Simultaneous comprehensive multiplex autoantibody analysis for rapidly progressive glomerulonephritis

Crescentic glomerulonephritis in children: short-term follow-up predicts long-term outcome

Background

Crescentic glomerulonephritis (CrGN) is a relatively rare but severe condition in childhood with the clinical feature of rapidly progressive glomerulonephritis (RPGN). The aim of this study is to investigate the clinicopathological features and prognosis of CrGN in children.

Methods

We retrospectively analyzed the clinical and laboratory data, renal pathological results, treatment, and outcome of 147 CrGN in two Chinese pediatric nephrology centers.

Results

Among the 147 children, there were 22 cases of type I (15.0%), 69 cases of type II (46.9%), and 56 cases of type III (38.1%). The mean percentages of crescents in CrGN I, II, and III were 85.3%, 68.7%, and 73.6%, respectively. The children with type I CrGN presented with more severe clinical manifestations and pathological lesions. The 3-month cumulative renal survival rates of types I, II, and III CrGN were 66.3%, 93.6%, and 75.6%, respectively. The 1-year cumulative renal survival rates of types I, II, and III CrGN were 56.9%, 85.3%, and 73.1%, respectively, and the 5-year cumulative renal survival rates of types I, II, and III CrGN were 33.8%, 73.5%, and 47.1%, respectively. The Kappa Consistency Test between the 3-month and 1-year total renal survival (82.1% vs. 74.7%) of the children was 0.683 (P < 0.001), and between the 1-year and 5-year total renal-free survival (78.3% vs. 69.1%) of the children was 0.476 (P < 0.001). The Bowman's Capsule Rupture (BCR), crescent, interstitial inflammation, and interstitial fibrosis/tubular atrophy (IF/TA) score were predictors of end-stage kidney disease (ESKD) risk but BCR showed better predictive value for ESKD than interstitial inflammation score (P = 0.027) and IF/TA score (P = 0.047).

Conclusion

Patients with type I tended to have the worst renal survival rates. The three-month renal prognosis could partially reflect the 1-year renal prognosis, and the 1-year mortality rate could partially reflect the 5-year mortality rate of children with CrGN.

PR3-ANCAs Detected by Third-Generation ELISA Predicts Severe Disease and Poor Survival in Primary Sclerosing Cholangitis

A highly sensitive detection of anti-neutrophil cytoplasmic antibodies to serine proteinase-3 (PR3-ANCAs) aids in the serological diagnosis of autoimmune liver disorders and the prediction of severity in primary sclerosing cholangitis (PSC). Here, we evaluate a novel third-generation ELISA for the detection of PR3-ANCAs. In total, 309 patients with PSC, 51 with primary biliary cholangitis (PBC), and 120 healthy blood donors (BD) were analyzed. For the survival analysis in PSC, the outcome was defined as liver-transplantation-free survival during the follow-up. Positive PR3-ANCA levels were found in 74/309 (24.0%) of patients with PSC. No BDs and one patient with PBC demonstrated PR3-ANCA positivity. PR3-ANCAs were revealed as independent predictors for a poor PSC outcome (study endpoint: liver transplantation/death, log-rank test, p = 0.02). PR3-ANCA positivity, lower albumin levels, and higher bilirubin concentrations were independent risks of a poor survival (Cox proportional-hazards regression analysis, p < 0.05). The Mayo risk score for PSC was associated with PR3-ANCA positivity (p = 0.01) and the disease severity assessed with a model of end-stage liver disease (MELD) and extended MELD-Na (p < 0.05). PR3-ANCAs detected by a third-generation ELISA are diagnostic and prognostic markers for PSC. Their wider use could help to identify patients who are at-risk of a more severe disease.

Accuracy of Anti-GBM Antibodies in Diagnosing Anti-Glomerular Basement Membrane Disease: A Systematic Review and Meta-Analysis

BACKGROUND

The sensitivity and specificity of anti-glomerular basement membrane (GBM) antibodies have not been systematically analyzed. In this systematic review, we aimed to evaluate the diagnostic accuracy of anti-GBM antibodies for anti-GBM disease.

SUMMARY

Potential studies were searched using MEDLINE, Embase, the Cochrane Library, and the International Clinical Trials Registry Platform based on the index test and target condition. The inclusion criteria were prospective or retrospective cohort studies or case-control studies assessing the sensitivity and specificity of anti-GBM antibodies, and the reference standard was clinical diagnosis including biopsy results. The exclusion criteria were review articles, case reports, animal studies, and in vitro studies. Quality assessment was conducted based on the Quality Assessment of Diagnostic Accuracy Studies-2. The pooled estimates of sensitivity and specificity were calculated using a bivariate random-effects model. The overall quality was evaluated using the Grades of Recommendation, Assessment, Development, and Evaluation. Six studies (1,691 patients) and 11 index tests were included in our systematic review. A high risk of bias and concerns regarding the applicability of patient selection were noted because of the case-control design in 67% of the included studies. The pooled sensitivity and specificity were 93% (95% CI: 84-97%) and 97% (95% CI: 94-99%), respectively. The certainty of evidence was low because of the high risk of bias and indirectness. Key Messages: Anti-GBM antibodies may exhibit high sensitivity and specificity in the diagnosis of anti-GBM disease. Further cohort studies are needed to confirm their precise diagnostic accuracy and compare diagnostic accuracies among different immunoassays.

Anti-neutrophil cytoplasmic antibody testing by indirect immunofluorescence: Computer-aided versus conventional microscopic evaluation of routine diagnostic samples from patients with vasculitis or other inflammatory diseases

BACKGROUND

Detection of anti-neutrophil cytoplasmic antibodies (ANCA) by indirect immunofluorescence assays (IFA) is of diagnostic importance in vasculitides and some other inflammatory diseases. Automation of IFA may be beneficial in high-throughput clinical laboratories. An analytical appraisal of the EUROPattern (EPa) automated microscope and image analysis system has not been reported in a routine clinical laboratory setting testing samples from both vasculitis and non-vasculitis patients.

METHODS

Results of EPa and on-screen ANCA pattern recognition of 568 consecutive routine serum samples were compared to those of conventional visual evaluation.

RESULTS

Agreement of discrimination between negative and non-negative samples was 86.1% comparing EPa and conventional reading, and it increased to 96.7% after on-screen user validation. Importantly, from the 334 samples classified as negative by EPa 328 (98.2%) were also negative by conventional evaluation. Pattern recognition showed 'moderate' agreement between classical microscopic and EPa analysis (κ = 0.446) and 'very good' agreement after user validation (κ = 0.900). Misclassification by EPa was dominantly due to the presence of anti-nuclear/cytoplasmic antibodies (incorrect pattern, 80/568) and the lower fluorescence cut-off of the automated microscope (false positives, 73/568).

CONCLUSIONS

Automated ANCA testing by EPa is a reliable alternative of classical microscopic evaluation, though classification of sera needs correction by trained personnel during on-screen validation.

Role of anti-DNA auto-antibodies as biomarkers of response to treatment in systemic lupus erythematosus patients: hypes and hopes. Insights and implications from a comprehensive review of the literature

Introduction: Due to the polymorphic clinical presentations and manifestations of systemic lupus erythematosus (SLE), biomarkers with enough diagnostic and prognostic value are of paramount importance. Recently, anti-double stranded DNA (anti-dsDNA) auto-antibodies have been proposed to monitor the response to different therapies. It has also been suggested that they should be employed as entry markers in trial studies. However, their clinical use remains still debated and, sometimes, controversial, due to conflicting findings reported. Areas covered: Through an extensive literature review, we evaluated changes in anti-dsDNA auto-antibodies levels before and after the administration of the treatment (either biological or non-biological). Expert opinion: Anti-dsDNA auto-antibodies related findings are still difficult to compare mainly because of the different detecting methods employed, even though in most studies included in this review a consistent decreasing pattern after the treatment seems to emerge. Hence, if properly standardized, anti-dsDNA auto-antibody profile may be a reliable biomarker to monitor the effectiveness of biologics as well as of non-biological drugs, especially if grouped in composite outcomes scores, such as the 'Lupus Multivariable Outcome Score' (LUMOS) or measured with other biomarkers, such as anti-nucleosome auto-antibodies. We recommend the assessment of anti-dsDNA auto-antibodies levels in both daily practice and research settings.

An international survey on anti-neutrophil cytoplasmic antibodies (ANCA) testing in daily clinical practice

Background:

Detection of anti-neutrophil cytoplasmic antibodies (ANCA) is important for the diagnosis of the ANCA-associated vasculitides (AAV). For AAV, especially ANCA directed against myeloperoxidase (MPO) and proteinase 3 (PR3) are most relevant. ANCA with less well-defined specificities may, however, also be detected in other inflammatory and non-inflammatory conditions.

Methods:

A questionnaire, initiated by the European Autoimmunity Standardisation Initiative (EASI), was used to gather information on methods and testing algorithms used for ANCA in clinical laboratories of 12 European countries (EASI survey).

Results:

Four hundred and twenty-nine responses were included in the EASI survey analysis which revealed differences within countries and between countries. Laboratories overall were poor in adherence to international consensus on ANCA testing. Substantial variation was observed with respect to the use of ANCA indirect immunofluorescence (IIF) in the algorithm, application of distinct methods for MPO- and PR3-ANCA, the daily availability of new ANCA results, and interpretation of test results.

Conclusions:

Awareness of these differences may stimulate further harmonization and standardization of ANCA testing. This may be promoted by an update of the international ANCA consensus and the introduction of international standards.

Analysis of Antineutrophil Cytoplasm Antibody from 118 730 Patients in Tertiary Hospitals in Jiangxi Province, China

BACKGROUND The discovery of antineutrophil cytoplasm antibody (ANCA) makes the early diagnosis of primary vasculitis possible, and also has important guiding significance for the diagnosis and treatment of secondary vasculitis. This study aimed to investigate the clinical significance of ANCA. MATERIAL AND METHODS ANCA was detected by indirect immunofluorescence assay (IIF), and anti-myeloperoxidase (MPO) antibody, and anti-proteinase 3 (PR3) antibody were detected by ELISA. The results were analyzed retrospectively. RESULTS Among 118 730 patients, a total of 5853 (4.93%) were positive for ANCA. In the positive cases, 3.98% were male and 6.33% were female, with significant differences (χ²=123.38, P<0.01). For ANCA, the department with the highest positive rate (15.06%) was the Department of Rheumatology, followed by 7.78% in the Department of Dermatology, 6.79% in the Department of Nephrology, and 5.72% in the Department of Traditional Chinese Medicine (TCM). Anti-PR3 and cANCA were highly specific in primary vasculitis (P<0.01). Anti-MPO and pANCA had high specificity for other autoimmune diseases (P<0.01). CONCLUSIONS ANCA has important guiding significance for vasculitis-related diseases. Therefore, it is important in the diagnosis and treatment of this disease and has value in clinical practice.