapping Immune Signatures

Key Points

Skin IL-9, calprotectin, and KIR gene expression may be predictive of subsequent kidney involvement in patients with IgAV. Histologically similar patients with IgAN, IgAV, and IgA-IRGN can be distinguished by their immune transcriptomes. Kidney biopsies from patients with IgA-IRGN are enriched for transcripts involved in granulocyte chemotaxis.

Background

IgA vasculitis (IgAV), IgA nephropathy (IgAN), and IgA-dominant infection-related glomerulonephritis (IgA-IRGN) have shared histopathologic features, but differences in clinical management and prognosis. The most serious IgAV organ involvement is in the kidneys (IgAV nephritis). In this study, we hypothesized that targeted immune transcript profiling could aid in (1 ) predicting the development of IgAV nephritis in patients with cutaneous IgAV and (2 ) differentiating IgAN, IgAV, and IgA-IRGN.

Methods

RNA was extracted from 24 formalin-fixed paraffin-embedded tissue specimens (16 kidney, 8 skin) from 21 patients with IgAV nephritis (n=7), IgAN (n=5), and IgA-IRGN (n=4), and IgAV skin biopsies from patients with (n=3) and without (n=5) IgAV nephritis. Differential gene expression and gene set enrichment analysis were performed on a total of 594 transcripts (Nanostring immunology panel) profiled using the nCounter system.

Results

Skin biopsies in patients with IgAV who develop kidney involvement exhibit reduced S100A8/S100A9 , IL9 , and killer cell immunoglobulin-like receptor expression. The kidney tissue immune transcriptomes of IgAN, IgAV, and IgA-IRGN are largely overlapping. IgA-IRGN kidney biopsies are, however, uniquely enriched for transcripts involved in granulocyte chemotaxis.

Conclusion

This study identifies immune transcript signatures that may predict IgAV nephritis in skin biopsies and distinguish IgA-IRGN from IgAN and IgAV in kidney biopsies.

Ankle and Foot: Focus on Inflammatory Disease

The ankle and foot have numerous bones and complex joints that can be affected by several types of inflammatory arthritis with different patterns and various radiologic signs, depending on the phase of the disease. Involvement of these joints is most frequently seen in peripheral spondyloarthritis and rheumatoid arthritis in adults and juvenile idiopathic arthritis in children. Although radiographs are a mainstay in the diagnostic process, ultrasonography and especially magnetic resonance imaging allow early diagnosis and are crucial diagnostic tools. Some diseases have typical features based on target populations (e.g., adults versus children, men versus women), but others may have overlapping imaging characteristics. We highlight key diagnostic features and describe appropriate investigations to guide clinicians toward the correct diagnosis and provide support during disease monitoring.

Classic IgA-Vasculitis With Nephrotic Range Proteinuria - Rare Presentation in an Adult

IgA vasculitis formerly known as Henoch-Schonlein Purpura is characterized by leukocytoclastic vasculitis and IgA immune complex in small vessels of the affected organ. IgA vasculitis can involve any organ system depending upon the deposition of the IgA immune complex. IgA vasculitis is a clinical diagnosis which manifest with abdominal pain, arthralgia/arthritis, palpable purpura, and kidney involvement. Occasionally, serum IgA levels or skin or kidney biopsy can help in confirming the diagnosis. Treatment is usually supportive, but studies have proved that prednisone or immunosuppressive agents can help in the prevention or progression of the disease. Hereby we present a case of 54-year-old Caucasian male who developed classic tetrad findings of IgA vasculitis most likely after receiving monkeypox vaccine which patient received three weeks prior to presentation to the hospital. Kidney involvement was present but surprisingly proteinuria was above nephrotic range making it as a rare presentation of IgA vasculitis.

IgA Vasculitis Associated With COVID-19

IgA vasculitis, also known as Henoch-Schonlein Purpura (HSP), is an inflammatory disorder of small blood vessels that can present with palpable purpura, arthralgias, abdominal pain, and kidney disease. It is most commonly found in pediatric patients after an inciting infection but has been seen across all ages and associated with certain drugs and vaccines. COVID-19 has been associated with various cutaneous manifestations, but HSP is a rarely reported one. We present a case of a 21-year-old female presenting with a petechial rash found to be seronegative IgA vasculitis presenting concurrently with dyspnea secondary to COVID-19. She was initially seen by an outside practitioner, tested negative for COVID, and was prescribed a course of oral prednisone. Shortly thereafter, she visited the ED for worsening shortness of breath and tested positive for COVID-19, for which she received Paxlovid. Biopsy after a visit to a dermatologist confirmed intramural IgA deposition on immunofluorescence, and she was tapered off prednisone and started on azathioprine.

Socioeconomic, Clinical, and Laboratory Parameters Differentiating Pediatric Patients With MOG Antibody-Associated Disease and Multiple Sclerosis

Studies indicate differences in the clinical phenotypes and neuroimaging of children with myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD) compared to multiple sclerosis; however, there are limited data assessing the socioeconomic and paraclinical differences between these distinct disorders. This retrospective study identified patients aged <18 years at time of diagnosis with MOGAD or multiple sclerosis. Demographics, birth history, socioeconomic factors (insurance type, median income, parental education level), and paraclinical features (clinical manifestations, laboratory evaluation) were recorded for eligible participants. Seventy-eight patients (28 MOGAD, 50 multiple sclerosis) met inclusion criteria. Mothers of MOGAD children were more likely to have attended college compared to the mothers of children with multiple sclerosis (80% vs 49%; P = .02). Though MOGAD patients had greater rates of day care attendance (81% vs 57%), lower rates of birth complications (7% vs 21%), and higher rates of being breastfed (65% vs 46%), these findings did not meet predefined statistical significance. Clinically, children with MOGAD exhibited a lower body mass index percentile at presentation (58th ± 27th percentile vs 83rd ± 20th percentile; P = .0001) and were younger (7.6 ± 4.1 vs 14.8 ± 1.6 years; P < .0001) and more likely to exhibit an infectious prodrome (57% vs 10%; P < .0001). MOGAD patients were less likely to have evidence of remote Epstein-Barr virus infection (29% vs 100%; P < .0001) and less likely to have ≥3 unique oligoclonal bands in the cerebrospinal fluid (5% vs 87%; P < .001). Compared with multiple sclerosis, children with MOGAD exhibit lower body mass index percentiles at presentation, are more likely to have mothers with higher education levels, and are less likely to have had prior Epstein-Barr virus infection. Our data confirm that MOGAD patients are younger, more likely to exhibit infectious prodrome, and are less likely to exhibit intrathecal synthesis of oligoclonal bands. These features provide new insights into the differentiating pathobiology of MOGAD and may be helpful in differentiating these children from multiple sclerosis early in the diagnostic evaluation.

ASSOCIATION BETWEEN HIGH MOBILITY GROUP BOX 1 PROTEIN GENE (rs41369348) POLYMORPHISM AND IMMUNOGLOBULIN A VASCULITIS IN CHILDREN

Immunoglobulin A vasculitis (IgAV) or Henoch-Schönlein purpura is the most prevalent systemic small vessel vasculitis in childhood. High mobility group box 1 protein (HMBG1) is a pleiotropic cytokine that functions as a pro-inflammatory signal, important for the activation of antigen-presenting cells and propagation of inflammation. HMGB1 is implicated in the pathophysiology of a variety of inflammatory diseases. The aim of this study was to investigate the role of single nucleotide polymorphism rs41369348 for HMGB1 gene in the susceptibility and clinical features of patients meeting the classification criteria for IgAV. DNA was extracted from blood cells of 76 children with IgAV and 150 age-matched healthy controls. Clinical data and laboratory parameters were collected for all IgAV patients. Although there was a higher frequency of heterozygous A/delA genotype of this gene polymorphism in IgAV group as compared with control group, no genotype difference was observed between these two groups. No statistically significant genotype differences were disclosed when patients with different IgAV clinical features were compared. In conclusion, in this study, polymorphism rs41369348 for HMGB1 was not associated with increased susceptibility to childhood IgAV, its severity or different clinical manifestations.

Cardiac involvement and cardiovascular risk factors in pediatric primary systemic vasculitides

Pediatric primary systemic vasculitides are a complex group of diseases. Vasculitis subgroups are mainly determined according to the size of the predominantly affected vessels. In patients with primary systemic vasculitis, the location of vascular involvement, the size of the vessels, the extent of vascular damage, and the underlying pathology determine the disease phenotype and severity. Cardiac involvement is rare in some pediatric vasculitis, such as IgA vasculitis and polyarteritis nodosa, while it is more common in some others like Kawasaki disease and Takayasu arteritis. On the other hand, chronic inflammation in the setting of systemic vasculitis forms a major cardiovascular risk factor. Accelerated atherosclerosis and the tendency to thrombosis are the main issues determining the cardiovascular risks in pediatric systemic vasculitis. Early diagnosis and treatment are essential in these patients to minimize morbidity and mortality. In this review, we aimed to raise physicians' awareness of cardiac involvement and cardiovascular risks in pediatric patients with primary systemic vasculitis.

Acute pancreatitis associated with immunoglobulin A vasculitis: report of fifteen cases

OBJECTIVE

Immunoglobulin A vasculitis (IgAV) is a systemic small vessel vasculitis common in children. Pancreatic involvement in IgAV is rare. The purpose of this study was to analyze the clinical characteristics of IgAV-related acute pancreatitis in children.

METHODS

Records of patients with IgAV-related acute pancreatitis admitted to our institution between January 2016 and December 2019 were reviewed. We summarized the clinical characteristics, laboratory characteristics, imaging findings, treatment, and outcomes of 15 children with IgAV-related acute pancreatitis.

RESULTS

The patients' median age was 9.6 years. Pancreatitis was the initial manifestation of IgAV in 3 patients. All patients had abdominal manifestations, including abdominal pain (15/15), vomiting (10/15), and gastrointestinal bleeding (7/15). Serum amylase and lipase levels were elevated in all patients. Serum amylase in 4 cases reached more than three-fold elevation and serum lipase in 14 cases reached more than three-fold elevation. Morphological abnormalities and abnormal signals of the pancreas were observed in 13 cases by magnetic resonance imaging. Pancreaticobiliary maljunction was seen in 3 cases by magnetic resonance cholangiopancreatography. Glucocorticoid therapy and intravenous immunoglobulins were used to treat acute pancreatitis in IgAV. All patients showed clinical improvement after treatment. During the follow-up period of 6-12 months, all 15 cases with pancreatitis were cured without recurrence.

CONCLUSIONS

Pancreatic involvement is rare in IgAV; however, this should be considered in IgAV patients with severe abdominal pain. The timely application of steroid therapy is important for IgAV-associated pancreatitis. Key Points • Acute pancreatitis is a rare complication of immunoglobulin A vasculitis (IgAV). • Acute pancreatitis can be the initial manifestation of IgAV. It is important to evaluate for pancreatitis while IgAV patients with severe abdominal pain. • A common image finding of IgAV-associated pancreatitis was swelling of the pancreas. • Glucocorticoid therapy and intravenous immunoglobulins is helpful in alleviating acute pancreatitis in IgAV.

SARS-CoV-2 Infection as a Possible Trigger for IgA-Associated Vasculitis: A Case Report

BACKGROUND

IgA-associated vasculitis (IgAV), formerly known as Henoch-Schönlein purpura (HSP) disease, is the most common type of systemic vasculitis observed during developmental age. Available published studies associate the outbreak of the disease with streptococci, adenovirus, parvovirus, mycoplasma, respiratory syncytial virus (RSV), and influenza infection in approximately 50% of patients with HSP, while some emerging reports have described a few cases of COVID-19 infection being associated with HSP in both adults and children.

CASE PRESENTATION

a 7-year-old girl was diagnosed with HSP, fulfilling the four required clinical criteria (palpable purpura and abdominal pain, arthralgia and edema, and periodic renal involvement). Infection with SARS-CoV-2 was confirmed via the presence of IgM and IgG antibodies. The disclosure of the Henoch-Schönlein purpura (HSP) disease was preceded by a mild, symptomatically treated infection of the upper respiratory tract. High levels of inflammatory markers were observed during hospitalization, including leukocytosis, an increased neutrophil count and a high neutrophil-to-lymphocyte ratio (NLR). All of these markers are associated with IgAV gastrointestinal bleeding, which was also associated with rotavirus diarrhea observed in the patient.

CONCLUSIONS

This case presented by us and similar cases presented by other authors indicate the possible role of SARS-CoV-2 in the development of HSP, but this assumption requires further research and evidence-based verification.

Intussusception as a rare manifestation of immunoglobulin A vasculitis: Risk factors and treatment

AIM

To identify the risk factors associated with intussusception in children with immunoglobulin A vasculitis (IgAV)-gastrointestinal (GI) tract involvement and to evaluate the outcomes of medical treatment and surgical intervention and the course of patients with intussusception.

METHODS

This retrospective study was conducted in 157 patients under 18 years of age who were followed up with the diagnosis of IgAV-GI tract involvement between January 2015 and September 2022. The characteristics of the patients who developed intussusception were evaluated in detail.

RESULTS

One hundred and fifty-seven patients with GI tract involvement were included in the study. The mean age of patients with IgAV-GI tract involvement was 8.7 ± 3.7 years. The female-to-male ratio was 1:1.5. Intussusception was detected in 14 patients (8.9%). Two patients (14.3%) underwent surgery, and the remaining 12 patients (85.7%) had their medical therapy intensified. Patients with GI tract involvement were divided into two groups as with (n = 14) and without (n = 143) intussusception. There was a statistically significant difference between the groups in the time from the onset of the first symptom of IgAV to the onset of steroids (P = 0.001). There were no statistically significant differences between the groups in age at onset of IgAV, gender distribution, erythrocyte sedimentation rate and C-reactive protein levels.

CONCLUSIONS

The time from the onset of the first symptom of IgAV to the start of steroids is a risk factor for the development of intussusception in patients with IgAV-GI tract involvement. In these patients, medical treatment usually reduces intussusception without the need for surgical intervention.

Diagnostic and Management Strategies of IgA Vasculitis Nephritis/Henoch-Schönlein Purpura Nephritis in Pediatric Patients: Current Perspectives

IgA vasculitis (IgAV) or Henoch-Schönlein purpura (HSP) is the most common vasculitis in children, and nephritis (IgAVN or HSPN) is the most important and only chronic manifestation of the disease. Despite this, there are no diagnostic criteria and we rely on the European League Against Rheumatism/Paediatric Rheumatology International Trials Organization/Paediatric Rheumatology European Society-endorsed Ankara 2008 classification criteria in our daily practice. Basic investigations that should be done in every patient with IgAVN include blood pressure measurement, estimated glomerular filtration rate and urinalysis. Kidney biopsy is still the gold standard for the diagnosis of IgAVN since noninvasive confirmation of nephritis is still pending. According to the Single Hub and Access point for pediatric Rheumatology in Europe (SHARE) recommendations, the first-line treatment for with mild forms of IgAVN is oral glucocorticoids, for patients with moderate IgAVN parenterally administrated glucocorticoids in pulsed doses, while initial treatment for patients with the most severe forms of IgAVN include pulsed doses of glucocorticoids in combination with intravenous cyclophosphamide pulses. New therapeutic options are currently being tested, aiming to reduce the production of galactose-deficient IgA₁ and autoantibodies or suppress the alternative or lectin complement pathway and blocking mesangial cell activation.

IgA Vasculitis Following COVID-19 Vaccination

As new variants of SARS-CoV-2 continue to emerge worldwide, countries are striving to fully vaccinate their population in a bid to prevent severe disease, subsequent hospitalizations, and the associated strain on their healthcare systems and death. In this context, there is growing evidence of rare, potential side effects associated with COVID-19 vaccines. IgA vasculitis is a systemic, IgA-mediated vasculitis characterized by palpable purpura, arthralgia, abdominal pain, and renal involvement. It is the most common type of vasculitis in childhood, sporadically affecting the adult population. However, there have been multiple reports of IgA vasculitis following vaccination against COVID-19. Herein, we present the case of a 72-year-old patient with palpable purpura that developed two weeks after receiving the Pfizer BioNTech vaccine. Laboratory investigations revealed elevated serum creatinine (2.6 mg/dL), macroalbuminuria (8.6 g/24 h), and macroscopic hematuria. Histopathological examination confirmed necrotizing vasculitis, and a diagnosis of IgA vasculitis was established. Considering the clinical presentation, the laboratory and histopathological findings, and the time interval between the vaccination and the development of symptoms, we strongly believe that IgA vasculitis in this patient arose as a side effect of the Pfizer BioNTech vaccine.

Immunoglobulin a vasculitis with testicular/epididymal involvement in children: A retrospective study of a ten-year period

The clinical characteristics and risk factors for testicular/epididymal involvement in 73 children with immunoglobulin A vasculitis (IgAV) who were admitted to our hospital between January 2012 and November 2022 were reviewed. The demographic data, laboratory parameters, and follow-up data of the patients were compared to those of 146 males without testicular/epididymal involvement. A logistic regression analysis was performed to determine the variables associated with testicular/epididymal involvement. The prevalence of testicular/epididymal involvement among male patients with IgAV was 1.3% (73/5,556). Increased blood flow in the testes and/or epididymis on ultrasound was found in 71 patients. The remaining two patients underwent surgical exploration for loss or reduction of testicular blood flow. One patient underwent orchiectomy for intraoperative confirmation of complete right testicular infarction. Pathological findings revealed IgA immune complex deposition in the testis. Patient age (odds ratio [OR] = 0.792; 95% confidence interval [CI]: 0.682-0.919, p = 0.002), platelet count (OR = 1.011; 95% CI: 1.002-1.020, p = 0.013), and immunoglobulin M (IgM) levels (OR = 0.236; 95% CI: 0.091-0.608, p = 0.003) were strongly associated with the occurrence of testicular/epididymal involvement in IgAV. Therefore, young age, increased platelet count, and low IgM levels in patients with IgAV are potential risk factors for testicular/epididymal involvement. Doppler ultrasound can help differentiate IgAV from acute scrotum. Most patients with testicular/epididymal involvement have good prognoses, although serious complications such as testicular infarction may occur.

A chronic EBV infection causing persistent facial erythema multiforme and a retrospective literature review: A case report

RATIONALE

Epstein-Barr virus (EBV) infection is associated with a variety of diseases and can involve multiple organs and systems, with complex and nonspecific clinical manifestations that are easily misdiagnosed. Chronic EBV infection with persistent erythema multiforme (EM) on the cheek as the main manifestation is very rare and has been reported rarely.

PATIENT CONCERNS

This article reports a case of an adolescent female with chronic EBV infection who presented with chronic symmetrical erythema lesions on the face for 4 years, exacerbated with photophobia, lacrimation, Henoch-Schonlein purpura (HSP)-like rash, decline in granulocyte and erythrocyte lineages, hematuria, and proteinuria for 1 week.

DIAGNOSES

The disease was initially misdiagnosed as systemic lupus erythematosus (SLE) and later confirmed as chronic EBV infection by skin biopsy. In the case, EBV infection not only caused chronic facial EM, but also induced acute HSP and purpura nephritis (hematuria and proteinuria type).

INTERVENTIONS

The child was treated with 1 week of glucocorticosteroids in adequate doses combined with acyclovir antiviral therapy and 3 sessions of hemoperfusion. After discharge, she took prednisone acetate (15 mg twice a day) orally for 1 month and then discontinued.

OUTCOMES

She was discharged with her rash relieved and normal blood routine test and urine routine test. After 13 months of long-term follow-up, her facial erythema and hyperpigmentation became lighter, and there was no new rash on the whole body, and no abnormality in continuous monitoring of complete blood count and urine test.

LESSONS

This case suggests the need to be alert for chronic EBV infection in adolescent females with chronic facial EM rash and multiple organs and systems injury, in addition to connective tissue diseases such as SLE.

Increased Urinary IgA in Paediatric IgA Vasculitis Nephritis

IgA vasculitis (IgAV) is the most common form of paediatric vasculitis, with up to 50% of patients experiencing kidney inflammation. Much remains unknown about IgAV, but it is believed to arise due to galactose-deficient IgA1 promoting an auto-inflammatory response. This study assesses whether urinary IgA can be detected in children with IgAV to allow further evaluation of IgA1 and whether it has any relationship with nephritis. Urinary and serum IgA concentrations were measured using commercially available ELISA kits. Patients were grouped into IgAV nephritis (IgAVN) or IgAV without nephritis (IgAVwoN). Fifty-nine children were included: IgAVN n = 12, IgAVwoN n = 35, and healthy controls (HC) n = 12, with a mean age of 8.2 ± 4.1 years. Urinary IgA concentrations were statistically significantly higher in patients with IgAV (107.1 ± 136.3 μg/mmol) compared to HC (50.6 ± 26.3 μg/mmol; p = 0.027) and IgAVN (229.8 ± 226.3 μg/mmol) compared to both IgAVwoN (65.0 ± 37.8 μg/mmol; p = 0.002) and HC (p < 0.001). Urinary IgA concentrations were able to distinguish between renal status (AUC 0.838, 95%CI [0.704−0.973], p < 0.001) and did not correlate with proteinuria (r = 0.124; p = 0.407). Urinary IgA concentrations are increased in children with IgAVN, and it has the potential to act as a non-invasive biofluid to further evaluate nephritis in this disease.

Association between common laboratory indices and IgAV recurrence in children

Background

IgA vasculitis (IgAV) is a common type of vasculitis seen in children. IgAV recurrence can result in chronic kidney disease. We aimed to explore the association between common laboratory indices and IgAV recurrence in children, and to establish a prediction model.

Methods

This retrospective study included children with diagnosed with IgAV hospitalized in Bazhong Central Hospital, Sichuan, from January 2014 to December 2019. Children were assigned to two groups based on IgAV recurrence, and baseline clinical data were collected for comparison. A logistic regression model to predict IgAV recurrence was established. The receiver operating characteristic curve was plotted. The area under the curve (AUC) was used to detect performance of the predictive model.

Results

This study included 193 children (39 [20.2%], recurrence group; 154 [79.8%], non-recurrence group). Based on multivariate regression analysis, the duration of illness and joint involvement were independent predictors of IgAV recurrence in children (P < 0.05). No significant differences were observed in common laboratory indices (P > 0.05). The AUC of the prediction model was 0.766 (P < 0.001) with sensitivity of 74.4% and specificity of 68.8%.

Conclusion

Common laboratory indices were not associated with recurrence of IgAV in children.

Urinary complement proteins are increased in children with IgA vasculitis (Henoch-Schönlein purpura) nephritis

BACKGROUND

Children with immunoglobulin A vasculitis (IgAV Henoch-Schönlein purpura) frequently encounter nephritis (IgAV-N) with 1-2% risk of kidney failure. The pathophysiology of IgAV-N is not fully understood with speculation that complement may contribute. The aim of this study was to identify whether urinary complement proteins are increased in children with IgAV-N.

METHODS

A cross-sectional prospective cohort of children with IgAV were recruited together with controls including healthy children and children with systemic lupus erythematosus (SLE). Patients were subdivided according to the presence of nephritis. Urinary C3, C4, C5, and C5a were measured by enzyme-linked immunosorbent assay (ELISA) and corrected for urinary creatinine.

RESULTS

The study included 103 children; 47 with IgAV (37 IgAV without nephritis, IgAVwoN; 10 IgAV-N), 30 SLE and 26 healthy children. Urinary complement C3, C4, and C5 were all statistically significantly increased in all children with IgAV compared to SLE patients (all p < 0.05). In patients with IgAV-N, urinary complement C3, C4, C5, C5a were all statistically significantly increased compared to IgAVwoN (C3 14.65 μg/mmol [2.26-20.21] vs. 2.26 μg/mmol [0.15-3.14], p = 0.007; C4 6.52 μg/mmol [1.30-9.72] vs. 1.37 μg/mmol [0.38-2.43], p = 0.04; C5 1.36 μg/mmol [0.65-2.85] vs. 0.38 μg/mmol [0.03-0.72], p = 0.005; C5a 101.9 ng/mmol [15.36-230.0] vs. 18.33 ng/mmol [4.27-33.30], p = 0.01). Using logistic regression, the urinary complement components produced an outstanding ability to discriminate between patients with and without nephritis in IgAV (AUC 0.92, p < 0.001).

CONCLUSIONS

Children with IgAV-N have evidence of increased complement proteins present in their urine that may indicate a pathological role and may allow treatment stratification. A higher resolution version of the Graphical abstract is available as Supplementary information.

Development and validation of nomogram prediction model for severe kidney disease in children with Henoch–Schönlein purpura: A prospective analysis of two independent cohorts—forecast severe kidney disease outcome in 2,480 hospitalized Henoch–Schönlein purpura children

This study aimed to develop and validate a nomogram to forecast severe kidney disease (SKD) outcomes for hospitalized Henoch–Schönlein purpura (HSP) children. The predictive model was built based on a primary cohort that included 2,019 patients with HSP who were diagnosed between January 2009 and December 2013. Another cohort consisting of 461 patients between January 2014 and December 2016 was recruited for independent validation. Patients were followed up for 24 months in development/training and validation cohorts. The data were gathered at multiple time points after HSP (at 3, 6, 12, and 24 months) covering severe kidney disease as the severe outcome after HSP. The least absolute shrinkage and selection operator (LASSO) regression model was utilized to decrease data dimension and choose potentially relevant features, which included socioeconomic factors, clinical features, and treatments. Multivariate Cox proportional hazards analysis was employed to establish a novel nomogram. The performance of the nomogram was assessed on the aspects of its calibration, discrimination, and clinical usefulness. The nomogram comprised serious skin rash or digestive tract purpura, severe gastrointestinal (GI) manifestations, recurrent symptoms, and renal involvement as predictors of SKD, providing favorable calibration and discrimination in the training dataset with a C-index of 0.751 (95% CI, 0.734–0.769). Furthermore, it demonstrated receivable discrimination in the validation cohort, with a C-index of 0.714 (95% CI, 0.678–0.750). With the use of decision curve analysis, the nomogram was proven to be clinically useful. The nomogram independently predicted SKD in HSP and displayed favorable discrimination and calibration values. It could be convenient to promote the individualized prediction of SKD in patients with HSP.

Refractory Immunoglobulin A (IgA) Vasculitis in an Elderly Patient: A Case Report

Immunoglobulin A (IgA) vasculitis is small-vessel arteritis triggered by autoimmunity and allergies. IgA vasculitis among elderly patients is rare, and there is a lack of evidence regarding the choice of medicine and treatment duration. The main treatment for IgA vasculitis is steroids which can be cured with a small dose of prednisolone without immunosuppressants. Here, we report a case of a 90-year-old patient with the chief complaint of appetite loss and purpura on the legs who was diagnosed with IgA vasculitis based on biopsy results. The patient was initially treated with prednisolone effectively but exacerbated with steroid tapering, eventually requiring the use of an immunosuppressant. This case highlights the importance of monitoring the symptoms of IgA vasculitis while tapering steroids and clarifying the timing of immunosuppressant initiation.

Navigating the initial diagnosis and management of adult IgA vasculitis: A review

Background

IgA vasculitis in adults has not been thoroughly studied. This has left a practice gap related to the management and follow-up of a population that is at an increased risk of comorbidities and potentially poor outcomes. For this reason, it is important to synthesize evidence from the current literature because this can help direct the movement for more robust studies to clarify best practice recommendations.

Objective

We sought to create a narrative review for the practicing dermatologist when diagnosing and leading the care of IgA vasculitis in adult patients.

Methods

A broad literature search was performed with a focus on articles that were published after the introduction of the most updated European Alliance of Associations for Rheumatology/Pediatric Rheumatology International Trials Organization/Pediatric Rheumatology European Society criteria.

Results

The characteristics and management guidelines for IgA vasculitis in adults have been refined, although more rigorous studies are needed to develop best practice recommendations.

Limitations

Because of the lack of sufficient randomized controlled trials on IgA vasculitis in adults, this narrative review is composed of mostly observational, descriptive studies.

Conclusion

Adults with IgA vasculitis are at an increased risk of complicated disease course, necessitating formal diagnostic assessment and clear-cut follow-up recommendations to manage and prevent poor health outcomes related to various comorbidities.

Clinicopathological Spectrum of Henoch-Schönlein Purpura Vasculitis: An Experience from a Tertiary Care Center

Henoch-Schönlein purpura (HSP) is a small vessel vasculitis with multiorgan involvement. Renal involvement is the key factor predicting morbidity. We have aimed to analyze the clinicopathological spectrum of HSP vasculitis and HSP nephritis to assess the risk factors associated with kidney involvement. This retrospective study was performed in the department of pathology with collaboration of department of dermatology and department of nephrology of a tertiary care center. All clinical details along with biopsy findings were retrieved. Starting materials of the study were cases of leukocytoclastic vasculitis with only perivascular IgA deposit of more than ++ in the absence of other immunoglobulin and trace complements. To investigate the possible factors that are influential on the development of biopsy-proven HSP nephritis, we divided the whole study population in two groups -group 1: with and group 2: without biopsy-proven nephritis. One-way analysis of variance was carried out during comparative analysis between two groups using IBM SPSS statistics software, version 19 and MedCalc software, version 12.3.0.0. HSP vasculitis comprised 11.6% (n = 19) of total cutaneous vasculitis in 2 years (164 cases) with a mean age of 13.52 ± 8.10 (range: 4-33 years). Three cases developed de novo kidney disease (15.79%). A correlation analysis revealed that predictors were seasonal variation (P = 0.018), severe gastrointestinal involvement (P = 0.03), and subcutaneous edema (P = 0.005). Various clinical and laboratory parameters were associated with renal consequences. Occult nephritis was the most common presentation with crescent as a constant histopathological feature.

Biologics for immunoglobulin A vasculitis: targeting vasculitis or comorbid disease?

In this study, we aimed to evaluate the clinical features and treatments, including the use of biological disease-modifying anti-rheumatic drugs (bDMARDs) in a large cohort of pediatric and adult immunoglobulin A vasculitis (IgAV). Since data on the use of bDMARDs in IgAV are very limited, we collated the reasons for use of bDMARDs during the disease course. Patients who were enrolled in the Hacettepe University Vasculitis Research Centre (HUVAC) registry were included. In this prospective database dating from 2014, there were 436 IgAV patients classified as IgAV according to Ankara 2008 and/or American College of Rheumatology 1990 criteria. 88 adults and 330 pediatric IgAV patients were included as the main study group. Concomitant spondyloarthritis (SpA) was observed only in adult patients (10% vs 0% in children, p < 0.001). IgAV relapse was more common in adults than in children (p: 0.017). Adult patients were mostly treated with corticosteroid (p < 0.001) and conventional synthetic disease-modifying anti-rheumatic drug treatment (< 0.001), while more than half of the pediatric patients were followed up without immunosuppressive treatment. Ten (11%) adult patients used biologics. Among them, two patients used rituximab due to IgAV disease activity, three used infliximab due to SpA, three used etanercept due to SpA (one patient had a pediatric onset enthesitis-related arthritis), and two used anakinra due to recurrent familial Mediterranean fever attacks. This is the first study evaluating the use of all bDMARDs for any reason in the IgAV cohorts in the literature. None of the pediatric patients used biologics. Our data suggest biologics are mainly used for comorbid inflammatory diseases over refractory vasculitis in adult IgAV.

Individualized medication based on pharmacogenomics and treatment progress in children with IgAV nephritis

Immunoglobulin A vasculitis (IgAV) nephritis, also known as Henoch-Schönlein purpura nephritis (HSPN), is a condition in which small blood vessel inflammation and perivascular IgA deposition in the kidney caused by neutrophil activation, which more often leads to chronic kidney disease and accounts for 1%–2% of children with end-stage renal disease (ESRD). The treatment principles recommended by the current management guidelines include general drug treatment, support measures and prevention of sequelae, among which the therapeutic drugs include corticosteroids, immunosuppressive agents and angiotensin system inhibitors. However, the concentration range of immunosuppressive therapy is narrow and the individualized difference is large, and the use of corticosteroids does not seem to improve the persistent nephropathy and prognosis of children with IgAV. Therefore, individualized maintenance treatment of the disease and stable renal prognosis are still difficult problems. Genetic information helps to predict drug response in advance. It has been proved that most gene polymorphisms of cytochrome oxidase P450 and drug transporter can affect drug efficacy and adverse reactions (ADR). Drug therapy based on genetics and pharmacogenomics is beneficial to providing safer and more effective treatment for children. Based on the pathogenesis of IgAV, this paper summarizes the current therapeutic drugs, explores potential therapeutic drugs, and focuses on the therapeutic significance of corticosteroids and immunosuppressants in children with IgAV nephritis at the level of pharmacogenomics. In addition, the individualized application of corticosteroids and immunosuppressants in children with different genotypes was analyzed, in order to provide a more comprehensive reference for the individualized treatment of IgAV nephritis in children.

Epidemiology of biopsy-proven Henoch–Schönlein purpura nephritis in children: A nationwide survey in Japan

Background

Little is known about the epidemiology of Henoch–Schönlein purpura nephritis (HSPN).

Methods

We conducted a nationwide epidemiological survey of Japanese children aged 1 to 15 years with HSPN. Children who were newly diagnosed with HSPN by biopsy between January 2013 and December 2015 were eligible for the survey to clarify the incidence of HSPN. We also conducted an institutional survey on kidney biopsy criteria and treatment protocols.

Results

A total of 353 of 412 institutions (85.7%) responded to the questionnaire. Of the 353 institutions, 174 reported to perform kidney biopsies at their institutions, and 563 children were diagnosed with HSPN. Considering the collection rate, the estimated incidence of biopsy-proven HSPN was 1.32 cases/100,000 children per year. The median age at biopsy was 7.0 years, and the male-to-female ratio was 1.2:1. The kidney biopsy criteria and treatment protocols for HSPN were as follows. Patients with acute kidney injury underwent biopsy at least one month after onset. For patients without kidney dysfunction, the timing for biopsy was determined by the amount of proteinuria. Regarding the treatment of HSPN, there were certain commonalities among the treatment protocols, they eventually differed depending on the institutions involved.

Conclusions

The incidence of biopsy-proven HSPN was 1.32 cases/100,000 children per year in Japan. The male-to-female ratio and date of diagnosis of HSPN were similar to those in previous studies. The kidney biopsy criteria and treatment protocols for HSPN varied among institutions. Further studies are warranted to establish an optimal treatment policy based on the prognosis.

An Emerging Role for Neutrophil Extracellular Traps in IgA Vasculitis: A Mini-Review

Immunoglobulin A vasculitis (IgAV) is the most common systemic small vessel vasculitis in childhood. Its clinical manifestations are non-thrombocytopenic purpura, accompanied by gastrointestinal tract, joint, kidney and other organ system involvement. The pathogenesis of IgAV has not been fully elucidated. It may be related to many factors including genetics, infection, environmental factors, and drugs. The most commonly accepted view is that galactose-deficient IgA1 and the deposition of IgA and complement C3 in small blood vessel walls are key contributors to the IgAV pathogenesis. Extensive neutrophil extracellular traps (NETs) in the peripheral circulation and skin, kidney, and gastrointestinal tissue of patients with IgAV has been identified in the past two years and is associated with disease activity. This mini-review provides a possible mechanism for NETs involvement in the pathogenesis of IgAV.

Urinary Protein Array Analysis to Identify Key Inflammatory Markers in Children with IgA Vasculitis Nephritis

Chronic kidney disease is a recognised complication of immunoglobulin A vasculitis, (IgAV; formerly Henoch–Schonlein purpura—HSP). The pathophysiology of IgAV and why some patients develop significant renal involvement remains largely unknown. Identifying urinary inflammatory markers could direct targets for earlier intervention. The aim of this cross-sectional exploratory study was to perform a large protein array analysis to identify urinary markers to provide insight into the mechanisms of kidney inflammation in children with established IgAV nephritis (IgAVN). Determination of the relative levels of 124 key proteins was performed using commercially available proteome profiler array kits. Twelve children were recruited: IgAVN, n = 4; IgAV without nephritis (IgAVwoN), n = 4; healthy controls (HCs), n = 4. The urinary concentrations of twenty proteins were significantly different in IgAVN compared to IgAVwoN. The largest fold changes were reported for B-cell activating factor (BAFF), Cripto-1, sex-hormone-binding globulin and angiotensinogen. The urinary levels of complement components C5/C5a and factor D were also significantly elevated in patients with IgAVN. A total of 69 urinary proteins significantly raised levels in comparisons made between IgAVN vs. HCs and nine proteins in IgAVwoN vs. HCs, respectively. This study identified key urinary proteins potentially involved in IgAVN providing new insight into the pathophysiology. Further longitudinal studies with larger cohorts are needed to quantitatively analyse these biomarkers.

Clinical spectrum of immunoglobulin A vasculitis in children and determining the best timing of urine examination to predict renal involvement

BACKGROUND

Immunoglobulin A (IgA) vasculitis (also known as Henoch-Schonlein purpura) is the most common small vessel vasculitis of childhood. The long-term prognosis depends on renal involvement. The aim of this study was to evaluate the risk factors associated with renal involvement in children with IgA vasculitis and to investigate the best timing of urine examination to predict the presence of renal involvement at the sixth month after the diagnosis.

METHODS

In this prospective observational study, medical records, demographic data, clinical findings, laboratory tests, and urine microscopic examinations of pediatric patients diagnosed with IgA vasculitis were evaluated to identify potential risk factors associated with renal involvement.

RESULTS

A total of 178 patients with a median age of 6 years were involved in the study. Renal involvement was found in 24 (13.5%) patients. Most of the patients (85.7%), whose urine examination was found to be abnormal at the sixth month after the diagnosis, also had abnormalities in the first month urine examination. Factors significantly associated with renal involvement were as follows: older age, presence of hematuria and or proteinuria in the first month urine examination and patients who presented the disease in the spring season. Multivariate logistic regression analysis showed age ≥8 years (p = 0.005), the season of onset (p = 0.025), serum creatinine levels (p = 0.016), and abnormal urine examinations at the first-month visits (p = 0.005) significantly increased the risk of renal involvement.

CONCLUSION

This study has demonstrated that the optimal date to predict the presence of hematuria and/or proteinuria in the sixth month is the urine examination performed in the first month of the disease. Therefore, we think that patients with IgA vasculitis who show a presence of hematuria and/or proteinuria in the first-month urine examination should be followed more closely.

IgA vasculitis nephritis

PURPOSE OF REVIEW

The purpose of this update is to summarize current knowledge on the pathophysiology of immunglobulin A (IgA) vasculitis nephritis (IgAVN) as well as to critically review evidence for established therapeutic regimes and available biomarkers. An additional purpose is to raise the discussion what could be done to further improve our understanding of IgAVN, identify patients at risk for adverse outcome and increase the evidence for therapy recommendations.

RECENT FINDINGS

Clinical and experimental studies have established the concept of a multilevel pathogenesis. Toll-like-receptor activation, B cell proliferation, micro-RNAs and complement activation have been identified or confirmed as potential therapeutic targets which can modify the course of the disease. Currently, kidney injury molecule-1, monocyte chemotactic protein-1, N-acetyl-β-glucosaminidase, and angiotensinogen are the most promising urinary biomarkers for early diagnosis of renal involvement in IgA vasculitis.

SUMMARY

Close surveillance of all IgAV patients for renal involvement is recommended. Given the multilevel pathogenesis, early treatment of even mild cases should be initiated. Further therapeutic options should be considered in case first-line therapy (mostly corticosteroids) has no effect. The evidence supporting current therapeutic regimes is predominantly based on expert opinion. Prospective studies are needed and should involve substances inhibiting B cell proliferation and complement activation.

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.