Histological prognostic factors in children with Henoch-Schönlein purpura nephritis

Outcome of children with IgA vasculitis with nephritis treated with steroids: a matched controlled study

BACKGROUND

IgA vasculitis (IgAV) is the most common vasculitis in children. IgAV long-term prognosis depends on kidney involvement or IgA vasculitis with nephritis (IgAVN). To date, steroid treatment (oral steroids or methylprednisolone pulses) has not proven to be formally efficient. This study aimed to assess the role of steroids on IgAVN outcome.

METHODS

All children with IgAVN diagnosed 2000-2019 in 14 French pediatric nephrology units with minimal follow-up of 6 months were retrospectively included. Outcomes of patients treated with steroids were compared with those of a control group of untreated patients matched for age, sex, proteinuria, eGFR, and histological features. The primary endpoint was IgAVN remission defined as urine protein-to-creatinine ratio < 20 mg/mmol without impaired eGFR one year after disease onset.

RESULTS

A total of 359 patients with IgAVN were included with a median follow-up time of 249 days (range 43-809). One hundred eight (30%) patients received oral steroids alone, 207 (51%) patients received three methylprednisolone pulses followed by oral steroids, and 44 patients (12.5%) did not receive steroids. Thirty-two children treated with oral steroids alone were compared with 32 matched control patients who did not receive steroids. One year after disease onset, IgAVN remission proportion was not different between these two groups: 62% versus 68%, respectively. Ninety-three children treated with oral steroids alone were compared with 93 matched patients treated with three methylprednisolone pulses followed by oral corticosteroids. IgAVN remission proportion was not different between these two groups: 77% versus 73%, respectively.

CONCLUSION

The benefit of oral steroids alone and methylprednisolone pulses could not be established based on this observational study. Randomized controlled trials are thus required to determine the efficacy of steroids in IgAVN. A higher resolution version of the Graphical abstract is available as Supplementary information.

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.

IgA vasculitis update: Epidemiology, pathogenesis, and biomarkers

Immunoglobulin A vasculitis (IgAV), formerly known as Henoch-Schönlein purpura, is the most common systemic vasculitis in children, characterized by diverse clinical manifestations with a wide spectrum ranging from isolated cutaneous vasculitis to systemic involvement. The incidence of IgAV is geographically and ethnically variable, with a prevalence in autumn and winter, suggesting a driving role that genetic and environmental factors play in the disease. Although IgAV has a certain degree of natural remission, it varies widely among individuals. Some patients can suffer from severe renal involvement and even progress to end-stage renal disease. Its pathogenesis is complex and has not been fully elucidated. The formation of galactose-deficient IgA1 (Gd-IgA1) and related immune complexes plays a vital role in promoting the occurrence and development of IgAV nephritis. In addition, neutrophil activation is stimulated through the binding of IgA to the Fc alpha receptor I expressed on its surface, resulting in systemic vascular inflammation and tissue damage. Starting from the epidemiological characteristics, this article will review the role of immunological factors such as Gd-IgA1, autoantibodies, circulating immune complexes, complement system, cellular immunization, and the contributions of environmental and genetic factors in the pathogenesis of IgAV, and conclude with the major biomarkers for IgAV.

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

Background

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

Methods

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

Results

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

Conclusions

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

To biopsy or not to biopsy: Henoch-Schönlein nephritis in children, a 5-year follow-up study

BACKGROUND

The prognosis of Henoch-Schönlein purpura (HSP), IgA vasculitis, depends on kidney involvement. There is no consensus on the initiation of treatment for HSP nephritis (HSPN). Some centres start treatment before performing a kidney biopsy (KB) while in others, treatment is dictated by the importance of the clinical, biological and histological signs. The aim of this study was to evaluate which of these two approaches is associated with a better kidney outcome at 5-year follow-up.

METHODS

This multicentre, retrospective, nonrandomised study included children treated for HSPN between 2006 and 2010 in a French paediatric nephrology unit. One group had an early KB at diagnosis (before starting treatment or in the 15 following days). In the second group, initial treatment was decided without performing a KB.

RESULTS

Among the 107 children included, 63.5% had an early KB at diagnosis. Follow-up at 5 years was completed in 44 children (28 KB at diagnosis, 16 no KB at diagnosis). Median urine protein/creatinine at 5 years was 2.5 mg/mmol in the early biopsy diagnosis group and 12.5 mg/mmol in the non-biopsy group. An antiproteinuric treatment was given, at 5 years, to 35.7% of the early biopsy at diagnosis children and in 62.5% of the non-biopsied children.

CONCLUSIONS

Children with early KB at diagnosis seem to have a better renal outcome at 5 years compared to those without an early biopsy at diagnosis or biopsied later. However, this is a small patient cohort and data are missing. Further work is needed to build consensual guidelines on the management of HSPN in children.

Risk assessment and prediction model of renal damage in childhood immunoglobulin A vasculitis

OBJECTIVES

To explore the risk factors for renal damage in childhood immunoglobulin A vasculitis (IgAV) within 6 months and construct a clinical model for individual risk prediction.

METHODS

We retrospectively analyzed the clinical data of 1,007 children in our hospital and 287 children in other hospitals who were diagnosed with IgAV. Approximately 70% of the cases in our hospital were randomly selected using statistical product service soltions (SPSS) software for modeling. The remaining 30% of the cases were selected for internal verification, and the other hospital's cases were reviewed for external verification. A clinical prediction model for renal damage in children with IgAV was constructed by analyzing the modeling data through single-factor and multiple-factor logistic regression analyses. Then, we assessed and verified the degree of discrimination, calibration and clinical usefulness of the model. Finally, the prediction model was rendered in the form of a nomogram.

RESULTS

Age, persistent cutaneous purpura, erythrocyte distribution width, complement C₃, immunoglobulin G and triglycerides were independent influencing factors of renal damage in IgAV. Based on these factors, the area under the curve (AUC) for the prediction model was 0.772; the calibration curve did not significantly deviate from the ideal curve; and the clinical decision curve was higher than two extreme lines when the prediction probability was ~15-82%. When the internal and external verification datasets were applied to the prediction model, the AUC was 0.729 and 0.750, respectively, and the Z test was compared with the modeling AUC, P > 0.05. The calibration curves fluctuated around the ideal curve, and the clinical decision curve was higher than two extreme lines when the prediction probability was 25~84% and 14~73%, respectively.

CONCLUSION

The prediction model has a good degree of discrimination, calibration and clinical usefulness. Either the internal or external verification has better clinical efficacy, indicating that the model has repeatability and portability.

CLINICAL TRIAL REGISTRATION

www.chictr.org.cn, identifier ChiCTR2000033435.

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.

Predicting Severe Renal and Gastrointestinal Involvement in Childhood Immunoglobulin A Vasculitis with Routine Laboratory Parameters

BACKGROUND

Immunoglobulin A vasculitis (IgAV) is the most common vasculitis in children. Although childhood IgAV is generally considered as a self-limited disease, progressive course and poor prognosis could occur in some cases which mostly result from severe renal involvement and gastrointestinal (GI) involvement.

METHODS

We performed a retrospective study of pediatric patients diagnosed as IgAV in our institution from 2016 to 2019. Patients were divided into groups based on the occurrence and severity of GI and renal involvement. Analysis of variance (ANOVA) and Kruskal-Wallis test were used to compare results of laboratory parameters among groups and prediction models were built by using logistic regression analysis.

RESULTS

A total of 286 patients were enrolled. GI involvement occurred in 148 (51.7%) patients, 30 (20.3%) of which were severe cases. Renal involvement developed in 120 (42.0%) patients, 22 (18.3%) of which were severe cases. Compared with patients with only cutaneous manifestations, white blood cell (WBC) count, neutrophil-to-lymphocyte ratio (NLR), and D-dimer levels were higher in those with GI involvement, and D-dimer level was found to be positively associated with severity. Increased NLR and lower complement 3 (C3) were found in patients with renal involvement, but only C3 was relevant in distinguishing moderate and severe cases. The prediction model for severe renal involvement was: Logit (P) = 6.820 + 0.270 (age) + 0.508 (NLR) - 16.130 (C3), with an AUC of 0.914. The prediction model for severe GI involvement was: Logit (P) = -5.459 + 0.005 (WBC) + 1.355 (D-dimer) - 0.020 (NLR), with an AUC of 0.849.

CONCLUSION

Our data suggest C3 to be an exclusive predictor for severe renal involvement and D-dimer level to be positively associated with the severity of GI involvement. Prediction models consisting of the above parameters were built for obtaining prognostic information in the early phase of IgAV.

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.

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.

Management of IgA Vasculitis with Nephritis

Immunoglobulin A (IgA) vasculitis (IgAV), previously called Henoch-Schönlein purpura, is characterized by IgA-dominant immune deposits affecting small vessels and often involves the skin, gastrointestinal tract, joints, and kidneys. IgAV is the most common cause of systemic vasculitis in children. The long-term prognosis is dependent on renal involvement: IgAV with nephritis (IgAVN) can progress to renal failure. IgAVN is an inflammatory disease, providing a rationale for the use of corticosteroids. However, data supporting the use of corticosteroids in patients with established IgAVN of any severity remain limited, although most clinicians use them. Even in patients with severe forms of IgAVN, methylprednisolone pulses added to oral corticosteroids appears to improve renal outcomes. Considering the multihit hypothesis for the pathogenesis of IgAVN, involving many other immune agents, there is a strong rationale for the use of other immunosuppressive drugs in patients with IgAVN, including mycophenolic acid, cyclophosphamide, rituximab, calcineurin inhibitors, and complement inhibitors. Thus, these immunosuppressive treatments have also been evaluated in IgAVN, usually in corticosteroid-dependent or corticosteroid-resistant forms and in small retrospective studies. However, their efficacy has not been proven. Thus, the risk of progression to renal failure and the ongoing debate about the best management of IgAVN justifies the interest in investigating and identifying treatments that can potentially preserve renal function in patients with IgAVN. This review reports on the efficacy of the different drugs currently used for the treatment of IgAVN in adults and children.

Clinical effect of alfacalcidol in children with Henoch-Schönlein purpura: a prospective randomized controlled trial

OBJECTIVES

To study the effects of alfacalcidol on serum 25-(OH)D3 level, cellular immune function, and inflammatory factors in children with Henoch-Schönlein purpura (HSP).

METHODS

A total of 200 children with HSP were prospectively enrolled from June 2018 to June 2020. According to the random number table method, they were divided into an observation group and a control group (n=100 each). The control group was treated with vitamin C, rutin tablets, dipyridamole, cimetidine, calcium supplements, and glucocorticoids. In addition to the treatment for the control group, the observation group received alfacalcidol capsules (0.25 μg/d) orally before bed for 4 weeks. The two groups were compared in terms of the level of 25-(OH)D3, the percentages of T lymphocyte subsets (CD3+, CD4+, and CD8+) and NK cells, and the levels of inflammatory factors, interleukin-6 (IL-6), interleukin-17 (IL-17), interleukin-21 (IL-21), and tumor necrosis factor-α (TNF-α), before treatment and after 4 weeks of treatment. The children were followed up for 6 months to determine the recurrence rate and the incidence of renal damage.

RESULTS

After treatment, the observation group showed a significantly higher serum 25-(OH)D3 level, significantly higher percentages of CD3+T cells, CD4+T cells, and NK cells, and significantly lower levels of IL-6, IL-17, IL-21, and TNF-α compared with the control group (P<0.05). After 6 months of follow-up, the recurrence rate and the incidence of renal damage in the observation group were significantly lower than those in the control group (P<0.05).

CONCLUSIONS

Alfacalcidol can increase the serum 25-(OH)D3 level, improve cellular immune function, decrease inflammatory factor levels, and reduce recurrence and renal damage in children with HSP.

Biopsy-proven Henoch-Schönlein purpura nephritis: a single center experience

BACKGROUND

Knowledge on normal progress and treatment of Henoch-Schönlein purpura nephritis (HSPN) is limited. This study reviews outcome, clinical, pathological, and therapeutic factors affecting the prognosis of HSPN patients.

METHODS

Forty-nine children with biopsy-confirmed HSPN diagnosed between September 2008 and 2018 were included. Demographics, clinical and laboratory data, treatment, and outcome were recorded at the time of biopsy, 3, 6, 12, and 24 months and at last visit. Clinical outcome was graded according to Meadow's criteria.

RESULTS

The median age at time of biopsy was 10.1 years (IQR:5.7) and female/male ratio 24/25. At presentation, 40.8% of patients had nonnephrotic proteinuria, 18.4% nephrotic syndrome (NS), 4.1% nephritic syndrome (NephrS), and 36.7% NephrS+NS. There were 11 patients with an estimated glomerular filtration rate below 90 ml/min/1.73 m². Biopsy specimens were classified according to International Study of Kidney Diseases in Children (ISKDC) and Oxford Classification MEST-C scoring systems. Forty-one patients received angiotensin-converting enzyme inhibitors/angiotensin receptor blockers, 37 patients steroids, and 35 patients other immunosuppressive medications. At last visit, 24 patients had stage 1 chronic kidney disease (CKD), three stage 2 CKD, and two had stage 5 CKD. Neither clinical parameters nor ISKDC biopsy grade or treatment modalities effected the final outcome. The Oxford classification showed significantly increased segmental glomerulosclerosis in patients with unfavorable outcome. Favorable outcome was associated with shorter time from kidney involvement to biopsy and start of treatment.

CONCLUSION

A large proportion of patients continued to show signs of CKD at last follow-up while only a small proportion developed stage 5 CKD.

Renal Survival in Children with Glomerulonephritis with Crescents: A Pediatric Nephrology Research Consortium Cohort Study

There is no evidence-based definition for diagnosing crescentic glomerulonephritis. The prognostic implications of crescentic lesions on kidney biopsy have not been quantified. Our objective was to determine risk factors for end-stage kidney disease (ESKD) in patients with glomerulonephritis and crescents on kidney biopsy. A query of the Pediatric Nephrology Research Consortium’s Pediatric Glomerulonephritis with Crescents registry identified 305 patients from 15 centers. A retrospective cohort study was performed with ESKD as the primary outcome. Median age at biopsy was 11 years (range 1–21). The percentage of crescents was 3–100% (median 20%). Etiologies included IgA nephropathy (23%), lupus (21%), IgA vasculitis (19%) and ANCA-associated GN (13%), post-infectious GN (5%), and anti-glomerular basement membrane disease (3%). The prevalence of ESKD was 12% at one year and 16% at last follow-up (median = 3 years, range 1–11). Median time to ESKD was 100 days. Risk factors for ESKD included %crescents, presence of fibrous crescents, estimated GFR, and hypertension at biopsy. For each 1% increase in %crescents, there was a 3% decrease in log odds of 1-year renal survival (p = 0.003) and a 2% decrease in log odds of renal survival at last follow-up (p < 0.001). These findings provide an evidence base for enrollment criteria for crescentic glomerulonephritis in future clinical trials.