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

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.

II Brazilian Society of Rheumatology consensus for lupus nephritis diagnosis and treatment

OBJECTIVE

To develop the second evidence-based Brazilian Society of Rheumatology consensus for diagnosis and treatment of lupus nephritis (LN).

METHODS

Two methodologists and 20 rheumatologists from Lupus Comittee of Brazilian Society of Rheumatology participate in the development of this guideline. Fourteen PICO questions were defined and a systematic review was performed. Eligible randomized controlled trials were analyzed regarding complete renal remission, partial renal remission, serum creatinine, proteinuria, serum creatinine doubling, progression to end-stage renal disease, renal relapse, and severe adverse events (infections and mortality). The Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach was used to develop these recommendations. Recommendations required ≥82% of agreement among the voting members and were classified as strongly in favor, weakly in favor, conditional, weakly against or strongly against a particular intervention. Other aspects of LN management (diagnosis, general principles of treatment, treatment of comorbidities and refractory cases) were evaluated through literature review and expert opinion.

RESULTS

All SLE patients should undergo creatinine and urinalysis tests to assess renal involvement. Kidney biopsy is considered the gold standard for diagnosing LN but, if it is not available or there is a contraindication to the procedure, therapeutic decisions should be based on clinical and laboratory parameters. Fourteen recommendations were developed. Target Renal response (TRR) was defined as improvement or maintenance of renal function (±10% at baseline of treatment) combined with a decrease in 24-h proteinuria or 24-h UPCR of 25% at 3 months, a decrease of 50% at 6 months, and proteinuria < 0.8 g/24 h at 12 months. Hydroxychloroquine should be prescribed to all SLE patients, except in cases of contraindication. Glucocorticoids should be used at the lowest dose and for the minimal necessary period. In class III or IV (±V), mycophenolate (MMF), cyclophosphamide, MMF plus tacrolimus (TAC), MMF plus belimumab or TAC can be used as induction therapy. For maintenance therapy, MMF or azathioprine (AZA) are the first choice and TAC or cyclosporin or leflunomide can be used in patients who cannot use MMF or AZA. Rituximab can be prescribed in cases of refractory disease. In cases of failure in achieving TRR, it is important to assess adherence, immunosuppressant dosage, adjuvant therapy, comorbidities, and consider biopsy/rebiopsy.

CONCLUSION

This consensus provides evidence-based data to guide LN diagnosis and treatment, supporting the development of public and supplementary health policies in Brazil.

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.

Lupus Nephritis Biomarkers: A Critical Review

Lupus nephritis (LN), a major complication in individuals diagnosed with systemic lupus erythematosus, substantially increases morbidity and mortality. Despite marked improvements in the survival of patients with severe LN over the past 50 years, complete clinical remission after immunosuppressive therapy is achieved in only half of the patients. Therefore, timely detection of LN is vital for initiating prompt therapeutic interventions and improving patient outcomes. Biomarkers have emerged as valuable tools for LN detection and monitoring; however, the complex role of these biomarkers in LN pathogenesis remains unclear. Renal biopsy remains the gold standard for the identification of the histological phenotypes of LN and guides disease management. However, the molecular pathophysiology of specific renal lesions remains poorly understood. In this review, we provide a critical, up-to-date overview of the latest developments in the field of LN biomarkers.

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.

Clinicopathological characteristics and outcomes of lupus nephritis patients with scanty immune depositions in kidney biopsies

BACKGROUND

The clinicopathological features, outcomes, and pathogenesis of lupus nephritis with scanty immune deposits in the kidney biopsy remain unclear.

METHODS

Four hundred ninety-eight biopsy-proven lupus nephritis patients were included, and clinical and pathological data were collected. The primary endpoint was mortality, while the secondary endpoint was doubling baseline serum creatinine or end-stage renal disease. Associations between scanty immune deposits lupus nephritis and adverse outcomes were analyzed by Cox regression models.

RESULTS

Among 498 lupus nephritis patients, 81 were diagnosed with scanty immune deposits. Patients with scanty immune deposits had significantly higher serum albumin and serum complement C4 than those with immune complex deposits. The proportion of anti-neutrophil cytoplasmic antibodies was similar between the two groups. In addition, patients with scanty immune deposits showed less proliferative features at kidney biopsy and lower activity index score, accompanied by milder mesangial cell and matrix hyperplasia, endothelial cell hyperplasia, nuclear fragmentation, and glomerular leukocyte infiltration. Patients in this group also had a milder degree of foot process fusion. Overall, renal survival and patient survival showed no significant difference between the two groups. 24-h proteinuria and chronicity index were significant risk factors for renal survival, and 24-h proteinuria and positive anti-neutrophil cytoplasmic antibodies were risk factors for patient survival in scanty immune deposits lupus nephritis patients.

CONCLUSIONS

Compared with other lupus nephritis patients, scanty immune deposits lupus nephritis patients had significantly lower activity features on kidney biopsy, but have similar outcomes. Positive anti-neutrophil cytoplasmic antibodies may be a risk factor for patient survival in scanty immune deposits lupus nephritis patients.

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.

Prevalence and clinical significance of ANCA positivity in lupus nephritis: a case series of 116 patients and literature review

The prevalence and clinical significance of anti-neutrophil cytoplasmic antibodies [ANCAs] in patients with lupus nephritis [LN] is not fully elucidated. Our aim was to determine whether LN patients with ANCA positivity had different clinicopathological features and outcomes compared to ANCA-negative patients.

METHODS

Among our LN patients we retrospectively selected those who underwent ANCA testing the day of the kidney biopsy and before the start of induction treatment. Clinical/histopathological features at kidney biopsy and renal outcome of ANCA-positive patients were compared with those of ANCA-negative subjects.

RESULTS

We included 116 Caucasian LN patients in the study; 16 patients [13.8%] were ANCA-positive. At kidney biopsy, ANCA-positive patients presented more frequently with an acute nephritic syndrome than ANCA-negative ones; the difference however does not reach statistical significance [44 vs. 25%, p = 0.13]. At histological evaluation, proliferative classes [100% vs 73%; p = 0.02], class IV [68.8% vs 33%; p < 0.01] and necrotizing tuft lesions [27 vs 7%, p = 0.04] were more frequent, and the activity index was higher [10 vs 7; p = 0.03] in ANCA-positive than in ANCA-negative patients. Despite worse histological features, after a 10-year observation period, there were no significant differences in the number of patients with chronic kidney function impairment (defined as eGFR < 60 mL/min per 1.73 m²) between the ANCA-positive and negative groups [24.2 vs 26.6%, p = 0.9]. This could be the result of the more aggressive therapy, with rituximab plus cyclophosphamide, that ANCA-positive patients received more frequently than ANCA-negative ones [25 vs. 1.3%, p < 0.01].

CONCLUSIONS

ANCA-positive LN patients frequently have histological markers of severe activity (proliferative classes and high activity index) that require timely diagnosis and aggressive therapy to limit the development of irreversible chronic kidney damage.

Involvement of neutrophil extracellular traps in the pathogenesis of glomerulonephritis in a case of systemic lupus erythematosus and antineutrophil cytoplasmic antibody-associated vasculitis overlap syndrome

Systemic lupus erythematosus (SLE) and antineutrophil cytoplasmic antibody-associated vasculitis (AAV) are autoimmune diseases that often cause rapidly progressive glomerulonephritis, with neutrophil extracellular traps (NETs) involved in their pathogenesis. However, the involvement of NETs in the renal damage caused by SLE/AAV overlap syndrome has not been clarified yet. In this study, we detected renal deposition of NETs in a patient with SLE/AAV overlap syndrome. In addition, a significantly increased level of NET-inducing activity was observed in the patient's serum, which improved with treatment. On the other hand, a markedly lower level of NET degradation was observed in the patient's serum as compared to healthy subjects' sera, without any posttreatment changes. These findings suggest that NETs may play a role in the pathogenesis of renal injury associated with SLE/AAV overlap syndrome.

Diagnostic value of TWEAK for predicting active lupus nephritis in patients with systemic lupus erythematosus: a systematic review and meta-analysis

Purpose

Accumulative studies showed that tumor necrosis factor (TNF)-like weak inducer of apoptosis (TWEAK) was up-regulated in the blood and urine from patients diagnosed with lupus nephritis (LN) and that it might be used as a novel biomarker for active LN. This meta-analysis aimed to determine the diagnostic value of TWEAK in active LN.

Methods

We searched the Cochrane Library, Embase, PubMed, Springer, Wanfang and CNKI databases for articles published up to 20 August 2020. The diagnostic capacity of TWEAK for active LN was assessed using pooled sensitivity and specificity, positive and negative likelihood ratios (PLR and NLR), diagnostic odds ratio (DOR), and area under the receiver operating characteristic curve (AUC). Quality assessment and publication bias were also evaluated. STATA 11.0 and Meta-Disc 1.4 were used to perform these analyses.

Results

Nine cross-sectional studies were included in this meta-analysis. The overall pooled sensitivity of TWEAK for the diagnosis of active LN was 0.69 (95% CI, 0.63–0.75), and specificity was 0.77 (95% CI, 0.71–0.82). The overall pooled PLR and NLR were 3.31 (95% CI, 2.05–5.35) and 0.38 (95% CI, 0.26–0.55), respectively, with a DOR of 10.89 (95% CI, 6.73–17.63) and AUC (SE) of 0.8276 (0.0289). Deeks’ funnel plot revealed that the publication bias was insignificant in the study (p = .32).

Conclusions

Our results suggest that TWEAK might be a potential biomarker for patients with active LN. Future cross-sectional and longitudinal studies are needed to confirm its diagnostic value, as well as to establish more definite cutoff for active LN.

[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.