Risk Factors for Renal Survival in Chinese Patients with Myeloperoxidase-ANCA-Associated GN

Low platelet count at diagnosis of anti-neutrophil cytoplasmic antibody-associated vasculitis is correlated with the severity of disease and renal prognosis

Antineutrophil cytoplasmic antibody-associated vasculitis (AAV) is an autoimmune disease that involves inflammation of blood vessels. There is increasing evidence that platelets play a crucial role not only in hemostasis but also in inflammation and innate immunity. In this study, we explored the relationship between platelet count, clinical characteristics, and the prognosis of patients with AAV. We divided 187 patients into two groups based on their platelet count. Clinicopathological data and prognostic information were retrospectively gathered from medical records. Univariate and multivariate regression analyses were used to identify risk factors for prognosis, including end-stage renal disease (ESRD) and mortality. The cutoff point for platelet count was set at 264.5 × 109/L, as determined by the receiver operating characteristic (ROC) curve for predicting progression to ESRD in patients with AAV. We observed patients with low platelet count (platelets < 264.5 × 109/L) had lower leukocytes, hemoglobin, complement, acute reactants, and worse renal function (P for eGFR < 0.001). They were also more likely to progress to ESRD or death compared to the high platelet count group (platelets > 264.5 × 109/L) (P < 0.0001, P = 0.0338, respectively). Low platelet count was potentially an independent predictor of poor renal prognosis in the multivariate regression analysis [HR 1.670 (95% CI 1.019-2.515), P = 0.014]. Lower platelet count at diagnosis is associated with more severe clinical characteristics and impaired renal function. Therefore, platelet count may be an accessible prognostic indicator for renal outcomes in patients with AAV.

Clinical features and prognosis of ANCA-associated vasculitis patients who were double-seropositive for myeloperoxidase-ANCA and proteinase 3-ANCA

Anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) patients with dual positivity for proteinase 3-ANCA (PR3-ANCA) and myeloperoxidase-ANCA (MPO-ANCA) are uncommon. We aimed to investigate these idiopathic double-positive AAV patients' clinical features, histological characteristics, and prognosis. We reviewed all the electronic medical records of patients diagnosed with AAV to obtain clinical data and renal histological information from January 2010 to December 2020 in a large center in China. Patients were assigned to the MPO-AAV group or PR3-AAV group or idiopathic double-positive AAV group by ANCA specificity. We explored features of idiopathic double-positive AAV. Of the 340 patients who fulfilled the study inclusion criteria, 159 (46.76%) were female, with a mean age of 58.41 years at the time of AAV diagnosis. Similar to MPO-AAV, idiopathic double-positive AAV patients were older and had more severe anemia, lower Birmingham Vasculitis Activity Score (BVAS) and C-reactive protein (CRP) levels, less ear, nose, and throat (ENT) involvement, higher initial serum creatinine and a lower estimated glomerular filtration rate (eGFR) when compared with PR3-AAV (P < 0.05). The proportion of normal glomeruli of idiopathic double-positive AAV was the lowest among the three groups (P < 0.05). The idiopathic double-positive AAV patients had the worst remission rate (58.8%) among the three groups (P < 0.05). The relapse rate of double-positive AAV (40.0%) was comparable with PR3-AAV (44.8%) (P > 0.05). Although there was a trend toward a higher relapse rate of idiopathic double-positive AAV (40.0%) compared with MPO-AAV (23.5%), this did not reach statistical significance (P > 0.05). The proportion of patients who progressed to ESRD was 47.1% and 44.4% in the idiopathic double-positive AAV group and MPO-AAV group respectively, without statistical significance. Long-term patient survival also varied among the three groups (P < 0.05). Idiopathic double-positive AAV is a rare clinical entity with hybrid features of MPO-AAV and PR3-AAV. MPO-AAV is the "dominant" phenotype in idiopathic double-positive AAV.

Impact of different ANCA serotypes on the long-term outcome of ANCA-associated vasculitis patients

OBJECTIVES

To investigate the clinical features and long-term outcomes of Chinese anti-neutrophil cytoplasmic antibodies (ANCAs)-associated vasculitis (AAV) patients with different ANCA serotypes.

METHODS

Two hundred and twenty-four AAV patients from January 2010 to June 2021 were divided into myeloperoxidase (MPO)-ANCA and proteinase 3 (PR3)-ANCA groups. Clinical and long-term outcomes were compared.

RESULTS

In this study, the average follow-up was 46.4 months (range 0.3-188.4 months). One hundred and seventy-seven (79.0%) patients were MPO-ANCA-positive and 47 were PR3-ANCA-positive; the mean age of MPO-ANCA positive patients at diagnosis was elder than that of PR3-ANCA positive patients (67.0 vs. 60.0 years, p = .004). Among PR3-ANCA-positive patients, ear, nose and throat symptoms were more common (p = .014). Between two ANCA serotypes, there were no differences in complement 3 (C3), Birmingham vasculitis activity score (BVAS), five-factor score (FFS) or other organ involvements. For all AAV patients, the overall survival rates at one, three and five years were 80.0%, 67.0% and 56.4%, respectively. The cumulative relapse-free rates of one, three and five years were 89.5%, 76.4% and 68.4%, respectively. The survival of AAV patients was unaffected by the ANCA serotype (p = .23). The ANCA serotype also had no effect on either disease relapse (p = .20) or remission rates (p = .10). In our study, PR3-ANCA patients showed a better long-term survival, as the 5-year survival rate and the 5-year relapse-free survival rate of PR3-ANCA patients were 60.7% and 76.9%, while that of MPO-ANCA patients were 55.2% and 65.8%, respectively. Rather than ANCA serotype, younger patients with milder kidney involvement and lower disease assessment scores (BVAS and FFS) might be more relevant to better prognosis.

CONCLUSIONS

The likelihood of induced remission, patient survival or disease recurrence is all unaffected by ANCA serotypes. A better prognosis is seen in younger patients with milder kidney involvement and lower BVAS/FFS scores.

Serum Complement C4 Levels Are a Useful Biomarker for Predicting End-Stage Renal Disease in Microscopic Polyangiitis

This study aimed to evaluate the risk factors for end-stage renal disease (ESRD) in microscopic polyangiitis (MPA). In total, 74 patients with MPA were enrolled, and we compared the baseline clinical characteristics and disease activity between MPA patients who have progressed to ESRD and those without ESRD to select predictive factors for ESRD. Out of 74 patients, 12 patients (16.2%) had ESRD during follow-up. Serum C4 levels were significantly higher in MPA patients who have progressed to ESRD than in those without ESRD (p = 0.009). Multivariate analyses revealed that high serum creatinine levels (odds ratio (OR) 4.4, 95% confidence interval (CI) 1.25-15.5) and high serum C4 levels (OR 1.24, 95% CI 1.03-1.49) were risk factors for ESRD. Using receiver operating characteristic analysis, the cut-off value for initial serum C4 levels and serum creatinine levels were 29.6 mg/dL and 3.54 mg/dL, respectively. Patients with MPA with a greater number of risk factors (serum C4 levels > 29.6 mg/dL and serum creatinine levels > 3.54 mg/dL) had a higher ESRD progression rate. Serum C4 levels were significantly positively correlated with serum creatinine levels and kidney Birmingham vasculitis activity score (p = 0.02 and 0.04, respectively). These results suggest that serum C4 levels are useful tools for assessing renal disease activity and prognosis in MPA.

CD8 T Cell-Derived Exosomal miR-186-5p Elicits Renal Inflammation via Activating Tubular TLR7/8 Signal Axis

T cells play an important role in the development of focal segmental glomerulosclerosis (FSGS). The mechanism underlying such T cell-based kidney disease, however, remains elusive. Here the authors report that activated CD8 T cells elicit renal inflammation and tissue injury via releasing miR-186-5p-enriched exosomes. Continuing the cohort study identifying the correlation of plasma level of miR-186-5p with proteinuria in FSGS patients, it is demonstrated that circulating miR-186-5p is mainly derived from activated CD8 T cell exosomes. Renal miR-186-5p, which is markedly increased in FSGS patients and mice with adriamycin-induced renal injury, is mainly delivered by CD8 T cell exosomes. Depleting miR-186-5p strongly attenuates adriamycin-induced mouse renal injury. Supporting the function of exosomal miR-186-5p as a key circulating pathogenic factor, intravenous injection of miR-186-5p or miR-186-5p-containing T cell exosomes results in mouse renal inflammation and tissue injury. Tracing the injected T cell exosomes shows their preferential distribution in mouse renal tubules, not glomerulus. Mechanistically, miR-186-5p directly activates renal tubular TLR7/8 signal and initiates tubular cell apoptosis. Mutating the TLR7-binding sequence on miR-186-5p or deleting mouse TLR7 largely abolishes renal tubular injuries induced by miR-186-5p or adriamycin. These findings reveal a causative role of exosomal miR-186-5p in T cell-mediated renal dysfunction.

Outcomes and risk factors in patients with crescentic glomerulonephritis: a multicenter cohort study

BACKGROUND

Patients with crescentic glomerulonephritis have a poor prognosis despite immunosuppressive therapy. This study investigated the clinicopathologic features, outcomes, and risk factors in Chinese patients with crescentic glomerulonephritis.

METHODS

The multicenter cohort study included consecutive individuals with crescentic glomerulonephritis and a minimum follow-up of 1 year after biopsy, observed from January 2013 to December 2020. Primary outcome was the occurrence of death or end stage kidney disease (ESKD) for surviving patients. Multivariable adjusted Cox proportional hazards model was applied.

RESULTS

Of 109 patients enrolled, 73 (67%) suffered primary outcomes, including 39 deaths, and 34 ESKDs among the 70 surviving patients, with a mean follow-up of 26 months. All 26 patients with over 90% glomeruli with crescents reached a primary outcome. Patients with type III crescentic glomerulonephritis had the worst prognosis for primary outcomes (HR, 95% CI for type I vs. type III: 0.29, 0.14-0.58; type II vs. type III: 0.44, 0.22-0.91) and a significantly faster rate of eGFR decline after adjusting for baseline variables. In patients with 75%-100% glomeruli with crescents, the risk of a primary outcome increased nearly fourfold (HR 3.96; 95% CI 2.17-7.23) compared with patients with 50-75% glomeruli with crescents after adjusting for baseline variables. Type of crescentic glomerulonephritis and percentage of cellular and total glomeruli with crescents were independent risk factors for early primary outcomes (within 6 months).

CONCLUSIONS

This study provides new insights into crescentic glomerulonephritis, including a description of the worst outcomes occurring in patients with type III crescentic glomerulonephritis, and suggests that the quantification of the percentage of crescents may be of use for guiding therapeutic decisions, due to their role in identifying the risk of primary outcomes.

Meta-Analytical Accuracy of ANCA Renal Risk Score for Prediction of Renal Outcome in Patients With ANCA-Associated Glomerulonephritis

Background: To evaluate the diagnostic accuracy of antineutrophil cytoplasmic antibody (ANCA) renal risk score (ARRS) for prediction of renal outcome in patients with ANCA-associated glomerulonephritis (ANCA-GN).

Methods: We searched PubMed, EMBASE, Ovid, Web of Science, the Cochrane Library, and ClinicalTrials.gov for studies, which used ARRS to predict end-stage renal disease (ESRD) in patients with ANCA-GN. Two reviewers independently screened articles for inclusion, assessed the quality of studies with both an adapted Quality Assessment of Diagnostic Accuracy Studies 2 (QUADAS-2) tool. We calculated the combined patients with ESRD in the ARRS categories and presented the summary and individual estimates based on the ARRS categories. Then, the sensitivity, specificity, diagnostic odds ratio (DOR), positive/negative likelihood ratio, and the area under the receiver operating characteristic (AUROC) curves of the pooled data for ARRS were used to assess the accuracy of the “above the low-risk threshold” (ARRS ≥ 2) and “high-risk grade” (ARRS ≥ 8) for renal outcome of patients with ANCA-GN. The hierarchical summary ROC (HSROC) was used to verify the accuracy value. The clinical utility of ARRS was evaluated by the Fagan plot. Heterogeneity was explored using meta-regression and subgroup analysis.

Results: A total of 12 distinct cohorts from 11 articles involving 1,568 patients with ANCA-GN were analyzed. The cumulative patients with ESRD at the maximum follow-up of 60 months was 5% (95% CI: 0.02–0.07; p < 0.001) for ANCA-GN with low ARRS (0–1 points) and significantly increased to 22% (95% CI: 0.15–0.29; p < 0.001) medium ARRS (2–7 points). The combined cumulative patients with ESRD was 59% (95% CI: 0.49–0.69; p < 0.001) high ARRS (8–11 points). The pooled sensitivity of ARRS ≥ 2 in predicting ESRD was 98% with a specificity of 30% and a DOR of 15.08 and the mean AUROC value was 0.82. The pooled sensitivity of ARRS ≥ 8 in predicting ESRD was 58% with a specificity of 86% and a DOR of 7.59. The meta-regression and subgroup analysis indicated that variation in the geographic regions, study design, index risk, follow-up time, age of patient, publication year, and number of patient could be the potential sources of heterogeneity in the diagnosis of ARRS ≥ 8.

Conclusion: This meta-analysis emphasized the good performance of the ARRS score in predicting the renal outcome in patients with ANCA-GN. However, these findings should be verified by future large-scale prospective studies.

Risikostratifizierung bei ANCA-assoziierten Vaskulitiden

ANCA-assoziierte Vaskulitiden (AAV) sind nekrotisierende Vaskulitiden der kleinen bis mittelgroßen Gefäße, welche die Granulomatose mit Polyangiitis (GPA), die mikroskopische Polyangiitis (MPA) und die Eosinophile Granulomatose mit Polyangiitis (EGPA) umfassen. AAV gehen häufig mit Organfunktion-bedrohenden Manifestationen und einer entsprechend erhöhten Mortalität einher. Für die Planung von Diagnostik, Therapie und Langzeitbetreuung ist daher eine Risikostratifizierung im Hinblick auf Mortalität, Entwicklung schwerer Organinsuffizienzen, insbesondere einer terminalen Niereninsuffizienz, mögliche Therapieresistenz, Rezidive, Infektionen und Malignome erforderlich. Wichtige Risikofaktoren für erhöhte Mortalität und/oder terminale Niereninsuffizienz sind neben der renalen Beteiligung per se eine bereits zum Zeitpunkt der Diagnose deutlich eingeschränkte renale Funktion einschliesslich initialer Dialysepflichtigkeit, eine hohe initiale Aktivität der AAV gemessen am Birmingham Vaskulitis Activity Score, aber auch kardiale und gastrointestinale Manifestationen, Infektionen, Anämie sowie ein Alter von>65 Jahren. Histologisch ist der Nachweis chronischer irreversibler glomerulärer und tubulärer Läsionen in der Nierenbiopsie mit einer schlechten Prognose im Hinblick auf die Nierenfunktion assoziiert. Basierend auf der histopathologischen Klassifikation der ANCA-assoziierten Glomerulonephritis (GN) ist der Befund einer sklerosierenden GN mit einer besonders ungünstigen Prognose assoziiert, während die fokale GN sehr selten zur terminalen Niereninsuffizienz führt. MPO-ANCA zeigen eine Assoziation mit chronischen Läsionen in der Nierenbiopsie sowie erhöhter Mortalität und erhöhtem Risiko für terminale Niereninsuffizienz. Im Hinblick auf die pulmonale Beteiligung sind alveoläre Hämorrhagie und interstitielle Lungenerkrankung mit einer erhöhten Mortalität assoziiert. Bei EGPA wird die Prognose entscheidend durch die Kardiomyopathie bestimmt. Risikofaktoren für Rezidive weichen erheblich von denen für Mortalität und terminale Niereninsuffizienz ab. Ein erhöhtes Rezidivrisiko besteht bei Nachweis von PR3-ANCA, GPA und pulmonaler Beteiligung. Auch bei granulomatösen Läsionen, Beteiligung des oberen Respirationstraktes und kardiovaskulären Manifestationen wird ein erhöhtes Rezidivrisiko beschrieben. Im Gegensatz zur Assoziation einer initial schlechten Nierenfunktion mit Mortalität und terminaler Niereninsuffizienz, wurde für Patienten mit initial guter Nierenfunktion ein erhöhtes Rezidivrisiko gezeigt. Weitere Risikofaktoren für Rezidive sind Staphylokokken-Besiedelung der Nase, frühere Rezidive und ANCA-Positivität nach Remissionsinduktion. Titeranstieg oder Wiederauftreten von ANCA zeigen nur eine moderate Beziehung zum Rezidivrisiko. Der prädiktive Wert für Rezidive ist offenbar bei bestimmten Subgruppen, wie bei Patienten mit renaler Beteiligung und pulmonaler Hämorrhagie sowie bei mit Rituximab-behandelten Patienten besser als bei Patienten mit granulomatösen Manifestationen. Daher ist eine Therapieentscheidung allein auf Basis der Entwicklung der ANCA-Titer nicht möglich. Risikofaktoren für schwere Infektionen sind höher dosierte und prolongierte Glukokortikoidtherapie, Leuko- und Lymphopenie, höheres Lebenalter, Niereninsuffizienz und pulmonale Beteiligung. Die Malignomrate insbesondere für Nicht-Melanom-Hauttumoren, Harnblasenkarzinome und Leukämie ist bei AAV erhöht und zeigt eine Assoziation mit hohen kumulativen Cyclophosphamiddosen. Da insbesondere frühzeitige irreversible Organschäden die Prognose bestimmen und Rezidive die Entwicklung irreversibler Schäden treiben, sind frühestmögliche Diagnose und Therapie sowie rasches Erkennen und Vermeiden von Rezidiven essentiell für die Risikominimierung.

Glomerular Immune Deposition in MPO-ANCA Associated Glomerulonephritis Is Associated With Poor Renal Survival

Background

Rapidly progressive glomerulonephritis caused by antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) is typically characterized as pauci-immune glomerulonephritis. However, immune complex (IC) deposition in the glomerulus has been reported in a growing number of studies. Here, we assess the presence of glomerular immune deposits alongside renal outcome in myeloperoxidase (MPO)-ANCA associated glomerulonephritis (MPO-ANCA GN).

Methods

Clinical and histopathologic characteristics of 97 patients with MPO-ANCA GN classified by renal biopsy from January 2008 to December 2019 were extracted retrospectively from electronic medical records. The extent of immune deposits in the kidney (C3, C4, C1q, IgA, IgG, IgM) at diagnosis were analyzed by immunofluorescence (IF). Patients were followed up for a median period of 15 months. The response to treatment and outcomes of renal and histological lesion changes were also assessed.

Results

In our study, 41% (40/97) of patients showed positive IF (≥2+) for at least one of the six immunoglobulin or complement components tested. Patients with IC deposits showed higher levels of serum creatinine (p=0.025), lower platelet counts (p=0.009), lower serum complement C3 (sC3) (≤790 ml/L) (p=0.013) and serum IgG (p=0.018) than patients with pauci-immune (PI) deposition at diagnosis. End-stage renal disease was negatively associated with eGFR (HR 0.885, 95% CI 0.837 to 0.935, p<0.0001), platelet count (HR 0.996, 95% CI 0.992 to 1.000, p=0.046) and serum globulin (HR 0.905, 95% CI 0.854 to 0.959, p=0.001). Patients with lower sC3 levels showed a worse renal outcome than the patients with normal sC3 at diagnosis (p=0.003). Analysis of the components of the renal deposits found that patients with IgG deposits exhibited a poorer renal outcome compared to patients that were IgG negative (p=0.028). Moreover, Bowman’s capsule rupture occurred less frequently in patients with IgM deposition compared with IgM negative counterparts (p=0.028). Vascular lesions and granuloma-like lesions had been seen more frequently in cases with IgA deposition than those without IgA deposition (p=0.03 and 0.015, respectively).

Conclusion

In conclusion, patients with immune complex deposits in the kidney showed less platelet count, lower sC3 and sIgG levels, and higher serum creatinine levels. Patients with low sC3 at initial and with continued low sC3 during the treatment displayed a trend toward poorer kidney survival. Moreover, the IC group showed a worse renal outcome than the PI group, further enforcing the present strategy of introducing complement targeted therapies in AAV.

Outcome Predictors of Biopsy-Proven Myeloperoxidase-Anti-Neutrophil Cytoplasmic Antibody-Associated Glomerulonephritis

Objective

To determine the prognostic values of histopathologic classification of myeloperoxidase-anti-neutrophil cytoplasmic antibody (ANCA)-associated glomerulonephritis and other clinical and laboratory features at the time of presentation on renal and patient survival associated with myeloperoxidase-ANCA-associated glomerulonephritis (MPO-ANCA-GN).

Methods

A total of 112 patients diagnosed with MPO-ANCA-GN from October 2005 to December 2018 were enrolled. The baseline clinical characteristics, renal histopathological data, and risk factors predictive of renal and patient survival were retrospectively analyzed.

Results

All 112 patients underwent renal biopsy. Disease in 32 patients was classified as focal, 26 as mixed, 29 as crescentic, and 25 as sclerotic. Over a median follow-up period of 41.5 months, there were 44 patients dialysis-dependent. The renal survival rate was significantly higher in the focal group than the other groups (p < 0.001) and significantly lower in the sclerotic group (p < 0.05). In addition, disease histopathologically classified as sclerotic (p = 0.044), high serum creatinine level (≥320 μmol/L, p < 0.001), low albumin (<30 g/L, p = 0.024) and hemoglobin level (<90 g/L, p = 0.044) were associated with a greater risk of ESRD. After follow-up, 70 (62.5%) of 112 patients survived. Old age (≥60 years, p = 0.018) and low serum albumin (<30 g/L, p = 0.006) was significant risk factor for patient survival.

Conclusion

Among patients with MPO-ANCA-GN, those with poor renal function, disease histopathologically classified as sclerotic, and lower albumin and hemoglobin levels were risk factors for ESRD, while older age and low serum albumin level were associated with a greater risk for all-cause mortality.

Developments in the Histopathological Classification of ANCA-Associated Glomerulonephritis

BACKGROUND AND OBJECTIVES

The histopathologic classification for ANCA-associated GN distinguishes four classes on the basis of patterns of injury. In the original validation study, these classes were ordered by severity of kidney function loss as follows: focal, crescentic, mixed, and sclerotic. Subsequent validation studies disagreed on outcomes in the crescentic and mixed classes. This study, driven by the original investigators, provides several analyses in order to determine the current position of the histopathologic classification of ANCA-associated GN.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

A validation study was performed with newly collected data from 145 patients from ten centers worldwide, including an analysis of interobserver agreement on the histopathologic evaluation of the kidney biopsies. This study also included a meta-analysis on previous validation studies and a validation of the recently proposed ANCA kidney risk score.

RESULTS

The validation study showed that kidney failure at 10-year follow-up was significantly different between the histopathologic classes (P<0.001). Kidney failure at 10-year follow-up was 14% in the crescentic class versus 20% in the mixed class (P=0.98). In the meta-analysis, no significant difference in kidney failure was also observed when crescentic class was compared with mixed class (relative risk, 1.15; 95% confidence interval, 0.94 to 1.41). When we applied the ANCA kidney risk score to our cohort, kidney survival at 3 years was 100%, 96%, and 77% in the low-, medium-, and high-risk groups, respectively (P<0.001). These survival percentages are higher compared with the percentages in the original study.

CONCLUSIONS

The crescentic and mixed classes seem to have a similar prognosis, also after adjusting for differences in patient populations, treatment, and interobserver agreement. However, at this stage, we are not inclined to merge the crescentic and mixed classes because the reported confidence intervals do not exclude important differences in prognosis and because an important histopathologic distinction would be lost.

Validation of a renal risk score in a cohort of ANCA-associated vasculitis patients with severe kidney damage

OBJECTIVE

To validate the renal risk score in a cohort of patients with advanced kidney damage.

METHODS

A total of 72 patients with biopsy-proven ANCA glomerulonephritis with >12 months of follow-up were studied. The renal risk score was calculated and evaluated by survival analysis for time of renal survival. Cohort-specific clinical, histopathologic, and post-treatment factors associated with renal survival were determined by Cox regression analysis.

RESULTS

Kidney biopsies were classified as focal, crescentic, mixed, and sclerotic classes in 6 (8%), 4 (6%), 25 (35%), and 37 (51%) patients, respectively. The 1-, 3-, and 5-year renal survival rates were 79%, 73%, and 68%, respectively. Patients were segregated by the risk score in low- (18%), medium- (47%), and high-risk (35%) groups. Patients in the low-risk group had 36-, 60-, and 84-month renal survival of 100%; those in the medium risk 85% (95% CI 72-92), 81% (95% CI 66-95), and 76% (95% CI 60-92), respectively; and those in the high risk 37% (95% CI 17-57), 26% (95% CI 7-45), and 18% (95% CI 1-36), respectively. Six (43%) of the 14 patients in the high-risk group recovered renal function after the initial episode, and 2 (14%) remained dialysis-free. Other parameters associated with renal survival included age, proteinuria, general symptoms, cellular crescents, glomerulosclerosis, tubulointerstitial lesions, best post-treatment eGFR, and renal relapses.

CONCLUSIONS

We validated the renal risk score as a prognostic tool in a cohort with predominantly mixed and sclerotic histologic categories. Since patients in the high-risk group still benefited from immunosuppressive therapy, this score should be used in conjunction with other predictive parameters to aid therapeutic decisions.Key Points• The ANCA renal risk score is validated in a cohort with advanced kidney damage.• Patients in the high-risk group still benefited from immunosuppressive therapy.• Parameters not included in the risk score are associated with renal survival and may be useful.

Management of End-stage Renal Disease Associated with Systemic Rheumatic Diseases

The outcomes of rheumatic diseases (RDs) have improved over the past decades. However, a significant proportion of the patients still suffer from end-stage renal disease (ESRD) and have to bear the burden of hemodialysis. It is crucial to prevent patients with RDs from developing ESRD from viewpoints of medicine and medical economics. For those who already have ESRD, it is important to improve vial prognosis and quality of life through appropriate management of disease activity and comorbidities related to ESRD. Thus, rheumatologists and nephrologists need to recognize risk factors associated with progression to ESRD along with their appropriate management. Although the activity of most RDs tends to decrease after initiation of hemodialysis, disease activity may still increase, and recognizing how to appropriately use immunosuppressive agents even after the development of ESRD is crucial. The treatment of RDs needs extra attention as hydroxychloroquine requires more frequent monitoring for adverse drug reactions; therapeutic drug monitoring is necessary for mycophenolate mofetil, cyclosporine A, and tacrolimus; cyclophosphamide and azathioprine need dose adjustments; methotrexate and bucillamine are contraindicated in patients with ESRD; leflunomide and sulfasalazine do not require significant dose reduction and iguratimod should be carefully administered. The pharmacokinetics of biological agents such as rituximab or belimumab are not affected by ESRD, and dose adjustments are not necessary. Collaboration between rheumatologists and nephrologists is needed more than ever and is expected to produce a complementary effect and achieve better outcomes in clinical settings, although this cooperation has not always been conducted appropriately.

Epidemiology and clinical features of childhood-onset anti-neutrophil cytoplasmic antibody-associated vasculitis: a clinicopathological analysis

BACKGROUND

This study was performed to determine the clinical features and outcomes of childhood-onset anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV), particularly microscopic polyangiitis (MPA).

METHODS

A retrospective Japanese multicenter study was performed in patients diagnosed with AAV before 16 years of age.

RESULTS

Of 49 patients with AAV, 36 were female. The diagnoses were as follows: MPA (n = 38, 78%), granulomatosis with polyangiitis (GPA; n = 9, 18%), eosinophilic granulomatosis with polyangiitis (EGPA; n = 1, 2%), and other (n = 1, 2%). The median age at onset was 10.7 years, and median time to diagnosis was 2.0 months. Twenty-seven (55%) patients were identified through a school urinary screening program. Initial symptoms included fever and fatigue (45%), and renal (71%), pulmonary (29%), ocular (20%), and mucocutaneous involvement (22%). Although 27 (55%) patients achieved remission and none had died at the last follow-up, at least one recurrence occurred in 13 (48%) patients after a median of 48 months and was more common in patients with GPA (P < 0.01). After a median follow-up of 43 months, seven (14%) patients (all with MPA) progressed to end-stage renal disease (ESRD).

CONCLUSIONS

Childhood-onset AAV has an estimated prevalence of 3.41-4.28 per million children and is characterized by female predominance and high frequency of detection in school urinary screening programs. More than 10% of patients with childhood-onset AAV still progress to ESRD without achieving remission. Histological chronicity is a factor associated with ESRD.

Pathological severity determines the renal recovery for anti-myeloperoxidase antibody-associated vasculitis requiring dialysis at disease onset: a retrospective study

Background

Many patients with anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) need dialysis at disease onset due to severe kidney injury. Determining whether they can become dialysis independent is an important clinical assessment.

Methods

Forty kidney biopsy-proved myeloperoxidase (MPO)-ANCA associated AAV patients who required dialysis at disease onset were enrolled. Relationships between laboratory and pathological characteristics and prognoses were analyzed.

Results

Twenty-five patients obtained dialysis independence within 3 months, while the other 15 patients remained dialysis dependent. No sclerotic class was identified among the 40 patients. Only two biopsies exhibited focal class diagnoses and both these patients recovered their renal function. The renal recovery rate of the 20 patients with mixed class was significantly lower than that of the 18 patients with crescentic class (40.0% vs. 83.3%, p = 0.006). Receiver operating characteristics (ROC) curves showed fibrous crescent+global glomerulosclerosis greater than 32.6% was a strong predictor of dialysis dependence with a sensitivity of 93.3% and specificity of 88.0%. When the percentage of fibrous crescent+global glomerulosclerosis exceeded 47.9%, dialysis independence was not possible. Correlation analysis indicated that platelet counts were negatively correlated with the percentage of fibrous crescent+global glomerulosclerosis (R = -0.448, p = 0.004). Most patients with increased platelets (84.62%) obtained renal recovery. Compared with methylprednisolone pulse therapy, plasma exchange accelerated renal recovery (29.4 ± 15.6 vs. 41.4 ± 11.7 days, p = 0.039).

Conclusions

For MPO-ANCA AAV who required dialysis at disease onset, crescentic and mixed classes accounted for the majority of patients in our cohort. The renal outcome of mixed class patients was worse than that of crescentic class. A high proportion of fibrous crescent+global glomerulosclerosis is a predictor of dialysis dependence. Increased platelet count is associated with active and reversible renal lesions.

Urinary Fibrinogen as a Predictor of Progression of CKD

BACKGROUND AND OBJECTIVES

Fibrinogen has been reported to be involved in kidney tubulointerstitial fibrosis and podocyte injury in mouse models. However, the relationship between urinary fibrinogen and kidney outcomes has not been clarified in patients with CKD.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

We evaluated 402 patients with CKD and kidney biopsies, including 101 with diabetic nephropathy, 94 with idiopathic membranous nephropathy, 55 with idiopathic FSGS, and 152 with IgA nephropathy. We quantified urinary fibrinogen by ELISA and tested associations with kidney histology and progression to ESRD.

RESULTS

Median (interquartile range) urinary fibrinogen-to-creatinine ratio was 536 (191-1461) ng/mg for patients with CKD, significantly higher than 2 (2-3) ng/mg for healthy controls (P<0.001). Urinary fibrinogen was positively correlated with urine protein (r=0.64; P<0.001) and interstitial fibrosis and tubular atrophy (r=0.10; P=0.04), and it was negatively correlated with eGFR (r=-0.20; P<0.001). Over a median follow-up period of 35 months (interquartile range, 24-78 months), 68 of 402 patients (17%) developed ESRD. Higher urinary fibrinogen level was associated with increased risk of ESRD (hazard ratio, 2.12; 95% confidence interval, 1.31 to 3.26) per log10 higher urinary fibrinogen-to-creatinine ratio (P=0.003) adjusting for age, sex, BP, urine protein, disease type, eGFR, and interstitial fibrosis and tubular atrophy. For prediction of ESRD, the addition of urinary fibrinogen to eGFR, urine protein, and BP increased the area under the receiver operating curve from 0.73 to 0.76, and the Akaike information criterion improved from 333.6 to 327.0.

CONCLUSIONS

Urinary fibrinogen correlated with interstitial fibrosis and tubular atrophy and was an independent risk factor for progression of CKD to ESRD.

C3 deposits worsens the prognosis in type iii extracapillary glomerulonephritis

INTRODUCTION

Type iii extracapillary glomerulonephritis (PEGN) is a common cause of rapidly progressive glomerulonephritis and it is usually associated with circulating anti-neutrophil cytoplasmic antibodies (ANCAs). Recent evidence points to complement activation as an important factor in the pathogenesis of PEGN. The aim of the present study was to assess the value of C3 deposits in the prognosis of PEGN.

METHODS

All patients diagnosed of PEGN from 1995 to 2015 (n=72) were included in this study. Progression of renal disease in patients with positive staining for C3 by immunofluorescence was compared with those with negative staining. Mean follow up was 73 months. Progression to end-stage renal disease in relation to clinical and histological variables was analyzed.

RESULTS

Positive staining for C3 was observed in 22 out of the 72 patients (30.5%). At the time of diagnosis, patients with C3 deposits had higher serum creatinine concentration than those without C3 staining (5.00 vs. 3.85mg/dl, P=0.050). Renal survival at 10 years was 36.9% in patients with positive C3 staining vs. 64.4% in patients with negative staining (P=0.005). Mortality at 10 years was higher in patients with C3 deposits than in patients without deposits (77 vs. 49.3%).

CONCLUSIONS

Thus, our study shows that PEGN with deposits of C3 is associated with worse renal prognosis and greater mortality. These results would support the hypothesis that activation of the alternative pathway complement may play an important role in the generation of renal injury associated with PEGN.

ANCA and IgA glomerulonephritis all in one: prognosis and complications

We present the case of a 75-year-old Hispanic woman with known stage 3 chronic kidney disease, long-standing hypertension and type 2 diabetes mellitus who presented with right-sided abdominal pain and acute kidney injury, nephrotic range proteinuria with positive antimyeloperoxidase antibody. A renal biopsy revealed IgA nephropathy with superimposed pauci-immune antineutrophilic cytoplasmic antibody (ANCA)-associated crescentic glomerulonephritis. The patient was treated with pulse intravenous methylprednisolone, cyclophosphamide and plasmapheresis. One week after her second dose of cyclophosphamide, she was readmitted for infectious complications including influenza A respiratory infection, Rothia bacteraemia associated with diarrhoea and herpes zoster of the trunk. In this report, we review the prevalence, treatment and prognosis of coexistent IgA nephropathy and pauci-immune ANCA-associated crescentic glomerulonephritis. We propose that a reduced-dose treatment regimen should be considered in elderly patients due to their higher risk of infectious complications. Current literature suggests that this treatment approach may reduce infectious complications without compromising therapeutic efficacy.