The Challenging Management of Cancer: An Immunonephrologist's Perspective.

INTRODUCTION: Onconephrology is an emerging medical subspecialization that focuses on the numberless interrelations between cancer and kidney diseases. Tumor cells evade immune surveillance through activation of immune checkpoint pathways that suppress antitumor immune responses. By blocking checkpoints, new anticancer agents disrupt immune homeostasis but potentially induce immune-mediated diseases. Nephrologists and nephroimmunologists should be able to treat the nephrotoxic sequelae of cancer therapy and ensure continuation of the life-saving treatment. METHODS: Thirty-seven renal biopsies have been carried out over 42 months in oncologic patients, that is, 5.2% of the total native renal biopsies were carried out in the same period. The commonest diagnoses (>6 cases) were interstitial tubular nephritis, membranous glomerulopathy, IgA nephropathy, vasculitis, and focal and segmental glomerulosclerosis. CASE PRESENTATION: Three example cases, including focusing on key questions which could involve the nephrologists are reported in detail. They include a cancer-related Goodpasture Syndrome, the peculiar toxic effects of pemetrexed on tubular cells, and the intriguing relationship between bevacizumab and cryoglobulinemic glomerulonephritis. CONCLUSION: As shown by these 3 example cases, nephrologists need to be open-minded with regard to kidney biopsy in order to get a timely diagnosis. Nephrologists also need to improve their knowledge of cancer biology and therapy in order to prevent kidney problems, manage therapy-related immune-mediated disorders, and improve patient life expectancy.

Rituximab in severe immunoglobulin-A vasculitis (Henoch-Schönlein) with aggressive nephritis.

OBJECTIVES: Immunoglobulin-A vasculitis (IgAV) is a systemic small-vessel vasculitis in which renal involvement indicates severity of illness, and chronic kidney disease represents the most serious long-term complication. No treatment at present is specifically recommended for IgAV. Recently, rituximab (RTX) has been shown to be effective in case series of adults with IgAV. However, long term results are lacking. Aim of the study is to evaluate the effectiveness of RTX as induction therapy and maintenance of remission in adults with severe IgAV and aggressive glomerulonephritis. METHODS: This study included 12 adult-onset patients, 8 males and 4 females, mean age 45.1 years (range 19-75) with a mean follow-up duration of 33.7 months (range 6-144). All patients had a severe IgAV with biopsy proven crescentic nephritis. RTX was given for the treatment of a refractory disease or because of definite contraindications to standard therapies. RESULTS: Eleven patients (91.7%) achieved a clinical response at 6 months. Ten patients had a complete response (CR) while one had a partial response and was given an additional dose of RTX after 12 months for persistent proteinuria (1gr/24 hrs) despite systemic remission. He achieved a CR 6 months later. One patient was considered unresponsive to RTX and was switched to MMF. Among the 10 patients with CR, 1 needed maintenance doses of RTX every 6 months for iterative relapsing of severe purpura, 1 relapsed after 15 months and received a new induction course showing a CR again. A significant decrease in BVAS (p=0.031) and 24-hour-proteinuria (p=0.043) from RTX initiation through the last follow-up has been detected. One patient, who had a CR with RTX alone died after 6 months for therapy-unrelated cardiovascular cause. CONCLUSIONS: RTX proved to be effective and safe for induction and maintenance of long-lasting remission in severe IgAV with aggresive renal involvement. Data also suggest that RTX can be indicated not only for refractory cases, but can be also proposed as a first line therapy.

Complement-mediated microangiopathy in IgA nephropathy and IgA vasculitis with nephritis.

Complement factor C4d was recently observed in renal biopsies from patients who had IgA nephropathy and a poor prognosis. We previously reported that C4d is a common denominator in microangiopathies. In this retrospective cohort study, we investigated whether C4d is a marker of microangiopathy in both IgA nephropathy and IgA vasculitis with nephritis, and whether patients with C4d and microangiopathy have poor renal outcome. We examined 128 renal biopsies from adult and pediatric patients, including normotensive and hypertensive patients, who presented with IgA nephropathy or IgA vasculitis with nephritis. Biopsies were re-evaluated in accordance with the Oxford classification, scored for additional lesions, and stained for complement proteins using immunohistochemistry, including C4d and C5b-9. Clinical data were collected with a mean (±SD) follow-up period of 51 ± 39 months. Changes in estimated glomerular filtration rate over time were compared using linear mixed-effects models. Renal survival was analyzed using multivariable Cox regression. Microangiopathic lesions were present in 20% of all biopsies (23% and 9% of patients with IgA nephropathy and IgA vasculitis with nephritis, respectively). Microangiopathy was associated with C4d and C5b-9 deposits, a higher number of chronic lesions, and hypertension (all p < 0.05). Patients with C4d and microangiopathic lesions had significantly poorer renal survival than patients without these findings, corrected for hypertension (p < 0.01). In conclusion, patients with IgA nephropathy or IgA vasculitis with nephritis with a combination of C4d positivity and microangiopathy comprise a clinical subgroup with an increased number of chronic lesions, lower estimated glomerular filtration rate, and poorer renal survival, even when corrected for hypertension. These data suggest that complement activation is involved in the development of microangiopathy in patients with IgA nephropathy and IgA vasculitis with nephritis, and that complement-mediated microangiopathy contributes to disease progression.

Novel therapeutic strategies for renovascular disease.

PURPOSE OF REVIEW: Renovascular disease (RVD) remains an important cause of hypertension and renal dysfunction. Given the failure of renal revascularization to provide consistent clinical benefit in the Cardiovascular Outcomes for Renal Artery Lesions trial among others, further research has underscored the need for mechanistically targeted interventions to improve renal outcomes in patients in RVD. This review discusses novel therapeutic approaches for RVD in the post-Cardiovascular Outcomes for Renal Artery Lesions era. RECENT FINDINGS: Emerging evidence indicates that renal inflammation, microvascular remodeling, and mitochondrial damage accelerate progression of renal injury and are important determinants of the response to revascularization. Experimental studies have identified interventions capable of ameliorating renal inflammation (e.g., cytokine inhibitors, mesenchymal stem cells), microvascular remodeling (proangiogenic interventions), and mitochondrial injury (mito-protective drugs), alone or combined with renal revascularization, to preserve the structure and function of the poststenotic kidney. Recent prospective pilot studies in patients with atherosclerotic RVD demonstrate the safety and feasibility of some of such interventions to protect the kidney. SUMMARY: Experimental studies and pilot clinical trials suggest that therapies targeting renal inflammation, microvascular remodeling, and mitochondrial damage have the potential to preserve the structure and function of the stenotic kidney. Further studies in larger cohorts are needed to confirm their renoprotective effects and clinical role in human RVD.

Targeting kidney inflammation as a new therapy for primary hyperoxaluria?

The primary hyperoxalurias (PHs) are inborn errors of glyoxylate metabolism characterized by endogenous oxalate overproduction in the liver, and thus elevated urinary oxalate excretion. The urinary calcium-oxalate (CaOx) supersaturation and the continuous renal accumulation of insoluble CaOx crystals yield a progressive decline in renal function that often ends with renal failure. In PH Type 1 (AGXT mutated), the most frequent and severe condition, patients typically progress to end-stage renal disease (ESRD); in PH Type 2 (GRHPR mutated), 20% of patients develop ESRD, while only one patient with PH Type 3 (HOGA1 mutated) has been reported with ESRD so far. Patients with ESRD undergo frequent maintenance (haemo)dialysis treatment, and finally must receive a combined liver-kidney transplantation as the only curative treatment option available in PH Type 1. In experimental models using oxalate-enriched chow, CaOx crystals were bound to renal tubular cells, promoting a pro-inflammatory environment that led to fibrogenesis in the renal parenchyma by activation of a NACHT, LRR and PYD domains-containing protein 3 (NALP3)-dependent inflammasome in renal dendritic cells and macrophages. Chronic fibrogenesis progressively impaired renal function. Targeting the inflammatory response has recently been suggested as a therapeutic strategy to treat not only oxalate-induced crystalline nephropathies, but also those characterized by accumulation of cystine and urate in other organs. Herein, we summarize the pathogenesis of PH, revising the current knowledge of the CaOx-mediated inflammatory response in animal models of endogenous oxalate overproduction. Furthermore, we highlight the possibility of modifying the NLRP3-dependent inflammasome as a new and complementary therapeutic strategy to treat this severe and devastating kidney disease.

Bone mesenchymal stem cells pretreated with erythropoietin enhance the effect to ameliorate cyclosporine A-induced nephrotoxicity in rats.

An increasing number of experiments and clinical trials have demonstrated the safety, feasibility, and efficacy of mesenchymal stem cells (MSCs)-based therapies for the treatment of various diseases. The main drawbacks of MSC therapy are the lack of specific homing after systemic infusion and early death of injected cells because of the injury micro-environment. We pretreated bone mesenchymal stem cells (BMSCs) with erythropoietin (EPO) to investigate their positive effect on cyclosporine A (CsA)-induced nephrotoxicity. BMSCs were incubated with different concentrations of EPO (10, 100, 500, and 1000 IU/mL) for 24 and 48 h, and their proliferation rate, cytoskeletal morphology, migration ability, and the expression of CXCR4 were evaluated to determine the optimal pretreatment conditions. To investigate the therapeutic effects of BMSCs pretreated with EPO in CsA-induced nephrotoxicity, we established CsA-induced in vitro and in vivo toxicity models. In our in vitro study, preconditioning of BMSCs with 500 IU/mL EPO for 48 h induced a marked increase in their proliferation rate, cytoskeletal rearrangement, migration in the scrape-healing assay, and migration toward injured HK2 cells. In vivo, EPO-BMSCs showed higher ability to improve renal function than BMSCs, and in CsA-induced rats treated with EPO-BMSCs, interstitial lymphocyte infiltration, tubular swelling, necrosis, and interstitial fibrosis decreased. We demonstrated that pretreatment with 500 IU/mL EPO before infusion markedly increased the homing ability of BMSCs, and obviously ameliorate CsA-induced nephrotoxicity in rats.

Acute Focal Bacterial Nephritis Can Lead to Unnecessary Invasive Procedures: A Report of Three Cases.

Acute focal bacterial nephritis (AFBN) is a rarely diagnosed interstitial bacterial infection of the kidney. Due to the non-specific clinical presentation of this entity, correct diagnosis can be challenging. In this work, we present three cases of AFBN aiming to stress the diversity of clinical presentation associated with the disease and the fact that patients with AFBN are at risk of undergoing unnecessary invasive procedures. The employment of invasive diagnostic and therapeutic procedures on the management of AFBN should be limited, as the majority of patients respond well to conservative therapy.

[Sarcoidosis : Renal manifestations]. / Sarkoidose : Renale Manifestationen.

Renal involvement in sarcoidosis is much more common than generally assumed from old epidemiological studies and is often only detected when actively searched for. Many patients with renal sarcoidosis present with no or only few symptoms. The diagnostic work-up of sarcoidosis should always include a possible renal involvement. In cases of impaired renal function, proteinuria or a pathological urine sediment, a renal biopsy specimen should be obtained to assess the type, severity and prognosis of the kidney disease. Treatment is primarily based on the use of corticosteroids. Steroid-sparing agents, such as disease-modifying antirheumatic drugs and infliximab can be applied; however, the evidence for efficacy of these therapies is mostly based on case series and expert opinions. Discontinuation of immunosuppression therapy bears a high risk of relapse.

Renal dysfunction and intragraft proMMP9 activity in renal transplant recipients with interstitial fibrosis and tubular atrophy.

Chronic renal allograft injury is reflected by interstitial fibrosis and tubular atrophy (IF/TA) and by the accumulation of extracellular matrix (ECM). Metalloproteinases (MMPs) are renal physiologic regulators of ECM degradation. Changes in MMPs expression or activity may disturb ECM turnover leading to glomerular scarring and worsening renal function. Our goal was to investigate intragraft MMP2 and MMP9 activities and their correlation with renal dysfunction. Plasma MMP2 and MMP9 activities were analyzed as noninvasive markers of renal allograft deterioration. Transplanted patients were biopsied and histopathologically characterized as IF/TA+ or IF/TA-. Renal function was evaluated by serum creatinine, glomerular filtration rate (GFR) estimated by Modification of Diet in Renal Disease equation and urinary protein/creatinine ratio. Kidney and plasma MMP2 and MMP9 activities were analyzed by zymography. A significant renal dysfunction was observed in IF/TA+ patients. Intragraft proMMP9 showed a significant higher activity in IF/TA+ than in IF/TA- samples and was inversely correlated with the GFR. Intragraft proMMP2 activity tended to increase in IF/TA+ samples, although no statistic significance was reached. Circulating proMMP2 and proMMP9 activities did not show significant differences between groups. Our data provide evidence that correlates intragraft proMMP9 activity with the fibrotic changes and renal dysfunction observed in IF/TA.

Acute focal bacterial nephritis, pyonephrosis and renal abscess in children.

BACKGROUND-AIM: Acute focal bacterial nephritis (AFBN), renal abscess and pyonephrosis are uncommon and not fully addressed forms of urinary tract infection (UTI) which may be underdiagnosed without the appropriate imaging studies. Here, we review the characteristics and outcome of these renal entities in children managed at a single medial centre. PATIENTS AND METHODS: The medical files of all children hospitalized for episodes of AFBN, renal abscess and pyonephrosis during a 10-year period (2003-2012) were reviewed. RESULTS: Among the 602 children hospitalized for UTI, 21 presented with AFBN, one with abscess and three with pyonephrosis. All 25 children (13 girls), ranging in age from 0.06 to 13.4 years, were admitted with fever and an impaired clinical condition, and 18 had urological abnormalities. More than one lesion, often of different types, were identified in 11 episodes. Urine cultures from 13 episodes grew non-Escherichia coli pathogens and those from two episodes were negative. Antibiotics were administered for 14-60 days, and emergency surgery was required in three cases. During follow-up, 13 patients underwent corrective surgery. Permanent renal lesions were identified in 16 patients. CONCLUSIONS: AFBN, renal abscess and pyonephrosis should be suspected in children with severe presentation and urological history. Appropriate imaging is crucial for management planning. Prognosis is often guarded despite appropriate treatment. Based on the results of this study we propose a management algorithm.

Smad7 inhibits AngII-mediated hypertensive nephropathy in a mouse model of hypertension.

The TGFß (transforming growth factor ß)/SMAD and NF-κB (nuclear factor κB) signalling pathways play a key role in hypertensive nephropathy. The present study examined whether targeting these pathways by SMAD7, a downstream inhibitor of both pathways, blocks AngII (angiotensin II)-induced hypertensive kidney disease in mice. A doxycycline-inducible SMAD7-expressing plasmid was delivered into the kidney by a non-invasive ultrasound-microbubble technique before and after AngII infusion. Results showed that pre-treatment with SMAD7 prevented AngII-induced progressive renal injury by inhibiting an increase in proteinuria and serum creatinine while improving the glomerular filtration rate. Similarly, treatment with SMAD7 in the established hypertensive nephropathy at day 14 after AngII infusion halted the progressive renal injury. These preventive and therapeutic effects of SMAD7 on hypertensive kidney injury were associated with inhibition of AngII-induced up-regulation of SMURF2 (SMAD-specific E3 ubiquitin protein ligase 2) and Sp1 (specificity protein 1), blockade of TGFß/Smad3-mediated renal fibrosis and suppression of NF-κB-driven renal inflammation. Moreover, overexpression of SMAD7 also prevented AngII-induced loss of renal miR-29b, an miRNA with an inhibitory role in both TGFß/Smad3 and NF-κB pathways. In conclusion, SMAD7 may be a therapeutic agent for AngII-mediated hypertensive nephropathy. Inhibition of the Sp1/SMAD3/NF-κB/miR-29b regulatory network may be a mechanism by which SMAD7 inhibits hypertensive nephropathy.

Comparison of double filtration plasmapheresis with immunoadsorption therapy in patients with anti-glomerular basement membrane nephritis.

BACKGROUND: Double filtration plasmapheresis (DFPP) and (IA) are both used to clear antibody. However, the clinical efficacy and safety of DFPP in patients with anti-glomerular basement membrane (anti-GBM) disease are unclear. METHODS: The 28 enrolled patients diagnosed serologically and pathologically with anti-GBM disease from 2003 to 2013 included 16 treated with DFPP and 12 with IA, with all patients administered immunosuppressive agents. DFPP consisted of an EC50W filter for plasma separation and an EC20W filter for plasma fractionation. A double volume of plasma was processed, and each patient received a 30-40 g human albumin supplement during each session. IA consisted of 10 cycles per session, with 8-10 sessions performed daily or every other day and each session regenerating 30-60 L of plasma. Serum anti-GBM antibodies and IgG were measured, and urinary and blood tests were performed, before and after each procedure. Renal function and outcome were determined. RESULTS: The 28 patients consisted of 13 males and 15 females, of median age 44.5 years (range, 22.5-57 years). Six patients had pulmonary hemorrhage and 18 had serum creatinine concentrations >500 umol/L. The average serum creatinine concentration at early onset of disease was 525 umol/L while the peak concentration was 813 umol/L. All patients showed progressive increases in serum creatinine and required CRRT during the course of disease. Pathological examination showed an average 73.9% of crescents (range, 54.6-95.4%).The clinical and pathological features of the DPPP and IA groups were similar. Efficacy of clearing anti-GBM antibody was similar in the two groups (59.0 vs. 71.2%, P = 1.00), although fewer patients in the DFPP group experienced reduced IgG (62.7 vs. 83.5%, p = 0.002). One patient each had a pulmonary hemorrhage and a subcutaneous hemorrhage during treatment, but there were no other serious complications. At the end of follow-up, patient survival and renal survival were similar in the DFPP and IA groups. CONCLUSION: DPPP plus immunosuppressive therapy efficiently and safely removed anti-GBM antibodies. The fewer plasma-associated side effects and reduced loss of IgG suggest that DFPP may be a better treatment choice for anti-GBM disease, especially in patients with insufficient plasma.

Use of Fever Duration to Guide Management of Urinary Tract Infection.

BACKGROUND: The appropriate duration of antimicrobial therapy for febrile urinary tract infection (fUTI) in children has not been established. This study examined the optimal duration of treatment for fUTI in children. METHODS: We created a protocol that used fever duration to determine the duration of antibiotic administration. Transvenous antibiotics were administered until 3 days after resolution of fever, followed by oral antibiotics for 1 week. Diagnosis of fUTI was based on a fever of 37.5°C or higher and a quantitative culture of catheterized urine yielded a bacteria count of ≥5 × 104. Acute focal bacterial nephritis (AFBN) and pyelonephritis (PN) were diagnosed on the basis of contrast-enhanced computed tomography (eCT) findings. We retrospectively reviewed treatment outcomes. RESULTS: Of the 78 patients treated according to our protocol, data from 58 were analyzed-49 children (30 boys) had PN and nine (three boys) had AFBN. Blood test results showed that patients with AFBN had significantly higher white blood cell counts and C-reactive protein levels than did those with PN; however, urinary findings and causative bacteria did not differ between groups. Time to resolution of fever and duration of intravenous antibiotic administration were significantly longer in patients with AFBN than in those with PN. However, average duration of AFBN treatment was 14.2 days, which was shorter than the previously reported administration period of 3 weeks. No recurrence was observed in AFBN patients. CONCLUSIONS: A protocol that used fever duration to determine the duration of antimicrobial treatment was useful. Invasive examinations, such as eCT, were not required.

Henoch-Schönlein purpura nephritis and IgA nephropathy: a comparative clinical study.

OBJECTIVES: Henoch-Schönlein purpura nephritis (HSPN) and IgA nephropathy (IgAN) are related syndromes. In the present study we aimed to compare the clinical characteristics and outcome of a large and unselected series of patients diagnosed as having HSPN and IgAN. METHODS: Comparative study of a wide and unselected population of HSPN (142 patient) and IgAN (61 patients) from a teaching hospital of Northern Spain. RESULTS: All of the following comparisons were expressed between HSPN vs. IgAN, respectively. HSPN patients were younger (30.6±26.4 vs. 37.1±16.5 years, p<0.001). Precipitating events, usually an upper respiratory tract infection and/or drug intake, were more frequently observed in HSPN (38% vs. 23%, p=0.03). Extra-renal manifestations were also more common in HSPN than in IgAN; skin lesions (100% vs. 1.8%; p<0.001), gastrointestinal (62% vs. 7.4%; p<0.001), and joint involvement (61.3% vs. 3.6%; p<0.001). However, nephritis was less severe in HSPN, renal insufficiency (25% in HSPN vs. 63.4% in IgAN; p<0.001), nephrotic syndrome (12.5%, vs. 43.7%; p<0.001), and nephritic syndrome (6.8% vs. 10.7%; NS). Leukocytosis was more frequent in HSPN (22.5% vs. 8.2%; p=0.015) and anaemia in IgAN (12.7% in HSPN vs. 36% in IgAN, p<0.001). The frequency of corticosteroid (79.6% vs. 69%; NS) and cytotoxic drug (19% vs. 16.5%, NS) use was similar. The frequency of relapses was similar (38.6% in HSPN vs. 36.3% in IgAN). After a median follow-up of 120.8 (IQR; 110-132) months in HSPN and 138.6 (IQR; 117-156) in IgAN, requirement for dialysis (2.9% vs. 43.5%; p<0.001), renal transplant (0% vs. 36%, p<0.001) and residual chronic renal insufficiency (4.9% vs. 63.8%; p<0.001) was more frequently observed in patients with in IgAN. CONCLUSIONS: HSPN and IgAN represent different syndromes. IgAN has more severe renal involvement while HSPN is associated with more extra-renal manifestations.

Etiology and outcomes of acute kidney injury in Chinese children: a prospective multicentre investigation.

BACKGROUND: The incidence of AKI appears to have increasing trend. Up to now, prospective, multi-center, large-sample epidemiological study done on pediatric AKI on aspects of epidemiological characteristics, causes and outcomes have not reported. It is necessary to develop prospective, multi-center, large-sample epidemiological study in our country on pediatric AKI. The aim of this study was to determine the clinical features, etiology, and outcomes of acute kidney injury (AKI) in Chinese children. METHOD: Paediatric patients (≤18 years old) admitted to 27 hospitals (14 children's hospitals and 13 general hospitals) affiliated with the Medical University were investigated. AKI was defined using the 2005 Acute Kidney Injury Network criteria. RESULTS: During the study period, 388,736 paediatric patients were admitted. From this total, AKI was diagnosed in 1,257 patients, 43 of whom died. The incidence and mortality of AKI was 0.32% and 3.4% respectively. The mean (± SD) age of patients was 48.4 ± 50.4 months. Among the 1,257 AKI paediatric patients, 632 were less than one year old. Among the AKI paediatric patients, 615 (48.9%) were in stage 1, 277 (22.0%) in stage 2, and 365 (29.0%) in stage 3. The most common causes of AKI were renal causes (57.52%), whereas postrenal (25.69%) and prerenal (14.96%) causes were the least common. The three most common causes of AKI according to individual etiological disease were urolithiasis (22.35%), of which exposure to melamine-contaminated milk accounted for the highest incidence (63.7%); acute glomerulonephritis (10.10%); and severe dehydration (7.48%). A total of 43 AKI patients (3.4%) died during their hospital stay; 15 (34.9%) of the 43 died as a result of sepsis. CONCLUSION: Primary renal diseases are a major risk factor for paediatric AKI in China. In terms of specific etiological disease, urolithiasis (postrenal disease) was the leading cause of paediatric AKI in 2008, when the disease was linked to exposure to melamine-contaminated milk. Sepsis is the leading cause of death in Chinese paediatric AKI patients. Future studies should focus on effective ways of controlling renal disorders and sepsis to improve the clinical management of paediatric AKI in China.

[Henoch Schonlein nephrites in children : clinical features and outcome : about 34 cases]. / La néphropathie du purpura rhumatoïde de l'enfant ; étude clinique et évolutive

AIM: To describe epidemiological, clinical, histological aspects, treatment and outcome of Henoch-Schönlein nephrits in children. METHODS: A retrospective study was conducted on medical data of 34 patients with Henoch-Schönlein nephritis From January 1, 1996 to December 31, 2010 in the Pediatric Department of Charles Nicolle Hospital. RESULTS: Nephritis occured in 68,7%. The average patient age was 7 years 2 months and sex ratio was 0,6. Microscopic hematuria was noted in 23,5%, moderate proteinuria with or without hematuria was observed in 20,5%. Nephrotic syndrome was noted in 29,5%; nephritic syndrome was associated to nephritic syndrome in 23,5%. Isolated hypertension was noted in one patient. Follow-up was 2 years 6 months. Remission was noted in 26 cases (76,4%) , minor urinary abnormalities in 7 cases (20,5%) and renal active disease in one case. Relapse was observed in 6 cases. CONCLUSION: Our study was characterized by the predominance of severe renal manifestations and low grade histological aspects as well as favourable outcome in most 90% of cases.

Clinical outcomes, when matched at presentation, do not vary between adult-onset Henöch-Schönlein purpura nephritis and IgA nephropathy.

Henöch-Schönlein purpura nephritis (HSPN) is considered a systemic form of immunoglobulin A nephropathy (IgAN). Although these are different pictures of a single disease, there are no studies directly comparing long-term outcomes of these two clinical entities. To clarify this, we studied 120 patients with biopsy-proven HSPN and 1070 patients with IgAN. The primary outcome was the composite of a doubling of baseline serum creatinine, end-stage renal disease, or death. Secondary outcomes included the individual renal outcomes or the rate of decline in estimated glomerular filtration rate. In the unmatched cohort, patients with HSPN had more vasculitic symptoms, more favorable histologic features, and were more commonly treated with steroids than patients with IgAN. The risk of reaching the primary outcome was significantly lower in HSPN patients than patients with IgAN (hazard ratio, 0.67). The 1:2 propensity score matching gave matched pairs of 89 patients with HSPN and 178 patients with IgAN, resulting in no differences in baseline conditions. In this matched cohort, there were no significant differences in reaching the primary and secondary outcomes between the two groups. Thus, after adjustment by propensity score matching, clinical outcomes did not differ between HSPN and IgAN, suggesting the two forms of the same disease have a similar prognosis.

Treatment of children with Henoch-Schönlein purpura nephritis with mycophenolate mofetil.

BACKGROUND: Henoch-Schönlein purpura (HSP) can progress to Henoch-Schönlein purpura nephritis (HSPN), and the most effective management remains unclear. Our aim was to evaluate the efficacy of mycophenolate mofetil (MMF) for treating pediatric patients with HSPN and nephrotic-range proteinuria. METHODS: Twelve children, seven boys and five girls, mean age 8.33 (range 6-12) years at the time of HSPN diagnosis with nephrotic-range proteinuria, were treated with MMF. All patients failed steroid treatment, and mean proteinuria at the time of MMF initiation was 5.6 g/d. MMF dosage ranged from 20 to 25 mg/kg per day. Patients also received an angiotensin-converting enzyme inhibitor (cliazapril) at MMF initiation. Mean follow-up was 3.9 (range 2.3-5.5) years. RESULTS: All patients responded to MMF at a mean of 2.5 (range 1-4 months). Among the 12 patients, MMF was administered for 10 months in five, 12 months in six, and 15 months in one. At last follow-up, all patients had negative proteinuria and normal renal function, and no relapses were noted. No serious adverse effects of MMF were noted in any patient. CONCLUSION: MMF is useful for treating pediatric patients with HSPN and nephrotic-range proteinuria.

Lectin and alternative complement pathway activation in cutaneous manifestations of IgA-vasculitis: A new target for therapy?

IgA-vasculitis is a systemic small-vessel leucocytoclastic vasculitis and is associated with a high morbidity. The disease can progress to IgA-vasculitis with nephritis (IgAVN) which can result in chronic renal failure. Complement activation is involved in the pathogenesis of IgA-vasculitis. A recent study has shown that cutaneous C3c deposition in IgA-vasculitis is associated with a higher risk to develop IgAVN. In the current study we investigated the different complement pathways that are activated in cutaneous IgA-vasculitis in order to reveal potential targets for intervention. In addition, we analyzed the association of complement factors with IgAVN and the clinical course of the disease. In this retrospective study, the clinicopathological features of 17 patients with IgA-vasculitis were compared with 25 non-IgA-vasculitis cases. Deposition of immunoglobulins and complement was analyzed by direct immunofluorescence for IgA, IgG, IgM, C1q, C4d, properdin, mannan-binding lectin (MBL), ficolin-2 (FCN2), MBL-associated serine protease 1/3 (MASP1/3), MASP2 and C3c. The vascular intensity and positive area was scored on a nominal scale and cumulative score was calculated by multiplying the intensity x area. Properdin was positive in 82% of IgA-vasculitis cases, reflecting alternative pathway activation. C4d was positive in 88% of IgA-vasculitis cases reflecting classical and/or lectin pathway activation, although only 12% of cases were positive for C1q. Lectin pathway activation was demonstrated by deposition of MBL (47%), MASP1/3 (53%) and MASP2 (6%) while FCN2 was found negative. Significantly more deposition of MASP1/3 was found in IgA-vasculitis versus non-IgA-vasculitis. This study demonstrates for the first time activation of lectin and alternative pathways in cutaneous manifestations of IgA-vasculitis. Hence, drugs that intervene in these complement pathways may be an interesting more targeted alternative to the current drugs, in reducing local cutaneous symptoms of the disease, with potentially less side-effects. No association was found between complement activation and IgAVN and/or response to therapy. Therefore, it is unlikely that intervention in complement activation will lead to a better clinical course of the disease.

Targeting endogenous kidney regeneration using anti-IL11 therapy in acute and chronic models of kidney disease.

The kidney has large regenerative capacity, but this is compromised when kidney damage is excessive and renal tubular epithelial cells (TECs) undergo SNAI1-driven growth arrest. Here we investigate the role of IL11 in TECs, kidney injury and renal repair. IL11 stimulation of TECs induces ERK- and p90RSK-mediated GSK3ß inactivation, SNAI1 upregulation and pro-inflammatory gene expression. Mice with acute kidney injury upregulate IL11 in TECs leading to SNAI1 expression and kidney dysfunction, which is not seen in Il11 deleted mice or in mice administered a neutralizing IL11 antibody in either preemptive or treatment modes. In acute kidney injury, anti-TGFß reduces renal fibrosis but exacerbates inflammation and tubule damage whereas anti-IL11 reduces all pathologies. Mice with TEC-specific deletion of Il11ra1 have reduced pathogenic signaling and are protected from renal injury-induced inflammation, fibrosis, and failure. In a model of chronic kidney disease, anti-IL11 therapy promotes TEC proliferation and parenchymal regeneration, reverses fibroinflammation and restores renal mass and function. These data highlight IL11-induced mesenchymal transition of injured TECs as an important renal pathology and suggest IL11 as a therapeutic target for restoring stalled endogenous regeneration in the diseased kidney.