Multisystemic manifestations of IgA vasculitis

Extracellular CIRP co-stimulated T cells through IL6R/STAT3 in pediatric IgA vasculitis

Immunoglobulin A vasculitis (IgAV) is the most common vasculitis of childhood. Disordered immune responses play important roles in its pathogenesis, but the comprehensive immune profile of the disease and the underlying mechanisms are still largely unknown. Here we found a potential disease biomarker cold inducible RNA binding protein (CIRP) in our pediatric IgAV cohort. Serum CIRP level in these patients were elevated and positively correlated with the increased early memory (CD45RA+CD62L+CD95+) T cells revealed using multicolor flow cytometry. Immune phenotyping of the patients showed they had more activated T cells with higher IL6Ra expression. T cell culture experiment showed CIRP further activated both human CD4+ and CD8+ T cells as indicated by increased perforin secretion and phosphorylation of STAT3. Blockade of IL6Rα attenuated CIRP-induced T cell toxicity in vitro. RNA-sequencing data further supported CIRP stimulation promoted human T cell activation and migration, fueled inflammation through the JAK-STAT signaling pathway. Therefore, IL6Ra-mediated T cell activation by extracellular CIRP may contribute to pathogenesis of IgAV in children, both CIRP and IL6Ra could be new therapeutic targets for IgAV.

Ang-1, Ang-2, and Tie2 are diagnostic biomarkers for Henoch-Schönlein purpura and pediatric-onset systemic lupus erythematous

Henoch-Schönlein purpura (HSP) and pediatric-onset systemic lupus erythematosus (pSLE) are closely associated with vasculitis and vascular diseases. This study aimed to investigate the clinical diagnostic values of Ang-1, Ang-2, and Tie2 for HSP and pSLE. We surveyed 82 HSP patients, 34 pSLE patients, and 10 healthy children. The expression levels of Ang-1, Ang-2, and Tie2 in the serum and urine were assessed using enzyme-linked immunosorbent assay. The diagnostic values of Ang-1, Ang-2, and Tie2 for HSP and pSLE were evaluated using receiver operating characteristic curve analysis. The results revealed that the serum and urine expression levels of Ang-2 and Tie2 were significantly elevated in HSP and pSLE patients, whereas the Ang-1/Ang-2 values were reduced. Additionally, Ang-1 was highly expressed in the serum and urine of HSP patients and in the serum of pSLE patients. Ang-1, Ang-2, and Tie2 showed differential expression in various types of HSP and pSLE compared with their expression in healthy controls. In summary, Ang-1, Ang-2, and Tie2 can serve as biomarkers for HSP and pSLE. Moreover, Ang-1/Ang-2 values are reduced in HSP and pSLE patients. Ang-1, Ang-2, and Tie2 can be used as biomarkers for HSP and pSLE.

Imaging of Childhood Cerebral Vasculitis

Childhood cerebral vasculitis is a condition that affects the blood vessels in the brain of children and is rare but life-threatening. Imaging plays a crucial role in the diagnosis and monitoring of the disease. This article describes the classification, diagnostic algorithm, and various imaging modalities used in the evaluation of childhood cerebral vasculitis and the imaging findings associated with primary and secondary vasculitis. Understanding the imaging features of this condition can assist in early diagnosis, effective treatment, and improve outcomes.

Immunological Features of Children with Gastrointestinal Bleeding Due to Henoch-Schönlein Purpura

Background

This study aims to evaluate the immunological features of gastrointestinal (GI) bleeding in children with Henoch-Schönlein purpura (HSP).

Study Design

This retrospective study was conducted on children with HSP. Demographic and clinical data were collected, including serum immunoglobulin (Ig) levels, complement C3 and C4 levels, and lymphocyte subtype percentage.

Results

A total of 446 hospitalized children had HSP. Eighty-six children with HSP had GI bleeding, 114 had proteinuria, and 107 had hematuria. Lower arthralgia, prolonged glucocorticoid use, increased white blood cell counts, elevated neutrophils and neutrophil-to-lymphocyte ratio, reduced IgG and C3 levels, elevated CD19+ cell percentage, and reduced CD3+ cell and natural killer cell percentages were associated with GI bleeding risk in patients with HSP. Multivariate regression analysis revealed that arthralgia, glucocorticoid use, increased neutrophil percentage, reduced IgG and C3 levels, and increased CD19+ cell percentage were independent predictors of GI bleeding. Further analysis indicated that the combination of C3 and CD19+ cell percentages had a high predictive ability for GI bleeding in children with HSP.

Conclusion

This study indicated that reduced C3 and increased CD19+ cell percentages contributed to the development of GI bleeding in children with HSP. Specific immunologic profiles may be strongly correlated with GI bleeding risk in children with HSP.

Clinical characteristics and risk factors of IgA vasculitis with intussusception and intestinal perforation

AIM

Intussusception is the most common surgical complication of IgA vasculitis (IgAV), and intestinal perforation is usually associated with intussusception. If they are not recognised and treated in a timely manner, serious consequences may occur. The objective is to summarise the clinical features of IgAV complicated by intussusception and intestinal perforation and explore its risk factors.

METHODS

The clinical data of 32 patients with IgAV complicated by surgical complications (25 cases of intussusception and 7 cases of intestinal perforation) were retrospectively analysed. A total of 160 IgAV children with gastrointestinal (GI) involvement but without surgical complications were randomly selected as a control group. Binary logistic regression analysis was performed to explore the risk factors for IgAV with intussusception and intestinal perforation.

RESULTS

Compared with the intussusception group, the intestinal perforation group had a significantly higher number of patients with GI symptoms prior to skin purpura and GI bleeding, a significantly higher number of days of abdominal pain, a significantly higher Wong-Baker score, and a significantly higher white blood cell count. Multivariate logistic regression analysis indicated that age ≤7 years, GI symptoms prior to skin purpura, abdominal pain intensity (Wong-Baker scale) and timing of glucocorticoid treatment were independent risk factors of IgAV with intussusception and intestinal perforation.

CONCLUSION

Age less than 7 years, severe abdominal pain, and GI symptoms prior to skin purpura were risk factors for IgAV with intussusception and intestinal perforation. Early use of glucocorticoids may prevent intussusception and intestinal perforation.

Investigating patients for bleeding disorders when most of the "usual" ones have been ruled out

A State of the Art lecture titled "Investigating Patients for Bleeding Disorders When Most of the Usual Ones Have Been Ruled Out" was presented at the International Society on Thrombosis and Haemostasis Congress in 2023. Mild to moderate bleeding disorders (MBDs) in patients in whom no diagnosis of an established disorder, such as platelet function defect, von Willebrand disease, or a coagulation factor deficiency, can be identified are classified as bleeding disorders of unknown cause (BDUCs). Prospective data from the Vienna Bleeding Biobank and other studies have revealed a high proportion of BDUCs of up to 70% among patients with MBD who have a similar bleeding phenotype as other MBDs. As BDUC is a diagnosis of exclusion, the accuracy of the diagnostic workup is essential. For example, repeated testing for von Willebrand disease should be considered if von Willebrand factor values are <80 IU/dL. Current evidence does not support the clinical use of global assays such as thromboelastography, platelet function analyzer, or thrombin generation potential. Rare and novel bleeding disorders due to genetic variants in fibrinolytic factors or natural anticoagulants are rare and should only be analyzed in patients with specific phenotypes and a clear family history. In BDUC, blood group O was identified as a risk factor for increased bleeding severity and bleeding risk after hemostatic challenges. Future studies should improve the phenotypical characterization and ideally identify novel risk factors in BDUC, as a multifactorial pathogenesis is suspected. Finally, we summarize relevant new data on this topic presented during the 2023 International Society on Thrombosis and Haemostasis Congress.

Clinical features of paediatric immunoglobulin A vasculitis patients with scrotal involvement

OBJECTIVES

Immunoglobulin (Ig) A vasculitis (IgAV), is the most common vasculitis of childhood, is a leucocytoclastic vasculitis that affects small vessels of the skin, gastrointestinal (GI) tract, joints, and kidneys. Scrotal involvement is relatively rare. In this study, we aimed to reveal the clinical and laboratory characteristics of patients with scrotal involvement in IgAV and its relationship with other clinical features of the disease.

METHODS

A total number of 301 male patients with a diagnosis of IgAV between January 2005 and 2022 were retrospectively analysed. The patients were divided into two groups as with and without scrotal involvement. The clinical and laboratory characteristics of the groups were compared.

RESULTS

Scrotal involvement was detected in 16.3% (49) of male IgAV patients. Scrotal involvement was unilateral in 51% of patients. While single acute scrotal attack was present in 93.9% of patients, only three patients had recurrent acute scrotal involvement. In patients with scrotal involvement, the age at diagnosis was younger (p = .007), and disease recurrence was higher (p = .003). Glucocorticoid use was more common in patients with scrotal involvement (p < .001). In multivariable analysis, a statistically significant relation between scrotal involvement and age at diagnosis (odds ratio = 0.85, 95% confidence interval 0.76-0.96, p =  .006) was detected.

CONCLUSIONS

In IgAV patients with scrotal involvement, the age at diagnosis is lower, steroid use is more common, and recurrent disease is more frequent.

First Onset of IgA Vasculitis and Nephritis Following COVID-19 Vaccination

The article presents a case of a 32-year-old male who developed IgA vasculitis (IgAV) and IgA vasculitis nephritis (IgAVN) after receiving the second dose of the AstraZeneca COVID-19 vaccine. IgAVN can be a rare side effect of COVID-19 vaccines. Healthcare providers should be aware of this potential adverse event, and promptly recognize and manage it. However, the benefits of vaccination in reducing the morbidity and mortality associated with COVID-19 far outweigh the risks of this rare adverse event.

[Wounds caused by vasculitis-Current classification, diagnostics and treatment]

Wounds of the skin can have very different causes. Especially in clinically atypical or non-healing wounds, the very heterogeneous group of vasculitides is of particularly important differential diagnostic significance. Nowadays, the classification of vasculitis is based on the affected vessels according to the Chapel Hill consensus conference. Thus, potentially any part of the vascular system can be affected. It becomes clear that there is often a risk of systemic diseases with high interdisciplinary relevance.Clinically, the usually very painful wounds in cutaneous vasculitis develop from necrosis and are typically surrounded by an erythematous-livid rim in the florid phase. In addition to clinical inspection, the histopathological examination of biopsies is of particular importance in the usually extensive diagnostic work-up.Therapeutically, adequate wound treatment should always be performed with a focus on pain prevention and infection prophylaxis. In the case of edema, compression therapy also supports wound healing. In addition, it is often necessary to initiate systemic treatment with immunosuppressive or immunomodulating drugs. Whenever possible, causally relevant factors and comorbidities should be diagnosed early and avoided or treated. Otherwise, there is a risk of severe or even fatal disease progression.

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.

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.

Preadolescent-versus adolescent-onset immunoglobulin A vasculitis: The impact of age on prognosis

BACKGROUND

This study aimed to investigate the characteristics of patients with preadolescent- and adolescent-onset immunoglobulin A vasculitis (IgAV) and to determine whether age affects IgAV outcomes in adolescents.

METHODS

Demographic, clinical, and laboratory data of 333 patients diagnosed with IgAV at the Department of Pediatric Rheumatology, University of Health Sciences, Ankara City Hospital, were evaluated retrospectively. The patients were classified into two groups: preadolescents (<10 years) and adolescents (10-19 years). Subgroup analyses were also performed by grouping the adolescent patients into early, middle, and late adolescent groups.

RESULTS

Of the 333 patients, 219 (65.8%) and 114 (34.2%) were preadolescents and adolescents. Palpable purpura, renal, joint, and gastrointestinal (GI) tract involvement were detected in 333 (100%), 78 (23.4%), 79 (23.7%), and 124 (37.2%) patients, respectively; testicular involvement was observed in 25 (13.3%) of 187 male patients. The frequency of renal involvement was significantly higher in the adolescent group than in the preadolescent group at the time of diagnosis (p = 0.030). Notably, joint involvement was significantly higher in the adolescent group (p = 0.001). The need for aggressive therapy was significantly higher in the adolescent group than in the preadolescent group (p = 0.003). There was no significant difference in clinical data, demographic characteristics, and laboratory findings between the adolescent subgroups (p > 0.05).

CONCLUSIONS

Immunoglobulin A vasculitis can occur at any age but the disease prognosis appears to worsen with age. The present study reported that joint involvement, kidney involvement, and the need for more aggressive treatment were higher in the adolescent group than in the preadolescent group.

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.

Prediction of renal damage in children with IgA vasculitis based on machine learning

This article is objected to explore the value of machine learning algorithm in predicting the risk of renal damage in children with IgA vasculitis by constructing a predictive model and analyzing the related risk factors of IgA vasculitis Nephritis in children. Case data of 288 hospitalized children with IgA vasculitis from November 2018 to October 2021 were collected. The data included 42 indicators such as demographic characteristics, clinical symptoms and laboratory tests, etc. Univariate feature selection was used for feature extraction, and logistic regression, support vector machine (SVM), decision tree and random forest (RF) algorithms were used separately for classification prediction. Lastly, the performance of four algorithms is compared using accuracy rate, recall rate and AUC. The accuracy rate, recall rate and AUC of the established RF model were 0.83, 0.86 and 0.91 respectively, which were higher than 0.74, 0.80 and 0.89 of the logistic regression model; higher than 0.70, 0.80 and 0.89 of SVM model; higher than 0.74, 0.80 and 0.81 of the decision tree model. The top 10 important features provided by RF model are: Persistent purpura ≥4 weeks, Cr, Clinic time, ALB, WBC, TC, Relapse, TG, Recurrent purpura and EB-DNA. The model based on RF algorithm has better performance in the prediction of children with IgA vasculitis renal damage, indicated by better classification accuracy, better classification effect and better generalization performance.

Development and Validation of a Differential Diagnosis Model for Acute Appendicitis and Henoch-Schonlein Purpura in Children

Objective: To study and develop a predictive model for the differential diagnosis of acute appendicitis (AA) and Henoch-Schonlein purpura (HSP) in children and to validate the model internally and externally. Methods: The complete data of AA and HSP cases were retrospectively analyzed and divided into internal and external verification groups. SPSS software was used for single-factor analysis and screening of independent variables, and R software was used for the development and verification of the diagnostic model. Lasso regression analysis was used to screen predictors and Lasso-logistic regression model was constructed, and K-fold cross-validation was used for the internal verification. In addition, nonfever patients were selected for model development and validation in the same way. Receiver operating characteristic (ROC) curves and calibration curves were drawn, respectively, to evaluate the 2 models. Results: Internal development and validation of the model showed that fever, neutrophil ratio (NEUT%), albumin (ALB), direct bilirubin (DBIL), C-reactive protein (CRP), and K were predictive factors for the diagnosis of HSP. The model was presented in the form of a nomogram, and the area under ROC curve of the development group and verification group was 0.9462 (95% confidence interval [CI] = 0.9402-0.9522) and 0.8931 (95% CI = 0.8724-0.9139), respectively. In the model of patients without fever, NEUT%, platelets (PLT), ALB, DBIL, alkaline phosphatase (ALP), CRP, and K were predictive factors for the diagnosis of HSP, and the area under ROC curve of the development group and verification group was 0.9186 (95% CI = 0.908-0.9293) and 0.8591 (95% CI = 0.8284-0.8897), respectively. Conclusion: In this study, 2 diagnostic models were constructed for fever or not, both of which had good discrimination and calibration, and were helpful to distinguish AA and HSP in children.

The pathogenesis of COVID-19-induced IgA nephropathy and IgA vasculitis: A systematic review

OBJECTIVE

IgA nephropathy (IgAN) and IgA vasculitis (IgAV) are part of a similar clinical spectrum. Both clinical conditions occur with the coronavirus disease 2019 (COVID-19). This review aims to recognize the novel association of IgAN and IgAV with COVID-19 and describe its underlying pathogenesis.

METHODS

We conducted a systematic literature search and data extraction from PubMed, Cochrane, ScienceDirect, and Google Scholar following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines.

RESULTS

Our search identified 13 cases reporting IgAV and IgAN associated with COVID-19 infection and 4 cases of IgAN following COVID-19 vaccination. The mean, mode, and median ages of patients were 23.8, 4, and 8 years, respectively. Most cases associated with COVID-19 infection were reported in males (77%). Rash and purpura (85%) were the most common clinical features, followed by gastrointestinal symptoms (62%). In symptomatic cases, skin or renal biopsy and immunofluorescence confirmed the diagnosis of IgAN or IgAV. Most patients were treated with steroids and reported recovery or improvement; however, death was reported in two patients.

CONCLUSION

There is a paucity of scientific evidence on the pathogenesis of the association of IgAN and IgAV with COVID-19, which thus needs further study. Current research suggests the role of IgA-mediated immune response, evidenced by early seroconversion to IgA in COVID-19 patients and the role of IgA in immune hyperactivation as the predominant mediator of the disease process. Clinicians, especially nephrologists and paediatricians, need to recognize this association, as this disease is usually self-limited and can lead to complete recovery if prompt diagnosis and treatment are provided.

A case of vasculitis triggered by infective endocarditis in a patient undergoing maintenance hemodialysis: a case report

Background

Immunoglobulin A vasculitis (IgA vasculitis) is one of the most common forms of vasculitis in children. It rarely occurs in adults. It is a systemic vasculitis with IgA deposition and is characterized by the classical tetrad of purpura, arthritis/arthralgia, gastrointestinal and renal involvement. Certain types of infections, and pharmacological agents have been reported to be associated with IgA vasculitis. Here, we describe a case of IgA vasculitis triggered by infective endocarditis in a patient undergoing maintenance hemodialysis.

Case presentation

A 70-year-old man undergoing hemodialysis was admitted because of skin purpura, abdominal pain, diarrhea, and lower back pain. We suspected him as IgA vasculitis based on the clinical features and skin biopsy findings. Transesophageal echocardiography revealed infective endocarditis, which predisposed him to IgA vasculitis. He was treated with antibiotics and low-dose corticosteroids, which led to resolution of vasculitis.

Conclusions

This is the first case of IgA vasculitis triggered by infective endocarditis in a patient undergoing hemodialysis. Patients undergoing hemodialysis are at a high risk of infection because of immune dysfunction and frequent venipuncture. The incidence of infective endocarditis associated with IgA vasculitis is very low, but it has been repeatedly reported. Therefore, it is necessary to consider infective endocarditis in patients with clinical features that indicate IgA vasculitis.

Association of the clinicopathological characteristics and proteinuria remission of pediatric IgAV with nephrotic-range proteinuria: A retrospective cohort study

BACKGROUND

IgA vasculitis (IgAV) combined with nephrotic-range proteinuria is uncommon, and nephrotic-range proteinuria is considered a risk factor for poor prognosis in children with IgAV. There are few clinical studies with large samples.

METHODS

Children with IgAV and nephrotic-range proteinuria who were hospitalized at the Department of Nephrology, Rheumatology and Immunology, Hunan Children's Hospital, from March 2008 to January 2020 were retrospectively studied; the patients were aged ≤18 years and were followed up for ≥12 months. We analyzed clinical characteristics, pathological changes, treatment responses, and their relationships in patients with IgAV combined with nephrotic-range proteinuria.

RESULTS

Two hundred seventy-seven children with an average age at onset of IgAV with nephritis (IgAVN) of 8.0 years (interquartile range (IQR), 6.0-10.0) were enrolled; 65.7% were aged 6-10 years. The male-to-female ratio was 1.35:1. All children had both nephrotic-range proteinuria and hematuria, 49 (17.7%) had hypoalbuminemia, and 9 (3.2%) had estimated glomerular filtration rate  < 90 (mL/min/1.73 m²). All included children were followed up for at least 1 year. At 3, 6, and 12 months of follow-up, the remission rates of proteinuria in children with IgAV combined with nephrotic-range proteinuria were 27.8%, 62.1%, and 83.0%, respectively, and the remission rates of hematuria were 1.4%, 8.7%, and 35.7%, respectively. In addition, children with age at onset of IgAV with nephrotic-range proteinuria ≥10 years, who were female, who had proteinuria ≥100 mg/kg/24 h, and who had a pathological grade III or above had lower remission rates of hematuria and proteinuria (P < 0.05). Multivariate factor analysis was performed by logistic regression and showed age at onset of IgAVN ≥ 10 years and crescents to be risk factors for nonremission of proteinuria at 12 months of follow-up (P < 0.05).

CONCLUSIONS

Age at onset of IgAVN, sex, proteinuria level, pathological grade, and crescents significantly affect proteinuria remission in children with IgAV combined with nephrotic-range proteinuria.

Immunoglobulin A vasculitis induced by atypical pneumonia infection with Chlamydophila pneumonia

Infections are a common trigger for IgA vasculitis. Among the bacteria that cause atypical pneumonia, Mycoplasma pneumoniae infection has strongly been associated with IgA vasculitis, with Chlamydophila pneumoniae reported with IgA vasculitis in only one case. Though IgA vasculitis is a self-limiting disease, patients with infection-related vasculitis have shown to benefit from early identification and treatment with antimicrobial therapy. Here, we report a case of IgA vasculitis due to C. pneumoniae infection in a 19-year-old male who presented with an acute onset of rash, that was later followed by symptoms of cough and fever.

Epidemiological and clinical aspects of immunoglobulin A vasculitis in childhood: a retrospective cohort study

Background

A retrospective study was conducted in order to investigate and describe the characteristics of Immunoglobulin A vasculitis (IgAV), previously known as Henoch-Schӧnlein purpura, in the paediatric population of a community-based healthcare delivery system in the Italian region of Abruzzo.

Methods

This is a population-based retrospective chart review of the diagnosis of IgAV in children ages 0 to 18, admitted to the Department of Paediatrics of Chieti and Pescara between 1 January 2000 and 31 December 2016. All children enrolled presented with clinical symptoms and laboratory findings and met the EULAR/PRINTO/PRES 2008 criteria.

Results

Two-hundred-eight children met the criteria for IgAV, with the highest incidence reported among children below 7-years of age. A correlation with recent infections was found in 64% of the cohort; the onset was more frequently during the winter and fall. Purpura had a diffuse distribution in the majority of patients; joint impairment was the second most frequent symptom (43%), whereas the gastrointestinal tract was involved in 28% of patients.

Conclusions

Hereby, we confirm the relative benignity of IgAV in a cohort of Italian children; with regards to renal involvement, we report a better outcome compared to other studies. However, despite the low rate of renal disease, we observed a wide use of corticosteroids, especially for the treatment of persistent purpura.

Fc receptors gone wrong: A comprehensive review of their roles in autoimmune and inflammatory diseases

Systemic autoimmune and inflammatory diseases have a complex and only partially known pathophysiology with various abnormalities involving all the components of the immune system. Among these components, antibodies, and especially autoantibodies are key elements contributing to autoimmunity. The interaction of antibody fragment crystallisable (Fc) and several distinct receptors, namely Fc receptors (FcRs), have gained much attention during the recent years, with possible major therapeutic perspectives for the future. The aim of this review is to comprehensively describe the known roles for FcRs (activating and inhibitory FcγRs, neonatal FcR [FcRn], FcαRI, FcεRs, Ro52/tripartite motif containing 21 [Ro52/TRIM21], FcδR, and the novel Fc receptor-like [FcRL] family) in systemic autoimmune and inflammatory disorders, namely rheumatoid arthritis, Sjögren's syndrome, systemic lupus erythematosus, systemic sclerosis, idiopathic inflammatory myopathies, mixed connective tissue disease, Crohn's disease, ulcerative colitis, immunoglobulin (Ig) A vasculitis, Behçet's disease, Kawasaki disease, IgG4-related disease, immune thrombocytopenia, autoimmune hemolytic anemia, antiphospholipid syndrome and heparin-induced thrombocytopenia.

Acute Arthritis in Children: How to Discern between Septic and Non-Septic Arthritis?

The term septic arthritis refers to an infection of the synovial space. This is an infrequent condition in healthy children, but it should be considered a medical emergency potentially leading to irreversible articular damage. Therefore, prompt diagnosis and antimicrobial treatment play a crucial role in improving the prognosis. Although septic arthritis is the most common cause of acute arthritis, many other diseases may mimic a similar clinical picture, constituting a diagnostic challenge for the clinician who first approaches the patient. Herein we analyze the main features of septic arthritis, offering an overview of the main conditions involved in the differential diagnosis and suggesting a diagnostic workup plan.

IgA Vasculitis: Etiology, Treatment, Biomarkers and Epigenetic Changes

IgA, previously called Henoch-Schönlein vasculitis, is an essential immune component that drives the host immune response to the external environment. As IgA has the unique characteristic of a flexible response to broad types of microorganisms, it sometimes causes an autoreactive response in the host human body. IgA vasculitis and related organ dysfunction are representative IgA-mediated autoimmune diseases; bacterial and viral infections often trigger IgA vasculitis. Recent drug developments and the presence of COVID-19 have revealed that these agents can also trigger IgA vasculitis. These findings provide a novel understanding of the pathogenesis of IgA vasculitis. In this review, we focus on the characteristics of IgA and symptoms of IgA vasculitis and other organ dysfunction. We also mention the therapeutic approach, biomarkers, novel triggers for IgA vasculitis, and epigenetic modifications in patients with IgA vasculitis.

IgA and FcαRI: Versatile Players in Homeostasis, Infection, and Autoimmunity

Mucosal surfaces constitute the frontiers of the body and are the biggest barriers of our body for the outside world. Immunoglobulin A (IgA) is the most abundant antibody class present at these sites. It passively contributes to mucosal homeostasis via immune exclusion maintaining a tight balance between tolerating commensals and providing protection against pathogens. Once pathogens have succeeded in invading the epithelial barriers, IgA has an active role in host-pathogen defense by activating myeloid cells through divers receptors, including its Fc receptor, FcαRI (CD89). To evade elimination, several pathogens secrete proteins that interfere with either IgA neutralization or FcαRI-mediated immune responses, emphasizing the importance of IgA-FcαRI interactions in preventing infection. Depending on the IgA form, either anti- or pro-inflammatory responses can be induced. Moreover, the presence of excessive IgA immune complexes can result in continuous FcαRI-mediated activation of myeloid cells, potentially leading to severe tissue damage. On the one hand, enhancing pathogen-specific mucosal and systemic IgA by vaccination may increase protective immunity against infectious diseases. On the other hand, interfering with the IgA-FcαRI axis by monovalent targeting or blocking FcαRI may resolve IgA-induced inflammation and tissue damage. This review describes the multifaceted role of FcαRI as immune regulator between anti- and pro-inflammatory responses of IgA, and addresses potential novel therapeutic strategies that target FcαRI in disease.

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