Antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) is a group of systemic vasculitides, that are characterized by inflammation in the small vessels, ranging from capillaries to arterioles or venules. AAV is divided into three variants based on the clinical manifestations and histological findings such as microscopic polyangiitis (MPA), granulomatosis with polyangiitis (GPA) and eosinophilic GPA (EGPA). MPA often induces rapid progressive necrotising glomerulonephritis, and occasionally induces diffuse alveolar hemorrhage. In contrast, GPA preferentially affects the respiratory tracts from the bronchus to the nasal cavity. GPA can also involve the kidneys, but the frequency of renal involvement is less than MPA. EGPA is based on allergic components such as asthma, peripheral eosinophilia, migratory eosinophilic pneumonia and eosinophil infiltration. Since 1982, when the association between ANCA and systemic vasculitis was first reported, several classification criteria for AAV have been proposed. This review describes the classification criteria for and nomenclature of AAV from the 1990 American College of Rheumatology (ACR) classification criteria to the 2012 revised Chapel Hill consensus conference (CHCC) nomenclature of Vasculitides. New classification trials for AAV such as AAV based on the ANCA-types (myeloperoxidase-ANCA vasculitis, proteinase 3-ANCA vasculitis and ANCA negative vasculitis) and the ACR/European League Against Rheumatism (EULAR) 2017 provisional classification criteria for GPA were also introduced. In addition, the histopathological classification of ANCA-associated glomerulonephritis and the revised 2017 international consensus on testing of ANCAs in GPA and MPA are also discussed.
Antibodies, Antineutrophil Cytoplasmic ; Arterioles ; Asthma ; Bronchi ; Capillaries ; Classification ; Consensus ; Cytoplasm ; Eosinophilia ; Eosinophils ; Glomerulonephritis ; Granulomatosis with Polyangiitis ; Hemorrhage ; Inflammation ; Kidney ; Microscopic Polyangiitis ; Nasal Cavity ; Pulmonary Eosinophilia ; Respiratory System ; Rheumatic Diseases ; Rheumatology ; Systemic Vasculitis ; Vasculitis ; Venules

BACKGROUND/AIMS: The Oxford classification of immunoglobulin A nephropathy (IgAN) is a pathology-based prognostic classification system. However, further study is needed to determine its validity. We studied the relationships between the Oxford classification and established prognostic factors and renal survival. We also examined associations between electron microscopy findings and these parameters. METHODS: We reviewed and reclassified 213 patients who were diagnosed with IgAN from 1997 to 2007 using the Oxford and World Health Organization (WHO) classification systems. The patients were also categorized by a pathologist using electron microscopy findings, including foot process fusion, glomerular basement membrane thickness, and electron-dense deposits. We examined the correlations between light and electron microscopy data and known prognostic factors (e.g., age, sex, proteinuria, serum creatinine, estimated glomerular filtration rate [eGFR], and blood pressure). The same procedure was applied to renal survival. RESULTS: Patient age increased with the grades of segmental sclerosis (S) and tubular atrophy/interstitial fibrosis (T) (P < 0.05). eGFR decreased significantly with increasing mesangial hypercellularity (M) (p = 0.0034), S (p = 0.0003), endocapillary hypercellularity (E) (p = 0.0411), and T (P < 0.0001). MSET differed significantly by sex (P < 0.0001). The 24-h urine protein/creatinine ratio increased significantly with the degrees of S (p = 0.036), E (p = 0.0155), and T (p = 0.015). The serum creatinine level was significantly higher in patients with T2 than T1 or T0 (P < 0.0001). At the time of biopsy, the degree of tubular atrophy/interstitial fibrosis affected the doubling of serum creatinine or end-stage renal disease. However, the electron microscopy findings did not predict the renal outcome. CONCLUSIONS: Our study suggests that tubular atrophy/interstitial fibrosis is significantly associated with proteinuria and renal progression in IgAN.
Biopsy ; Classification ; Creatinine ; Fibrosis ; Foot ; Glomerular Basement Membrane ; Glomerular Filtration Rate ; Glomerulonephritis, IGA* ; Humans ; Kidney Failure, Chronic ; Microscopy, Electron ; Pathology* ; Prognosis ; Proteinuria ; Sclerosis ; World Health Organization

OBJECTIVEIgA nephropathy is the most common type of glomerulonephritis in the world. Its clinical and pathological manifestations vary. A few of the patients with IgA nephropathy present with rapidly progressive glomerulonephritis (RPGN) and/or crescent formation. Their conditions are serious and acute, but there are few reports on their characteristics, treatment and outcome. This study aimed to analyze the clinicalopathological features, treatment and prognosis of primary IgA nephropathy in children, to provide a reference for clinical diagnosis and treatment.

METHODA retrospective study was conducted in children with primary IgA nephropathy with crescent formation and/or rapidly progressive glomerulonephritis admitted to our department from 2000 to 2014. The patients meeting the inclusion and exclusion criteria were included. Patients were divided into RPGN group and non-RPGN group according to the clinical manifestations, crescent formation group and non-crescent group, crescentic IgA nephropathy group and non-crescentic IgA nephropathy group according to renal biopsy. Their clinical manifestations and pathological features, treatment and prognosis were compared.

RESULTA total of 265 patients were recruited, 10 patients (3.8%) had RPGN, 151 patients (57.0%) had crescent formation, 19 cases (7.2%) showed crescentic IgA nephropathy.Compared with non-RPGN group, RPGN group showed more gross hematuria, higher serum creatinine, lower creatinine clearance correction at biopsy and follow-up, and more crescentic IgA nephropathy (P<0.05). The percent of patients who received methylprednisolone pulse and blood purification therapy in RPGN group is higher than that of non-RPGN group (P<0.05). Compared with non-crescent group, crescent formation group showed more gross hematuria at biopsy and follow-up, higher serum creatinine at biopsy, lower creatinine clearance correction, more 24-hour urinary protein at biopsy and higher serum creatinine at follow-up (P<0.05). The percentage of patients received more methylprednisolone pulse, oral steroids, cyclophosphamide pulse in crescent formation group was higher than that of non-crescent group (P<0.05). Compared with non-crescentic IgA nephropathy group, crescentic IgA nephropathy group showed more RPGN percent, higher serum creatinine, more 24-hour urinary protein at biopsy (P<0.05). The percentage of patients who received more methylprednisolone pulse and blood purification therapy in crescentic IgA nephropathy group was more than non-crescentic IgA nephropathy group (P<0.05). At follow-up, 20.0% of the patients with RPGN and crescent nephritis returned to normal renal function and the percent of crescent glomerulonephritis but not RPGN was 71.4%, RPGN but not crescent glomerulonephritis was 80.0%, crescent formation but not crescent nephritis was 87.5%.

CONCLUSIONIn primary IgA nephropathy with crescent formation and/or rapidly progressive glomerulonephritis, the patients with both RPGN and crescentic IgA nephropathy showed the worst clinical manifestations, its prognosis was worst while the patients with crescent formation showed the mildest clinical manifestations and best prognosis.

Biopsy ; Child ; Creatinine ; blood ; Cyclophosphamide ; therapeutic use ; Disease Progression ; Glomerulonephritis, IGA ; classification ; diagnosis ; physiopathology ; therapy ; Hematuria ; diagnosis ; Humans ; Kidney ; physiopathology ; Kidney Function Tests ; Methylprednisolone ; therapeutic use ; Nephritis ; diagnosis ; Prognosis ; Retrospective Studies

OBJECTIVETo compare the clinical and pathological features between children with various genotypes of hepatitis B virus-associated glomerulonephritis (HBV-GN).

METHODSForty-one children with HBV-GN concurrently undergoing liver and renal biopsy were randomly selected. Serum specimens were collected for genotyping and hepatitis B virus (HBV) cccDNA assay. The clinical, pathological, and HBV cccDNA differences between HBV-GN children of various genotypes were analyzed.

RESULTSAmong the 41 HBV-GN children, 29 (71%) were genotype C, 10 (24%) were genotype B, and 2 (5%) were genotype B/C. The incidence rates of hematuria, albuminuria, complement 3 decrease, alanine transaminase increase, and renal insufficiency in the genotype C group were significantly higher than those in the genotype B group (P<0.05). Similarly, the HBV cccDNA positive rate was significantly higher in the genotype C group than that in the genotype B group. No difference was observed in the distribution of pathological types of renal tissues betwee the two geonotype groups. There were no significant differences in the degrees of hepatic inflammation and fibrosis between the two groups.

CONCLUSIONSMainly genotypes C and B occur in children with HBV-GN and the former genotype is dominant. The clinical symptoms of patients with genotype C are more serious than those with genotype B. However, there is no difference in the pathological features between them.

Adolescent ; Child ; DNA, Viral ; analysis ; Female ; Genotype ; Glomerulonephritis ; etiology ; pathology ; Hepatitis B ; complications ; Hepatitis B virus ; classification ; genetics ; Humans ; Kidney ; pathology ; Male

BACKGROUND: All types of membranoproliferative glomerulonephritis (MPGN) are progressive diseases with poor prognoses. Recently, a newly proposed classification of these diseases separated them into immune complex- and complement- mediated diseases. We investigated the frequency of C3 glomerulonephritis among previously diagnosed MPGN patients. METHODS: We conducted a retrospective study of patients diagnosed with MPGN at three tertiary care institutions between 2001 and 2010. We investigated the incidence of complement-mediated disease among patients diagnosed with MPGN. Progressive renal dysfunction was defined as a 50% reduction in the glomerular filtration rate or the need for renal replacement therapy. RESULTS: Among the 3,294 renal biopsy patients, 77 (2.3%) were diagnosed with MPGN; 31 cases were excluded, of which seven were diagnosed with systemic lupus nephritis, and the others were not followed for a minimum of 12 months after biopsy. Based on the new classification, complement-mediated MPGN was diagnosed in two patients (4.3%); only one patient developed progressive renal dysfunction. Among the immune complex-mediated MPGN patients, 17 patients developed progressive renal dysfunction. Serum albumin and creatinine levels at the time of MPGN diagnosis were risk factors of renal deterioration, after adjusting for low C3 levels and nephrotic syndrome. CONCLUSION: Complement-mediated glomerulonephritis was present in 4.3% of patients previously diagnosed with MPGN.
Biopsy ; Classification* ; Complement C3 ; Creatinine ; Diagnosis ; Glomerular Filtration Rate ; Glomerulonephritis ; Glomerulonephritis, Membranoproliferative* ; Glomerulonephritis, Membranous ; Humans ; Incidence ; Lupus Nephritis ; Nephrotic Syndrome ; Prognosis ; Renal Replacement Therapy ; Retrospective Studies ; Risk Factors ; Serum Albumin ; Tertiary Healthcare

No abstract available.
Classification* ; Glomerulonephritis, Membranoproliferative*

OBJECTIVETo explore the relationship between the major allergens of 6 common allergic foods and IgA nephropathy.

METHODSA sensitive sandwich enzyme-linked immunosorbent assay (ELISA) was used to detect the serum levels of food-specific IgA1, IgG and IgE in 31 patients with IgA nephropathy and 80 healthy volunteers. All the patients were examined for a history of food allergy using a questionnaire.

RESULTSSerum levels of IgA1 and IgG against the major allergens of the 6 common allergic foods were significantly higher in patients with IgA nephropathy than in healthy volunteers (P<0.05). There was no detectable food-specific IgE antibodies in the two groups. No patients had a clear history of food allergy. All the patients with increased IgG levels specific to 4 or more foods simultaneously had proteinuria.

CONCLUSIONSSome foods especially the highly allergic ones may participate in the pathogenesis and progression of IgA nephropathy.

Adult ; Antibody Specificity ; Case-Control Studies ; Female ; Food Hypersensitivity ; classification ; immunology ; Glomerulonephritis, IGA ; blood ; immunology ; Humans ; Immunoglobulin A ; blood ; Immunoglobulin E ; blood ; Immunoglobulin G ; blood ; Male ; Young Adult

OBJECTIVETo investigate the potential of renal pathological index as a differential diagnosis factor for Chinese medicine (CM) syndromes typing in IgA nephropathy (IgAN).

METHODSA total of 1,016 patients with IgAN was recruited from November 2001 to November 2004. All the signs and symptoms including picture of the tongue and pulse tracings were collected. All patients were typed according to the CM syndrome typing scheme for chronic primary glomerulopathy. The severity of glomerulus and tubulointerstitial lesions (mild, moderate-severe) were evaluated using lee's grading system and the Katafuchi score system.

RESULTSThe syndrome types transform in turn by deficiency of both the Spleen (Pi) and Lung (Fei) qi, deficiency of both qi and yin, deficiency of Liver (Gan) and Kidney (Shen) yin and deficiency of Spleen-Kidney (Shen) yang, with the aggravation of pathogenetic condition and that the manifestation of deficiency of qi clinically showed proliferative lesion of glomerular mesangium, while the glomerular sclerosis pathologically showed the manifestation of yin deficiency.

CONCLUSIONRenal pathological findings may be a candidate of objective factors to refine CM syndrome typing process.

Adolescent ; Adult ; Aged ; Child ; Child, Preschool ; Female ; Glomerulonephritis, IGA ; classification ; immunology ; pathology ; therapy ; Humans ; Kidney ; blood supply ; pathology ; Kidney Glomerulus ; pathology ; Male ; Medicine, Chinese Traditional ; Middle Aged ; Renal Artery ; pathology ; Syndrome ; Young Adult

OBJECTIVETo validate the value of the Oxford classification of IgA nephropathy in predicting the renal outcome in Chinese population.

METHODSRetrospective study was done in patients with IgA nephropathy. All slides were re-assessed according to the Oxford classification of IgA nephropathy. The primary end point is doubling serum creatinine, or a 50% reduction in estimated glomerular filtration rate (eGFR), or end-stage renal disease. Pathologic predictors for the progression to the end point were determined by univariate and multivariate Cox regression.

RESULTSTotally 533 patients were enrolled in the study. During the follow-up (median: 39 months; range: 12-263 months), 5.07% of the patients reached the end point. While tubular atrophy and interstitial fibrosis and arterial/ arteriolar lesion were associated with the endpoint in univariate analysis, only the T score was predictive of the renal outcome in multivariate Cox regression. Combination of the patho- logic lesions had no impact on renal outcome.

CONCLUSIONAccording to the Oxford classification of IgA nephropathy, the degree of tubulointerstitial fibrosis is the only feature independently predictive of renal outcome.

Adolescent ; Adult ; Aged ; Female ; Follow-Up Studies ; Glomerulonephritis, IGA ; classification ; pathology ; Humans ; Kidney ; pathology ; Male ; Middle Aged ; Prognosis ; Retrospective Studies ; Young Adult

BACKGROUND/AIMS: The recently published Oxford classification of IgA nephropathy (IgAN) proposed a split system for histological grading, based on prognostic pathological features. This new classification system must be validated in a variety of cohorts. We investigated whether these pathological features were applicable to an adult Korean population. METHODS: In total, 69 adult Korean patients with IgAN were analyzed using the Oxford classification system at Soonchunhyang University Hospital, Seoul, Korea. All cases were categorized according to Lee's classification. Renal biopsies from all patients were scored by a pathologist who was blinded to the clinical data for pathological variables. Inclusion criteria were age greater than 18 years and at least 36 months of follow-up. We excluded cases with secondary IgAN, diabetic nephropathy combined other glomerulopathies, less than 36 months of follow-up, and those that progressed rapidly. RESULTS: The median age of the patients was 34 years (range, 27 to 45). Mean arterial blood pressure was 97 +/- 10 mmHg at the time of biopsy. The median follow-up period was 85 months (range, 60 to 114). Kaplan-Meier analysis showed significant prognostic predictions for M, E, and T lesions. A Cox proportional hazard regression analysis also revealed prognostic predictions for E and T lesions. CONCLUSIONS: Using the Oxford classification in IgAN, E, and T lesions predicted renal outcome in Korean adults after taking clinical variables into account.
Adult ; *Asian Continental Ancestry Group ; Biopsy ; Chi-Square Distribution ; Disease Progression ; Female ; Fish Oils/therapeutic use ; Glomerulonephritis, IGA/classification/*diagnosis/ethnology/pathology/therapy ; Hospitals, University ; Humans ; Immunosuppressive Agents/therapeutic use ; Kaplan-Meier Estimate ; Kidney/*pathology ; Male ; Middle Aged ; Multivariate Analysis ; Predictive Value of Tests ; Prognosis ; Proportional Hazards Models ; Reproducibility of Results ; Republic of Korea/epidemiology ; Retrospective Studies ; Severity of Illness Index ; Time Factors