Risk factors associated with IgA vasculitis with nephritis (Henoch-Schönlein purpura nephritis) progressing to unfavorable outcomes: A meta-analysis

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

OBJECTIVES

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

METHODS

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

RESULTS

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

CONCLUSION

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

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSION

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

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Differences of clinicopathological characteristics and outcomes of IgA nephropathy patients with and without nephrotic syndrome

PURPOSE

To evaluate the differences in clinicopathological features and outcomes of IgA nephropathy (IgAN) patients with and without nephrotic syndrome.

METHODS

In this retrospective cohort study, IgAN patients from January 2006 to December 2011 in the First Affiliated Hospital of Sun Yat-sen University were enrolled and followed up to Dec 31, 2013. Logistic and Cox regression were conducted to evaluate the associated factors of nephrotic syndrome (NS) and its relation with outcomes of creatinine doubling and progression to end-stage kidney disease (ESKD).

RESULTS

A total of 1413 patients with IgAN were enrolled in this study, 57 (4.0%) of whom exhibited NS. Meanwhile, 13 (22.8%) of NS IgAN patients had minimal change disease (MCD). Logistic regression showed that more presence of hypertension, less glomerular sclerosis, less tubular atrophy/interstitial fibrosis, and lower density of IgA deposition in mesangial region were significantly associated with NS IgAN that were independent of age and gender. In addition, a total of 921 patients (890 with non-NS IgAN and 31 with NS IgAN) were followed up to Dec 31, 2013. After adjusting for age, sex, baseline estimated glomerular rate, hypertension and hemoglobin, no significant difference was observed in outcomes of serum creatinine doubling and ESKD between patients with or without NS IgAN.

CONCLUSIONS

Prevalence of NS IgAN patients was 4.0%, and 22.8% of them had MCD. Patients with NS IgAN had more severe clinical but less severe pathological features. However, outcomes of serum creatinine doubling and ESKD were not significantly different between patients with or without NS IgAN.

Outcome of immunosuppression in children with IgA vasculitis-related nephritis

BACKGROUND

Immunoglobulin A vasculitis with nephritis (IgAVN) is the most common vasculitis in children. Due to a lack of evidence, treatment recommendations are based on expert opinion, resulting in variation. The aim of this study was to describe the clinical presentation, treatment and outcome of an extremely large cohort of children with biopsy-proven IgAVN in order to identify prognostic risk factors and signals of treatment efficacy.

METHODS

Retrospective data were collected on 1148 children with biopsy-proven IgAVN between 2005 and 2019 from 41 international paediatric nephrology centres across 25 countries and analysed using multivariate analysis. The primary outcome was estimated glomerular filtration rate (eGFR) and persistent proteinuria at last follow-up.

RESULTS

The median follow-up was 3.7 years (interquartile range 2-6.2). At last follow-up, 29% of patients had an eGFR <90 mL/min/1.73 m2, 36% had proteinuria and 3% had chronic kidney disease stage 4-5. Older age, lower eGFR at onset, hypertension and histological features of tubular atrophy and segmental sclerosis were predictors of poor outcome. There was no evidence to support any specific second-line immunosuppressive regimen being superior to others, even when further analysing subgroups of children with reduced kidney function, nephrotic syndrome or hypoalbuminemia at onset. Delayed start of immunosuppressive treatment was associated with a lower eGFR at last follow-up.

CONCLUSION

In this large retrospective cohort, key features associated with disease outcome are highlighted. Importantly, there was no evidence to support that any specific immunosuppressive treatments were superior to others. Further discovery science and well-conducted clinical trials are needed to define accurate treatment and improve outcomes of IgAVN.

Overview of childhood vasculitis

Pediatric vasculitis and adult vasculitis differ in several aspects. While both involve inflammation of blood vessels, pediatric vasculitis tends to present with distinct clinical features and may involve different types of blood vessels compared to adult vasculitis. Despite its relatively rare occurrence compared to adult vasculitis, pediatric vasculitis warrants careful attention due to its potential for profound and diverse clinical manifestations, ranging from mild cutaneous symptoms to life-threatening systemic complications. Childhood vasculitis should be suspected in children who present symptoms attributable to systemic inflammation and complications arising from multi-organ dysfunction. However, achieving a diagnosis necessitates thorough exclusion of alternative conditions manifesting similar symptoms and findings. Hence, children suspected of vasculitis should undergo meticulous history-taking, comprehensive physical examination, and requisite laboratory investigations, imaging studies, and sometimes tissue biopsies to elucidate the diagnosis. Early detection and treatment of childhood vasculitis are crucial, as the condition can affect various organs and potentially lead to life-threatening complications or long-term sequelae in adulthood if left untreated. This review aimed to provide an exhaustive overview of childhood vasculitis, outlining its epidemiology, classification, clinical presentation, diagnostic modalities, therapeutic strategies and outcome.

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.

[Urinary protein and renal pathological features in children with immunoglobulin A vasculitis with nephritis and hypercoagulability]

OBJECTIVES

To study the association of hypercoagulability with urinary protein and renal pathological damage in children with immunoglobulin A vasculitis with nephritis (IgAVN).

METHODS

Based on the results of coagulation function, 349 children with IgAVN were divided into a hypercoagulability group consisting of 52 children and a non-hypercoagulability group consisting of 297 children. Urinary protein and renal pathological features were compared between the two groups, and the factors influencing the formation of hypercoagulability in children with IgAVN were analyzed.

RESULTS

Compared with the non-hypercoagulability group, the hypercoagulability group had significantly higher levels of urinary erythrocyte count, 24-hour urinary protein, urinary protein/creatinine, urinary immunoglobulin G/creatinine, and urinary N-acetyl-β-D-glucosaminidase (P<0.05). The hypercoagulability group also had a significantly higher proportion of children with a renal pathological grade of III-IV, diffuse mesangial proliferation, capillary endothelial cell proliferation, or >25% crescent formation (P<0.05). The multivariate logistic regression analysis showed that capillary endothelial cell proliferation and glomerular crescent formation >25% were associated with the formation of hypercoagulability in children with IgAVN (P<0.05).

CONCLUSIONS

The renal injury in IgAVN children with hypercoagulability is more severe, with greater than 25% crescent formation and increased proliferation of glomerular endothelial cells being important contributing factors that exacerbate the hypercoagulable state in IgAVN.

Clinical characteristics and risk factors for kidney involvement in children with immunoglobulin A vasculitis

BACKGROUND

Immumoglobulin A (IgA) vasculitis (IgAV), formerly known as Henoch-Schönlein purpura (HSP), is a self-limiting systemic vasculitis in children. Kidney involvement is associated with a long-term unfavorable outcome and can lead to significant morbidity. This study was conducted to describe the clinical and laboratory characteristics of childhood IgAV with kidney involvement and to identify risk factors associated with IgAV nephritis (IgAVN).

METHODS

This was an ambidirectional descriptive study of 77 children with IgAV. All demographic data, clinical features, and laboratory tests were collected from electronic medical records from January 2010 to December 2022. Risk factors for kidney involvement in IgAV were assessed using multivariate logistic regression. Kaplan-Meier survival analysis was used to calculate the time to commencement of kidney involvement.

RESULTS

Twenty-five children (32.4% of the IgAV patients) developed IgAVN. The common findings in IgAV with kidney involvement were microscopic hematuria (100%), nephrotic range proteinuria (44%), and non-nephrotic range proteinuria (40%). Multivariate logistic regression showed that age greater than 10 years (adjusted hazard ratio, AHR 4.66; 95% confidence interval, CI, 1.91-11.41; p = 0.001), obesity (body mass index, BMI, z-score ≥ +2 standard deviations, SDs) (AHR 3.59; 95% CI 1.41-9.17; p = 0.007), and hypertension at onset (AHR 4.78; 95% CI 1.76-12.95; p = 0.002) were associated significantly with kidney involvement. During follow up, most IgAV patients developed nephritis within the first 9 months.

CONCLUSION

Age greater than 10 years, obesity, and hypertension at presentation were predictive factors for IgAVN. Our study emphasized that IgAV patients with risk factors should be closely monitored for at least 1 year after the onset of the disease.

Long-term outcome of combination therapy with corticosteroids, mizoribine and RAS inhibitors as initial therapy for severe childhood IgA vasculitis with nephritis

BACKGROUND

Patients with severe IgA vasculitis with nephritis (IgAVN) typically receive aggressive therapy as an initial approach. We have consistently performed combination therapy including corticosteroids and immunosuppressants as initial therapy for severe IgAVN over a 20-year-plus period, with only minor changes to the treatment protocol. This study seeks to reveal the efficacy of combination therapy for severe IgAVN.

METHODS

We retrospectively studied 50 Japanese children diagnosed between 1996 and 2019 with clinicopathologically severe IgAVN who were defined as ISKDC classification grade IIIb-V and/or serum albumin < 2.5 g/dL.

RESULTS

The median age at the onset of IgAVN was 8.0 years (IQR: 6.0-10.0). At biopsy, 44% of patients had nephrotic syndrome and 14% had kidney dysfunction. All patients were treated with combination therapy after biopsy. Abnormal proteinuria resolved after initial therapy in all 50 patients. However, eight patients (16%) had recurrence of proteinuria. Abnormal proteinuria was again resolved in three of these patients with additional treatment. At the last follow-up (median 59.5 months; IQR, 26.2-84.2), the median urine protein-to-creatine ratio was 0.08 g/gCr (IQR, 0.05-0.15), and only one patient had kidney dysfunction.

CONCLUSIONS

Combination therapy provided good kidney outcomes for Japanese children with severe IgAVN. Even including recurrent cases, the degree of proteinuria was slight, and kidney function was good at the last follow-up. A higher resolution version of the Graphical abstract is available as Supplementary information.

Clinical course and management of children with IgA vasculitis with nephritis

BACKGROUND

IgA vasculitis is the most common vasculitis in children and is often complicated by acute nephritis (IgAVN). Risk of chronic kidney disease (CKD) among children with IgAVN remains unknown. This study aimed to describe the clinical management and kidney outcomes in a large cohort of children with IgAVN.

METHODS

This observational cohort study used the PEDSnet database to identify children diagnosed with IgAV between January 1, 2009, and February 29, 2020. Demographic and clinical characteristics were compared among children with and without kidney involvement. For children followed by nephrology, clinical course, and management patterns were described. Patients were divided into four categories based on treatment: observation, renin-angiotensin-aldosterone system (RAAS) blockade, corticosteroids, and other immunosuppression, and outcomes were compared among these groups.

RESULTS

A total of 6802 children had a diagnosis of IgAV, of whom 1139 (16.7%) were followed by nephrology for at least 2 visits over a median follow-up period of 1.7 years [0.4,4.2]. Conservative management was the most predominant practice pattern, consisting of observation in 57% and RAAS blockade in 6%. Steroid monotherapy was used in 29% and other immunosuppression regimens in 8%. Children receiving immunosuppression had higher rates of proteinuria and hypertension compared to those managed with observation (p < 0.001). At the end of follow-up, 2.6 and 0.5% developed CKD and kidney failure, respectively.

CONCLUSIONS

Kidney outcomes over a limited follow-up period were favorable in a large cohort of children with IgAV. Immunosuppressive medications were used in those with more severe presentations and may have contributed to improved outcomes. A higher resolution version of the Graphical abstract is available as Supplementary information.

Recurrence of Henoch Schoenlein Purpura Nephritis in Children: A Retrospective Study

The aim of the study was to identify predictive patient characteristics for Henoch Schoenlein Purpura (HSPN) relapse in childhood HSPN. One hundred and thirty-five Chinese children with HSPN were enrolled in this study, mean age 10.25 ± 3.39 years. The pathology of HSPN was according to the International Study of Kidney Disease in Children criteria.(ISKDC); ISKDC II(mesangial proliferation (MP)) AND ISKDC III (MP with <50 % crescents).Recurrence of HSPN was observed in 66.3 % patients; male to female ratio (2:1)Statistically significant correlation existed between biopsy grade(p < 0.001), gender(p < 0.001),age ranges(p = 0.002) and treatment regimen (p < 0.001)in the frequency of recurrent HSPN episodes. We identified some significant predictors for HSPN relapse such as the severity of HSPN, adjunctive therapies administered to these patients,and close attention should be paid in patients between the ages 7 and 12 years old. In addition, the use of mycophenolate mofetil as an adjunctive therapy in the treatment of HSPN may reduce the frequency of HSPN relapse episodes in children.

Glomerulonephritis

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

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

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

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

Semiquantitative classification (SQC) and Oxford classifications predict poor renal outcome better than The International Study of Kidney Disease in Children (ISKDC) and Haas in patients with IgAV nephritis: a multicenter study

INTRODUCTION

Several histologic classifications are used in the evaluation of IgA vasculitis nephritis (IgAVN), however, to date, no studies have determined which one has the strongest association with the severity of IgAVN and, as a consequence, its outcomes.

MATERIALS AND METHODS

Patients included in the study were diagnosed with IgAV and IgAVN in seven tertiary university medical centers in Croatia, Italy and Israel. The International Study of Kidney Disease in Children (ISKDC), Haas, Oxford, and Semiquantitative classification (SQC) classifications were used in the analysis and description of renal biopsy. Time from biopsy to outcome evaluation was a statistically significant factor in outcome prediction that was used to define the base model, and was a covariate in all the tested models.

RESULTS

Sixty-seven patients were included in this study. The SQC classification proved to be the best one in outcome prediction, followed by the Oxford classification. The ISKDC and Haas classifications could not predict renal outcome. The Oxford parameters for mesangial hypercellularity and tubular atrophy, as well as the SQC parameters for cellular crescents showed an independent statistically significant contribution to outcome prediction. High level of twenty-four hour protein excretion was associated with a higher grade in the Oxford, SQC and ISKDC classifications. Endocapillary proliferation was positively associated with the Pediatric Vasculitis Activity Score (PVAS) at diagnosis, while tubular atrophy was negatively associated.

CONCLUSION

The SQC, followed by the Oxford classification were found to provide the best classifications of renal biopsy analysis in patients to predict the outcome in patients with IgAVN. Cellular crescents, mesangial hypercellularity and tubular atrophy showed significant contributions, indicating that active and chronic variables should be included in the estimation.

Time of Onset and Risk Factors of Renal Involvement in Children with Henoch-Schönlein Purpura: Retrospective Study

Background: Henoch-Schönlein purpura (HSP) is a common systemic vasculitis in children, involving the skin, musculoskeletal system, gastrointestinal tract and kidneys. Some studies in children have shown possible risk factors linked with the development and severity of HSP Nephritis (HSPN). The aim of this study was to research predicting factors for the development of HSPN. Methods: We retrospectively evaluated 132 pediatric patients with HSP, according to EULAR/PRINTO/PRESS criteria. All patients were screened for HSPN by urinalysis. Finally, we compared demographic, clinical and laboratory data in HSP patients with and without nephritis. Results: The median age at HSP diagnosis [6.2 (2.6–17.5) vs. 5.5 (0.8–15.4) years, p = 0.03] and the incidence of abdominal pain (48 vs. 27%, p = 0.01) were significantly higher in HSPN patients. No differences were evidenced regarding gender, allergic diseases, skin recurrences, gastrointestinal involvement, musculoskeletal involvement, scrotal involvement, and laboratory data (white blood cell count, neutrophil count, lymphocyte count, platelet count, C-reactive protein, erythrocyte sedimentation rate, and blood concentration of IgA). Conclusions: The age at diagnosis and abdominal pain were independent risk factors for renal involvement in HSP patients. However, due to the retrospective nature of this study, further long-term and prospective studies will be necessary.

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

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

Neutrophil-to-lymphocyte ratio as an independent inflammatory indicator for poor renal prognosis in adult IgA vasculitis with nephritis

BACKGROUND

Skin-limited IgAV patients usually present self-limiting disease and good prognosis, while adult IgA vasculitis with nephritis (IgAV-N) present severe phenotype and poor prognosis. Previous studies showed that neutrophil-to-lymphocyte ratio (NLR) was an inflammatory indicator for predicting systemic involvement in children IgAV patients. In this study, we focused on adult IgAV-N patients to explore the relationship of NLR with disease phenotype and long-term renal prognosis.

METHODS

In this study, 245 IgAV-N patients, 1151 IgAN patients and 251 healthy controls were recruited. Composite endpoint was defined as 30% eGFR declined or end stage kidney disease.

RESULTS

IgAV-N patients presented increased white blood cells (WBC), neutrophils (NE), platelet-to-lymphocyte ratio (PLR), and NLR levels, while decreased lymphocyte (LY) than healthy controls. When compared to clinical and pathological features matched IgAN patients, IgAV-N patients still showed higher WBC, NE, and NLR levels. NLR showed the best performance for the diagnosis of IgAV-N with the highest area under the ROC curves (0.738). IgAV-N patients in high NLR group (>2.41) presented with sever baseline manifestations and more acute pathological lesions than low NLR group (≤2.41). 77 patients with regular follow-up were used for survival analysis. After adjusting some well-known risk factors, NLR levels remained as an independent risk factor for poor renal outcome in adult patients with IgAV-N (HR, 1.913; 95% CI, 1.314 to 2.787, P = 0.001).

CONCLUSIONS

NLR levels were associated with the clinical and pathological phenotypes, and NLR may serve as an independent risk factor for poor renal outcome in adult IgAV-N patients.

Construction of Prediction Model of Renal Damage in Children with Henoch-Schönlein Purpura Based on Machine Learning

Objective

The children with Henoch-Schönlein purpura (HSP) may suffer from renal insufficiency, which seriously affects the life and health of the children. This study aims to construct a prediction model of Henoch-Schönlein purpura nephritis (HSPN).

Methods

A total of 240 children with HSP treated in dermatology and pediatrics in our hospital were selected. The general information, patients' clinical symptoms, and laboratory examination indicators were collected for feature selection, and the XGBoost algorithm prediction model was built.

Results

According to the input feature indexes, the top ten crucial feature indicators output by the XGBoost model were urine N-acetyl-β-D-aminoglucosidase, urinary retinol-binding protein, IgA, age, recurrence of purpura, purpura area, abdominal pain, 24-h urinary protein quantification, percentage of neutrophils, and serum albumin. The areas under the curves of the training set (0.895, 95% CI: 0.827-0.963) and test set (0.870, 95% CI: 0.799-0.941) models were similar.

Conclusion

The prediction model based on XGBoost is used to predict HSP renal damage based on clinical data of children, which can reduce the harm caused by invasive examination for patients.

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

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

A retrospective study on the characteristics of renal pathological grades in HSPN children with mild to moderate proteinuria

OBJECTIVE

To investigate the characteristics of renal pathological grades in Henoch-Schönlein purpura nephritis (HSPN) children with mild to moderate proteinuria and the correlation between pathological grade and severity of proteinuria among this population.

METHODS

HSPN children who were presented with mild (150 mg <24 h urinary protein <25 mg/kg) to moderate (25 mg/kg ≤24 h urinary protein <50 mg/kg) proteinuria and performed renal biopsy without steroid ± immunosuppressant treatment in the Second Xiangya Hospital between January 2010 and March 2021 were involved. We retrospectively analyzed the correlation between age, disease course, degree of proteinuria, type of immunoglobulin deposits, C3 deposits in glomeruli and renal pathological grade.

RESULTS

(1) 72 HSPN children including 46 boys and 26 girls were included, with a mean age of onset of 9.01 ± 2.65 years old. The majority of these patients (62.5%) had a disease course between 1 week to 1 month. 51 patients presented with mild proteinuria and 21 patients with moderate proteinuria. (2) Renal biopsy results showed that ISKDC Grade IIIa were both predominant in mild proteinuria group (25, 49%) and moderate proteinuria group (11, 52.4%). 32 patients had grade II (44.4%), 2 had grade IIIb (2.8%), 1 had grade IV (1.4%), and 1 had grade VI (1.4%). There was no correlation between age, disease course and renal pathological grade (p > 0.05). (3) In patients with mild proteinuria (n = 51), 27 (52.9%) HSPN children had a pathological grade ≥ grade III. In patients with moderate proteinuria (n = 21), 13 (61.9%) HSPN children had grade ≥ III. There was no significant difference in the proportion of renal pathological grade between the 2 groups (p > 0.05). (4) There was no significant correlation between glomerular C3 deposits or immunoglobulin deposit types and renal pathological grade (p = 0.776 and p = 0.056 respectively).

CONCLUSION

In HSPN children with mild to moderate proteinuria, longer disease course or heavier urinary protein level is not completely parallel with higher renal pathological grade. ISKDC grade IIIa is the most common pathological grade. Clinicians should pay great attention to the renal injury in patients with mild to moderate proteinuria.

Cutaneous manifestations of acute kidney injury

Acute kidney injury (AKI) is a common medical problem with a multitude of aetiologies. Prompt diagnosis and management is key in the prevention of complications. Cutaneous signs can often give diagnostic clues of underlying systemic diseases causing AKI.

This review summarises cutaneous findings of diseases causing AKI in adults. Knowledge of such cutaneous signs could lead to earlier diagnosis of underlying kidney disease and facilitate management strategies in a timely manner.

Acute interstitial nephritis, polyarteritis nodosa, Kawasaki's disease, granulomatosis with polyangiitis (previously Wegener's granulomatosis), microscopic polyangiitis, eosinophilic granulomatosis with polyangiitis (previously Churg-Strauss syndrome), Henoch-Schonlein purpura, cryoglobulinaemia, Sjogren's Syndrome, systemic sclerosis, nephrogenic systemic fibrosis, dermatomyositis, systemic lupus erythematosus, amyloidosis, and cholesterol embolisation syndrome were highlighted as diseases causing AKI with cutaneous manifestations.

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.

IgA vasculitis nephritis clinical course and kidney biopsy - national study in children

The aim of the study was to investigate the relationship between the severity of typical clinical symptoms, severity of histopathological lesions in kidney biopsies in IgA vasculitis nephritis (IgAVN) and to propose indications for kidney biopsy in children.

MATERIAL AND METHODS

This retrospective study enrolled 106 patients, included in the IgAVN registry of Polish children, diagnosed by kidney biopsy. Renal and extrarenal symptoms at onset of the disease were analyzed. Biopsy results were assessed using Oxford classifications (MEST-C). The patients were divided into 3 groups depending on the severity of proteinuria: A-nephrotic proteinuria with hematuria; B-non-nephrotic proteinuria with hematuria; C-isolated hematuria.

RESULTS

The first symptoms of nephropathy were observed at the 0.7 (1-128.4) months from the onset of extrarenal symptoms. Kidney biopsy was performed on 39 (6-782) days after the onset of nephropathy symptoms. MEST-C score 4 or 5 was significantly more frequent in children from group A than in groups B and C. Significantly higher mean MEST-C score was found in patients with abdominal symptoms than without. In group A: S0 and T0 we found in significantly shorter time to kidney biopsy than in S1, T1-2 p < 0.05) and in group B the significantly shorter time in T0 compare to T1-2 p < 0.05). The ROC analysis shows that S1 changes appear in kidney biopsies in group A with cut off 21 days (AUC 0,702, p = 0.004, sensitivity 0.895 specificity 0.444) T1-2 changes after 35 days (AUC 0.685, p = 0.022, sensitivity 0.750, specificity 0.615), and in goupn B T1-2 cut off is 74 days (AUC 0,738, p = 0.002, sensitivity 0.667, specificity 0.833).

CONCLUSIONS

In childhood IgAVN, the severity of changes in the urine is clearly reflected in the result of a kidney biopsy. The biopsy should be performed in patients with nephrotic proteinuria no later than 3 weeks after the onset of this symptom in order to promptly apply appropriate treatment and prevent disease progression. Accompanying abdominal symptoms predispose to higher MESTC score.

IgA vasculitis nephritis in children and adults: one or different entities?

The clinical features of the kidney involvement in immunoglobulin A (IgA) vasculitis (IgAVN) differ in children and adults for both clinical presentation and progression. IgAVN in children has mostly a self-limiting course and favorable resolution, while in adults the kidney involvement is frequently severe with unfavorable outcome. However, a subset of children is at risk of progression within the pediatric age or decades later in adulthood, particularly when the diagnosis and a prompt intervention are delayed. Factors predicting progression and outcome in the whole spectrum of age have been investigated in recent research, as well as the relationship between IgAVN and primary IgAN, which share the same pathology features, in the light of peculiar clinical differences and progression tendencies, and hence need for selective treatments. The search for a personalized treatment in children with IgAV and in different ages of life should rely on the identification of different risks for progression. This review will focus on recent studies which contribute to improve our knowledge in this still largely unclear area.

Efficacy and safety of low-dose corticosteroid with azathioprine in the treatment of elderly-onset IgA vasculitis with nephritis

The diagnosis of elderly-onset IgA vasculitis (IgAV) and its prognosis can be difficult to ascertain because of its rarity and the frequent presence of comorbidities. Furthermore, the treatment of elderly-onset IgAV remains controversial. We report a case of IgAV in an 87-year-old patient. Renal involvement was detected early during the IgAV follow-up. He was treated with low-dose corticosteroid and azathioprine, which led to a complete remission without any adverse effects. This suggests that precise intervention with early diagnosis and careful renal follow-up may prevent renal failure and that low-dose steroids with azathioprine can be an effective treatment for elderly-onset IgAV with nephritis.

Clinical effect of combined western medicine and traditional Chinese medicine on children with Henoch-Schönlein purpura nephritis

OBJECTIVE

To investigate the efficacy of combined Chinese and western medicine in the treatment of children with Henoch-Schönlein purpura nephritis (HSPN) and its effects on immune function, interleukin (IL)-16, and IL-18 expressione.

METHODS

The clinical data of 91 children with HSPN were retrospectively collected and divided into two groups according to the treatment regimen. Group A (n=45) was treated only with western medicine, while group B (n=46) was treated with combined Chinese and western medicine. The clinical efficacy, traditional Chinese medicine (TCM) syndrome points before and after treatment, immune function indices, urinary indices, levels of IL-16 and IL-18, and the recurrence rate were compared between the two groups.

RESULTS

The total effective rate was 95.65% in group B, higher than 75.56% in group A (P<0.05). The TCM scores after treatment in group B was lower than that in group A (P<0.05). The levels of immunoglobulin IgA and IgM after treatment were lower while IgG levels were higher in group B than those in group A (P<0.05); Urinary microalbumin, urinary beta₂ microglobulin, 24 h urine protein elimination, and red blood cells (RBC) in the urine were lower in group B after treatment than in group A (P<0.05). The serum levels of IL-16 and IL-18 in group B were lower than those in group A after treatment (P<0.05). The recurrence rate was 4.35% in group B, lower than 26.67% in group A (P<0.05).

CONCLUSION

Combined regimen of western and Chinese medicine in children showed significant efficacy on improving immune function and reducing recurrence rate and IL-16 and IL-18 levels in patients with HSPN.

Long term outcome of immunoglobulin A (IgA) nephropathy: A single center experience

INTRODUCTION

IgA nephropathy (IgAN) has a heterogeneous presentation and the progression to end stage renal disease (ESRD) is often influenced by demographics, ethnicity, as well as choice of treatment regimen. In this study, we investigated the long term survival of IgAN patients in our center and the factors affecting it.

METHODS

This study included all biopsy-proven IgAN patients with ≥ 1year follow-up. Patients with diabetes mellitus at diagnosis and secondary IgAN were excluded. Medical records were reviewed for demographics, clinical presentation, blood pressure, 24-hour urine protein, serum creatinine, renal biopsy and treatment received. The primary outcome was defined as combined event of 50% estimated glomerular filtration rate (eGFR) reduction or ESRD.

RESULTS

We included 130 (74 females; 56 males) patients of mean age 38.0 ± 14.0 years and median eGFR of 75.2 (interquartile range (IQR) 49.3-101.4) ml/min/1.73m2. Eighty-four (64.6%) were hypertensive at presentation, 35 (26.9%) had nephrotic syndrome and 57 (43.8%) had nephrotic range proteinuria (NRP). Median follow-up duration was 7.5 (IQR 4.0-13.0) years. It was noted that 18 (13.8%) developed ESRD and 34 (26.2%) reached the primary outcome. Annual eGFR decline was -2.1 (IQR -5.3 to -0.1) ml/min/1.73m2/year, with median survival of 20 years. Survival rates from the combined event (50% decrease in eGFR or ESRD) at 10, 20 and 30 years were 80%, 53% and 25%, while survival from ESRD were 87%, 73% and 65%, respectively. In the univariate analysis, time-average proteinuria (hazard ratio (HR) = 2.41, 95% CI 1.77-3.30), eGFR <45ml/min/1.73m2 at biopsy (HR = 2.35, 95% CI 1.03-5.32), hypertension (HR = 2.81, 95% CI 1.16-6.80), mean arterial pressure (HR = 1.02, 95% CI 1.01-1.04), tubular atrophy/interstitial fibrosis score (HR = 3.77, 95% CI 1.84-7.73), and cellular/fibrocellular crescent score (HR = 2.44, 95% CI 1.19-5.00) were found to be significant. Whereas only time-average proteinuria (TA-proteinuria) remained as a significant predictor in the multivariate analysis (HR = 2.23, 95% CI 1.57-3.16).

CONCLUSION

In our cohort, TA-proteinuria was the most important predictor in the progression of IgAN, irrespective of degree of proteinuria at presentation.

Morbidity and mortality in adult-onset IgA vasculitis: a long-term population-based cohort study

OBJECTIVES

With sparse data available, we investigated mortality and risk factors in adults with IgAV.

METHODS

Observational population-based cohort study using state-wide linked longitudinal health data for hospitalised adults with IgAV (n = 267) and matched comparators (n = 1080) between 1980-2015. Charlson comorbidity index (CCI) and serious infections (SI) were recorded over an extensive lookback period prior to diagnosis. Date and causes of death were extracted from WA Death Registry. Mortality rate (deaths/1000 person-years) ratios (MRR) and hazard ratio (HR) for survival were assessed.

RESULTS

During 9.9 (±9.8) years lookback patients with IgAV accrued higher CCI scores (2.60 vs1.50 p < 0.001) and had higher risk of SI (OR 8.4, p < 0.001), not fully explained by CCI scores. During 19 years follow-up, the rate of death in Patients with IgAV (n = 137) was higher than in comparators (n = 397) (MRR 2.06, CI 1.70-2.50, p < 0.01) and the general population (SMRR 5.64, CI 4.25, 7.53, p < 0.001). Survival in IgAV was reduced at five (72.7 vs. 89.7%) and twenty years (45.2% vs. 65.6%) (both p < 0.05). CCI (HR1.88, CI:1.25 - 2.73, p = 0.001), renal failure (HR 1.48, CI: 1.04 - 2.22, p = 0.03) and prior SI (HR 1.48, CI:1.01 - 2.16, p = 0.04) were independent risk factors. Death from infections (5.8 vs 1.8%, p = 0.02) was significantly more frequent in patients with IgAV.

CONCLUSIONS

Premorbid comorbidity accrual appears increased in hospitalized patients with IgAV and predicts premature death. As comorbidity does not fully explain the increased risk of premorbid infections or the increased mortality due to infections in IgAV, prospective studies are needed.

Risk factors associated with renal crescentic formation in pediatric Henoch-Schönlein purpura nephritis: a retrospective cohort study

BACKGROUND

The long-term prognosis of Henoch-Schönlein purpura (HSP) depends on the severity of renal involvement, and crescent formation is considered an important risk factor for poor prognosis of Henoch-Schönlein purpura nephritis (HSPN). The objective of this study was to evaluate factors affecting crescent formation in children with HSPN.

METHODS

Demographic factors, clinical characteristics, and laboratory data of children with HSPN with or without crescents were retrospectively analyzed. Univariate and multivariate logistic regression analyses were used to determine the risk factors of crescent formation in HSPN.

RESULTS

A total of 191 children with HSPN were enrolled in the study. There were 107 (56%) males and 84 (44%) females, with a median age of 7 years (range: 2 years-15 years). International Study of Kidney Disease in Children (ISKDC) grading was used to divide subjects into two groups: those without glomerular crescent formation (ISKDC grades I-II, n = 146 cases) and those with glomerular crescent formation (ISKDC grades III-V, n = 45 cases). Logistic regression analysis showed that higher urinary white blood cell (WBC) count (OR = 3.300; 95% CI, 1.119-9.739; P = 0.0306) and higher urinary microalbumin/creatinine ratio (ACR) (OR = 25.053; 95% CI, 1.354-463.708; P = 0.0305) were independent risk factors for the formation of crescents in HSPN. The area under the receiver operating characteristic curve of urinary WBC and ACR were 0.753 and 0.698 respectively, with the Hosmer and Lemeshow goodness-of-fit test (P = 0.0669, P > 0.05).

CONCLUSION

These results suggest that higher urinary WBC count and ACR should be strictly monitored for children with HSPN. Adequate clinical intervention for these risk factors may limit or prevent renal crescent formation.

JAK2 mutation-positive polycythaemia vera associated with IgA vasculitis and nephrotic syndrome: a case report

We report a case of polycythaemia vera (PV) associated with IgA vasculitis. A 45-year-old man was admitted for evaluation of abdominal pain and palpable purpura. IgA vasculitis was diagnosed, and oral prednisolone therapy (30 mg/day) was initiated. On day 6, the patient developed left hemiparesis, and magnetic resonance imaging revealed acute cerebral infarction. Bone marrow biopsy results and the identification of a Janus kinase 2 (JAK2) mutation led to the diagnosis of PV. Despite steroid therapy, urine protein levels increased to 15 g/g・Cre. Renal biopsy demonstrated mild mesangial proliferation with IgA deposits, but immunosuppressive therapy was partially effective. This case suggests that PV can be a complication of IgA vasculitis and that preventive measures for thrombosis should be taken in such cases.