Treatment and clinicopathological characteristics of lupus nephritis with anti-neutrophil cytoplasmic antibody positivity: a case-control study

Serum antineutrophil cytoplasmic antibody positivity at the time of renal biopsy is associated with disease activity of lupus nephritis

OBJECTIVE

To investigate the correlations between serum antineutrophil cytoplasmic antibody (ANCA) and clinicopathological features, induction treatment response, and prognosis of lupus nephritis (LN) patients.

METHODS

In this retrospective study, biopsy-proven LN patients from October 2010 to September 2020 were tested for serum ANCA by indirect immunofluorescence and ELISA and were divided into ANCA-positive group and ANCA-negative group. The clinicopathological data of the two groups were analyzed and compared.

RESULTS

Thirty-five of 115 patients (30.43%) were seropositive for ANCA. ANCA-positive patients had significantly higher systemic lupus erythematosus activity index and activity index scores, higher 24-h urinary protein, and lower complement three levels (p = 0.001, 0.028, 0.023, 0.009, respectively). The incidences of oral ulcers, thrombocytopenia, and leukocyturia, and the positive rates of anti-dsDNA antibody and anti-histone antibody were significantly higher in ANCA-positive group (p = 0.006, 0.019, 0.012, 0.001, 0.019, respectively). Class IV LN and fibrinoid necrosis/karyorrhexis were significantly more common in the ANCA-positive group (p = 0.027, 0.002). There was no significant difference in the total remission rate of ANCA-positive patients receiving cyclophosphamide and mycophenolate mofetil as induction therapies (83.33% vs. 66.67%, p > 0.05), while patients receiving cyclophosphamide as induction therapy had a higher total remission rate than those receiving other immunosuppressants (83.33% vs. 20%, p = 0.028).

CONCLUSIONS

LN patients with ANCA seropositivity at renal biopsy have a significantly higher disease activity, and their pathological manifestations are predominantly proliferative LN. These patients require a more active immunosuppressive therapy with cyclophosphamide or mycophenolate mofetil to improve their remission rate.

The uncertain correlation of ANCAs in patients with lupus nephritis and crescents, an experience from Chinese centers

BACKGROUND

The precise role of anti-neutrophil cytoplasmic antibodies (ANCAs) in the pathologic course of crescentic lupus nephritis (LN) remains unclear. Our study aimed to assess whether ANCA-positive serology in patients with LN and crescents is associated with different clinicopathologic features and outcomes.

METHODS

We reviewed the records of 658 patients diagnosed with LN between 2010 and 2022. Among them, 64 (9.7%) patients who had complete follow-up and clinical data were reclassified as crescentic glomerulonephritis. Of these, 11 patients with incomplete ANCA data and 7 patients with less than 10 glomeruli under light microscopy were excluded; ultimately, 46 patients were enrolled: 12 with ANCA positivity and 34 with ANCA negativity. Clinicopathological characteristics and outcomes were analysed and compared.

RESULTS

Our data did not reveal any differences in clinical or laboratory parameters or histopathological features except for a significantly higher level of proteinuria or proportion of nephrotic syndrome (p < 0.05) at presentation before biopsy in the ANCA-negative group than in the ANCA-positive group,and a lower level of serum albumin (p < 0.05) in the ANCA-negative group than in the ANCA-positive group. No significant differences in complete remission or partial response were detected between the two groups based on the 2021 KDIGO criterion.

CONCLUSION

Short-term follow-up (average follow-up time of less than 3 years) did not reveal any difference in outcomes between ANCA-positive and ANCA-negative crescentic LN. However, the role of ANCAs in the pathological course of crescentic lupus nephropathy and the effect of ANCAs on long-term outcomes remain to be determined.

A Glimpse into Humoral Response and Related Therapeutic Approaches of Takayasu's Arteritis

Takayasu's arteritis (TAK) manifests as an insidiously progressive and debilitating form of granulomatous inflammation including the aorta and its major branches. The precise etiology of TAK remains elusive, with current understanding suggesting an autoimmune origin primarily driven by T cells. Notably, a growing body of evidence bears testimony to the widespread effects of B cells on disease pathogenesis and progression. Distinct alterations in peripheral B cell subsets have been described in individuals with TAK. Advancements in technology have facilitated the identification of novel autoantibodies in TAK. Moreover, emerging data suggest that dysregulated signaling cascades downstream of B cell receptor families, including interactions with innate pattern recognition receptors such as toll-like receptors, as well as co-stimulatory molecules like CD40, CD80 and CD86, may result in the selection and proliferation of autoreactive B cell clones in TAK. Additionally, ectopic lymphoid neogenesis within the aortic wall of TAK patients exhibits functional characteristics. In recent decades, therapeutic interventions targeting B cells, notably utilizing the anti-CD20 monoclonal antibody rituximab, have demonstrated efficacy in TAK. Despite the importance of the humoral immune response, a systematic understanding of how autoreactive B cells contribute to the pathogenic process is still lacking. This review provides a comprehensive overview of the biological significance of B cell-mediated autoimmunity in TAK pathogenesis, as well as insights into therapeutic strategies targeting the humoral response. Furthermore, it examines the roles of T-helper and T follicular helper cells in humoral immunity and their potential contributions to disease mechanisms. We believe that further identification of the pathogenic role of autoimmune B cells and the underlying regulation system will lead to deeper personalized management of TAK patients. We believe that further elucidation of the pathogenic role of autoimmune B cells and the underlying regulatory mechanisms holds promise for the development of personalized approaches to managing TAK patients.

ANCA in patients with systemic lupus erythematosus. A cross sectional study in Brazilian patients and review of literature

BACKGROUND

Antineutrophil cytoplasmatic antibodies (ANCA) have been detected in patients with systemic lupus erythematosus (SLE). In this study, we investigated the presence of ANCA in a sample of Brazilian SLE patients and its possible associations with clinical and serological outcomes. Additionally, we reviewed the literature of on ANCA in SLE.

RESULTS

The presence of ANCA was detected in 130 patients using indirect immunofluorescence (IIF). The test was positive in 29.9% of the cases (17.6% pANCA and 11.5% cANCA). Male sex and peripheral vasculitis were more prevalent in the ANCA-positive sample. cANCA was associated with lupus anticoagulant and pANCA had a positive association with peripheral vasculitis and a negative association with anti- SSB/La antibodies. In the 22 studies included in the literature review, a wide range of ANCA positivity was found (13% to 81.1% by IIF and 0 to 22.2% by ELISA). ANCA was associated with renal damage in the Asian population. Although other associations have been found in isolated studies, they were not consistently reported.

CONCLUSIONS

The ANCA prevalence found in this Brazilian sample was within the range reported in the literature and these autoantibodies were more frequent in males and in patients with vasculitis. The literature showed controversial results on the association between ANCA and SLE disease activity or clinical characteristics.

Clinical features and outcomes of patients with antineutrophil cytoplasmic antibody-positive systemic lupus erythematosus

Purpose: To investigate the clinical characteristics, pathological features, and outcomes of patients with antineutrophil cytoplasmic antibody (ANCA)-positive systemic lupus erythematosus (SLE) in northwest China.Methods: This retrospective study included 491 patients with SLE tested for ANCA antibodies and 171 patients with ANCA-associated vasculitis (AAV) as controls. Subgroup analysis limited to those with renal involvement, and by ANCA antibody subtype (PR3 vs MPO). To compare the proteinuria remission rates between ANCA-positive and ANCA-negative lupus nephritis (LN) groups, a logistic regression model was used for propensity score matching based on age, hemoglobin, and baseline estimated glomerular filtration rate (eGFR).Results: Compared to ANCA-negative SLE (n = 442), ANCA-positive SLE (n = 46) occur in older patients; however, these patients were younger than those with AAV (n = 167). The eGFR of patients with ANCA-positive LN (n = 25) was higher than that of patients having AAV with renal involvement (n = 56) but lower than that of patients with ANCA-negative LN (n = 163). Patients with SLE who had MPO-ANCA (n = 16) had higher levels of serum creatinine compared to those with PR3-ANCA (n = 30) (156.5 µmol/L vs. 45.5 µmol/L, p = 0.005). During the follow-up period, the remission rate of proteinuria in patients with ANCA-positive LN was lower than that of patients with ANCA-negative LN (50% vs. 75%, p = 0.008).Conclusion: Patients with ANCA-positive LN may have worse baseline renal function and lower protein remission rates compared to patients with ANCA-negative LN. ANCA titers should be regularly monitored throughout the follow-up period in patients with SLE, especially in cases of renal involvement.

A Rare Case of Anca Positivity and Antiphospholipid Antibodies in a Patient with Takayasu Arteritis: Case Report and Review of the Literature

Takayasu arteritis (TA) is a chronic large-vessel vasculitis characterized by immune-mediated panarteritis, which predominantly affects the aorta and its main branches and is most prevalent in young women. TA is unusually associated with the presence of antiphospholipid antibodies. We present a case report of a 48-year-old Caucasian woman with acute aortic dissection as an initial feature of TA, where detailed clinical, imaging and laboratory studies were performed. Computed tomography angiography (CTA) of the chest and abdomen revealed aortic dissection DeBakey I. Bentall and De Bono surgery was performed. Additional immunological tests revealed positive antineutrophil cytoplasmic antibodies (ANCAs) with the simultaneous presence of pANCA and cANCA antibodies on indirect immunofluorescence, along with anti-MPO+PR3+antibodies positivity in the absence of a clinically relevant disease. Surprisingly, antiphospholipid antibodies (aPLs) were detected. Then, we performed a thorough review of the current literature. The coexistence of aPL antibodies and dual specificity for MPO and PR3 in a patient diagnosed with Takayasu arteritis is unusual and poses a diagnostic challenge. The presented case report outlines a rare case of aortic dissection as a presenting symptom of TA, along with atypical ANCA positivity and positive APL antibodies.

Rare case of exostosin 1/exostosin 2-related membranous lupus nephritis concomitant with dual ANCA- and anti-GBM antibody-associated crescentic glomerulonephritis effectively diagnosed by mass spectrometry: a case report

BACKGROUND

Recent developments in mass spectrometry (MS) have revealed target antigens for membranous nephropathy (MN), including phospholipase A2 receptor and exostosin 1/exostosin 2 (EXT1/2). EXT1/2 are known antigens of autoimmune disease-related MN, especially membranous lupus nephritis. We describe the case of an elderly man who developed nephrotic syndrome followed by progressive renal dysfunction.

CASE PRESENTATION

A 78-year-old man presented with rapidly progressive renal dysfunction with proteinuria and hematuria. Three years previously, he had developed leg edema but did not receive any treatment. Laboratory tests showed elevated anti-nuclear antibody (Ab), anti-dsDNA Ab titer, and hypocomplementemia, indicating systemic lupus erythematous. Myeloperoxidase anti-neutrophil cytoplasmic Ab (ANCA) and anti-glomerular basement membrane (GBM) Ab were also detected. The renal pathologic findings were compatible with crescentic glomerulonephritis (GN), whereas non-crescentic glomeruli exhibited MN without remarkable endocapillary or mesangial proliferative change. Immunofluorescence microscopy revealed glomerular IgG, C3, and C1q deposition. All IgG subclasses were positive in glomeruli. Anti-PLA2R Ab in serum was negative. MS analysis was performed to detect the antigens of MN, and EXT1/2 was detected in glomeruli. Therefore, we reached a diagnosis of membranous lupus nephritis concurrent with both ANCA-associated vasculitis and anti-GBM-GN. The simultaneous occurrence of these three diseases is extremely rare.

CONCLUSIONS

This is the first report of EXT1/2-related membranous lupus nephritis concurrent with ANCA-associated vasculitis and anti-GBM-GN. This case demonstrates the usefulness of MS in diagnosing complicated cases of MN.

Clinicopathologic features in childhood-onset lupus nephritis with antineutrophil cytoplasmic antibody positivity--a multi-center retrospective study

BACKGROUND

Positive antineutrophil cytoplasmic antibody (ANCA) serology in adult-onset lupus nephritis (LN) is associated with more active disease and distinct renal pathology, but data with respect to childhood-onset LN remain scarce. Here, we aimed to determine the impact of positive ANCA serology on clinical and histopathologic features and renal outcomes in children with LN from multiple centers.

METHODS

Clinical and histopathologic data of 61 ANCA-positive and 330 ANCA-negative LN children (1<age≤18 years) retrospectively enrolled from three pediatric nephrology centers were analyzed. Among them, 217 children were followed and survival analysis was performed.

RESULTS

Among 61 ANCA-positive LN children, 86.9% of them had antimyeloperoxidase antibodies. Both ANCA-positive and ANCA-negative children had high disease activities with median SLEDAI-2K of 16 (13, 20). Hematuria was more prominent (urinary RBC +++ ∼ ++++: 45.9% vs 26.7%, p = 0.011), while fever (42.6% vs. 58.2%, p = 0.035), alopecia (3.3% vs. 14.5%, p = 0.019), photosensitivity (0% vs. 8.2%, p = 0.013), and pleurisy (4.9% vs. 15.8%, p = 0.026) were less common in ANCA-positive children. Higher proportions of segmental sclerosis (23.7% vs. 9.8%, p = 0.025), crescentic formation (36.4% vs. 16.3%, p = 0.009), and capillary wall thickening (24.5% vs. 11.0%, p = 0.01) were observed in biopsies of ANCA-positive children. Long-term renal survival did not differ significantly between two groups (p = 0.300).

CONCLUSIONS

Positive ANCA serology in LN children was associated with different clinical and histopathologic features compared to those with negative ANCA serology. Further studies are needed to clarify the pathogenic role of ANCAs in childhood-onset LN and confirm their association with prognosis.

A Case of Systemic Lupus Erythematosus and Antineutrophil Cytoplasmic Antibodies-Associated Vasculitis Overlap Syndrome

An overlap of systemic lupus erythematosus (SLE) and antineutrophil cytoplasmic antibodies- (ANCA-) associated vasculitis (AAV) is extremely rare: approximately 40 cases have been reported to date. A literature review indicates that they are more common in women in their forties, and simultaneous onset has been reported in 69% of cases. In addition, both lupus nephritis and ANCA-associated glomerulonephritis were observed on renal biopsy. This report presents the case of a 35-year-old woman with an 8-month history of polyarthralgia who was admitted to our hospital. She was diagnosed with SLE due to typical clinical presentation of the disease: polyarthritis, lymphocytopenia, hypocomplementemia, presence of antinuclear and anti-dsDNA antibodies, and proteinuria. However, purpura were scattered, and the titer of antimyeloperoxidase-antineutrophil cytoplasmic antibodies (MPO-ANCA) was high. A skin biopsy revealed leukocytoclastic vasculitis that involved poor immune complex deposition. A renal biopsy showed necrotizing glomerulonephritis with cellular and fibrocellular crescent formation that involved deposition of IgM and C3c only in the mesangial area and the peripheral capillaries. Additionally, no electron-dense deposits were observed under electron microscopy. These pathological findings were consistent with AAV rather than with SLE. Therefore, we finally diagnosed the patient with both SLE and microscopic polyangiitis. After treatment with methylprednisolone and intravenous cyclophosphamide pulse therapies, renal function improved and MPO-ANCA levels decreased. In cases of suspected overlap between SLE and AAV, appropriate diagnosis and treatment are important.

Clinicopathologic characteristics and outcomes of lupus nephritis with positive antineutrophil cytoplasmic antibody

Aims: The aim was to determine whether anti-neutrophil cytoplasmic antibody (ANCA)-positive serology in patients with lupus nephritis (LN) is associated with different clinicopathologic features and outcomes.Methods: In our retrospective analysis, 283 patients were enrolled between 2013 and 2018. Thirty-six patients were ANCA-positive, and this group was compared with the remaining 247 patients who were confirmed as ANCA-negative at the time of biopsy.Results: ANCA-positive LN patients exhibited higher anti-dsDNA antibody titers and serum creatinine levels and lower serum hemoglobin concentrations than ANCA-negative LN patients. On pathological evaluation, segmental endocapillary hypercellularity observed by light microscopy was significantly more common in the ANCA-positive group. This feature was not significantly different in the treatment group, but the response to treatment was significantly different, as was remission (76.1% vs 69.4%, p < 0.001), between the ANCA-negative and ANCA-positive groups. During follow-up, the times to renal replacement therapy (RRT) and death were significantly different between the two unmatched groups (chi-square test, p = 0.041). Multivariate Cox analysis revealed that neurological disorders, ANCA positivity, and the chronicity index (CI) remained independent risk factors for patient survival. Pulmonary infection was the main cause of death and was most often due to fungal infection.Conclusion: ANCA-positive LN patients typically exhibited higher anti-dsDNA antibody titers, lower serum hemoglobin concentrations and worse renal function than ANCA-negative LN patients. Fungal infection was the main cause of death. We observed that ANCA positivity was an independent risk factor for patient survival.

[Clinicopathological features of children with lupus nephritis with positive antineutrophil cytoplasmic antibody]

OBJECTIVE

To study the clinicopathological features of children with lupus nephritis (LN) with positive anti-neutrophil cytoplasmic antibody (ANCA).

METHODS

A retrospective analysis was performed for the children who were diagnosed with LN in the First Affiliated Hospital of Sun Yat-sen University from January 2003 to December 2019. According to the results of serum ANCA, they were divided into two groups: ANCA-positive group (n=59) and ANCAnegative group (n=454). The two groups were compared in terms of clinical manifestations, histopathological features, remission rate, and prognosis.

RESULTS

Compared with the ANCA-negative group, the ANCA-positive group had a significant reduction in leukocytes and a significant increase in erythrocyte sedimentation rate (P < 0.05). There were no significant differences between the two groups in serum creatinine, urine protein, and urine red blood cell count (P > 0.05). A total of 308 children underwent kidney biopsy. The results on light microscopy showed that compared with the ANCAnegative group, the ANCA-positive group had a significantly higher proportion of children with cellular fibrous crescents (P < 0.05) and a significantly lower proportion of children with immune complex deposition (P < 0.05). There were no significant differences between the two groups in the remission rate and survival rate (P > 0.05).

CONCLUSIONS

Children with ANCA-positive LN tend to have more severe renal pathological injury, which is not exactly parallel with clinical manifestations, suggesting that timely renal biopsy is of great importance.

[Clinicopathological features of children with lupus nephritis with positive antineutrophil cytoplasmic antibody]

OBJECTIVE

To study the clinicopathological features of children with lupus nephritis (LN) with positive anti-neutrophil cytoplasmic antibody (ANCA).

METHODS

A retrospective analysis was performed for the children who were diagnosed with LN in the First Affiliated Hospital of Sun Yat-sen University from January 2003 to December 2019. According to the results of serum ANCA, they were divided into two groups: ANCA-positive group (n=59) and ANCAnegative group (n=454). The two groups were compared in terms of clinical manifestations, histopathological features, remission rate, and prognosis.

RESULTS

Compared with the ANCA-negative group, the ANCA-positive group had a significant reduction in leukocytes and a significant increase in erythrocyte sedimentation rate (P < 0.05). There were no significant differences between the two groups in serum creatinine, urine protein, and urine red blood cell count (P > 0.05). A total of 308 children underwent kidney biopsy. The results on light microscopy showed that compared with the ANCAnegative group, the ANCA-positive group had a significantly higher proportion of children with cellular fibrous crescents (P < 0.05) and a significantly lower proportion of children with immune complex deposition (P < 0.05). There were no significant differences between the two groups in the remission rate and survival rate (P > 0.05).

CONCLUSIONS

Children with ANCA-positive LN tend to have more severe renal pathological injury, which is not exactly parallel with clinical manifestations, suggesting that timely renal biopsy is of great importance.

Absence of Anti-Glomerular Basement Membrane Antibodies in 200 Patients With Systemic Lupus Erythematosus With or Without Lupus Nephritis: Results of the GOODLUPUS Study

Introduction

Anti-glomerular basement membrane (GBM) antibodies are pathogenic antibodies first detected in renal-limited anti-GBM disease and in Goodpasture disease, the latter characterized by rapidly progressive crescentic glomerulonephritis combined with intra-alveolar hemorrhage. Studies have suggested that anti-GBM antibody positivity may be of interest in lupus nephritis (LN). Moreover, severe anti-GBM vasculitis cases in patients with systemic lupus erythematosus (SLE) have been described in the literature, but few studies have assessed the incidence of anti-GBM antibodies in SLE patients.

Objective

The main study objective was to determine if positive anti-GBM antibodies were present in the serum of SLE patients with or without proliferative renal damage and compared to a healthy control group.

Methodology

This retrospective study was performed on SLE patients’ sera from a Franco-German European biobank, developed between 2011 and 2014, from 17 hospital centers in the Haut-Rhin region. Patients were selected according to their renal involvement, and matched by age and gender. The serum from healthy voluntary blood donors was also tested. Anti-GBM were screened by fluorescence enzyme immunoassay (FEIA), and then by indirect immunofluorescence (IIF) in case of low reactivity detection (titer >6 U/ml).

Results

The cohort was composed of 100 SLE patients with proliferative LN (27% with class III, 67% with class IV, and 6% with class V), compared to 100 SLE patients without LN and 100 controls. Patients were mostly Caucasian and met the ACR 1997 criteria and/or the SLICC 2012 criteria. Among the 300 tested sera, no significant levels of anti-GBM antibodies were detected (>10 U/ml) by the automated technique, three sera were found “ambivalent” (>7 U/ml): one in the SLE with LN group and two in the SLE without LN group. Subsequent IIF assays did not detect anti-GBM antibodies.

Conclusion

Anti-GBM antibodies were not detected in the serum of Caucasian patients with SLE, even in case of renal involvement, a situation favoring the antigenic exposure of glomerular basement membranes. Our results reaffirm the central role of anti-GBM antibodies as a specific diagnostic biomarker for Goodpasture vasculitis and therefore confirm that anti-GBM antibody must not be carried out in patients with SLE (with or without LN) in the absence of disease-suggestive symptoms.

2020 international consensus on ANCA testing beyond systemic vasculitis

This document follows up on a 2017 revised international consensus on anti-neutrophil cytoplasm antibodies (ANCA) testing in granulomatosis with polyangiitis and microscopic polyangiitis and focuses on the clinical and diagnostic value of ANCA detection in patients with connective tissue diseases, idiopathic interstitial pneumonia, autoimmune liver diseases, inflammatory bowel diseases, anti-glomerular basement membrane (GBM) disease, infections, malignancy, and during drug treatment. Current evidence suggests that in certain settings beyond systemic vasculitis, ANCA may have clinical, pathogenic and/or diagnostic relevance. Antigen-specific ANCA targeting proteinase-3 and myeloperoxidase should be tested by solid phase immunoassays in any patient with clinical features suggesting ANCA-associated vasculitis and in all patients with anti-GBM disease, idiopathic interstitial pneumonia, and infective endocarditis associated with nephritis, whereas in patients with other aforementioned disorders routine ANCA testing is not recommended. Among patients with autoimmune liver diseases or inflammatory bowel diseases, ANCA testing may be justified in patients with suspected autoimmune hepatitis type 1 who do not have conventional autoantibodies or in case of diagnostic uncertainty to discriminate ulcerative colitis from Crohn's disease. In these cases, ANCA should be tested by indirect immunofluorescence as the target antigens are not yet well characterized. Many questions concerning the optimal use of ANCA testing in patients without ANCA-associated vasculitis remain to be answered.

Clinical characteristics of patients with vasculitis positive for anti-neutrophil cytoplasmic antibody targeting both proteinase 3 and myeloperoxidase: a retrospective study

Anti-neutrophil cytoplasmic antibody (ANCA) may target proteinase 3 (PR3) or myeloperoxidase (MPO). Although a few patients with vasculitis have both MPO- and PR3-ANCA, the details of their clinical characteristics are not known. The objective of this study was to analyze the characteristics of patients with dual MPO- and PR3-ANCA-positive vasculitis. The medical records of patients with ANCA and vasculitis confirmed by biopsy were reviewed. The age at diagnosis, sex, and data on organ involvement of the kidney, lung, upper airways, skin, nervous system, and gastrointestinal tract were collected. Clinical variables were analyzed according to ANCA specificity. Of 85 patients with ANCA and vasculitis included in this study, 67 (78.8%) had MPO-ANCA, 10 (11.8%) had PR3-ANCA, and 8 (9.4%) had both MPO- and PR3-ANCA. Patients with MPO- PR3 + ANCA-associated vasculitis (AAV) were younger at diagnosis (median, 54.4 years; p < 0.05) than patients with MPO + PR3- AAV (67.0 years) or dual-ANCA AAV (MPO + PR3 + , 68.5 years). The initial glomerular filtration rate in patients with MPO + PR3- AAV (22.0 ml/min) was significantly lower than that in patients with MPO- PR3 + AAV (108.6 ml/min, p < 0.05), but was not different from that in dual-ANCA AAV patients (16.5 ml/min). Upper airway involvement also differed with ANCA type (MPO+ PR3- , 35.8% vs. MPO- PR3 + , 70.0% vs. MPO + PR3+ , 75.0%, p < 0.05). The involvement of other organs did not differ according to ANCA type. Age at diagnosis, kidney involvement, and upper airway involvement were associated with ANCA type. Patients with dual-ANCA-positive vasculitis had considerably more kidney dysfunction than patients with MPO- PR3+ AAV. They also had more upper airway involvement than patients with MPO+ PR3- AAV.

Differences in clinico-pathological characteristics and outcomes between proteinase 3-ANCA positivity and myeloperoxidase-ANCA positivity in lupus nephritis

BACKGROUND

Owing to the low prevalence of anti-neutrophil cytoplasmic antibodies (ANCA) in lupus nephritis (LN), there is no study about the differences between proteinase 3 (PR3)-ANCA positivity and myeloperoxidase (MPO)-ANCA positivity in LN until now.

METHODS

Here we perform a retrospective study to determine whether there are differences in clinic-pathological characteristics and renal outcomes between PR3-ANCA-positive LN patients and MPO-ANCA-positive LN patients.

RESULTS

A total of 26 (27.4%) PR3-ANCA-positive LN patients and 69 (72.6%) MPO-ANCA-positive LN patients (p < 0.001) were eligible for this study. Compared with PR3-ANCA-positive LN patients, MPO-ANCA-positive LN patients had significantly higher levels of serum creatinine (109.6 µmol/l vs. 74.3 µmol/l, p = 0.02), lower titers of antinuclear antibodies (ANA) (128 vs. 256, p = 0.01), and higher serum concentrations of C3 and C4 (0.54 g/l vs. 0.36 g/l, p = 0.002; 0.12 g/l vs. 0.06 g/l, p < 0.001; respectively). Furthermore, the MPO-ANCA-positive group had higher scores for chronicity index (p = 0.007), including interstitial fibrosis (p = 0.001) and tubular atrophy (p = 0.03) on biopsy specimens. The renal survival rates for MPO-ANCA-positive LN patients were 94.1% at 1 year, 83.2% at 5 years and 79.6% at 10 years; these values were worse when compared with those of the PR3-ANCA-positive group, which were 100%, 100% and 100%, respectively.

CONCLUSION

MPO-ANCA-positive LN patients had more severely impaired baseline renal function and less active lupus serology. More severely chronic pathological changes, including interstitial fibrosis and tubular atrophy on renal specimens, occurred in MPO-ANCA-positive LN patients. We found that MPO-ANCA-positive LN patients had worse renal outcomes.

ANCA positivity at the time of renal biopsy is associated with chronicity index of lupus nephritis

We investigated the association of antineutrophil cytoplasmic antibody (ANCA) positivity with lupus nephritis (LN) activity, histological features and prognosis in Korean patients with biopsy-proven LN having the results of both myeloperoxidase (MPO-ANCA) and proteinase 3 (PR3)-ANCA. We retrospectively reviewed the medical records of 91 LN patients having the results of ANCA. We divided patients with LN into the two groups according to the ANCA positivity. We collected clinical and laboratory data at kidney biopsy and histological features such as LN class including class I, II, III, IV-S, IV-G and V, and activity and chronicity index. We evaluated prognosis of LN during the follow-up by death and kidney failure. Twelve of 91 patients (13.2%) had ANCA at kidney biopsy. There were no differences in demographic data, comorbidities, reasons for kidney biopsy and laboratory data at kidney biopsy between patients with and without ANCA. In 12 LN patients with ANCA, Class III was the most frequently observed LN class (41.7%), while in 79 LN patients without ANCA, class IV-G was the most often detected LN class (35.4%). There were no meaningful differences in classes of LN between the two groups. On the other hand, patients with ANCA exhibited the higher median chronicity index than those without (2.5 vs. 1.0, P = 0.028), unlike activity index. ANCA positivity exhibited no association with death or kidney failure during the follow-up. ANCA positivity at kidney biopsy is associated with chronicity index of LN.

ANCA-Associated Necrotizing Glomerulonephritis Overlapping with Mesangial Proliferative Lupus Nephritis Refractory to Plasmapheresis, Steroid Pulse Therapy, and a Combination of Mycophenolate Mofetil and Rituximab

Necrotizing glomerulonephritis (GN) associated with antineutrophil cytoplasmic antibody (ANCA) has been increasingly recognized in the context of class III or IV lupus nephritis (LN), hereafter designated as ANCA-associated necrotizing LN. While this subset of GN appears to portend an unfavorable renal outcome, it is not clear whether it represents a distinct entity and benefits from a more aggressive therapy. We report a 78-year-old woman who presented with rapidly progressive GN and was found to have a double-stranded DNA (dsDNA) antibody, hypocomplementemia, antiphospholipid antibody, and strongly positive myeloperoxidase antibody. Renal pathology showed necrotizing and crescentic GN on a background of mesangial proliferative GN. Her kidney disease did not improve despite the treatment with plasmapheresis, three doses of methylprednisolone pulse therapy followed by prednisone at 1 mg/kg/day, rituximab, and mycophenolate mofetil. This case not only reinforces the notion that ANCA-associated necrotizing LN is associated with high dsDNA antibody, hypocomplementemia, and worse renal outcome but also adds new insight into the full spectrum of this emerging disease entity by demonstrating that the concurrence of ANCA-associated vasculitis is not specific for class III or IV LN but can also be seen on a background of class II LN.