IgA vasculitis update: Epidemiology, pathogenesis, and biomarkers

The extent of intestinal involvement is closely related to the severity of IgAV: a risk stratification study based on CT

OBJECTIVES

To analyze the differences in clinical manifestations between children and adults with intestinal involvement in IgAV and to identify the specific subtypes requiring particular attention.

METHODS

A systematic review of the HIS system was conducted on patient data from four centers at Tongji Hospital between January 2015 and October 2022. Patients with a diagnosis of IgAV with intestinal involvement were further analyzed. Clinical manifestations, laboratory data, and CT findings at the time of initial hospitalization were recorded. The differences in clinical manifestations between children and adults were analyzed. The extent of intestinal involvement, linked to disease severity, was quantitatively assessed by evaluating the number of affected intestinal segments on CT imaging. Laboratory markers that could reflect severe intestinal involvement were explored. Furthermore, patients were classified based on the sites of involved intestinal segments: L1 type (duodenum and/or jejunum), L2 type (ileum), L3 type (duodenum and/or jejunum and ileum), and L4 type (limited to the colorectum). A comparison of the first three types was performed.

RESULTS

A total of 148 patients were enrolled (67 children and 81 adults). The proportion of joint pain and renal involvement was higher in adults. D-dimer level was an independent risk factor for severe intestinal involvement (OR = 1.104, p = .016). In the first three types patients based on the sites of involved intestinal segments, it found that L3 type patients had a longer hospital stay.

CONCLUSION

With the exception of joint pain and renal involvement, there were no significant differences in clinical symptoms between children and adults. CT imaging provided objective insights into the extent of intestinal involvement, which correlated with disease severity. Patients with widespread small bowel involvement displayed a more severe disease state.

IgA nephropathy and IgA vasculitis in a pediatric Crohn's disease patient with early IgA deposition in vascular walls of intestines

Patients with inflammatory bowel disease may present with extraintestinal manifestations. Crohn's disease complicated with IgA nephropathy or IgA vasculitis is relatively rare. In this case, an 11-year-old girl was diagnosed with Crohn's disease and infliximab was administered. 1 year after treatment, she presented with asymptomatic but persistent microscopic hematuria. The child was diagnosed with IgA vasculitis and IgA nephropathy at the fourth year of follow-up. To explore the association between Crohn's disease and IgA associated diseases, immunostaining for IgA and GdIgA1 deposition was retrospectively conducted in intestinal biopsy tissues obtained at the time of initiation and relapse of Crohn's disease. GdIgA1 deposition in intestinal tissues was found not only at the time of relapse of Crohn's disease, but also at the beginning of Crohn's disease when patient had neither exposure to any drug nor any symptom of IgA vasculitis or IgA nephropathy. The early appearance of GdIgA1 deposition indicated that Crohn's disease played a greater role in its formation than infliximab induction and the child might be prone to IgA associated diseases. Patients with Crohn's disease, especially those who receive tumor necrosis factor-alpha inhibitors are recommended to receive regular kidney examinations.

Correlation between the course of kidney injury and clinicopathology and prognosis of children with Henoch-Schönlein purpura nephritis

PURPOSE

Henoch-Schönlein purpura nephritis (HSPN) has a poor prognosis and variable pathophysiology. The present study aimed to analyze the kidney injury, clinicopathology, and prognosis of HSPN children.

METHODS

This retrospective study examined 249 children with HSPN. The patients' pathological and clinical data were collected. The patients were divided into the following groups according to the duration of their kidney injury: groups with disease duration of < 2 weeks, 2 weeks to 1 month, 1-2 months, 2-4 months, 4-6 months, and ≥ 6 months. The clinicopathological and prognostic relationships were examined between the groups.

RESULTS

We enrolled 249 children with HSPN (average age of 10.12 ± 3.01 years). There were 161 boys (64.66%) and 88 girls (35.34%). Altogether, 191 children (76.71%) developed kidney injury within 2 months. A total of 37 children (14.86%) showed recurrent renal damage after 6 months. Most patient groups exhibited hematuria and proteinuria, with type III pathology being the most common. During 2 weeks and 1 month of kidney injury, the acute pathology index peaked and then decreased; then, it increased again after 4 months as recurrence occurred. The chronic pathology index was the highest in the group with a disease duration of 2-4 months and it increased with increasing disease duration. The prognosis worsens with the disease duration.

CONCLUSION

Children with HSPN showed disease remission after a duration of 4-6 months. The acute and chronic pathology indexes peaked between 2 weeks to 1 month and 2-4 months, respectively. Patients with kidney injury occurring within a month had a much higher remission rate.

Gastrointestinal features of pediatric iga vasculitis and their association with renal complications: an observational study

Immunoglobulin A (IgA) vasculitis is the most common systemic vasculitis in childhood, primarily affecting the skin, gastrointestinal system (GIS), joints, and kidneys. This study aimed to evaluate the clinical and laboratory characteristics of mild and severe GIS involvement in pediatric patients with IgA vasculitis and to investigate its association with renal involvement. A retrospective review was conducted on 794 pediatric patients diagnosed with IgA vasculitis between 1997 and 2024. Demographic data, clinical findings, and laboratory parameters were collected from patient records. GIS involvement was classified as mild (abdominal pain, vomiting, or occult blood in stool) or severe (melena, hematochezia, or intussusception). Renal involvement was defined based on hematuria, proteinuria, hypertension, or renal insufficiency. Among 794 patients, 430 (54.2%) were male, with a mean age at diagnosis of 7.8 ± 3.3 years. GIS involvement was observed in 422 (53.1%) patients, of whom 333 (78.9%) had mild GIS involvement and 89 (21.1%) had severe GIS involvement. Renal involvement was detected in 171 (21.5%) patients, and was more frequent in those with GIS involvement (26.3% vs. 16.1%, p = 0.001). GIS (55.6% (n = 306) vs. 47.1% (n = 115)) and renal (24.5% (n = 134) vs. 15.2% (n = 37)) involvement were more common in patients aged > 5 years than in patients ≤ 5 years (p = 0.027, p = 0.004, respectively). GIS involvement was significantly associated with leukocytosis (p < 0.001) and elevated C-reactive protein (CRP) (p = 0.018), but these parameters did not correlate with renal involvement. Patients with positive fecal occult blood tests had a significantly higher risk of renal involvement (p < 0.001). However, there was no significant difference in renal involvement between patients with mild and severe GIS involvement (p = 0.082).

CONCLUSION

GIS involvement, older age (> 5 years), and the presence of occult blood in stool were associated with a higher likelihood of renal involvement in pediatric IgA vasculitis. However, the severity of GIS involvement did not correlate with renal involvement, suggesting that renal pathology may be influenced by independent mechanisms rather than the severity of GIS symptoms.

WHAT IS KNOWN

• Older age, persistent palpable purpura, abdominal pain, GIS involvement, recurrent disease episodes are risk factors for renal involvement in IgA vasculitis.

WHAT IS NEW

• GIS involvement, fecal occult blood positivity, and age over five years were significantly associated with renal involvement in pediatric IgA vasculitis. However, the severity of GIS involvement did not predict the presence or severity of renal involvement.

Laboratory Findings and Clinical Features in IgA Vasculitis: Identifying Predictors of Kidney Involvement and Disease Relapse in Pediatric Patients

Objective: This study aimed to identify clinical and laboratory predictors of kidney involvement and disease relapse in pediatric patients with IgA vasculitis (Immunoglobulin A vasculitis, IgAV). Materials and Methods: A retrospective cohort study was conducted on 173 children diagnosed with IgAV at the Children's Clinical Hospital of the Medical University of Warsaw between 2018 and 2022. Patients were categorized into groups based on renal involvement (IgAVN+ vs. IgAVN-) and disease recurrence. The analysis included demographic data, clinical manifestations, allergy history, presence of infection, duration of hospitalization, relapse occurrence, the interval between the first and second hospitalization, and laboratory markers. Results: Renal involvement was observed in 42% of cases, while disease recurrence occurred in 9.25% of patients. IgAVN+ patients were older, had longer hospital stays, and more frequently exhibited gastrointestinal symptoms, consistent with previous research. A history of allergic conditions was more prevalent in both the IgAVN+ and recurrence groups. An increase in IgA levels over time was associated with a higher risk of nephropathic development. Patients with recurrences had higher IgM levels and an elevated neutrophil-to-lymphocyte ratio (NLR) (p = 0.07). In the ROC (Receiver Operating Characteristic) analysis, a cutoff value of 1.67 for NLR (AUC 0.71; p = 0.0002; sensitivity 0.87; specificity 0.58) was identified as a risk factor for disease recurrence. Conclusions: Older age at disease onset, gastrointestinal involvement, and allergies are associated with renal involvement in pediatric IgAV. Immune dysregulation, reflected by elevated NLR and IgM, may contribute to disease recurrence. It is important to monitor changes in IgA levels over time, as an increase in IgA concentration is a risk factor for the development of nephropathy. Additionally, calculating the NLR is recommended, as it may indicate the probability of disease recurrence.

A case-based review of IgA vasculitis complicated with gastrointestinal infections: insights from a norovirus-associated case in an adolescent

Immunoglobulin A vasculitis (IgAV), formerly known as Henoch-Schönlein purpura, is a self-limited leukocytoclastic vasculitis targeting small-sized vessels. It is the most common vasculitis in children, but also targets adults who have usually worse prognosis. It typically presents with purpuric rash, arthritis, colicky abdominal pain and potential renal involvement. Gastrointestinal (GI) manifestations, although frequent, may be severe and occasionally complicated by infections. We present a 11-year-old male with a recent diagnosis of IgAV who was admitted with severe abdominal pain, hematemesis and hematochezia. Stool analysis identified Norovirus as the causative pathogen for the severe gastrointestinal symptoms. Treatment with proton pump inhibitors, high-dose corticosteroids and intravenous fluids resulted in symptoms resolution and clinical improvement. In addition, a case-based review of the literature was conducted to evaluate the prevalence of GI infections occurring after the development of IgAV that may result in severe complications or disease relapses. Thirty-five patients with a median age of 14 years were included in our study. Among these patients, 42.9% were diagnosed with a concomitant bacterial gastrointestinal pathogen, followed by 25.7% with viral gastroenteritis and 17.1% with parasitic gastrointestinal disease. Treatment was individualized, with 48.5% receiving corticosteroids and 8.6% receiving immunosuppressive therapy. This case and case-based review highlights the significance of careful management and monitoring of patients with IgAV complicated by infections, because severe complications can cause significant morbidity and mortality especially in adults.

Therapeutic plasma apheresis for IgA vasculitis-related gastrointestinal bleeding

INTRODUCTION

Adult-onset IgA vasculitis (IgAV) often presents with severe renal and gastrointestinal (GI) complications, yet therapeutic guidelines for life-threatening manifestations remain unclear.

METHODS

We conducted a systematic text-mining analysis of all PubMed-indexed case reports of IgAV treated with therapeutic plasma exchange (TPE).

RESULTS

We describe an 80-year-old woman with refractory GI bleeding and rapidly progressive glomerulonephritis. Despite high-dose corticosteroids and cyclophosphamide, GI bleeding persisted and necessitated multiple transcatheter embolization. A total of seven sessions of TPE using fresh frozen plasma successfully controlled disease activity, resulting in improvement of GI bleeding. Literature review suggests that TPE may provide additive benefits in IgAV patients, particularly in those unresponsive to standard immunosuppressants.

CONCLUSION

This case supports the utility of TPE as a valuable adjunctive therapy in severe IgAV with organ-threatening manifestations and highlights the need for further studies to define optimal indications.

Epigastric pain of unknown origin, esophageal and gastric involvement: a Henoch-Schönlein Purpura case report

Henoch-Schönlein Purpura (HSP) is an acute systemic vasculitis that primarily affects the skin, gastrointestinal tract, kidneys and joints. It predominantly occurs in children but can occur at any age. We report a case of 48-year-old male patient suffering from unexplained epigastric pain alternating between relapses and remissions. The patient's initial clinical manifestation was atypical, starting with severe epigastric pain, without cutaneous purpura, and with normal rheumatologic and immunologic markers, making diagnosis difficult. The patient was eventually diagnosed with HSP. This case highlights the importance of considering this diagnosis in patients with unexplained abdominal pain and emphasize the role of endoscopy in diagnosing complex cases.

Construction and diagnostic efficacy assessment of the urinary exosomal miRNA-mRNA network in children with IgA vasculitis nephritis

This study aimed to comprehensively evaluate the diagnostic potential of urinary exosomal microRNA (miRNA) in IgA vasculitis (IgAV) kidney injury by meticulously comparing the miRNA expression profiles in urine exosomes between children diagnosed with IgAV and those with IgA vasculitis nephritis (IgAVN). Urine samples were obtained from children with IgAV who were treated at our hospital from October 2022 to October 2023. These samples were then categorized into the IgAV group and the IgAVN group. High-throughput sequencing and bioinformatics analysis techniques were employed to conduct a thorough analysis of the differentially expressed miRNAs between the two groups. Additionally, the correlation between urinary exosomal miRNA and clinical parameters was evaluated. A total of 57 urinary exosomal miRNAs exhibited differential expression between the IgAV and IgAVN groups. Specifically, in the IgAVN group, 42 miRNAs were upregulated, while 15 were downregulated. Lasso regression analysis and ROC analysis identified five candidate urinary exosomal miRNAs with high diagnostic accuracy. A prediction of 95 target genes related to the candidate miRNAs led to the construction of an exosomal miRNA-mRNA regulatory network consisting of four key miRNAs and ten hub genes. Gene function and metabolic pathway analyses indicated that these ten hub genes were predominantly enriched in pro-fibrotic and inflammatory pathways. The analysis incorporating clinical parameters demonstrated a significant correlation between hsa-miR-383-5p and urinary protein levels. This research identified exosomal miRNAs and mRNAs with differential expression patterns associated with IgAVN and constructed the corresponding exosomal miRNA-mRNA network. It was determined that hsa-miR-3065-5p, hsa-miR-383-5p, hsa-miR-25-3p, and hsa-miR-450b-5p might mediate the pathogenesis of IgAVN by targeting pro-fibrotic and inflammatory pathways. Among them, exosomal hsa-miR-383-5p is highly likely to serve as a novel non-invasive biomarker for assessing the disease status of IgAVN, thereby offering new perspectives on the non-invasive diagnosis and treatment of IgAVN.

Identification of risk factors for renal progression in adults with IgAV: a retrospective cohort study of a single center in northwest China

OBJECTIVES

This investigation sought to examine the clinical and pathological characteristics, outcomes, and risk factors linked to the progression of renal function in adult-onset immunoglobulin A (IgA) vasculitis within a single center in northwest China.

METHODS

Data were retrospectively gathered from cases of adult-onset IgA vasculitis recorded at a tertiary hospital in northwest China, covering the period from January 2013 to August 2024. During the follow-up, clinical information was compared between patients who advanced to chronic kidney disease (CKD) stage 3 and those who did not.

RESULTS

A sum of 1082 adult-onset IgA vasculitis patients (632 men; median age of 37 years) were included. Among patients with baseline proteinuria >0.5 g/24h (43.9%), 40.7% progressed to chronic kidney disease (CKD) stage 3, while 5.1% developed end-stage renal disease (ESRD). COX regression analysis indicated that older age, renal pathological grade IV, hypertension (HTN), diabetes, hyperlipidemia, and hyperuricemia were independent risk factors for CKD stage 3 progression in individuals with adult-onset IgA vasculitis.

CONCLUSIONS

Older age and comorbidities such as hypertension and diabetes significantly increase the risk of renal progression in adult-onset IgAV. Early management of these comorbidities may mitigate the risk of CKD progression.

Association between immune cells and allergic purpura: a Mendelian randomization study

BACKGROUND

Increasing evidence indicates a substantial correlation between the immune cells and the risk of allergic purpura. We utilized Mendelian randomization (MR) to investigate causal effect of immune cell on allergic purpura.

METHODS

Genetic instrumental variables for immune cells were sourced from an extensive genome-wide association study (GWAS) comprising 3757 participants. Summary statistics of allergic purpura, involving 470 cases and 216,099 controls, were obtained from FinnGen. The primary analysis employed the inverse-variance weighted (IVW) method. Rigorous sensitivity analyses including MR-Egger, weighted median and MR-PRESSO were conducted to ensure the reliability of the causal estimate.

RESULTS

We identified two immunophenotypes associated with an increased risk of allergic purpura: HLA-DR on CD14 + CD16- monocyte (OR: 1.2379; 95% CI: 1.0612-1.4440; P = 0.0066) and CD11b on basophil (OR: 1.2973; 95% CI: 1.0905-1.5433; P = 0.0033). The sensitivity analyses consistently yielded similar results for these immunophenotypes.

CONCLUSIONS

Our analyses confirmed a potential causal effect of HLA-DR on CD14 + CD16- monocyte, as well as CD11b on basophils, in relation to the risk of allergic purpura. Further studies are necessary to clarify the mechanisms by which these immunophenotypes influence the development of allergic purpura.

The Recurrence of Systemic Diseases in Kidney Transplantation

Kidney transplantation is the most effective replacement therapy for kidney failure, providing the best outcomes in terms of patient survival and offering a better quality of life. However, despite the progressive improvement in kidney survival, the recurrence of original disease remains one of the most important causes of graft loss and a major challenge that requires clinical vigilance throughout the transplant's duration. Additionally, the type and severity of recurrence affect both treatment options and graft survival. This is especially true for the recurrence of systemic diseases. In this narrative review, we will discuss the timing, frequency, severity, and treatment of post-transplant recurrence in three systemic diseases: lupus nephritis (LN), Antineutrophil Cytoplasmic Antibodies (ANCA)-associated glomerulonephritis (ANCA-GN), and Henoch-Schönlein purpura (HSP). The recurrence of lupus nephritis is less common than that of primary focal segmental glomerulosclerosis or C3 glomerulopathy. Its severity can range from mild mesangial to diffuse proliferative forms, with varying prognoses and treatment options, much like the original disease. In some patients with LN, as well as in those with ANCA-GN or HSP, the reactivation of the primary disease can affect other organs besides the kidneys, potentially leading to life-threatening conditions. These cases may require a multidisciplinary approach, making these transplants clinically more challenging. Extrarenal flare-ups often necessitate an increase in immunosuppression, which in turn raises the risk of infections. In these autoimmune diseases, the role of immunological tests in determining the timing of kidney transplants remains a topic of ongoing debate. However, elevated levels of certain immunological markers, such as anti-dsDNA antibodies, ANCA titers, or serum immunoglobulin A may indicate a reactivation of the disease, suggesting the need for more intensive patient monitoring.

Deciphering the Pharmacological Mechanism of Compound Purpura Decoction in Treating Henoch-Schonlein Purpura by Network Pharmacology, Molecular Docking and Experimental Validation

Henoch-Schonlein purpura (HSP) is an immunoglobulin A (IgA)-mediated systemic vasculitis that frequently develops in children and may progress to serious complications. Compound purpura decoction (CPD), a classical herbal combination, exerts favourable effects on the clinical symptoms and prognosis of HSP; however, the underlying molecular mechanism remains unclear. First, high-performance liquid chromatography analysis identified five bioactive components in CPD, including protocatechuic acid, chlorogenic acid, mangiferin, baicalin and buddleoside, with contents of 0.011 ± 0.02, 0.577 ± 0.33, 0.150 ± 0.05, 1.132 ± 0.23 and 0.369 ± 0.23 mg/g, respectively. Additionally, we established an animal model of allergic purpura to evaluate the therapeutic effects of CPD on HSP. CPD effectively alleviated renal and cutaneous vasculitis and reduced IgA deposition. CPD could regulate the Treg/Th17 cell balance, decrease the levels of the proinflammatory factors interleukin-6 and tumour necrosis factor-α, and suppress the expression of C3 and C5 (p < 0.05). Network pharmacology analysis suggested that the mechanism of CPD in HSP treatment mainly involved epidermal growth factor receptor (EGFR)-related targets and pathways, followed by molecular docking confirming strong binding affinity between EGFR and the bioactive components (binding energy< -4.25 kcal/mol). Real-time quantitative polymerase chain reaction and western blot showed that CPD suppressed the activation of the EGFR/extracellular signal-regulated kinase (ERK) signalling pathway (p < 0.05), which could be associated with the inhibition of complement system activation. This study provides a new perspective for understanding the pathogenesis and treatment of HSP.

Adenovirus: a possible trigger for IgA vasculitis in children

IgA vasculitis (IgAV), also called Henoch-Schönlein purpura (HSP), is an immune complex vasculitis characterised by IgA1-dominant immune deposits affecting small vessels (predominantly capillaries, venules or arterioles). It often involves the skin and gastrointestinal tract, frequently causes arthritis and rarely causes vasculitis in the kidney indistinguishable from IgA nephropathy. It usually presents as a purpuric non-blanching rash mostly on the lower limbs, although it may extend to the upper limbs and the trunk, and more rarely to the face. Respiratory tract infection or a history of exposure to antigens from certain foods, insects, drugs or vaccines may trigger the pathogenesis of IgAV. Adenovirus mostly causes acute respiratory diseases and occasionally causes gastroenteritis. Literature on the adenovirus as a trigger or direct involvement in the onset of IgAV is scarce. We report a few cases where IgAV is associated with adenovirus infection, and more research is required to establish this association.

Antibiotic-induced IgA vasculitis: insights from a real-world retrospective analysis and pharmacovigilance assessment

IgA vasculitis (IgAV) is a small-vessel vasculitis characterized by the deposition of immunoglobulin A (IgA) in the vessel walls, often presenting with cutaneous manifestations such as palpable purpura. Drug-induced IgAV is a rare but potentially severe condition. Several studies have suggested a possible association between antibiotics and IgAV. However, research on this link remains limited. This study aimed to identify antibiotics implicated in the onset of IgAV and to analyze the clinical characteristics of IgAV induced by antibiotics. Data on antibiotic-induced IgAV events were extracted from the FDA Adverse Event Reporting System (FAERS) database, and case reports were collected through literature searches. A pharmacovigilance analysis was conducted using FAERS data from 2003 to 2023 to evaluate adverse events related to IgAV caused by antibiotics, and case reports up to November 23, 2024, were reviewed for retrospective analysis. A total of 150 reports of antibiotic-induced IgAV were analyzed, with 13 antibiotics identified as associated with IgAV. The three antibiotics most strongly linked to IgAV were ofloxacin, vancomycin, and clarithromycin based on the FAERS database analysis. The median age of the cases was 58 years, with a male predominance. IgAV typically developed 4 days (1-15 days) after drug administration. Clarithromycin, vancomycin, and ciprofloxacin were the most frequently reported antibiotics in the literature, and they were also associated with poor renal outcomes, emphasizing the importance of regular follow-up to improve long-term renal prognosis. In conclusion, this study identified 13 antibiotics associated with IgAV, with ofloxacin, vancomycin, and clarithromycin being the most strongly linked to the condition.

An Atypical Presentation of Henoch-Schönlein Purpura With Features of Acute Hemorrhagic Edema of Infancy and Koebnerization: A Case Report

Immunoglobulin A vasculitis, also known as Henoch-Schönlein purpura (HSP), is a type of vasculitis that is most commonly found in children. Palpable purpura is a key feature and is often associated with joint, abdominal, or renal involvement. This case report presents an atypical presentation of HSP in a four-year-old male, characterized by overlapping features of Acute Hemorrhagic Edema of Infancy (AHEI) and Koebnerization (isomorphic response), which complicates the diagnosis. The patient initially presented with redness around his mouth and nose, followed by hematuria and the development of palpable purpura on the lower extremities and buttocks. Vascular swellings were noted on the palms, feet, and face, and cockade purpura appeared on the upper extremities. The patient also exhibited episodic joint pain, genital edema, and Koebnerization on the lower back and buttocks. The diagnosis of this case was challenged by the presence of AHEI-like features and Koebnerization. The patient responded well to treatment with prednisone and colchicine. This atypical case presentation of HSP underscores the clinical overlap between HSP and AHEI, as well as the rare occurrence of Koebnerization in HSP. It emphasizes the importance of recognizing atypical presentations to ensure timely and accurate diagnosis. Further research is required to explore the frequency, pathophysiology, and clinical implications of such cases to enhance diagnostic accuracy and management in pediatric vasculitis.

The influence of respiratory infections on Henoch-Schönlein purpura in children

OBJECTIVE

To explore the influence of respiratory infections on the onset of Henoch-Schönlein Purpura (HSP) in children, along with exploring potential underlying mechanisms.

METHOD

The present study conducted a statistical analysis on renal involvement indicators in 296 children with HSP who came to the Children's Hospital of Zhejiang University, as well as the IgA levels in 400 children with respiratory infections and 400 children with HSP.

RESULTS

Compared with the control group, children with HSP exhibited a significant increase in urine red blood cell count, urine microalbuminuria, and urine protein/creatinine ratio (P < 0.001). The monthly outpatient visits for children with respiratory infections exhibited a similar pattern to those with HSP, demonstrating a heightened prevalence during the autumn and winter. The level of IgA in children with respiratory infections and HSP were significantly higher than those in the control group (P < 0.001).

CONCLUSION

HSP can give rise to complications such as renal involvement. There exists a certain correlation between respiratory infections and the occurrence of HSP, which may be attributed to the elevation of IgA induced by respiratory infections. In conclusion, children with HSP should reinforce protective measures during the peak influenza season in order to prevent respiratory infections.

Clinical characteristics and risk factors analysis of abdominal symptoms in IgA vasculitis patients: a retrospective cohort study

About 50% of children with IgA vasculitis (IgAV) have abdominal symptoms, usually colic mimic to acute abdomen. Since signs and symptoms of vasculitis may appear in any order, this may affect the diagnosis of children whose abdominal symptoms precede the appearance of purpura. It is necessary to identify the risk factors, pathogenesis, and specific biomarkers to improve the prevention and management of IgAV patients with abdominal symptoms. All the 278 patients were children who had been diagnosed with IgAV in Nanyang Central Hospital between January 2018 and December 2018. The patient's age, gender, clinical manifestations, laboratory examination, and medical history were retrospectively collected. All the patients were divided into two groups based on whether they had abdominal symptoms. Ridge regression and multivariate logistic regression model were used to find risk factors of IgAV patients with abdominal symptoms. Of the 278 patients, 54 patients had abdominal symptoms, and the remaining 224 patients had no abdominal symptoms. Patients with abdominal symptoms had a lower proportion of infections and higher IgM concentrations than patients with other symptoms. For patients over 12 years of age, platelet counts were lower in patients with abdominal symptoms. In addition, basophil count was identified as a protective factor, while IgM was identified as a risk factor. Infections, platelet counts, basophil count, and IgM concentration may be associated with abdominal symptoms in IgAV patients. Basophils and IgM may be involved in the pathological mechanism of abdominal symptoms.

Impact of gender on baseline presentation and outcome in adult IgA vasculitis

OBJECTIVES

Adult IgA vasculitis (IgAV) is more common in males, but the potential impact of gender remains unclear. We aimed to describe the impact of gender on presentation and outcome in adult IgAV.

METHODS

We retrospectively analysed data from a multicentre retrospective cohort of 260 patients (IGAVAS). Comparisons were made according to gender status.

RESULTS

Data from 259 patients (95 females and 164 males) were analysed. Compared with females, baseline presentation in males was similar for cutaneous involvement (100% vs 100%, P = 1.0), joint involvement (60% vs 63%, P = 0.7), gastrointestinal involvement (57% vs 45%, P = 0.093) and glomerulonephritis (73% vs 64%, P = 0.16). Glomerulonephritis was more severe at baseline in males than in females, with a lower median estimated glomerular filtration rate (eGFR) [90 (IQR 59-105) vs 97 ml/min/1.73 m2 (76-116), P = 0.015] and increased median proteinuria (0.84 vs 0.58 g/day, P = 0.01). There were no differences in histological findings in patients who had a kidney biopsy. Methylprednisolone was more frequently used in males (40% vs22%, P = 0.015), as were immunosuppressants, especially cyclophosphamide (24% vs 6%, P = 0.0025) and azathioprine (10% vs 2%, P = 0.038). Analysis of treatment response showed that males had more frequent refractory disease (30% vs 13%, P = 0.004). Long-term outcomes (mortality and progression to chronic kidney failure) did not differ.

CONCLUSION

Kidney involvement in IgAV appears to be more severe in males, which is supported by more intensive treatment contrasting with a lower response rate. This study raises the question of gender as a new prognostic factor in adult IgAV.

National recommendations for the management of children and young people with IgA vasculitis: a best available evidence, group agreement-based approach

OBJECTIVE

IgA vasculitis (IgAV) is the most frequently experienced subtype of vasculitis seen in children. Most children fully recover, however, complications including chronic kidney disease are recognised. The aim of this project was to use a best available evidence, group agreement, based approach to develop national recommendations for the initial management of IgAV and its associated complications.

METHODS

A fully representative multiprofessional guideline development group (GDG), consisting of 28 members, was formed and met monthly. Graded recommendations were generated using nationally accredited methods, which included a predefined scope, open consultation, systematic literature review, evidence appraisal, review of national or international guidelines and a period of open consultation. Audit measures and research priorities were incorporated.

RESULTS

The IgAV GDG met over a 14-month period. A total of 82 papers were relevant for evidence synthesis. For the initial management, four topic areas were identified with five key questions generating six graded recommendations related to classification, specialist referral and musculoskeletal involvement. For the associated complications, five topic areas with 12 key questions generated 15 graded recommendations covering nephritis, gastrointestinal and testicular involvement, atypical disease and follow-up. Open consultation feedback was incorporated. The guidelines were endorsed by the UK Kidney Association and Royal College of Paediatrics and Child Health and are available online.

CONCLUSION

Despite IgAV being a rare disease with limited evidence, a national standardised approach to the clinical management for children and young people has been achieved. This should unite approaches to care and act as a foundation for improvement.

Exploration of the pathogenesis of nephrotic syndrome and traditional Chinese medicine intervention based on gut microbiota

Nephrotic syndrome (NS) represents a prevalent syndrome among various chronic kidney disease pathologies and is known for its higher severity and worse prognosis compared with chronic glomerulonephritis. Understanding its pathogenesis and identifying more effective treatment modalities have long been a concern of kidney specialists. With the introduction of the gut-kidney axis concept and the progress in omics technologies, alterations in the gut microbiota have been observed in primary and secondary NS. This link has been extensively researched in conditions such as diabetic nephropathy and immunoglobulin A (IgA) nephropathy. Thus, dysbiosis of the gut microbiota is seen as a crucial contributing factor in NS; however, there is a lack of comprehensive reviews that elucidate the changes in the gut microbiota across different NS conditions and that describe its mechanistic role in the disease. Moreover, serving as an innate regulator of the gut microbiota, traditional Chinese medicine (TCM) has the potential to exert a profound impact on the expression of inflammation-promoting agents, decreasing the levels of endotoxins and uremic toxins. In addition, it strengthens the stability of the intestinal barrier while controlling the metabolic function of the body through its efficient modulation of the gut microbiota. This intricate process yields far-reaching consequences for NS.

Abdominal imaging and endoscopic characteristics of adult abdominal IgA vasculitis: a multicenter retrospective study

BACKGROUND

IgA vasculitis (IgAV), previously known as Henoch-Schönlein purpura, is an IgA-mediated systemic small vessel vasculitis that tends to be more severe in adults than in children. Early diagnosis of IgAV involving the gastrointestinal tract remains difficult, especially in patients who present with gastrointestinal symptoms before purpura. This study aims to systematically analyze the abdominal imaging and endoscopic features of adult patients with abdominal IgAV, providing assistance to clinicians in the early recognition of this condition.

PATIENTS AND METHODS

This multicenter retrospective study was conducted in three large tertiary hospitals in China from January 2017 to January 2024. A total of 108 adult patients with abdominal IgAV, who had complete abdominal imaging and/or endoscopy results, were enrolled. The clinical manifestations, abdominal imaging findings, endoscopic characteristics, and serological indicators of the patients were analyzed.

RESULTS

The median age of the patients was 40 years (IQR: 26-55), with a male-to-female ratio of 2:1. Acute abdominal pain was the most common presenting symptom (100 patients, 92.59%). Bowel wall thickening was the most frequent finding on abdominal imaging (50/86 patients, 58.14%). Gastrointestinal endoscopy showed findings of congestion and erosion (32/67 patients, 47.76%), and erosion with ulcers (21/67 patients, 31.34%). Among patients with both imaging and endoscopic results, the duodenum (28/51 patients, 54.90%) and ileum (28/51 patients, 54.90%) were the most commonly affected sites. Laboratory findings revealed elevated white blood cell count (WBC), neutrophil-to-lymphocyte ratio (NLR), C-reactive protein (CRP), D-dimer and fibrinogen levels, along with decreased albumin level. Comparing patients with gastrointestinal symptoms versus purpura as the initial symptom, those with gastrointestinal symptoms had higher levels of WBC (p < 0.05) and NLR (p < 0.01).

CONCLUSIONS

The most common symptom in adult abdominal IgAV patients is acute abdominal pain. In the early stage of the disease, most patients exhibit elevated levels of WBC, NLR, CRP, D-dimer, and fibrinogen, along with decreased albumin level. The duodenum and ileum are the most commonly affected sites. By integrating these findings, clinicians can identify abdominal IgAV patients earlier and more accurately.

Clinicopathological features and prognosis of IgA vasculitis nephritis with nephrotic-range proteinuria in children

BACKGROUND

To investigate the clinical features, kidney pathology, treatment regimens, and clinical outcomes of IgA vasculitis nephritis (IgAVN) with nephrotic-range proteinuria in children.

METHODS

A retrospective review of children diagnosed with IgAVN between January 2019 and December 2022 was conducted. Participants were divided into two groups based on their urine protein/creatinine (UPCR) levels. Biodata, clinical characteristics, laboratory findings, pathologic features, treatment regimens, and outcomes were abstracted from case records and analyzed.

RESULTS

A total of 255 children were identified, 94 with nephrotic-range proteinuria (UPCR ≥ 200 mg/mmol) and 161 with non-nephrotic proteinuria (UPCR < 200 mg/mmol). Patients in the nephrotic-range proteinuria group were significantly younger and had worse grades of glomerular and acute tubulointerstitial injury compared to those in the non-nephrotic proteinuria group. Higher levels of blood urea nitrogen (BUN), D-dimer (DD), and fibrin degradation products (FDP), and lower levels of total protein (TP), albumin (ALB), urine creatinine (Cr), prothrombin time (PT), activated partial thromboplastin time (APTT), IgG, CD3 + cells, and CD4 + cells were found in patients in the nephrotic-range proteinuria group. Clinical outcome of patients with nephrotic-range proteinuria was significantly associated with ISKDC grading, proportion of glomerular crescents and severity of acute tubulointerstitial injury.

CONCLUSIONS

Children with nephrotic-range proteinuria exhibit more severe disordered immunologic function, hypercoagulability, glomerular and tubulointerstitial pathological damage, and have worse outcomes than those with lower proteinuria levels. Clinicians should pay great attention to the kidney injury and more extensive studies are required to identify optimal treatment regimens to improve outcomes in patients.

Effective treatment with intravenous immunoglobulin for Henoch-Schönlein purpura with refractory gastrointestinal symptoms in an adolescent: A CARE-compliant case report

RATIONALE

This article presents a complex case of refractory Henoch-Schönlein purpura (HSP), initially manifesting with complex gastrointestinal (GI) symptoms, and discusses diagnostic and therapeutic challenges encountered. It aims to enhance understanding of the disease and provide evidence for the potential efficacy of intravenous immunoglobulin (IVIG) treatment in this condition.

PATIENT CONCERNS

A 16-year-old male patient presented with persistent abdominal pain, nausea, vomiting, and constipation for 8 days, leading to hospital admission.

DIAGNOSES

Establishing a definitive diagnosis was challenging initially due to the absence of typical petechiae. However, the appearance of characteristic petechiae subsequently confirmed the diagnosis of HSP.

INTERVENTIONS

Initial treatment with methylprednisolone sodium succinate for 3 days failed to elicit improvement. Subsequently, IVIG was introduced as a combination therapy.

OUTCOMES

Following the combined administration of IVIG, the patient experienced complete resolution of abdominal pain, petechiae, and arthralgia within 4 days.

LESSONS

This case highlights the importance of considering HSP in the differential diagnosis of patients with complex GI symptoms. Furthermore, it suggests that IVIG may be a valuable therapeutic option for HSP patients with refractory GI symptoms. High-quality comparative trials are needed to establish more definitive evidence for the effectiveness of IVIG and to develop specific treatment guidelines.

SARS-CoV-2 as a trigger of IgA vasculitis: a clinical case and literature review

Coronavirus Disease 2019 (COVID-19), caused by SARS-CoV-2, has negatively affected global health. COVID-19 has been associated with a variety of autoimmune and inflammatory disorders, complicating its respiratory manifestations. SARS-CoV-2 triggers inflammatory reactions which may involve multiple organs and systems. The proof for IgA involvement in the immune reactions to coronavirus infection is growing, particularly in the case of IgA immune complex deposition diseases such as IgA vasculitis (IgAV) and IgA nephropathy.This report presents a case of IgAV caused by SARS-CoV-2 in a 53-year-old man. His symptoms included papillomatous, bright red rashes, urticaria throughout the body, aphthous stomatitis, pain in all joints and muscles, weakness, malaise, abdominal pain, face swelling, and arterial hypertension (160/100 mmHg). He received intravenous methylprednisolone (250 mg) and then oral methylprednisolone (16 mg) treatment, which improved his condition. This improvement included the disappearance of abdominal and joint pain and skin rashes.This article also provides an overview of published cases of IgAV after SARS-CoV-2. It may alert rheumatologists and allied specialists of clinical features of IgAV and guide them how to diagnose and treat this disease.

Gastrointestinal manifestations and pathogenesis in childhood immunoglobulin A vasculitis

Immunoglobulin A vasculitis (IgAV), previously known as Henoch-Schönlein purpura, is the most common form of systemic vasculitis in childhood. The primary organs involved are the skin, gastrointestinal (GI) tract, joints, and kidneys. The spectrum of GI involvement in IgAV ranges from being mild and self-limited to severe manifestations often requiring surgical intervention. Galactose-deficient IgA1 on the immunoglobulin hinge region and its immune complexes are thought to play a central pathogenetic role in IgAV, however, an association between such molecules and specific GI mucosal damage remains unclear. GI endoscopy (both upper and lower) shows a variety of mucosal findings, many of which are not specific for IgAV. In upper GI endoscopy, however, the mucosal features can be diagnostic when found localized in the more distal part of upper GI tract (second and/or third parts of the duodenum). Abdominal computed tomography and capsule endoscopy have demonstrated that the small intestine is most commonly involved in IgAV. The GI mucosal involvement when evaluated microscopically shows IgA deposition which is histologically diagnostic. Conversely, leukocytoclastic vasculitis is less useful. Since the 1960s, cases of duodenojejunitis, in which IgAV was suspected but evident purpura was not dermatologically present, have often been labeled as "idiopathic". In a pediatric case series, IgA enteropathy, without dermatological manifestations (i.e., purpura), was reported to have similar symptoms, as well as endoscopic characteristics and immunohistological findings as in IgAV. Subsequently, several case reports provide additional supportive evidence that IgA enteropathy must be a variant of IgAV. Thus, the immunologically driven auto-immune vasculitis results in the symptom complex dependent on the organ system involved, and the subsequent clinical features which are manifested. Present classification criteria are useful and universally available for diagnosing IgAV. However, based upon current knowledge including IgA enteropathy, minor modification of the IgAV criteria is proposed in the review.

The relationship between the severity and complications of Henöch-Schönlein purpura in children and dietary inflammatory index: a retrospective cohort study

Purpose

To investigate the association between the Dietary Inflammatory Index (DII) and disease severity as well as complications in children diagnosed with Henöch-Schönlein purpura (HSP), shedding light on the potential influence of dietary factors on HSP.

Methods

A retrospective cohort study was conducted, enrolling children aged 2-14 years diagnosed with HSP. Participants were divided into low and Pro-inflammatory dietary groups based on their DII scores. Biomarkers, nutrient intake, blood lipid profiles and disease complications were compared between the two groups. Spearman correlation analysis was performed to assess the relationship between DII and complications.

Results

A total of 115 patients, including 56 patients with anti-inflammatory dietary and 59 with pro-inflammatory dietary, were included. The pro-inflammatory dietary group demonstrated significantly elevated of C-reactive protein, tumor necrosis factor-α, interleukin-6, erythrocyte sedimentation rate, white blood cell count, eosinophils, IgE, consumption of total calories, protein, carbohydrates, fiber, fat intake, total cholesterol, LDL cholesterol, HDL cholesterol, triglycerides, VLDL cholesterol, complications of renal, skin, gastrointestinal, coagulation and respiratory in comparison to the anti-inflammatory dietary group. DII was positively correlated with renal, skin, gastrointestinal, coagulation and respiratory complications.

Conclusion

The study highlights the potential influence of dietary inflammatory potential, as quantified by the DII, on disease severity and complications in children with HSP. Understanding the interplay between dietary patterns and inflammatory responses in pediatric vasculitis has implications for the management of HSP, emphasizing the relevance of considering dietary interventions to optimize clinical outcomes and improve the overall well-being of affected children.

IgA vasculitis induced by carboplatin + nab-paclitaxel + pembrolizumab in a patient with advanced lung squamous cell carcinoma: a case report

A 73-year-old man with lung squamous cell carcinoma was administered carboplatin + nab-paclitaxel + pembrolizumab for four cycles. Subsequently, he presented with multiple purpuras on his extremities, joint swelling on his fingers, abdominal pain, and diarrhea, accompanied by acute kidney injury (AKI), increased proteinuria, hematuria, and elevated C-reactive protein levels. Skin biopsy showed leukocytoclastic vasculitis as well as IgA and C3 deposition in the vessel walls. Based on these findings, the patient was diagnosed with IgA vasculitis as an immune-related adverse event (irAE) induced by carboplatin + nab-paclitaxel + pembrolizumab. After discontinuation of pembrolizumab and glucocorticoids, the symptoms immediately resolved. Regular monitoring of skin, blood tests, and urinalysis are necessary, and the possibility of irAE IgA vasculitis should be considered in cases of purpura and AKI during treatment with immune checkpoint inhibitors.

Navigating Adult-Onset IgA Vasculitis-Associated Nephritis

PURPOSE OF REVIEW

IgA vasculitis (IgAV), formerly Henoch-Schonlein purpura, is the most common systemic vasculitis in childhood. In adults, however, this condition is poorly understood, yet associated with more severe disease and poorer outcomes. This necessitates the need for early diagnosis and management.

SCOPE OF REVIEW

We describe the pathophysiology, clinical manifestations, and diagnosis of IgAV in adults. Poor outcomes are often due to the high frequency of glomerulonephritis in IgAV-IgA vasculitis-associated nephritis (IgAVN). We hence also aim to summarize the latest clinical data regarding treatment strategies in IgAVN. The diagnosis and differentiation in histology between IgAVN and IgA nephropathy (IgAN) remain a challenge. Review of treatment therapies: Pathological mechanisms between IgAVN and IgAN appear to be consistent between the two, and data from IgAN are often extrapolated to IgAVN. The role of various immunosuppression therapies remains controversial, and in this review, we will discuss immunosuppression use and highlight evidence surrounding emerging and promising novel therapies in IgAVN/IgAN. Our aim for this review is to guide future treatment strategies and direct future studies.

IgA vasculitis after COVID-19: a case-based review

IgA-associated vasculitis (IgAV) known as Henoch - Schönlein purpura (HSP) disease is an inflammatory disorder of small blood vessels. It's the most common type of systemic vasculitis in children which can be associated with the inflammatory process following infections. IgA vasculitis is a rare and poorly understood systemic vasculitis in adults. Coronavirus disease 2019 (COVID-19) has been associated with HSP in both adults and children. A 58-year-old woman was diagnosed with HSP, fulfilling the clinical criteria: palpable purpura, arthritis, hematuria. The disclosure of the HSP disease was preceded by a infection of the respiratory tract. COVID-19 infection was confirmed via the presence of IgM and IgG antibodies. This case indicates the possible role of SARS-CoV-2 in the development of HSP. The clinical course of IgAV in adults appears to be different from pediatric IgAV, especially due to higher risk of renal complications. Symptoms of the disease quickly resolved with low-dose of steroids.

Exploring potential predictors of Henoch-Schönlein purpura nephritis: a pilot investigation on urinary metabolites

Henoch-Schönlein purpura nephritis (HSPN) is the most severe manifestation of Henoch-Schönlein purpura (HSP). This study aimed to determine the role of urine metabolomics in predicting HSPN and explore the potential mechanisms of HSP. A liquid chromatography-tandem mass spectrometry-based untargeted metabolomics analysis was performed to investigate the urinary metabolic profiles of 90 participants, comprising 30 healthy children (group CON) and 60 patients with HSP, including 30 HSP patients without renal involvement (group H) and 30 HSPN patients (group HSPN). The differentially expressed metabolites (DEMs) were identified using orthogonal partial least squares discriminant analysis (OPLS-DA), and subsequent bioinformatics analysis was conducted to elucidate the perturbed metabolic pathways. A total of 43 DEMs between H and HSPN groups were analyzed by the Kyoto Encyclopedia of Gene and Genome (KEGG) database, and the result indicates that glycine, serine and threonine metabolism, and cysteine and methionine metabolism were significantly disturbed. A composite model incorporating propionylcarnitine and indophenol sulfate was developed to assess the risk of renal involvement in pediatric patients with HSP.   Conclusion: This study reveals the metabolic alterations in healthy children, HSPN patients, and HSP patients without renal involvement. Furthermore, propionylcarnitine and indophenol sulfate may be potential predictive biomarkers of the occurrence of HSPN. What is Known: • HSP is the predominant type of vasculitis observed in children. The long-term prognosis of HSP is contingent upon the extent of renal impairment. In severe nephritis, a delay in appropriate treatment may lead to fibrosis progression and subsequent development of chronic kidney disease (CKD), even leading to renal failure. • The application of metabolomics in investigating diverse renal disorders has been documented. Urine is a robust and sensitive medium for metabolomics detection. What is New: • The metabolic profiles were identified in urine samples of healthy children and those with HSP at the early stage of the disease. Different metabolites were identified between HSP patients without nephritis and those who developed HSPN. • These different metabolites may affect oxidative stress in the progression of HSPN.

Immunoglobulin A Vasculitis With Intussusception in Children

BACKGROUND

Immunoglobulin A (IgA) vasculitis with intussusception is acute and severe vasculitis combined with acute abdomen in children. The diagnosis of the disease depends on the results of imaging examinations, and its treatment mainly includes enema and surgery. The literature summarized the detailed diagnosis and treatment data in previous literature reports.

METHODS

We described the clinical manifestations, ultrasonic features, and treatment of patients admitted to a single center and reviewed previous literature regarding cases with detailed clinical data in the PubMed database within the past 20 years.

RESULTS

The review included 36 patients, including 22 boys and 14 girls. A total of 32 patients were diagnosed using ultrasound (88.9%). The main sites of intussusception were the ileum and ileocolon in 16 (44.4%) and 11 (30.6%) cases, respectively. Thirteen patients (36.1%) were treated with enema, with 6 responding to the treatment. 26 patients (72.2%) underwent surgical treatment. Patients with ileal intussusception were more likely to be treated with surgery than those with colonic intussusception (P < .05). The single-center clinical data of 23 patients showed that there was no significant difference in laboratory test findings between patients with and without surgical treatment (P > .05). Patients with long insertion lengths were more likely to require surgery and resection (P < .05).

CONCLUSIONS

Ultrasonography is the first-line investigation for diagnosis. The main sites of intussusception were ileum and ileocolon. The length of intubation was related to surgery; treatment is according to the intussusception site. Air enema is not suitable for intussusception of the small intestine.

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.

A Case Series of Unusual IgA Vasculitis

Introduction

Immunoglobulin A vasculitis (IgA)is a rare condition characterized by palpable purpura, often involving the skin, gastrointestinal tract, joints, and kidneys. Presentation is usually acute and is more common in children and adolescents of Southeast Asian and European descent. In the adult population, it is less common and therapies are not as well-established.

Case Presentation

Disease prevalence of IgA vasculitis outside Southeast Asian and European populations is not well-documented. In this case series, we present 2 cases of IgA vasculitis in 2 older adult males, one of Native American descent and one of African American descent.

Conclusion

IgA vasculitis must be considered within the adult population, and it is not limited to certain ethnic groups. Further research is needed to give clarity on the best treatment options for adults with IgA vasculitis. We believe that patients presenting with IgA vasculitis are best managed in a multidisciplinary approach, especially those patients with limited improvement despite the initiation of corticosteroids. Our 2 cases should raise awareness of IgA vasculitis in patients with skin rashes and elevated creatinine levels.

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.

Taxonomic and functional shifts of gut microbiome in immunoglobulin A vasculitis children and their mothers

Objectives

To examine the gut microbiota characteristics in children with immunoglobulin A vasculitis and their interrelationships with the host, while evaluate the vertical inheritance of microbiota in the development and progression of IgA vasculitis.

Methods

This study investigated the gut microbiome of 127 IgA vasculitis mother-child pairs and 62 matched healthy mother-child pairs, and compared the gut microbial composition of different groups. The pathway enrichment analysis evaluated potential gut microbiome-mediated pathways involved in the pathophysiology of IgA vasculitis. The Spearman correlation analysis illustrated the relationships between clinical variables and bacterial biomarkers.

Results

This study identified distinct intestinal microbiome in IgA vasculitis children compared to healthy children, and further pointed out the association in gut microbiota between IgA vasculitis children's and their mother's. The relative abundance of Megamonas and Lactobacillus in IgAV children was positively correlated with that in their mothers. The pathway enrichment analysis found microbial biosynthesis of vitamins and essential amino acids was upregulated in children with IgA vasculitis. Correlation analysis showed bacterial biomarkers were correlated with indicators of blood coagulation.

Conclusion

Children with IgA vasculitis have unique bacterial biomarkers and may affect coagulation function, and their gut microbiome was closely associated with that of their mothers. The observed association in gut microbiota between IgA vasculitis children and their mothers suggested a potential intergenerational influence of the maternal microbiota on the development or progression of IgA vasculitis in children.

Predictors of Gastrointestinal Involvement in Children with IgA Vasculitis: Results from a Single-Center Cohort Observational Study

Background and objective: IgA vasculitis (IgAV), a predominantly pediatric leukocytoclastic disease, has an unpredictable, though largely benign, evolution. The aim of this study was to retrospectively investigate any potential clinical or laboratory predictors of gastrointestinal involvement in a single-center cohort of children with IgAV. Patients and methods: A total of 195 children with a history of IgAV, regularly followed-up for an average period of 1 ± 2.6 years via outpatients clinics of the pediatric rheumatology unit in our University, were assessed, analyzing their clinical and laboratory variables in relationship with their disease evolution and outcome. Results: Univariate analysis showed that a higher neutrophil granulocyte count and lower lymphocyte count (expressed as a percentage of the total white blood cells) were significantly associated with the presence of gastrointestinal involvement at the first examination (65.2 ± 13% versus 58.8 ± 12%, p = 0.02, and 26.4 ± 11% versus 32.1 ± 11%, p = 0.02, respectively). A positive pharyngeal swab for Streptococcus pyogenes, a deficiency of 25-hydroxyvitamin D, a persistence of purpuric rash for more than 1 month, and purpuric lesions in the genital area were also associated with gastrointestinal involvement (p = 0.0001, p = 0.0001, p = 0.007 and p = 0.001, respectively). However, multiple logistic regressions with correction for the patients' sex and age showed that lower 25-hydroxyvitamin D levels, persistent rash, and genital lesions were independently and significantly associated with signs of gastrointestinal involvement. We then performed a secondary analysis (both univariate and multivariate) to investigate whether vitamin D deficiency was associated with other IgAV manifestations: we found that only 25-hydroxyvitamin D deficiency remained significantly associated with gastrointestinal involvement in IgAV. Conclusions: Patients with IgAV and vitamin D deficiency might be more prone to developing gastrointestinal manifestations of variable severity.

Transcriptome profile analysis in spinal cord injury rats with transplantation of menstrual blood-derived stem cells

Introduction

Menstrual blood-derived stem cells (MenSCs) are vital in treating many degenerative and traumatic disorders. However, the underlying molecular mechanisms remain obscure in MenSCs-treating spinal cord injury (SCI) rats.

Methods

MenSCs were adopted into the injured sites of rat spinal cords at day 7 post surgery and the tissues were harvested for total RNA sequencing analysis at day 21 after surgery to investigate the expression patterns of RNAs. The differentially expressed genes (DEGs) were analyzed with volcano and heatmap plot. DEGs were sequentially analyzed by weighted gene co-expression network, functional enrichment, and competitive endogenous RNAs (ceRNA) network analysis. Next, expression of selected miRNAs, lncRNAs, circRNAs and mRNAs were validated by quantitative real-time polymerase chain reaction (qRT-PCR). Bioinformatics packages and extra databases were enrolled to scoop the genes functions and their interaction relationships.

Results

A total of 89 lncRNAs, 65 circRNAs, 120 miRNAs and 422 mRNAs were significantly upregulated and 65 lncRNAs, 72 circRNAs, 74 miRNAs, and 190 mRNAs were significantly downregulated in the MenSCs treated rats compared to SCI ones. Current investigation revealed that MenSCs treatment improve the recovery of the injured rats and the most significantly involved pathways in SCI regeneration were cell adhesion molecules, nature killer cell mediated cytotoxicity, primary immunodeficiency, chemokine signaling pathway, T cell receptor signaling pathway and B cell receptor signaling pathway. Moreover, the lncRNA-miRNA-mRNA and circRNA-miRNA-mRNA ceRNA network of SCI was constructed. Finally, the protein-protein interaction (PPI) network was constructed using the top 100 DE mRNAs. The constructed PPI network included 47 nodes and 70 edges.

Discussion

In summary, the above results revealed the expression profile and potential functions of differentially expressed (DE) RNAs in the injured spinal cords of rats in the MenSCs-treated and SCI groups, and this study may provide new clues to understand the mechanisms of MenSCs in treating SCI.

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.

[Research advances in the etiology and pathogenesis of immunoglobulin A vasculitis]

Immunoglobulin A vasculitis (IgAV), also known as Henoch-Schönlein purpura, has complex etiology and pathogenesis which have not been fully clarified. The latest research shows that SARS-CoV-2 and related vaccines, human papilloma vaccine, and certain biological agents can also induce IgAV. Most studies believe that the formation of galactose-deficient IgA1 (Gd-IgA1) and Gd-IgA1-containing immune complex plays a crucial role in the pathogenesis of IgAV. It is hypothesized that the pathogenesis of IgAV is associated with the binding of IgA1 to anti-endothelial cell antibodies. In addition, genetics also constitutes a major focus of IgAV research. This article reviews the new advances in the etiology of IgAV and summarizes the role of Gd-IgA1, Gd-IgA1-containing immune complex, anti-endothelial antibody, IgA1 conjugates, T lymphocyte immunity, and genetic factors in the pathogenesis of IgAV.

Analysis of IL-1β, TGF-β, IL-5, ACE, PTPN22 gene polymorphisms, and gene expression levels in Turkish children with IgA vasculitis

OBJECTIVE

Immunoglobulin-A vasculitis (IgAV) is an inflammatory disease that affects small blood vessels. This study was performed to identify an association between protein tyrosine phosphatase non-receptor type 22 (PTPN22) + 788G > A (rs33996649), transforming growth factor-beta (TGF-β) -509C > T (rs18004069), interleukin 1-beta (IL-1β) -511C > T (rs16944), interleukin 5 (IL-5) -746C/T (rs2069812), and angiotensin-converting enzyme (ACE) I/D (rs4646994) gene polymorphisms, susceptibility to IgAV, as well as the mRNA levels of IL-1β, IL-1β, and TGF-β.

METHOD

A total of 53 patients with IgAV and 50 healthy controls were enrolled. PTPN22, TGF-β, IL-1β, ACE gene polymorphisms, ACE gene I/D polymorphisms, and mRNA expression levels were analyzed using the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method, allele-specific PCR, and real-time PCR with TaqMan kits, respectively.

RESULTS

PTPN22, TGF-β, IL-1β, IL-5, and ACE variants showed no genotype or allele differences between patients with IgAV and controls. Increased levels of IL-1β and TGF-β mRNA expressions were observed in patients with IgAV (p < 0.001). Patients with the IL-1β AG genotype showed significantly increased amounts of arthritis than patients with non-AG (p = 0.004). Age at disease onset was found to be significantly different in patients with IgAV according to the presence of TGF-β TT genotype (p = 0.047).

CONCLUSION

Polymorphisms in PTPN22, TGF-β, IL-5, IL-1β, and ACE genes are unlikely to confer susceptibility to IgAV. However, the presence of the AG genotype of IL-1β is associated with susceptibility to IgAV-related arthritis. This is the first study to report a significant increase in serum mRNA levels of IL-1β and TGF-β in IgAV patients, supporting a susceptibility to IgAV in childhood.

New insights into epidemiological data and impact of the COVID-19 pandemic on IgA vasculitis in children and adults: a French nationwide cohort

IgA vasculitis (IgAV) is a small size vasculitis for which epidemiologic data are strikingly lacking, especially about the adult form. Additionally, the COVID-19 pandemic seems to have profoundly modified the incidence of this disease. Here, we aimed to establish some relevant epidemiological data in both pediatric and adult IgAV. We performed an observational study using a national database called "BNDMR" on IgAV, which gathers patients managed in the French network of experts on rare diseases. We primarily performed descriptive statistics over the 2010-2022 period. Then, we compared the North-South geographical areas, the seasonality, and the impact of COVID-19 with that of other patients reported in the same centers. We collected data from 1988 IgAV patients. The sex ratio was 1.57 for adults and 1.05 for children. The annual incidence in 2021 was 0.06 for 100,000 adults and 0.50 for 100,000 children. Compared with other diseases reported into the BNDMR, IgAV was more common in the South than in the North of France (OR 4.88 [4.17-5.74] in adults and OR 1.51 [1.35-1.68] in children). IgAV was also observed more frequently in winter and autumn. Strikingly, we observed a decrease in incidence during the COVID-19 pandemic period in children (OR 0.62 [0.47-0.81]). Our study provides both new insights and confirmations of IgAV epidemiological data: winter and autumn seasonality, more pronounced male predominance in adults, decreasing incidence of pediatric IgAV during the COVID-19 pandemic and increasing incidence in the South of France.

Causal relationships between circulating inflammatory factors and IgA vasculitis: a bidirectional Mendelian randomization study

Background

IgA vasculitis (IgAV) is an immune-associated vasculitis, yet its exact etiology remains unclear. Here, we explore the interaction between IgAV and inflammatory factors using bidirectional Mendelian randomization (MR).

Methods

We conducted a bidirectional summary-level MR analysis to delineate the causality of C-reactive protein (CRP), procalcitonin (PCT), and 41 circulating inflammatory regulators with IgAV. Data on genetic variants related to inflammation were obtained from three genome-wide association studies (GWASs) on CRP, PCT, and human cytokines, whereas data on IgAV was from large meta-analyses of GWAS among 216 569 FinnGen Biobank participants. The primary MR analysis was performed using the inverse-variance weighted (IVW) approach, and the sensitivity analyses were carried out using MR-Egger, weighted median, weighted mode, and MR-pleiotropy residual sum and outlier.

Results

This study revealed the association of CRP higher levels with increased risk of IgAV through IVW method (Estimate odds ratio [OR] = 1.41, 95% confidence interval [CI]: 1.01-1.98, P = 0.04), MR-Egger (OR = 1.87, CI: 1.15-3.02, P = 0.01), weighted median (OR = 2.00, CI: 1.21-3.30, P = 0.01) and weighted mode (OR = 1.74, CI: 1.13-2.68, P = 0.02). Furthermore, elevated IL-8 was strongly implicated with a higher risk of IgAV (IVW OR = 1.42, CI: 1.05-1.92; P = 0.02). Conversely, genetically predicted IgAV was associated with decreased levels of TNF-β (IVW estimate β = -0.093, CI: -0.178 - -0.007; P = 0.033). Additionally, no such significant statistical differences for other inflammatory factors were found.

Conclusion

Our current study using bidirectional MR analysis provides compelling evidence for a causal effect of CRP, PCT, and circulating inflammatory regulators on IgAV. These findings contribute to a better understanding of the pathogenesis of IgAV and emphasize the potential of targeting inflammatory factors for therapeutic interventions.

Diagnostic and prognostic value of galactose-deficient IgA1 in patients with IgA nephropathy: an updated systematic review with meta-analysis

Objectives

Galactose-deficient IgA1 (Gd-IgA1) is a critical effector molecule in the pathogenesis of IgA nephropathy (IgAN), a leading renal disease without noninvasive assessment options. This updated systematic review aimed to determine the diagnostic and prognostic value of Gd-IgA1 assessment in biological fluids in patients with IgAN.

Methods

PRISMA guidelines were followed in this review. We searched PubMed, Embase, Cochrane Library, China National Knowledge Infrastructure, China Biology Medicine disc, VIP Information/China Science and Technology Journal Database, and WANFANG for studies published between database inception and January 31, 2023. Eligible studies that evaluated aberrant IgA1 glycosylation in IgAN patients relative to controls were identified, and random effects meta-analyses were used to compare Gd-IgA1 levels in different groups. The quality of the evidence was assessed using the Newcastle-Ottawa Scale. This study was registered on PROSPERO (CRD42022375246).

Findings

Of the 2727 records identified, 50 were eligible and had available data. The mean Newcastle-Ottawa Scale score was 7.1 (range, 6-8). Data synthesis suggested that IgAN patients had higher levels of blood and/or urine Gd-IgA1 compared with healthy controls (standard mean difference [SMD]=1.43, 95% confidence interval [CI]=1.19-1.68, P<0.00001), IgA vasculitis patients (SMD=0.58, 95% CI=0.22-0.94, P=0.002), and other kidney disease patients (SMD=1.06, 95% CI=0.79-1.33, P<0.00001). Moreover, patients with IgAN had similar levels of serum Gd-IgA1 compared to first-degree relatives (SMD=0.38, 95% CI= -0.04-0.81, P=0.08) and IgA vasculitis with nephritis patients (SMD=0.12, 95% CI= -0.04-0.29, P=0.14). In addition, ten studies demonstrated significant differences in serum Gd-IgA1 levels in patients with mild and severe IgAN (SMD= -0.37, 95% CI= -0.64--0.09, P=0.009).

Conclusions

High serum and urine Gd-IgA1 levels suggest a diagnosis of IgAN and a poor prognosis for patients with this immunological disorder. Future studies should use more reliable and reproducible methods to determine Gd-IgA1 levels.

Systematic review registration

https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42022375246, identifier CRD42022375246.

[Clinical characteristics, pathology, and prognosis of children with diffuse endocapillary proliferative Henoch-Schönlein purpura nephritis]

OBJECTIVES

To investigate the clinical characteristics, pathology, and prognosis of children with diffuse endocapillary proliferative Henoch-Schönlein purpura nephritis (DEP-HSPN).

METHODS

A retrospective analysis was performed on the clinical, pathological, and prognosis data of 44 children with DEP-HSPN and 765 children without DEP-HSPN. The children with DEP-HSPN were diagnosed by renal biopsy in Jiangxi Provincial Children's Hospital from January 2006 to December 2021.

RESULTS

Among the 809 children with purpura nephritis, 44 (5.4%) had DEP-HSPN, with a mean age of (8±3) years, and there were 29 boys (65.9%) and 15 girls (34.1%). Compared with the non-DEP-HSPN group, the DEP-HSPN group had a significantly shorter time from onset to renal biopsy and a significantly higher proportion of children with respiratory infection or gross hematuria, and most children had nephrotic syndrome. The DEP-HSPN group had significantly higher levels of 24-hour urinary protein, urinary protein grading, microscopic hematuria grading, serum creatinine, and blood urea nitrogen and significantly lower levels of serum albumin and complement C3 (P<0.05). The DEP-HSPN group had a higher pathological grading, with predominant deposition of IgA in the mesangial area and capillary loops, and higher activity scores in the modified semi-quantitative scoring system (P<0.05). The Kaplan-Meier survival analysis showed that there was no significant difference in the renal complete remission rate between the two groups (P>0.05).

CONCLUSIONS

Children with DEP-HSPN have a rapid onset, severe clinical manifestations and pathological grading, and high activity scores in the modified semi-quantitative scoring system. However, most of the children with DEP-HSPN have a good prognosis, with a comparable renal complete remission rate to the children without DEP-HSPN.

The Spectrum and Age-Sex Patterns Among Outpatients with Allergic Diseases - Yichang City, Hubei Province, China, 2018-2021

What is already known about this topic?

Allergic diseases have affected an estimated 40% of the population in China. However, our understanding of the full spectrum of these diseases remains insufficient.

What is added by this report?

Between 2018 and 2021, Yichang City documented 625,929 outpatient visits mainly related to skin and mucous membrane allergies (77.90%) and allergic respiratory conditions (19.64%). In 2021, the occurrence of outpatient visits for conditions such as allergic rhinitis, acute atopic conjunctivitis, and atopic dermatitis increased. The demographic analysis revealed that male patients comprised the majority of the under 18 age bracket (56.05%), while female patients were predominantly represented in the 18 to 65 age bracket (61.79%).

What are the implications for public health practice?

This constitutes the first analysis of the spectrum of allergic diseases, utilizing regional outpatient data, which has substantial implications for understanding the disease burden.