Henoch-Schönlein purpura nephritis

Predicting renal damage in children with IgA vasculitis by machine learning

BACKGROUND

Children with IgA Vasculitis (IgAV) may develop renal complications, which can impact their long-term prognosis. This study aimed to build a machine learning model to predict renal damage in children with IgAV and analyze risk factors for IgA Vasculitis with Nephritis (IgAVN).

METHODS

50 clinical indicators were collected from 217 inpatients at our hospital. Six machine learning algorithms-Logistic Regression, Linear Discriminant Analysis, K-Nearest Neighbor, Support Vector Machine, Decision Trees, and Random Forest-were utilized to select the model with the highest predictive performance. A simplified model was developed through feature importance ranking and validated by an additional cohort with 46 patients.

RESULTS

The random forest model had the highest accuracy, precision, recall, F1 score, and area under the curve, with values of 0.91, 0.98, 0.70, 0.79 and 0.94, respectively. The top 11 features according to the importance ranking were anti-streptolysin O, corticosteroids therapy, antihistamine therapy, absolute eosinophil count, immunoglobulin E, anticoagulant therapy, C-reactive protein, prothrombin time, age at onset, D-dimer, recurrence of rash ≥ 3 times. A simplified model using these features demonstrated optimal performance with an accuracy of 84.2%, a sensitivity of 89.4%, and a specificity of 82.5% in external validation. Finally, we provided a web tool based on the simplified model, whose code was published on https://github.com/mulanruo/IgAVN_Prediction .

CONCLUSION

The model based on the random forest algorithm demonstrates good performance in predicting renal damage in children with IgAV, providing a basis for early clinical diagnosis and decision-making.

The Association of HMGB1 and RAGE Gene Polymorphisms with IgA Vasculitis

High-mobility group box 1 (HMGB1) is a pleiotropic cytokine that propagates inflammation by its extracellular action of interacting with the receptor for advanced glycation end products (RAGE). Both HMGB1 and RAGE play multiple roles in the pathogenesis of a variety of inflammatory and autoimmune diseases. We investigated the association of five single-nucleotide polymorphisms (SNPs) of the HMGB1 gene (rs1412125, rs2249825, rs1045411, rs1060348, rs41369348) and four SNPs of the RAGE gene (rs1800624, rs1800625, rs2070600, rs3134940) with the susceptibility and clinical features of paediatric patients with IgA vasculitis (IgAV), also known as Henoch-Schönlein's purpura. This case‒control study included 103 children with IgAV (experimental group) and 150 age-matched healthy individuals (control group). The strength of the association between different groups and alleles or genotypes of HMGB1 and RAGE was estimated using odds ratios (ORs) and 95% confidence intervals (CIs). The HMGB1 polymorphisms rs41369348, rs1045411, rs2249825 and rs1412125 were associated with the development of generalized purpuric rash, and rs1412125 was associated with IgAV nephritis (IgAVN). The RAGE polymorphism rs2070600 might be linked to the development of arthritis in IgAV patients. There was no statistically significant association between the analysed polymorphisms and susceptibility to IgAV. This is the first study to propose an association between several HMGB1 and RAGE polymorphisms and different phenotypes in the clinical course of IgAV in a paediatric population. Further research on other polymorphisms of HMGB1 and RAGE should be conducted in a larger number of patients.

Erythrocyte Glutathione S-Transferase Activity as a Sensitive Marker of Kidney Function Impairment in Children with IgA Vasculitis

IgA vasculitis (IgAV) is the most common childhood vasculitis. The main cause of morbidity and mortality in children with IgAV is nephritis (IgAVN), but the risk of its development, severity, and chronicity remain unclear. Erythrocyte glutathione S-transferase (e-GST) activity has been previously detected as a sensitive marker of kidney function impairment in several diseases. We spectrophotometrically assessed and correlated e-GST activity between 55 IgAV patients without nephritis (IgAVwN), 42 IgAVN patients, and 52 healthy controls. At disease onset, e-GST activity was significantly higher in IgAVN patients (median (interquartile range)) (5.7 U/gHb (4.4-7.5)) than in IgAVwN patients (3.1 U/gHb (2.2-4.2); p < 0.001), and controls (3.1 U/gHb (1.9-4.2); p < 0.001). Therewithal, there were no differences between the IgAVwN patients and controls (p = 0.837). e-GST activity was also significantly higher in the IgAVN patients than in the IgAVwN patients after 3 months (5.0 U/gHb (4.2-6.2) vs. 3.3 U/gHb (2.3-4.1); p < 0.001) and 6 months (4.2 U/gHb (3.2-5.8) vs. 3.3 U/gHb (2.1-4.1); p < 0.001) since the disease onset. Consistent correlations between e-GST activity and serum creatinine, estimated glomerular filtration rate (eGFR), and proteinuria levels were not detected. In conclusion, increased e-GST activity can serve as a subtle indicator of kidney function impairment in children with IgAV.

Ultrasound-Based Radiomics for the Classification of Henoch-Schönlein Purpura Nephritis in Children

Henoch-Schönlein purpura nephritis (HSPN) is one of the most common kidney diseases in children. The current diagnosis and classification of HSPN depend on pathological biopsy, which is seriously limited by its invasive and high-risk nature. The aim of the study was to explore the potential of radiomics model for evaluating the histopathological classification of HSPN based on the ultrasound (US) images. A total of 440 patients with Henoch-Schönlein purpura nephritis proved by biopsy were analyzed retrospectively. They were grouped according to two histopathological categories: those without glomerular crescent formation (ISKDC grades I-II) and those with glomerular crescent formation (ISKDC grades III-V). The patients were randomly assigned to either a training cohort (n = 308) or a validation cohort (n = 132) with a ratio of 7:3. The sonologist manually drew the regions of interest (ROI) on the ultrasound images of the right kidney including the cortex and medulla. Then, the ultrasound radiomics features were extracted using the Pyradiomics package. The dimensions of radiomics features were reduced by Spearman correlation coefficients and least absolute shrinkage and selection operator (LASSO) method. Finally, three radiomics models using k-nearest neighbor (KNN), logistic regression (LR), and support vector machine (SVM) were established, respectively. The predictive performance of such classifiers was assessed with receiver operating characteristic (ROC) curve. 105 radiomics features were extracted from derived US images of each patient and 14 features were ultimately selected for the machine learning analysis. Three machine learning models including k-nearest neighbor (KNN), logistic regression (LR), and support vector machine (SVM) were established for HSPN classification. Of the three classifiers, the SVM classifier performed the best in the validation cohort [area under the curve (AUC) =0.870 (95% CI, 0.795-0.944), sensitivity = 0.706, specificity = 0.950]. The US-based radiomics had good predictive value for HSPN classification, which can be served as a noninvasive tool to evaluate the severity of renal pathology and crescentic formation in children with HSPN.

Traditional Chinese medicine for the treatment of immune-related nephropathy: A review

Immune-related nephropathy (IRN) refers to immune-response-mediated glomerulonephritis and is the main cause of end-stage renal failure. The pathogenesis of IRN is not fully understood; therefore, treatment is challenging. Traditional Chinese medicines (TCMs) have potent clinical effects in the treatment of the IRN conditions immunoglobulin A nephropathy, lupus nephropathy, and diabetic nephropathy. The underlying mechanisms mainly include its inhibition of inflammation; improvements to renal interstitial fibrosis, oxidative stress, autophagy, apoptosis; and regulation of immunity. In this review, we summarize the clinical symptoms of the three IRN subtypes and the use of TCM prescriptions, herbs, and bioactive compounds in treating IRN, as well as the potential mechanisms, intending to provide a reference for the future study of TCM as IRN treatments.

Immunoglobulin A vasculitis nephritis: Current understanding of pathogenesis and treatment

The clinical spectrum of immunoglobulin A vasculitis nephritis (IgAVN) ranges from the relatively common transitory microscopic hematuria and/or low-grade proteinuria to nephritic or nephrotic syndrome, rapidly progressive glomerulonephritis, or even renal failure. Clinical and experimental studies have shown a multifactor pathogenesis: Infection triggers, impaired glycosylation of IgA1, complement activation, Toll-like-receptor activation and B cell proliferation. This knowledge can identify IgAVN patients at a greater risk for adverse outcome and increase the evidence for treatment recommendations.

Glomerulonephritis

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

Reporting the clinical spectrum of children with IgAV in a retrospective 24-year cohort: Influences of age and sex on clinical presentation

Background/aim

Immunoglobulin A vasculitis (IgAV) is one of the most common types of vasculitis in children. The aims of this study were to investigate the clinical characteristics of the disease, and the effects of age and sex on the clinical course in children with IgAV.

Materials and methods

This was a retrospective study including pediatric patients diagnosed with IgAV who attended follow-ups at the pediatric rheumatology department of a tertiary healthcare institution between January 1997 and December 2020. The patients were grouped and compared according to sex and age at diagnosis (<7 years vs. ≥7 years).

Results

The study included 709 children with IgAV, 392 (55.3%) of whom were male. The mean age at diagnosis was 7.9 ± 3.2 years. The most common disease onset season was autumn (31.2%). Upper respiratory infections (27.8%) were the most common predisposing factors. Gastrointestinal system (GIS), joint, and renal involvement were observed in 52.8%, 47.5%, and 17.5% of patients, respectively. Renal involvement, GIS involvement, and disease relapse were significantly more common among those diagnosed after 7 years of age compared to those diagnosed before the age of 7 (p < 0.001, p = 0.033, and p < 0.001, respectively). Scrotal involvement and subcutaneous edema were more common among those diagnosed at younger than 7 years compared to those aged ≥7 years at diagnosis (p < 0.001 and p = 0.016, respectively). GIS involvement was more frequently seen in males compared to females (p = 0.046).

Conclusion

It was demonstrated that being ≥7 years of age at diagnosis or being a male were associated with higher likelihood of renal and GIS involvement in children with IgAV.

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

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

Proteome analysis reveals novel serum biomarkers for Henoch-Schönlein purpura in Chinese children

PURPOSE

Henoch-Schönlein purpura (HSP) is diagnosed based on characteristic skin changes. This study aimed to identify the serum biomarkers of HSP in children.

EXPERIMENTAL DESIGN

We performed proteomic analysis of serum samples from 38 paired pre- and posttherapy HSP patients and 22 healthy controls using a combination of magnetic bead-based weak cation exchange and MALDI-TOF MS. ClinProTools was used to screen the differential peaks. Then, LC-ESI-MS/MS was performed to identify the proteins. ELISA was used to verify the expression of whole protein in the serum of 92 HSP patients, 14 peptic ulcer disease (PUD) patients and 38 healthy controls, which were prospectively collected. Finally, logistic regression analysis was performed to analyze the diagnostic value of the above predictors and existing clinical indicators.

RESULTS

Seven potential HSP serum biomarker peaks (m/z:1228.95, m/z:1781.22, m/z:1468.43, m/z:1619.53, m/z:1868.41, m/z:1694.05, m/z:1743.25) with higher expression in the pretherapy group and one peak (m/z:1947.41) with lower expression in the pretherapy group were all identified as peptide regions of albumin (ALB), complement C4-A precursor (C4A), tubulin beta chain (TUBB), isoform 1 of fibrinogen alpha chain (FGA), and ezrin (EZR). The expression of identified proteins was validated by ELISA. Multivariate logistic regression analysis showed that serum C4A EZR and ALB were independent risk factors for HSP, serum C4A and lgA were independent risk factors for HSPN, and serum D-dimer was an independent risk factor for abdominal HSP.

CONCLUSIONS AND CLINICAL RELEVANCE

These findings revealed the specific etiology of HSP from the perspective of serum proteomics. The identified proteins might serve as potential biomarkers for HSP and HSPN diagnoses.

SIGNIFICANCE

Henoch-Schönlein purpura (HSP) is the most common systemic vasculitis in children, and its diagnosis depends primarily on characteristic skin changes. Early diagnosis of non-rash patients is difficult, especially for abdominal and renal types (Henoch-Schönlein purpura nephritis, HSPN). HSPN has poor outcomes, is diagnosed based on urinary protein and/or haematuria, and cannot be detected early in HSP. Patients with an earlier diagnosis of HSPN appear to have better renal outcomes. Our plasma proteomic analysis of HSP in children revealed that HSP patients could be distinguished from healthy controls and peptic ulcer disease patients using complement C4-A precursor (C4A), ezrin, and albumin. C4A and IgA could distinguish HSPN from HSP in the early stages, and D-dimer was a sensitive index used to distinguish abdominal HSP; identifying these biomarkers could promote the early diagnosis of HSP, especially pediatric HSPN and abdominal HSP, thereby improving precision therapy.

Bullous Henoch-Schönlein Purpura and Associated Nephritis: A Pathological Case Report

Henoch-Schönlein purpura (HSP) is the most common vasculitis in childhood, presenting with purpura, predominantly of the lower extremities and occasionally with renal involvement as well. Although associated with childhood, HSP, although rarely, can also develop in adults as well. Here we present a patient in his sixties, presenting with a myriad of rash units on his lower extremities, including bullous ones, and a constellation of chronic kidney failure. Skin and renal biopsy specimens revealed morphological changes and immune depositions representative of HSP. Despite treatment, the patient's kidney failure slowly progressed, and he expired eight months after his presentation due to associated complications. Although rare, the bullous form of HSP can be viewed as a more aggressive form of the disease, as seen by the presentation constellation and rapid progression in our case.

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

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

The pathophysiologic significance of lymphocyte subset determination in children with infectious mononucleosis, mycoplasma pneumonia and Henoch-Schönlein purpura

OBJECTIVE

This study aimed to explore lymphocyte subset determinations as an aid to understanding the pathophysiology of infectious mononucleosis (IM), pneumonia due to mycoplasma infection (P-MI) and Henoch-Schönlein purpura in children.

METHODS

The peripheral blood lymphocyte subsets of 45 children with IM, 20 children with P-MI, and 31 children with Henoch-Schönlein purpura (HSP), who were treated in the pediatrics department of our hospital from April 2019 to February 2020, were determined by flow cytometry, and the number and percentage of lymphocyte subsets with CD3+, CD3 + CD4+, CD3 + CD8+, CD3 + CD4+/CD3 + CD8+, CD3-CD16 + CD56+, and CD3-CD19 + cells were observed, and the results were compared and analyzed.

RESULTS

(1) The percentages of CD3+, CD3 + CD8 + lymphocyte subsets in children in IM group were significantly higher than those in children with P-MI and HSP, and the percentages of CD3-CD19 + lymphocyte subsets in children in IM group were significantly lower than those in children with P-MI and HSP. The percentages of CD3 + CD4 + lymphocyte subsets in children in the three groups were the lowest in children with IM, and the highest in children with P-MI.The differences in the percentages of CD3+, CD3 + CD4+, CD + CD8+, and CD3-CD19 + lymphocyte subsets among the IM, P-MI, and HSP groups were statistically significant (P < 0.01). (2) The results of CD3 + CD4+/CD3 + CD8 + in the three groups were the lowest in children with IM and the highest in children with P-MI. There was a significant difference among the three groups (P < 0.01); The ages of the children with IM and P-MI were lower than that of the children with HSP (p < 0.01), while there was no difference in the ages of the children with IM and P-MI (p > 0.05). (3) The difference in the percentage of CD3-CD16 + CD56 + lymphocyte subsets among the three groups was not statistically significant (P > 0.05).

CONCLUSION

The determination of peripheral blood lymphocyte subsets is of significance for understanding the pathophysiology of IM, mycoplasma pneumonia, and HSP in children.

A simple nomogram for assessing the risk of IgA vasculitis nephritis in IgA vasculitis Asian pediatric patients

A nomogram for assessing the risk of IgA vasculitis nephritis (originally termed Henoch–Schönlein purpura nephritis, HSPN) in IgA vasculitis (originally termed Henoch–Schönlein purpura, HSP) pediatric patients can effectively improve early diagnosis and prognosis of IgA vasculitis nephritis. However, currently, no nomogram is available. 246 IgA vasculitis and 142 IgA vasculitis nephritis Asian pediatric patients confirmed by renal biopsy were enrolled. Univariate and multivariate logistic regressions were performed to identify the independent risk factors and construct a series of predictive models. The receiver operating characteristic curve, calibration plot, decision curve analysis, net reclassification index and integrated discrimination index were used to screen the best model. Stratification analysis was applied to optimize model’s clinical utility. An external validation set was introduced to verify the predictive efficiency. The final predictive model was converted to nomogram for visual use. We identified age, duration of rash (Dor), D-dimer and IgG as independent risk factors and constructed four models as follows: AIDD (Age + IgG + Dor + D-dimer), AIDi (Age + IgG + D-dimer), AIDo (Age + IgG + Dor) and ADD (Age + Dor + D-dimer), which achieved the receiver operator characteristic curve (AUROC) of 0.931, 0.920, 0.856 and 0.907, respectively. Finally, AIDi model with an AUROC of 0.956 and 0.897 in internal and external validating sets was proposed as a novel predictive model. In stratification analysis by gender and histological grade, the AUROC of AIDi was 0.949 in female, 0.926 in male, 0.933 in mild histological grades and 0.939 in severe histological grades, respectively. AIDi nomogram is an effective and visual tool for assessing the risk of nephritis in IgA vasculitis Asian pediatric patients, regardless of IgA vasculitis nephritis histological grades and gender.

Early clinical course of biopsy-proven IgA vasculitis nephritis

BACKGROUND

IgA vasculitis (IgAV) is the most common form of systemic vasculitis in childhood and frequently involves the kidney. A minority of patients with IgA vasculitis nephritis (IgAVN), especially those presenting with heavy proteinuria and/or kidney failure at onset, are at risk of chronic end-stage kidney disease. For deciding upon treatment intensity, knowledge of the short-term clinical course of IgAVN is needed to improve treatment algorithms.

METHODS

For this retrospective multicenter study, the medical records of 66 children with biopsy-proven IgAVN were reviewed. Age, gender, medical history and therapeutic interventions were recorded. Laboratory data included serum creatinine, albumin, urinary protein excretion (UPE) and glomerular filtration rate (eGFR). Threshold values were determined for each parameter, full remission was defined as no proteinuria and eGFR > 90 ml/min/1.73m².

RESULTS

Median age at onset of IgAVN was 8.9 years. 14.1% of the children presented with nephrotic syndrome, 50% had an eGFR below 90 ml/min/1.73 m² and 51.5% showed cellular crescents in renal histology. The treatment regimens varied notably. Forty-four patients were treated with immunosuppression; 17 patients with crescents or nephrotic syndrome were treated with corticosteroid (CS) pulse therapy. After 6 months, UPE had decreased from 3.7 to 0.3 g/g creatinine and the proportion of patients with a decreased eGFR had fallen from 50.0% to 35.5%. Thirteen children (26.5%) achieved full remission within 6 months.

CONCLUSIONS

In most patients with IgAVN proteinuria decreases slowly and kidney function improves, but full remission is reached only in a minority after 6 months. Persistent heavy proteinuria in the first two months rarely developed into long-term proteinuria. Therefore, decisions for more intense treatment should take into account the course of UPE over time. For a comparison of treatment effects, patient numbers were too small. Prospective, randomized controlled trials are necessary to clarify risk factors and the effect of immunosuppressive therapies.

Renal autoimmunity: The role of bacterial and viral infections, an extensive review

Autoimmunity is a process by which the loss of self-tolerance results in an immune attack against the body own tissues and organs. For autoimmunity to occur, various elements serving as triggers were described by which infections are considered one of the leading factors. In turn, renal involvement in autoimmune diseases, whether by an organ-specific attack, or as part of a systemic disease process, is well known. As bacterial and viral infections are considered to be common triggers for autoimmunity in general, we aimed to study their association with renal autoimmunity in particular. We performed an extensive search of the recent and relevant medical literature regarding renal autoimmunity syndromes such as infection-associated glomerulonephritis and vasculitis, associated with bacterial and viral infections. By utilizing PubMed and Google Scholar search engines, over 200 articles and case reports were reviewed. Among other mechanisms, direct infection of the renal parenchyma, molecular mimicry, induction of B-cells or secretion of superantigens, bacterial and viral pathogens were found to correlate with the development of renal autoimmunity. Nevertheless, this was not true for all pathogens, as some mimic autoimmune diseases and others show a surprisingly protective effect. The exact immunopathogenesis is yet to be determined, however. For conclusion, bacterial and viral infections are linked to renal autoimmunity by both direct damage and as mediators of systemic diseases. Further research particularly on the immunopathogenetic mechanisms of renal autoimmunity associated with infections is required.

IgA Vasculitis in an Oldest-old Patient Successfully Treated with Glucocorticoid

A 94-year-old man was diagnosed with immunoglobulin A vasculitis (IgAV), and losartan was initiated. His renal function rapidly deteriorated over a month; therefore, methylprednisolone was administered intravenously for three days followed by oral prednisolone. Renal function improvement and both proteinuria and hematuria remission were observed within six months. Prednisolone tapering was completed at eight months. In this case, we monitored the patient carefully and started glucocorticoids as soon as the patient's renal function deteriorated. We were thus able to treat the patient with a relatively small dose of glucocorticoids in a short treatment period without any adverse events due to glucocorticoids.

New Insights and Challenges Associated With IgA Vasculitis and IgA Vasculitis With Nephritis-Is It Time to Change the Paradigm of the Most Common Systemic Vasculitis in Childhood?

What are the challenges ahead and how have we responded so far when it comes to the non-granulomatous systemic vasculitis, characterized mainly by deposits of IgA immune complexes in the endothelium of small blood vessels-IgA vasculitis (IgAV)? That is the question to which we tried to answer. We summarized existing knowledge about epidemiology, pathogenesis, genetics, diagnostic tests and therapy in this somewhat neglected entity in pediatric rheumatology. Since etiopathogenesis of IgA vasculitis is complex, with factors other than galactose-deficient IgA₁-containing immune complexes also being important, and may involve numerous interactions between environmental and genetic factors, genomics alone cannot explain the entirety of the risk for the disease. The incidence of IgAV and nephritis varies worldwide and may be a consequence of overlapping genetic and environmental factors. In addition to the role of the HLA class II genes, some studies have pointed to the importance of non-HLA genes, and modern geostatistical research has also indicated a geospatial risk distribution, which may suggest the strong influence of different environmental factors such as climate, pathogen load, and dietary factors. The application of modern geostatistical methods until recently was completely unknown in the study of this disease, but thanks to the latest results it has been shown that they can help us a lot in understanding epidemiology and serve as a guide in generating new hypotheses considering possible environmental risk factors and identification of potential genetic or epigenetic diversity. There is increasing evidence that an integrative approach should be included in the understanding of IgA vasculitis, in terms of the integration of genomics, proteomics, transcriptomics, and epigenetics. This approach could result in the discovery of new pathways important for finding biomarkers that could stratify patients according to the risk of complications, without an invasive kidney biopsy which is still the gold standard to confirm a diagnosis of nephritis, even if biopsy findings interpretation is not uniform in clinical practice. Ultimately, this will allow the development of new therapeutic approaches, especially important in the treatment of nephritis, for which there is still no standardized treatment.

Necessity and choice of therapy for Henoch-Schönlein purpura nephritis

BACKGROUND

Henoch-Schönlein purpura nephritis often resolves spontaneously, without treatment, making decisions regarding therapeutic interventions difficult.

METHODS

Fifty-four patients who were diagnosed as having Henoch-Schönlein purpura nephritis between April 2004 and March 2018, and developed hematuria and/or proteinuria, were studied retrospectively. The observation period ended at the disappearance of hematuria or proteinuria, or the last observation date before December 2019 for each patient. Twenty-four of the patients received no treatment (Group A), 19 underwent renin-angiotensin-aldosterone system inhibitors only (B), 4 experienced steroid pulse therapy and combination therapy only (C) and the remaining 7 received steroid pulse therapy and combination therapy following renin-angiotensin-aldosterone system inhibitors (C). Clinical characteristics were examined according to the treatment method. Survival analysis for persistent urinary abnormalities was performed according to treatment modality, with multiple treatment records created per subject, if necessary.

RESULTS

The highest urine protein/creatinine levels were significantly higher in groups B and C than in group A. The lowest estimated glomerular filtration rate was not significantly different among the three groups. In groups A and B, proteinuria resolved in >90% of patients. Survival analysis showed that steroid pulse therapy and combination therapy was not related to the better resolution of hematuria or proteinuria than renin-angiotensin-aldosterone system inhibitors.

CONCLUSIONS

Several patients with Henoch-Schönlein purpura nephritis went into remission either without treatment or with renin-angiotensin-aldosterone system inhibitors alone. The treatment plan for patients with Henoch-Schönlein purpura nephritis needs to be determined carefully.

Clinico-Epidemiological Profile and Outcome of Children with IgA Vasculitis in Aseer Region, Southwestern Saudi Arabia

Introduction: Immunoglobulin A (IgA) vasculitis is one of the most common forms of primary vasculitis in children; it typically has a benign course but can be aggressive and require intervention. Aim of the work: The aim of this retrospective study was to evaluate the epidemiological and clinical profile and treatment modalities used for children with IgA vasculitis in the southwestern region of Saudi Arabia. Material and Methods: We reviewed the medical records of 89 children admitted to Abha Maternity and Children Hospital in the southwestern region of Saudi Arabia from January 2016 to December 2020 with a confirmed diagnosis of IgA vasculitis according to the European League Against Rheumatism/Paediatric Rheumatology International Trials Organisation/Pediatric Rheumatology European Society criteria. Results: Eighty-nine children had a confirmed diagnosis of IgA vasculitis, with 50 boys (56.2%) and 39 girls (43.8%; male-to-female ratio of 1.28:1) and a mean age at diagnosis of 5.87 ± 2.81 years. The mean hospital stay duration was 5.66 ± 4.72 days. Infections preceded 29.2% of the cases, with upper respiratory tract infections comprising 24.7%. Approximately 31.5% of the cases were diagnosed in summer, followed by autumn in 28% of the cases. Rash was present in 100%, arthritis in 72.2%, gastrointestinal tract involvement in 60.7%, and renal involvement in 23.5% of cases. Thrombocytosis and leukocytosis were found in 35% and 46% of all cases, and 52.3% and 47.6.25% of cases with renal involvement, respectively (OR = 2.035, 95% CI: 0.75-5.52 and OR = 1.393, 95% CI: 0.522-1.716, respectively). Approximately 26% of cases experienced relapses. Treatment was conservative in 23.6%, oral prednisolone in 23.6%, and pulse steroid in 45% of cases. Abdominal pain with lower gastrointestinal tract bleeding was the primary indication for initiating pulse steroid treatment. Conclusions: There were similarities and differences in the epidemiology and frequency of clinical manifestations of patients with IgA vasculitis compared to previous studies. Children presenting with such epidemiological and clinical profile need to be closely monitored and long-term follow-up is recommended to improve the outcomes.

Clinical predictive model for the 1-year remission probability of IgA vasculitis nephritis

PURPOSE

Early remission of Immunoglobulin A vasculitis nephritis (IgAVN) substantially affects its prognosis. In this work, a multivariate model to predict the 1-year remission probability of patients with IgAVN was developed on the basis of clinical laboratory data.

METHODS

Data of 187 patients with IgAVN confirmed by renal biopsy were retrospectively assessed. Least absolute shrinkage and selection operator regression analysis were conducted to establish a multivariate logistic regression model. A nomogram based on the multivariate logistic regression model was constructed for easy application in clinical practice. Concordance index, receiver operating characteristic (ROC) curves, decision curve analysis (DCA), and clinical impact curves (CIC) were used to evaluate the predictive accuracy and clinical value of this nomogram.

RESULTS

The predictive factors contained in the multivariate model included duration, gender, respiratory infection, arthritis, edema, estimated glomerular filtration rate, 24 h urine protein, uric acid, and renal ultrasound intensity. The area under the curves (AUC) of the nomogram in the training set and testing set were 0.814 and 0.822, respectively, indicating its good predictive ability. Moreover, the DCA curve and CIC revealed its clinical utility.

CONCLUSION

The developed multivariate predictive model combines the clinical and laboratory factors of patients with IgAVN and is useful in the individualized prediction of the 1-year remission probability aid for clinical decision-making during treatment and management of IgAVN.

Risk factors for renal involvement in Henoch-Schönlein purpura

OBJECTIVE

Henoch-Schönlein purpura is a systemic vasculitis that mainly occurs in children. Renal impairment is a major complication of Henoch-Schönlein purpura, but there is no established predictive marker for renal involvement. Thus, in this study, we investigated the risk factors for renal involvement in children with Henoch-Schönlein purpura.

METHOD

The medical records of children newly diagnosed as having Henoch-Schönlein purpura between 2005 and 2020 were reviewed retrospectively. Selected laboratory data were recorded before treatment initiation. The date and the age at diagnosis; sex; and the presence of arthralgia, gastrointestinal and renal involvement were obtained retrospectively.

RESULTS

This study included a total of 186 patients with Henoch-Schönlein purpura. Among them, 36.0% had renal involvement; 28.4% had only microscopic hematuria, 53.7% had non-nephrotic range proteinuria, and 17.9% had nephrotic-range proteinuria during follow-up. The mean age was higher (p = 0.016) and female sex was predominant (p = 0.001) in patients with renal involvement than in those without renal involvement. Blood neutrophil/lymphocyte ratio (p = 0.002) and platelet/lymphocyte ratio (p = 0.002) were significantly higher than that of the patients without renal involvement. No statistically significant differences were observed in the hemoglobin concentration, platelet count, presence of arthralgia, and gastrointestinal involvement between patients with and without renal involvement. Logistic regression analysis revealed female sex (odd ratio = 3.213) and neutrophil/lymphocyte ratio (odd ratio = 1.329) as risk factors for renal involvement.

CONCLUSIONS

Female sex and high neutrophil/lymphocyte ratio were risk factors for renal involvement in Henoch-Schönlein purpura.

Association of kidney biopsy findings with short- and medium-term outcomes in children with moderate-to-severe IgA vasculitis nephritis

Assessing the initial severity of immunoglobulin A vasculitis nephritis (IgAV-N) is important due to its determining effect on kidney management and outcomes. This paper describes a multicentre paediatric cohort of IgAV-N patients and discusses relationships among clinical presentation, histological features, and kidney outcome. We retrospectively studied a cohort of 170 children with biopsy-proven IgAV-N, diagnosed between 2007 and 2017. One-quarter of the cohort (27%) presented with initial nephrotic syndrome (NS). Kidney biopsy revealed International Study of Kidney Disease (ISKDC) grade II or grade III in 83% of cases. Endocapillary proliferation was observed in 73% of patients, and chronic lesions were observed in 25%. Data analysis showed a significant association between NS at onset and endocapillary proliferation and cellular crescents. After a median follow-up of 21 months (IQR 12-39), 30% of patients had persistent proteinuria or decreased eGFR. At the end of follow-up, kidney impairment was more often observed in patients with NS at onset and those with cellular crescents and chronic lesions on initial kidney biopsy.Conclusion: This study highlights the relationship between the clinical and histological presentation of IgAV-N and the factors that affect kidney outcome. The ISKDC classification may be improved by including lesions that are more discriminating for disease severity and prognosis. What is Known: • Nephrotic syndrome (NS) or kidney failure at diagnosis and cellular crescents in more than 50% of the glomeruli are recognized as risk factors for poor kidney outcome in immunoglobulin A vasculitis nephritis (IgAV-N). • The reference histological classification of the International Study of Kidney Disease in Children (ISKDC) is primarily based on the presence and number of affected glomeruli (mesangial proliferation, cellular crescents). The updated Oxford classification, which emphasizes tubular atrophy and interstitial fibrosis, is also used to group pathological features of IgAV-N. Both classifications have limitations. What is New: • Medical treatment should not be postponed in patients with IgAV-N and NS until after biopsy, as NS at diagnosis is associated with initial histological severity and poorer kidney outcome. This proposal needs to be verified in further studies. • Endocapillary proliferation is associated with the initial severity of IgAV-N at diagnosis, while chronic glomerular changes and interstitial fibrosis are associated with poorer short- and medium-term kidney outcomes.

Targeting Enrichment and Correlation Studies of Glutathione and Homocysteine in IgAVN Patient Urine Based on a Core-Shell Zr-Based Metal-Organic Framework

Aminothiols are closely related to chronic kidney disease, but little is known regarding levels of related aminothiols in the urine of immunoglobulin A vasculitis with nephritis (IgAVN) patients. Herein, a well-defined core-shell Zr-based metal-organic framework (Zr-MOF) composite SiO₂@50Benz-Cys was constructed as a mercury ion affinity material via a solvent-assisted ligand exchange strategy for the selective extraction and enrichment of low-concentration aminothiols in IgAVN patient urine. SiO₂@50Benz-Cys was competent to enrich the total glutathione (GSH) and total homocysteine (Hcy) in virtue of the excellent affinity after chelation with mercury ions. The extraction efficiencies were closely related to the pH, dithiothreitol amount, and the dose of functional Zr-MOF. Coupled with HPLC-MS/MS in optimized conditions, GSH and Hcy were determined with low detection limits of 0.5 and 1 nmol L^-1, respectively. The recoveries of GSH and Hcy for the urine sample at three spiked levels were in the range of 85.3-105% and 79.5-103%, which showed good precision and accuracy. Benefiting from the matrix interference elimination in the process of extraction, the simultaneous detection of aminothiols in the urine of the healthy group and immunoglobulin A vasculitis (IgAV) and IgAVN patients was successfully carried out, suggesting that the Zr-MOF and the robust method together provided a potential application in the analysis of urinary biomolecules. The analysis of variance (ANOVA) showed that the levels of GSH and Hcy had significant differences between the patients and the control. This work is very valuable as it provides a better understanding of concentration alterations of GSH and Hcy in urine involved with IgAVN for clinical research.

Effect and safety evaluation of tacrolimus and tripterygium glycosides combined therapy in treatment of Henoch-Schönlein purpura nephritis

OBJECTIVE

Henoch-Schönlein purpura nephritis has become a significant threat to children's health. Traditional combined therapy of glucocorticoids and cyclophosphamide leads to severe toxicity and complications. Therefore, identifying a feasible and effective strategy with low side-effects for the treatment of Henoch-Schönlein purpura nephritis is of great significance.

METHODS

A randomized, controlled trial was carried out. A total of 279 children with Henoch-Schönlein purpura nephritis were recruited and randomly divided into three groups: control group (receiving the current standard therapy), TA group (receiving tacrolimus) and TA + tripterygium glycosides group (receiving tacrolimus + tripterygium treatment). The total duration of the trial was 6 months, and the duration of follow-up observation was 9 months.

RESULTS

Various therapies showed similar therapeutic effects in the third and sixth months. The relief of Henoch-Schönlein purpura nephritis symptoms caused by TA + tripterygium glycosides was slower than the TA and control groups. The incidence of adverse reactions in the TA + tripterygium glycosides group was lower in the control and TA groups. The final treatment effect of the experimental groups was better than the control group. The recurrence rate in the TA + tripterygium glycosides group was also significantly lower.

CONCLUSION

Tacrolimus and tripterygium glycosides combined therapy had better effects and safety for long-term treatment of Henoch-Schönlein purpura nephritis.

Clinical spectrum and outcome of immunoglobulin A vasculitis in children: A 10-year clinical study

BACKGROUND

Immunoglobulin A (IgA) vasculitis is the most common vasculitides of childhood. The aim of this study was to characterise the disease and identify clinical and laboratory factors associated with renal involvement.

METHODS

Medical records of children aged ≤18 years with the diagnosis of IgA vasculitis according to the EULAR/PRES criteria were retrospectively reviewed for demographic data, clinical manifestations and laboratory tests. Factors associated with renal involvement were determined using multivariable logistic regression analysis.

RESULTS

A total of 113 patients were involved in the study. There were 57.5% of males (male: female ratio of 1.4:1). The mean (SD) age was 7.1 (3.0) years. Most of the patients presented during the fall (37.2%) and winter (29.2%). The most common presenting complaints were skin rash (83.2%) and arthralgia (9.7%). The most frequent presentation of the skin was palpable purpuric rash, except for two patients (1.8%) presenting with blistering eruptions in the form of hemorrhagic bullae and ecchymoses of both extremities. We have encountered one patient with pulmonary-renal syndrome. Renal involvement was found in 27.4% of the patients. In the multivariate analysis, the strongest factors associated with renal involvement were older age and elevated creatinine level. Factors that improved model fit were higher platelet and lower white blood cell counts, elevated anti-streptolysin O and a history of preceding infection.

CONCLUSION

The clinical profile of the disease in our cohort was similar to other reports. However, we have encountered a few severe and rare atypical presentations. Over a quarter of children in our setting had renal involvement. Children presenting with these risk factors need to be closely monitored and long-term follow-up is recommended.

[Clinical effect and mechanism of total glucosides of paeony in the adjuvant therapy for children with Henoch-Schönlein purpura nephritis: a prospective randomized controlled study]

OBJECTIVE

To study the clinical effect and mechanism of total glucosides of paeony (TGP) in the adjuvant therapy for children with Henoch-Schönlein purpura nephritis (HSPN).

METHODS

Sixty-four HSPN children with moderate proteinuria were divided into a TGP treatment group (n=34) and a routine treatment group (n=30) using a random number table. Thirty healthy children who underwent physical examination were enrolled as the healthy control group. The children in the routine treatment group were given conventional treatment alone, and those in the observation group were given TGP in addition to the conventional treatment. The two groups were compared in the clinical outcome after 4 weeks of treatment. The proportion of follicular helper T (Tfh) cells in peripheral blood and the plasma levels of interleukin-21 (IL-21) and interleukin-4 (IL-4) were measured in the healthy control group and the two HSPN groups. The changes in serum cystatin C (CysC) level and urinary alpha 1-microglobulin (A1M) concentration were compared before and after treatment in the two HSPN groups.

RESULTS

Compared with the healthy children before treatment, the children with HSPN had higher proportion of Tfh cells and expression levels of IL-21 and IL-4 (P < 0.01). The TGP treatment group had a higher overall response rate to treatment than the routine treatment group (94% vs 67%, P < 0.05). After treatment, both groups had reductions in the proportion of Tfh cells in peripheral blood, the expression levels of IL-21, IL-4, serum CysC, and urinary A1M concentration. The TGP treatment group had greater reductions in these indices than the routine treatment group (P < 0.01).

CONCLUSIONS

TGP has a marked clinical effect in the treatment of HSPN and can reduce the inflammatory response of the kidney and exert a protective effect on the kidney by inhibiting the proliferation of Tfh cells and downregulating the expression of IL-21 and IL-4 in plasma.

Global Glomerulosclerosis and Segmental Glomerulosclerosis Could Serve as Effective Markers for Prognosis and Treatment of IgA Vasculitis With Nephritis

Background: This study was aimed at investigating the clinical significance and curative effect of global glomerulosclerosis (GS) and segmental glomerulosclerosis (S) in adult-onset IgA vasculitis with nephritis (IgAV-N) patients since there was no consensus pathological grading method for adult IgAV-N. Methods: A total of 188 biopsy-proven IgAV-N patients were prospectively identified. Patients were separately assigned to GS0/GS1/GS2 group and S0/S1/S2 based on the scores of global glomerulosclerosis and segmental glomerulosclerosis (0% /0-15% />15%, respectively). Results: GS0, GS1, and GS2 occurred in 56.4, 29.2, and 14.4% of the adult-onset IgAV-N, respectively. Patients in GS2 group tended to have the most serious renal deterioration and the highest levels of blood pressure. IgAV-N patients were also divided into S0 group (64.4%), S1 group (20.7%), and S2 group (14.9%), where no obvious differences in baseline data were noted. K-M curves indicated that GS2 group had the worst renal outcome (P = 0.05) while there seemed to be no significant differences between GS0 group and GS1 group. In addition, no remarkable differences in primary outcome were found among S0 group, S1 group, and S2 group though the prognosis of S2 group tended to be the worst. However, the prognosis of S0/S1 group was markedly better than that of S2 (P = 0.04). The discrimination of poor prognosis could be improved by adding the pathological indicators of global glomerulosclerosis and segmental glomerulosclerosis. Most importantly, immunosuppressive treatment might be a superior alternative in IgAV-N patients without sclerosis scores or with lower level of sclerosis scores. But addition of immunosuppression was not recommended in patients with higher sclerosis scores. Conclusions: Global glomerulosclerosis and segmental sclerosis might be used for management and treatment of adult-onset IgAV-N.

Decreased glycolysis induced dysfunction of NK cells in Henoch-Schonlein purpura patients

BACKGROUND

Henoch-Schonlein purpura (HSP) is the most common systemic vasculitis of the childhood. However, its mechanisms and pathogenesis still need more exploration. Natural killer (NK) cells are innate lymphocytes, and there is a growing appreciation that cellular metabolism is important in determining the immune responsiveness of lymphocytes. Thus, we aimed to analyze the NK cells phenotype and explore the association between glucose metabolism and NK cells function in HSP patients.

RESULTS

A total number of 64 HSP patients and 34 healthy children were included. The HSP patients were divided into two groups according to whether accompanied with nephritis or not. NK cells in HSP patients without nephritis showed a reduced frequency in peripheral blood, a down-regulated expression of activating receptors both NKp30 and NKp46, and an attenuated cytotoxic function against tumor cells. In addition, the function impairment of NK cells was shown to exacerbate in HSPN. Our data further revealed an aberrant metabolic reprogramming of NK cells in HSP patients. Upon stimulation with cytokines (IL-15, IL-12 and IL-2), NK cells from healthy controls switched to an elevated glycolysis rate to support their effector function. By contrast, the glycolysis rate of activated NK cells in HSP group was not significantly up-regulated from the resting level possibly owing to the inhibition of mTORC1.

CONCLUSIONS

Our study found that HSP patients were accompanied with dysfunction of NK cells. We concluded that the dysfunction of NK cells in HSP patients was induced with a decreased glycolysis rate and suggested that metabolic reprogramming of NK cells might be a player in the pathogenesis of HSP.

Patient Outcomes of Henoch-Schönlein Purpura Nephritis According to the New Semiquantitative Classification

Background: A new semiquantitative classification (SQC) for pediatric Henoch-Schönlein nephritis (HSN) was defined recently. The outcomes of pediatric HSN patients are reevaluated according to the new classification. Methods: Primary kidney biopsies from 80 HSN patients were scored using the new SQC. The International Study of Kidney Disease in Children (ISKDC) and SQC classifications were compared in terms of the patient outcomes. Outcomes were defined as: Outcome A (n = 44) patients with no sign of renal disease, Outcome B (n = 32) patients with minor urinary abnormalities, and Outcome C (n = 4) patients with active renal disease. Results: The patients with outcome C had significantly higher biopsy scores and chronicity indices than patients in group A. There was no significant difference in areas under the curve between total biopsy SQC scores and ISKDC findings. Conclusions: Our results suggest that the modified SQC is not more sensitive than ISKDC classification for predicting the outcome in HSN cases.

Serum levels of galactose-deficient IgA1 in Chinese children with IgA nephropathy, IgA vasculitis with nephritis, and IgA vasculitis

OBJECTIVE

IgA nephropathy (IgAN) and IgA vasculitis with nephritis (IgAV-N) are related diseases. Galactose-deficient IgA1 (Gd-IgA1) plays an important role in the pathology of IgAV-N and IgAN, so we aim to compare the serum levels of Gd-IgA1 in Chinese pediatric patients with IgAN, IgAV-N, and IgAV.

METHODS

We retrospectively enrolled 52 patients with IgAN, 57 patients with IgAV-N, 26 patients with IgAV, and 40 healthy children. The serum levels of Gd-IgA1 were measured at the time of biopsy using a lectin-based ELISA method.

RESULTS

Gd-IgA1 levels in IgAV-N patients and IgAN patients were higher than in healthy controls (303.94 ± 39.37 U/ml, 314.91 ± 47.79 U/ml vs. 273.57 ± 48.29 U/ml, P < 0.001), and Gd-IgA1 levels in IgAV-N patients were higher than in IgAV patients (303.94 ± 39/ml vs. 286. 21 ± 38.81 U/ml, P = 0.059), but the latter result is not statistically significant. The Gd-IgA1 levels in IgAV patients were comparable with those in healthy controls (286.21 ± 38.81 U/ml vs. 273.57 ± 48.29 U/ml, P = 0.267). Among the four groups, we did not observe significant correlations of Gd-IgA1 levels with eGFR, proteinuria, or the MEST-C score.

CONCLUSION

Serum Gd-IgA1 maybe involved in the pathogenesis of the IgAV-N and IgAN. However, we found no statistically significant correlation between Gd-IgA1 levels and clinical and pathological features.

Analysis of the association between kidney injury biomarkers concentration and nephritis in immunoglobulin A vasculitis: A pediatric cohort study

OBJECTIVE

The aim of this study was to investigate the clinical course, selected biochemical parameters and concentrations of renal injury biomarkers such as neutrophil gelatinase-associated lipocalin (NGAL), kidney injury molecule-1 (KIM-1) and liver-fatty acid binding protein (L-FABP) in patients with immunoglobulin A vasculitis (IgAV) to identify the markers associated with nephritis in the course of the disease (IgAVN).

METHODS

The study involved 29 children with IgAV and 34 healthy controls. Eleven (38%) patients had renal involvement (IgAV-N) and 18 (62%) did not exhibit nephritis (IgAV-noN). Initial laboratory tests, determining the concentrations of NGAL, KIM-1 and L-FABP in serum and urine, were conducted on children from the study group in an acute phase of IgAV as well as after an average of 6 months, during a follow-up visit. The interconnection between renal involvement, anthropometric measurements, epidemiological data, laboratory parameters and levels of examined biomarkers have been thoroughly evaluated.

RESULTS

The serum and urine levels of NGAL, KIM-1 and L-FABP were significantly higher in children with an acute phase of IgAV as compared to the control group (P < .001) and markedly lower during follow-up retesting in comparison with the values obtained at inclusion (P < .001). However, the concentration of none of the evaluated biomarkers correlated with nephrological indices. Among all examined parameters, only male subjects were associated with nephritis (P = .017).

CONCLUSIONS

We have established no evident association between the concentrations of NGAL, KIM-1 and L-FABP and nephritis in the course of IgAV in children. Additionally, we confirmed a significant male predominance in patients with nephritis.

Multisystemic manifestations of IgA vasculitis

Immunoglobulin A vasculitis (IgAV), also known as Henoch-Schönlein Purpura, is one of the most common kind of systemic vasculitis in children, and due to the involvement of small blood vessels throughout the body, this disease can cause a variety of symptoms in different organs. Our aim was to review the data on various systemic manifestations of IgAV. A research of the literature was performed in PubMed database, utilizing the MeSH terms "IgA vasculitis" and "Henoch Schönlein Purpura". According to the predetermined structure of the manuscript, we extracted and sorted out the relevant data. Clinically, almost all the patients will present with palpable skin purpura, together with arthritis, gastrointestinal tract involvement, or kidney damage. Other rare systemic manifestations include neurological symptoms, scrotal involvement, and cardiopulmonary disease. When uncommon complications occur, patients may be misdiagnosed as other diseases, thus delaying treatment. Although the course of IgAV is mostly self-limited, misdiagnosis can also lead to a poor prognosis. A comprehensive awareness to the clinical manifestations of IgAV is the necessary prerequisite for its timely diagnosis. Prompt diagnosis and adequate treatment are essential for optimal results.

Urinary proteomics of Henoch-Schönlein purpura nephritis in children using liquid chromatography-tandem mass spectrometry

BACKGROUND

Henoch-Schönlein purpura nephritis (HSPN) is the principal cause of morbidity and mortality in children with Henoch-Schönlein purpura (HSP). However, the criteria for risk assessment currently used is not satisfactory. The urine proteome may provide important clues to indicate the development of HSPN.

METHODS

Here, we detected and compared the urine proteome of patients with HSPN and healthy controls by liquid chromatography-tandem mass spectrometry (LC-MS/MS) in the data-independent acquisition (DIA) mode. The differentially expressed proteins were analysed by gene ontology (GO) analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis. For validation, enzyme-linked immunosorbent assay (ELISA) was used to analyse the selected proteins.

RESULTS

A total of 125 proteins (29 upregulated and 96 downregulated) were found to be differentially expressed in children with HSPN compared with the controls. Forty-one proteins were predicted to have direct interactions. The enriched pathways mainly included focal adhesion, cell adhesion molecules, the PI3K-Akt signalling pathway, ECM-receptor interactions and so on. Cell adhesion related to the pathogenesis of HSPN was the main biological process identified in this study. The decrease in two proteins (integrin beta-1 and tenascin) was validated by ELISA.

CONCLUSIONS

Our study provides new insights into the assessment of HSPN progression in children, as well as new potential biomarkers. The data confirm the value of the urinary proteome in capturing the emergence of HSPN.

Does MEST-C score predict outcomes in pediatric Henoch-Schönlein purpura nephritis?

BACKGROUND

Children with Henoch-Schönlein purpura nephritis (HSPN) have an increased risk of chronic kidney disease (CKD). Renal biopsy diagnostic of HSPN is graded using the International Study of Kidney Disease in Children criteria, which do not predict outcomes. The 2016 Oxford Classification's MEST-C scoring system predicts outcomes in adults with histologically identical IgA nephropathy, but evidence of its utility in pediatric HSPN is lacking. Our hypothesis was that MEST-C scores predict outcomes in children with HSPN.

METHODS

A retrospective cohort analysis of data from 32 children with HSPN who underwent renal biopsy was performed. We used logistic regression and receiver operator characteristic curves to analyze the ability of MEST-C to predict the composite outcome of hypertension (blood pressure ≥ 95% for age/sex/height), CKD (estimated glomerular filtration rate < 90 mL/min/1.73 m²), or proteinuria (urine protein-to-creatinine ratio > 0.2 mg/mg).

RESULTS

The median age at diagnosis was 7.9 years (IQR 5.8, 11.7); 56% were male, 19% were Hispanic, and 9% were Black. After a median follow-up of 2.7 years, 38% of patients (n = 12) reached the outcome. S1 score was significantly associated with the outcome (OR 7.9, 95% CI 1.5-42.6). S1 accurately predicted the outcome (area under the curve 0.72, 95% CI 0.55-0.88) with 58.3% sensitivity and 85.0% specificity, indicating a positive predictive value of 70.0% and a negative predictive value of 77.3%.

CONCLUSIONS

S1 accurately predicted our composite outcome of hypertension, CKD, and proteinuria in a diverse cohort of U.S. children with HSPN. Further investigation is warranted to validate these findings.

Beneficial Effects of Qingzixiaoban Granule on Henoch–Schönlein Purpura Nephritis Mice through Inhibiting Immune Complex Deposition and Th2 Immunodeviation

Background

Henoch–Schönlein purpura nephritis (HSPN) is the principal cause of morbidity and mortality in Henoch–Schönlein purpura (HSP). However, there is no absolute consensus for the best management of severe HSPN till now. Qingzixiaoban Granule (QZXB GR), a traditional Chinese medicine formula, has been applied to treat HSP in clinical in China. However, the therapeutic effects and potential mechanism of QZXB GR on HSPN is still unknown.

Methods

A Gliadin plus Indian Ink-induced HSPN mice model was established. Renal histopathologic changes and the subcutaneous hemorrhage on left legs were assessed. Hematuria and proteinuria were determined using hemocytometer and bicinchoninic acid assay, respectively. The serum circular immune complex and interleukin-6 were quantified by ELISA. Using blood biochemical analyzer, the renal biochemical parameters, including serum total protein, albumin, creatinine, and blood urea nitrogen, were measured. The deposition of immune complex in renal tissues and the lymphocyte subsets in peripheral blood and spleen was investigated by immunohistochemistry and flow cytometry.

Results

QZXB GR treatment significantly ameliorated renal injury in HSPN mice, by attenuating renal histopathological changes, reducing subcutaneous hemorrhage, decreasing proteinuria/hematuria, regulating renal biochemical parameters, and inhibiting the release of serum interleukin-6. Furthermore, QZXB GR treatment significantly decreased the level of serum circular immune complex, decreased immune complex IgA and IgG deposition in renal tissue, and suppressed Th2 immunodeviation.

Conclusion

QZXB GR could prevent renal injury in HSPN mice, and its renoprotective mechanism might be exerted partly through suppressing immune complexes deposition and Th2 immune deviation.

Efficacy of montelukast for the treatment of pediatric allergic purpura

BACKGROUND

This study aims to evaluate the efficacy and safety of montelukast for the treatment of patients with pediatric allergic purpura (PAP).

METHODS

We will retrieve the following electronic databases from inception to the present: MEDILINE, Embase, CENTRAL, CINAHL, AMED, Chinese Biomedical Literature Database, China National Knowledge Infrastructure Database, Wanfang, and VIP database without language limitation. Two authors will carry out study selection, data extraction, and quality evaluation independently. RevMan V5.3 software will be used for statistical software.

RESULTS

This study will summarize high-quality evidence-based medicine to evaluate the efficacy and safety of montelukast for the treatment of PAP.

CONCLUSION

This study will provide strong evidence to determine whether montelukast is an effective and safety treatment for PAP.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42019145472.

Autoantibodies Specific for Galactose-Deficient IgA1 in IgA Vasculitis With Nephritis

Introduction

Patients with IgA nephropathy (IgAN) have elevated serum levels of galactose-deficient IgA1 (Gd-IgA1) that are bound by Gd-IgA1–specific autoantibodies in pathogenic immune complexes. Renal biopsy histopathologic features of IgA vasculitis (IgAV) with nephritis (IgAV-N) are similar to those of IgAN. Mucosal infections often are associated with clinical onset and exacerbation in both diseases. We investigated whether patients with IgAV-N share pathogenic characteristics of IgAN.

Methods

We generated IgA1- and IgG-secreting cell lines from Epstein-Barr virus (EBV)–immortalized cells of patients with IgAV without nephritis (IgAV-woN), IgAV-N, and IgAN and from healthy individuals. Sera and cell-culture supernatants were used for analysis of Gd-IgA1 and Gd-IgA1–specific IgG autoantibodies.

Results

IgA1-producing cells from patients with IgAV-N, like cells from patients with IgAN, secreted more Gd-IgA1 than did cells from patients with IgAV-woN or healthy control subjects, in agreement with elevated serum Gd-IgA1 levels in patients with IgAV-N and IgAN. IgA1-producing cells from patients with IgAV-N had altered expression of genes involved in O-glycan biosynthesis: decreased for core 1 synthase (glycoprotein-N-acetylgalactosamine 3-β-galactosyltransferase 1; C1GALT1) and C1GALT1 Specific Chaperone 1 (C1GALTC1; COSMC) and elevated for N-acetylgalactosaminide α-2,6-sialyltransferase 2 (ST6GALNAC2). Levels of Gd-IgA1–specific IgG in sera and supernatants of IgG-producing cells were similar for patients with IgAV-N and IgAN and higher than those for IgAV-woN patients or healthy control subjects. Moreover, patients with IgAV-N who had active disease, manifested by hematuria and substantial proteinuria, had higher serum levels of Gd-IgA1–specific IgG autoantibodies than did patients with IgAV-N who had inactive disease.

Conclusion

Serum levels and cellular production of Gd-IgA1 and Gd-IgA1–specific IgG autoantibodies were elevated in patients with IgAV-N, supporting the hypothesis that IgAV-N and IgAN share pathogenic features.

IgA1 isolated from Henoch-Schönlein purpura children promotes proliferation of human mesangial cells in vitro

Previous studies show that the proliferation of human mesangial cells (HMCs) played a significant part in the pathogenesis of Henoch-Schönlein purpura nephritis (HSPN). The aim of this study was to explore the proliferation of HMCs induced by IgA1 isolated from the sera of HSP patients. HMCs were cultured in three different types of media, including IgA1 from patients with HSP (HSP IgA1 group), healthy children (healthy IgA1 group) and medium (control group). The proliferation of HMCs incubated with IgA1 was determined by cell counting kit-8 assay and bromodeoxyuridine incorporation. The expression of ERK1/2 and phosphatidylinositol 3 kinase/protein kinase B/mammalian targets of the rapamycin (PI3K/AKt/mTOR) signals and transferrin receptor (TfR/CD71) was detected with the methods of immunoblotting. The results indicated that the proliferation of HMCs significantly increased in the HSP IgA1 group compared with that in the control group or the healthy IgA1 group (P < 0.001). Moreover, we found that IgA1 isolated from HSP patients activated ERK and PI3K/AKt/mTOR signals, and markedly increased TfR/CD71 expression in HMCs. These effects induced by IgA1 isolated from patients with HSP were inhibited by human TfR polyclonal antibody (hTfR pAb) and soluble human transferrin receptor (sTfR), indicating that IgA1-induced HMC proliferation and ERK1/2 and PI3K/AKt/mTOR activation were dependent on TfR/CD71 engagement. Altogether, these data suggested that TfR/CD71 overexpression and ERK1/2 and PI3K/AKt/mTOR activation were engaged in HMC proliferation induced by IgA1 from HSP patients, which might be related to the mesangial injury of HSPN.

Direct Immunofluorescence Results of the Skin Biopsy and Frequency of Systemic Involvement in Children with Henoch-Schonlein Purpura

OBJECTIVE

Henoch-Schonlein purpura (HSP) is a common vasculitis in children that can present with multi-organ involvement. The aim of this study is to investigate the correlation between direct immunofluorescence (DIF) results and the systemic involvements of the HSP in pediatric patients.

MATERIAL AND METHODS

Those HSP patients with leukocytoclastic vasculitis on their biopsies who also had documented immunoglobulin/complement deposition by DIF were included in our study. Their demographic and laboratory data and clinical manifestations were recorded and analyzed.

RESULTS

Medical records of 95 patients (1.5-15 years old) were studied. 26.3% of the patients showed renal, 86.3% articular, and 70.3% gastrointestinal involvement. The risk of renal involvement was significantly higher in those with C3 deposition in their skin DIF. IgM deposition was mostly associated with articular involvement.

CONCLUSION

Pediatric HSP patients who had C3 deposition in their skin DIF should be selected for further evaluation regarding HSP nephritis.

Different histological classifications for Henoch-Schönlein purpura nephritis: which one should be used?

BACKGROUND

Nephritis is the most important chronic complication of IgA Vasculitis (IgAV)/Henoch-Schönlein purpura (IGAV/HSP) and thus the main prognostic factor of this most common childhood vasculitis. Since the prognosis and treatment selection depends on the mode of interpretation of biopsy material, in this manuscript we have presented several issues related to the uneven application of different histological classifications in IgAV/Henoch-Schönlein purpura nephritis (HSPN). The nephritis of IgAV/IGAV/HSP will be abbreviated as HSPN for this paper.

MAIN BODY

In clinical practice we use different histological classifications for HSPN. It is not known which of these classifications best correlates with severity of renal disease and renal outcome in IgAV/IGAV/HSP. One of the major problem with existing histological classifications is that there is no consensus on the implementation of biopsy in the treatment of HSPN. There is a histologic classification system conventionally used in HSPN, of the International Study of Kidney Disease in Children (ISKDC). On the other hand there is the new classification system suggested for IgA nephropathy, the Oxford classification. The latter has been validated only in IgA nephropathy. There are also two further histologic classifications of Haas and Koskela that have been developed. Current treatment strategies in HSPN are not standardised nor predominantly based on histological classification.

CONCLUSION

One of the possible solutions to problems related to the application of different histological classification in HSPN is the implementation of multicenter multinational prospective studies with joint collaboration between pediatric rheumatologists, nephrologists and nephropathologists to correlate the clinical features and outcome with the classification systems as well among the classifications. This classification should be the basis for the construction of guidelines for the treatment of patients with HSPN.

Immunoglobulin A Nephropathy and Immunoglobulin A Vasculitis

Henoch-Schönlein purpura nephritis and immunoglobulin A nephropathy are common glomerulopathies in the pediatric population that deserve special attention. In some cases the primary care provider can follow the patient but others need more intensive management. Delaying this treatment can lead to worse morbidity. This article provides information on the pathogenesis, outcomes, and follow-up strategies that will aid in the diagnosis and referral of patients at risk for kidney disease.

Tubulointerstitial Infiltration of M2 Macrophages in Henoch-Schönlein Purpura Nephritis Indicates the Presence of Glomerular Crescents and Bad Clinical Parameters

Henoch-Schönlein purpura (HSP) is the most common systemic vasculitis in children, and renal involvement (HSP nephritis, HSPN) is a severe manifestation. HSPN is histologically classified by the International Study of Kidney Disease in Children (ISKDC) based on mesangial hypercellularity and the extent of glomerular crescents. Macrophages, categorized as M1 or M2, frequently infiltrate in various glomerular and tubulointerstitial diseases and infiltration of specific subtypes is associated with disease progression. Therefore, to identify whether infiltration of M1 or M2 macrophages has clinical significance, we quantified the subtypes of macrophages in 49 HSPN specimens and correlated the counts with histologic features and clinical parameters. Higher tubulointerstitial M2 counts were associated with chronic renal failure (CRF), ISKDC classes III-IV, and crescents (P<0.001, 0.002, 0.001). Glomerular M2 counts were significantly related to ISKDC classes III-IV and crescents (area under curve, AUC 0.804, 0.833). Tubulointerstitial M2 counts were associated with CRF, ISKDC classes III-IV, and crescents (AUC 0.872, 0.778, 0.830). Tubulointerstitial M2 counts also revealed higher AUC than tubulointerstitial M1 counts for CRF (P=0.036) and ISKDC classes III-IV (P=0.047). Glomerular M2 counts revealed higher AUC than glomerular M1 counts for ISKDC classes III–IV (P=0.024). Tubulointerstitial M2 counts were the most powerful parameter for CRF (AUC 0.872) and revealed even higher AUC than ISKDC classification (AUC 0.716) with borderline significance (P=0.086) for CRF. In summary, tubulointerstitial M2 counts were a superior parameter to tubulointerstitial M1 counts and even to ISKDC classification indicating the presence of CRF.

Henoch-schonlein Purpura Nephritis with Renal Interstitial Lesions

Objective

To investigate the clinical pathology and prognosis & outcome of Henoch-Schonlein purpura nephritis (HSPN) with renal interstitial lesions.

Methods

All 148 patients were analyzed for clinical, renal pathological, and prognostic features. Patients with no, mild, and moderate- severe renal tubulo-interstitial lesions were included in group A, B and C, respectively.

Results

The estimated glomerular filtration rate (eGFR) of group B was significantly lower than that of group A. The levels of serum creatinine and blood urea nitrogen in group C were significantly higher than those in groups A and B. Clinical type II was correlated with pathological types II and IIIa; pathological type IV and IIIb were correlated with clinical type VI and IV. There were significant differences in the level of red blood cells in urinary sediment, levels of urine occult blood and in the prognosis among the 3 groups.

Conclusion

Clinically, Type II is the most common cause; pathologically, Type IIIa is more common. The severity of renal tubulo-interstitial lesions is positively correlated with a decline in renal function and GFR. There is a correlation between the severity of renal tubulo-interstitial lesions and the severity of hematuria. Most patients with HSPN have a good prognosis.

Acute renal insufficiency and pancreatitis in a child with atypical Henoch-Schönlein purpura: efficacy of a single dose of cyclophosphamide

A 9-year-old boy with petechiae on the legs and abdominal pain was unsuccessfully treated with steroids. He was admitted to our hospital for the onset of fever, ecchymosis, and arthralgia. Skin lesions suggested vasculitis, but they were not typical of Henoch–Schönlein purpura. He showed ecchymosis of the scrotal bursa, diffusion of petechiae to the trunk and arms, vomiting, severe abdominal pain, oliguria with hyponatremia, hypoalbuminemia, low C3 levels, high levels of creatinine, blood urea nitrogen, and tubular enzymes, proteinuria, and glycosuria. The urinary sediment showed macrohaematuria, and hyaline and cellular casts. Ultrasound showed polyserositis. He was treated with intravenous furosemide, albumin, and methylprednisolone. He underwent colonoscopy and gastroscopy because of development of acute pancreatitis and severe anaemia. Typical lesions of Henoch–Schönlein purpura were observed in the small intestine and colon mucosa. He received three high doses of methylprednisolone, followed by intravenous cyclophosphamide. A dramatic and persistent response was observed after these doses. A single high dose of cyclophosphamide is appropriate in Henoch–Schönlein purpura with acute renal failure and severe pancreatitis that are non-responsive to high-dose steroids.