Predictors of hypogammaglobulinemia in ANCA-associated vasculitis after a rituximab-based induction: a multicentre study.

OBJECTIVES: Rituximab has become the cornerstone of induction treatment in ANCA-associated vasculitis (AAV). B-cell depletion may increase the risk of hypogammaglobulinemia, potentially leading to severe infections. This study aims to assess factors associated with hypogammaglobulinemia in AAV patients treated with rituximab. METHODS: This retrospective cohort study included AAV patients treated with rituximab induction in 14 European centres. Severe adverse events (SAEs) were defined as episodes requiring hospitalization or intravenous antibiotics, malignancies, or death. Linear and logistic regression were used to identify predictors of IgG levels and of the risk of hypogammaglobulinemia, defined as IgG ≤7 g/l at 6 months. RESULTS: The study included 227 patients. IgG levels at 6 months were lower than baseline (P < 0.001). Patients requiring intravenous antibiotics during the first 6 months had lower IgG levels at 6 months (P = 0.004). Age [ß (95% CI): -0.23 (-0.38, -0.08) per 10 years, P = 0.003], oral glucocorticoid dose at induction [ß (95% CI): -0.37 (-0.51, -0.24) per sqrt-transformed mg prednisone, P < 0.001] and concomitant use of intravenous glucocorticoid pulses [ß (95% CI): -0.88 (-1.73, -0.02), P = 0.044] were associated with IgG levels at 6 months. Hypogammaglobulinemia was identified in 97 (42.7%) patients. In multivariable logistic regression, factors associated with the risk of hypogammaglobulinemia were age [OR (95% CI): 1.46 (1.15, 1.86) per 10 years, P = 0.002] and oral glucocorticoid dose at induction [OR (95% CI): 1.52 (1.23, 1.89) per 10 mg prednisone, P < 0.001]. CONCLUSIONS: In AAV patients treated with rituximab, hypogammaglobulinemia at 6 months after induction is common, and lower IgG levels are associated with serious infections. The risk of hypogammaglobulinemia in these patients increases with age and higher glucocorticoid doses.

Comparison of EULAR/PRINTO/PReS Ankara 2008 and 2022 ACR/EULAR Classification Criteria for Granulomatosis with Polyangiitis in Children.

OBJECTIVE: Granulomatosis with polyangiitis (GPA) is an antineutrophil cytoplasmic antibody-associated vasculitis. The 2022 American College of Rheumatology/European Alliance of Associations for Rheumatology (ACR/EULAR)-endorsed classification criteria for GPA was derived using data only from adult patients. We aimed to assess the performance of the ACR/EULAR classification criteria for GPA in pediatric patients and compare it with the EULAR/Pediatric Rheumatology International Trials Organization (PRINTO)/Pediatric Rheumatology European Society (PReS)-endorsed Ankara 2008 criteria for GPA. METHODS: Retrospective data of pediatric patients with GPA in 20 centers from 9 countries were evaluated. The diagnosis of GPA was made according to the expert opinion. The sensitivity, specificity, positive predictive value, and negative predictive value of the criteria sets were evaluated. RESULTS: The study included 77 patients with GPA and 108 controls (immunoglobulin A vasculitis (n = 44), Takayasu's arteritis (n = 20), microscopic polyangiitis (n = 16), polyarteritis nodosa (n = 14), Behçet's disease (n = 12), eosinophilic granulomatosis with polyangiitis (n = 1), and Cogan's syndrome (n = 1)) with a median age of 17.8 and 15.2 years, respectively. Of patients with GPA, constitutional symptoms (85.7%) and ear-nose-throat involvement (79.2%) were the most common presentations. In the GPA group, 73 patients fulfilled the Ankara 2008 criteria and 69 the ACR/EULAR classification criteria. Sensitivities of the Ankara 2008 criteria and the ACR/EULAR classification criteria were 94.8% and 89.6%, while specificities were 95.3% and 96.3%, respectively. No significant difference was found between sensitivities and specificities of both classification criteria (p= 0.229 and p= 0.733, respectively). CONCLUSION: In children, both the ACR/EULAR and EULAR/PRINTO/PReS Ankara 2008 classification criteria for GPA perform well and similarly.

Cluster Analysis to Explore Clinical Subphenotypes of Eosinophilic Granulomatosis With Polyangiitis.

OBJECTIVE: Previous studies suggested that distinct phenotypes of eosinophilic granulomatosis with polyangiitis (EGPA; formerly known as Churg-Strauss syndrome) could be determined by the presence or absence of antineutrophil cytoplasmic antibodies (ANCA), reflecting predominant vasculitic or eosinophilic processes, respectively. This study explored whether ANCA-based clusters or other clusters can be identified in EGPA. METHODS: This study used standardized data of 15 European centers for patients with EGPA fulfilling widely accepted classification criteria. We used multiple correspondence analysis, hierarchical cluster analysis, and a decision tree model. The main model included 10 clinical variables (musculoskeletal [MSK], mucocutaneous, ophthalmological, ENT, cardiovascular, pulmonary, gastrointestinal, renal, central, or peripheral neurological involvement); a second model also included ANCA results. RESULTS: The analyses included 489 patients diagnosed between 1984 and 2015. ANCA were detected in 37.2% of patients, mostly perinuclear ANCA (85.4%) and/or antimyeloperoxidase (87%). Compared with ANCA-negative patients, those with ANCA had more renal (P < 0.001) and peripheral neurological involvement (P = 0.04), fewer cardiovascular signs (P < 0.001), and fewer biopsies with eosinophilic tissue infiltrates (P = 0.001). The cluster analyses generated 4 (model without ANCA) and 5 clusters (model with ANCA). Both models identified 3 identical clusters of 34, 39, and 40 patients according to the presence or absence of ENT, central nervous system, and ophthalmological involvement. Peripheral neurological and cardiovascular involvement were not predictive characteristics. CONCLUSION: Although reinforcing the known association of ANCA status with clinical manifestations, cluster analysis does not support a complete separation of EGPA in ANCA-positive and -negative subsets. Collectively, these data indicate that EGPA should be regarded as a phenotypic spectrum rather than a dichotomous disease.

Goodpasture syndrome and anti-glomerular basement membrane disease.

Anti-glomerular basement membrane (anti-GBM) disease is a rare life-threatening small vessel vasculitis that typically affects the capillaries of kidneys and lungs, with most of patients developing rapidly progressive crescentic glomerulonephritis, and 40%-60% concomitant alveolar haemorrhage. It is caused by the deposition in alveolar and glomerular basement membrane of circulating autoantibodies directed against antigens intrinsic to the basement membrane. The exact mechanism that induces the formation of autoantibodies is unknown, but probably environmental factors, infections or direct damage to kidneys and lungs may trigger the autoimmune response in genetically susceptible individuals. Initial therapy includes corticosteroids and cyclophosphamide to prevent autoantibodies production, and plasmapheresis to remove the circulating autoantibodies. Good renal outcomes may be achieved by a prompt treatment initiation. However, when patients present with severe renal failure requiring dialysis or with a high proportion of glomerular crescents at biopsy, renal outcomes are bad. Relapses are rare and when renal involvement is present, the suspect of concomitant diseases, such as ANCA-associated vasculitis and membranous nephropathy, should be raised. Imlifidase is showing promising results, which if confirmed will cause a paradigm shift in the treatment of this disease.

Long-term kidney outcome of patients with rheumatological diseases and antineutrophil cytoplasmic antibody-glomerulonephritis: comparison with a primitive ANCA-glomerulonephritis cohort.

OBJECTIVES: Antineutrophil cytoplasmic antibody (ANCA) may appear in the course of rheumatic diseases (RD) but the kidney involvement is very rare and the prognosis poorly defined. METHODS: We retrospectively identified patients with RD among 153 patients with ANCA glomerulonephritis (ANCA-GN). Their clinical/histological presentation and outcome were compared with that of primitive ANCA-GN patients (1:4) matched for sex, age, ANCA type and follow-up. RESULTS: Nine patients (5.9%) were included: three had rheumatoid arthritis, two systemic sclerosis, two psoriatic arthritis, one ankylosing spondylitis and one seronegative spondylarthritis. Seven patients were MPO positive, two PR3 positive. ANCA-GN developed 74 months after RD with microscopic haematuria and acute kidney dysfunction in all but two patients. After 68-month follow-up, four patients (44.4%) achieved response to therapy defined as eGFR >60/min/1,73 m2 or stable, no microscopic haematuria and negative ANCA. At ANCA-GN diagnosis, serum creatinine and C-reactive protein were significantly lower in RD-ANCA-GN (2.38 vs. 3.34mg/dl, p=0.05 and 2.3mg/dl vs. 7.2mg/dl; p=0.05, respectively) while haemoglobin was higher (12.3g/dl vs. 9.3g/dl p<0.01) than in the 36 primitive ANCA-GN patients of control group. At kidney biopsy, focal forms were more frequent in RD patients (44.45% vs. 18.75%, p=0.11). The treatment between the two groups was not significantly different. At last observation, the percentage of patients with ESKD was lower in RD than in controls (11.1%vs. 30.5%; p=0.23). CONCLUSIONS: Patients with RD seem to develop ANCA-GN with less severe clinical/histological kidney involvement, and better long-term kidney survival than primitive ANCA-GN. This is probably due to the strict monitoring of RD patients that allows a prompter ANCA-GN diagnosis and treatment.

Towards the Definition of the Molecular Hallmarks of Idiopathic Membranous Nephropathy in Serum Proteome: A DIA-PASEF Approach.

Idiopathic membranous nephropathy (IMN) is a pathologically defined disorder of the glomerulus, primarily responsible for nephrotic syndromes (NS) in nondiabetic adults. The underlying molecular mechanisms are still not completely clarified. To explore possible molecular and functional signatures, an optimised mass spectrometry (MS) method based on next-generation data-independent acquisition combined with ion-mobility was applied to serum of patients affected by IMN (n = 15) or by other glomerulopathies (PN) (n = 15). The statistical comparison highlighted a panel of 57 de-regulated proteins with a significant increase in lipoprotein-related proteins (APOC1, APOB, APOA1, APOL1 and LCAT) and a substantial quantitative alteration of key serpins (including A4, D1, A7, A6, F2, F1 and 1) possibly associated with IMN or NS and podocyte stress. A critical dysregulation in metabolisms of lipids (e.g., VLDL assembly and clearance) likely to be related to known hyperlipidemia in IMN, along with involvement of non-classical complement pathways and a putative enrolment of ficolin-2 in sustaining the activation of the lectin-mediated complement system have been pinpointed. Moreover, mannose receptor CD206 (MRC1-down in IMN) and biotinidase (BTD-up in IMN) are able alone to accurately distinguish IMN vs. PN. To conclude, our work provides key proteomic insights into the IMN complexity, opening the way to an efficient stratification of MN patients.

Evidence for charge-based mimicry in anti dsDNA antibody generation.

Mechanisms for the generation of anti-dsDNA autoantibodies are still not completely elucidated. One theory states that dsDNA interacts for mimicry with antibodies raised versus other antigens but molecular features for mimicry are unknown. Here we show that, at physiological acid-base balance, anti-Annexin A1 binds IgG2 dsDNA in a competitive and dose-dependent way with Annexin A1 and that the competition between the two molecules is null at pH 9. On the other hand, these findings also show that dsDNA and Annexin A1 interact with their respective antibodies on a strictly pH-dependent basis: in both cases, the binding was minimal at pH 4 and maximal at pH9-10. The anionic charge of dsDNA is mainly conferred by the numerous phosphatidic residues. The epitope binding site of Annexin A1 for anti-Annexin A1 IgG2 was here characterized as a string of 34 amino acids at the NH2 terminus, 10 of which are anionic. Circulating levels of anti-dsDNA and anti-Annexin A1 IgG2 antibodies were strongly correlated in patients with systemic lupus erythematosus (n 496) and lupus nephritis (n 425) stratified for age, sex, etc. These results show that dsDNA competes with Annexin A1 for the binding with anti-Annexin A1 IgG2 on a dose and charged mediated base, being able to display an inhibition up to 75%. This study provides the first demonstration that dsDNA may interact with antibodies raised versus other anionic molecules (anti-Annexin A1 IgG2) because of charge mimicry and this interaction may contribute to anti-dsDNA antibodies generation.

Clinical and peculiar immunological manifestations of SARS-CoV-2 infection in systemic lupus erythematosus patients.

OBJECTIVES: The impact of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in patients with SLE remains unclear and data on clinical manifestations after infection are lacking. The aim of this multicentre study is to describe the effect of SARS-CoV-2 in SLE patients. METHODS: SLE patients referring to four Italian centres were monitored between February 2020 and March 2021. All patients with SARS-CoV-2 infection were included. Disease characteristics, treatment, disease activity and SARS-CoV-2-related symptoms were recorded before and after the infection. RESULTS: Fifty-one (6.14%) SLE patients were included among 830 who were regularly followed up. Nine (17.6%) had an asymptomatic infection and 5 (9.8%) out of 42 (82.6%) symptomatic patients developed interstitial pneumonia (no identified risk factor). The presence of SLE major organ involvement (particularly renal involvement) was associated with asymptomatic SARS-CoV-2 infection (P = 0.02). Chronic corticosteroid therapy was found to be associated with asymptomatic infection (P = 0.018). Three SLE flares (5.9%) were developed after SARS-CoV-2 infection: one of them was characterized by MPO-ANCA-positive pauci-immune crescentic necrotizing glomerulonephritis and granulomatous pneumonia. CONCLUSIONS: SARS-CoV-2 infection determined autoimmune flares in a small number of patients. Our data seem to confirm that there was not an increased risk of SARS-CoV-2 in SLE. Patients with asymptomatic SARS-CoV-2 infections were those having major SLE organ involvement. This may be explained by the high doses of corticosteroids and immunosuppressive agents used for SLE treatment.

Second Wave Antibodies in Autoimmune Renal Diseases: The Case of Lupus Nephritis.

Clinical Trial registry name and registration number: Zeus study, NCT02403115.

Definition of IgG Subclass-Specific Glycopatterns in Idiopathic Membranous Nephropathy: Aberrant IgG Glycoforms in Blood.

The podocyte injury, and consequent proteinuria, that characterize the pathology of idiopathic membranous nephropathy (IMN) is mediated by an autoimmune reaction against podocyte antigens. In particular, the activation of pathways leading to abundant renal deposits of complement is likely to involve the binding of mannose-binding lectin (MBL) to aberrant glycans on immunoglobulins. To obtain a landscape of circulatory IgG Fc glycosylation characterizing this disease, we conducted a systematic N-glycan profiling study of IgG1, 2, and 4 by mass spectrometry. The cohort included 57 IMN patients, a pathological control group with nephrotic syndrome (PN) (n = 20), and 88 healthy control subjects. The effect of sex and age was assessed in all groups and controlled by rigorous matching. Several IgG Fc glycan traits were found to be associated with IMN. Interestingly, among them, only IgG4-related results were specific for IMN and not for PN. Hypo-galactosylation of IgG4, already shown for IMN, was observed to occur in the absence of core fucose, in line with a probable increase of pro-inflammatory IgG. In addition, elevated levels of fucosylated IgG4, along with low levels of hybrid-type glycans, were detected. Some of these IgG4 alterations are likely to be more pronounced in high PLA2R (phospholipase A2 receptor) patients. IgG Fc glycosylation patterns associated with IMN warrant further studies of their role in disease mechanisms and may eventually enrich the diagnostic spectrum regarding patient stratification.

Serum IgG2 antibody multicomposition in systemic lupus erythematosus and lupus nephritis (Part 1): cross-sectional analysis.

OBJECTIVES: Serum anti-dsDNA and anti-nucleosome IgGs have been proposed as signatures for SLE and LN in limited numbers of patients. We sought to show higher sensitivity and specificity of the same antibodies with the IgG2 isotype and included IgG2 antibodies vs specific intracellular antigens in the analysis. METHODS: A total of 1052 SLE patients with (n = 479) and without (n = 573) LN, recruited at different times from the beginning of symptoms, were included in the study. Patients with primary APS (PAPS, n = 24), RA (RA, n = 24) and UCTD (UCTD, n = 96) were analysed for comparison. Anti-nucleosome (dsDNA, Histone2A, Histone3), anti-intracellular antigens (ENO1), anti-annexin A1 and anti-C1q IgG2 were determined by non-commercial techniques. RESULTS: The presence in the serum of the IgG2 panel was highly discriminatory for SLE/LN vs healthy subjects. Serum levels of anti-dsDNA and anti-C1q IgG2 were more sensitive than those of IgGs (Farr radioimmunoassay/commercial assays) in identifying SLE patients at low-medium increments. Of more importance, serum positivity for anti-ENO1 and anti-H2A IgG2 discriminated between LN and SLE (ROC T0-12 months), and high levels at T0-1 month were detected in 63% and 67%, respectively, of LN, vs 3% and 3%, respectively, of SLE patients; serum positivity for each of these was correlated with high SLEDAI values. Minor differences existed between LN/SLE and the other rheumatologic conditions. CONCLUSION: Nephritogenic IgG2 antibodies represent a specific signature of SLE/LN, with a few overlaps with other rheumatologic conditions. High levels of anti-ENO1 and anti-H2A IgG2 correlated with SLE activity indexes and were discriminatory between SLE patients limited to the renal complication and other SLE patients. TRIAL REGISTRATION: The Zeus study was registered at https://clinicaltrials.gov, NCT02403115.

Serum IgG2 antibody multi-composition in systemic lupus erythematosus and in lupus nephritis (Part 2): prospective study.

OBJECTIVES: Circulating anti-ENO1 and anti-H2A IgG2 have been identified as specific signatures of LN in a cross-over approach. We sought to show whether the same antibodies identify selected population of patients with LN with potentially different clinical outcomes. METHODS: Here we report the prospective analysis over 36 months of circulating IgG2 levels in patients with newly diagnosed LN (n=91) and SLE (n=31) and in other patients with SLE recruited within 2 years from diagnosis (n=99). Anti-podocyte (ENO1), anti-nucleosome (DNA, histone 2 A, histone 3) and anti-circulating proteins (C1q, AnnexinA1-ANXA1) IgG2 antibodies were determined by home-made techniques. RESULTS: LN patients were the main focus of the study. Anti-ENO1, anti-H2A and anti-ANXA1 IgG2 decreased in parallel to proteinuria and normalized within 12 months in the majority of patients while anti-dsDNA IgG2 remained high over the 36 months. Anti-ENO1 and anti-H2A had the highest association with proteinuria (Heat Map) and identified the highest number of patients with high proteinuria (68% and 71% respectively) and/or with reduced estimated glomerula filtration rate (eGFR) (58% for both antibodies) compared with 23% and 17% of anti-dsDNA (agreement analysis). Anti-ENO1 positive LN patients had higher proteinuria than negative patients at T0 and presented the maximal decrement within 12 months. CONCLUSIONS: Anti-ENO1, anti-H2A and anti-ANXA1 antibodies were associated with high proteinuria in LN patients and Anti-ENO1 also presented the maximal reduction within 12 months that paralleled the decrease of proteinuria. Anti-dsDNA were not associated with renal outcome parameters. New IgG2 antibody signatures should be utilized as tracers of personalized therapies in LN. TRIAL REGISTRATION: The Zeus study was registered at https://clinicaltrials.gov (study number: NCT02403115).

Lack of EULAR/ERA-EDTA response at 1 year predicts poor long-term renal outcome in patients with lupus nephritis.

OBJECTIVES: Short-term predictive endpoints of chronic kidney disease (CKD) are needed in lupus nephritis (LN). We tested response to therapy at 1 year. METHODS: We considered patients with LN who underwent renal biopsy followed by induction therapy between January 1970 and December 2016. LN was assessed using the International Society of Nephrology/Renal Pathology Society (2003) criteria and the National Institute of Health (NIH) activity and chronicity index. The renal outcome was CKD. Response was defined according to EULAR/European League Against Rheumatism/European Renal Association-European Dialysis and Transplant Association (EULAR/ERA-EDTA) recommendations: complete: proteinuria <0.5 g/24 hours, (near) normal estimated glomerular filtration rate (eGFR); partial: ≥50% proteinuria reduction to subnephrotic levels, (near) normal eGFR; and no response: all the other cases. Logistic regression analysis was employed for 12-month response and Cox regression for CKD prediction. RESULTS: We studied 381 patients (90.5% Caucasians). After 12-month therapy, 58%, 26% and 16% of patients achieved complete, partial and no response, respectively, according to EULAR/ERA-EDTA. During a median follow-up of 10.7 (IQR: 4.97-18.80) years, 53 patients developed CKD. At 15 years, CKD-free survival rate was 95.2%, 87.6% and 55.4% in patients with complete, partial and no response at 12 months, respectively (p<0.0001). CKD-free survival rates did not differ between complete and partial responders (p=0.067). Serum creatinine (HR: 1.485, 95% CI 1.276 to 1.625), eGFR (HR 0.967, 95% CI 0.957 to 0.977) and proteinuria at 12 months (HR 1.234, 95% CI 1.111 to 1.379) were associated with CKD, yet no reliable cut-offs were identified on the receiver operating characteristic curve. In multivariable analysis, no EULAR/ERA-EDTA response at 12 months (HR 5.165, 95% CI 2.770 to 7.628), low C4 (HR 1.053, 95% CI 1.019 to 1.089) and persistent arterial hypertension (HR 3.154, 95% CI 1.500 to 4.547) independently predicted CKD. CONCLUSIONS: Lack of EULAR/ERA-EDTA response at 12 months predicts CKD.

Anti-Neutrophil Cytoplasmic Antibodies Positivity and Anti-Leukotrienes in Eosinophilic Granulomatosis with Polyangiitis: A Retrospective Monocentric Study on 134 Italian Patients.

BACKGROUND: Eosinophilic granulomatosis with polyangiitis (EGPA) is a systemic vasculitis associated with asthma, anti-neutrophil cytoplasmic antibodies (ANCA) positivity, and tissue eosinophilia. OBJECTIVE: To describe the presenting clinical features, significant biochemical alterations, and also potential pathogenic factors in adult patients diagnosed in our Center over a period of >20 years. METHOD: A retrospective study of EGPA patients diagnosed from 1994 to 2019 at ASST Grande Ospedale Metropolitano Niguarda Ca' Granda, Milan (Italy), which was performed according to the 1990 American College of Rheumatology criteria and Chapel Hill Consensus Conference definition. A dataset was compiled, registering demographic and clinical features, biochemical analysis at onset, and also the therapies received 3 months prior to EGPA diagnose. Statistical analyses were subsequently conducted dividing patients in 2 groups based on ANCA positivity and comparing them. RESULTS: Two groups were clearly identified by ANCA serology and specific organ involvement in accordance with literature reports; however, our data underline for the first time the association between anti-leukotriene receptor antagonists (LTRAs) and ANCA positivity. The group of previously treated patients presents an OR of 6.42 to be ANCA positive. This finding could be attributed to an imbalanced stimulation of leukotriene receptors, inducing both mast cells activation and an increased neutrophil extracellular traps release from neutrophils. CONCLUSION: Despite the limitations of this retrospective study, the association between LTRAs and ANCA antibodies elucidates the mechanism by which innate immunity is directly involved in tolerance breakdown and autoantibodies production. Validation of our results with targeted studies could clarify the differences between ANCA-positive and ANCA-negative patients with important consequences on the use of some drug classes in the treatment of EGPA and asthmatic subjects.

Changing patterns in clinical-histological presentation and renal outcome over the last five decades in a cohort of 499 patients with lupus nephritis.

OBJECTIVES: To evaluate changes in demographic, clinical and histological presentation, and prognosis of lupus nephritis (LN) over time. PATIENTS AND METHODS: We studied a multicentre cohort of 499 patients diagnosed with LN from 1970 to 2016. The 46-year follow-up was subdivided into three periods (P): P1 1970-1985, P2 1986-2001 and P3 2002-2016, and patients accordingly grouped based on the year of LN diagnosis. Predictors of patient and renal survival were investigated by univariate and multivariate proportional hazards Cox regression analyses. Survival curves were compared using the log-rank test. RESULTS: A progressive increase in patient age at the time of LN diagnosis (p<0.0001) and a longer time between systemic lupus erythematosus onset and LN occurrence (p<0.0001) was observed from 1970 to 2016. During the same period, the frequency of renal insufficiency at the time of LN presentation progressively decreased (p<0.0001) and that of isolated urinary abnormalities increased (p<0.0001). No changes in histological class and activity index were observed, while chronicity index significantly decreased from 1970 to 2016 (p=0.023). Survival without end-stage renal disease (ESRD) was 87% in P1, 94% in P2% and 99% in P3 at 10 years, 80% in P1 and 90% in P2 at 20 years (p=0.0019). At multivariate analysis, male gender, arterial hypertension, absence of maintenance immunosuppressive therapy, increased serum creatinine, and high activity and chronicity index were independent predictors of ESRD. CONCLUSIONS: Clinical presentation of LN has become less severe in the last years, leading to a better long-term renal survival.

Anticoagulant-related nephropathy: a pathological note.

The wide employment of oral anticoagulants and the introduction of new anticoagulant agents highlight disparate kind of toxicities that can affect many different organ systems. Renal toxicity by oral anticoagulants is a well-known entity characterized by hematuria and the worsening of renal function associated with uncontrolled INR values. Although it is mainly a clinical diagnosis, renal biopsy may help especially in challenging cases when multiple comorbidities and underlying renal conditions exist. The mechanism of the anticoagulant-induced damage is still debated and special tissue stains (such as Perls') could help in detecting the direct tubular toxicity induced by chronic glomerular bleeding. The employment of a diagnostic clinic-pathological flow-chart can help in the prompt detection and full characterization of these cases, improving the management of the patient.

Low-dose rituximab is poorly effective in patients with primary membranous nephropathy.

BACKGROUND: The optimal dosing and the efficacy of rituximab for primary membranous nephropathy (PMN) has not been established. This multicentric prospective study evaluates the efficacy and safety of low-dose rituximab (RTX) therapy in patients with PMN in clinical practice. METHODS: Thirty-four consecutive patients with PMN and nephrotic syndrome were included and received RTX (375 mg/m2) once (18 patients) or twice (16 patients). RTX was the first-line therapy for 19 (56%) and the second line for 15 (44%) patients. All patients were followed for 12 months after RTX and 24 for at least 18 months (mean 23.9 ± 18.6 months). RESULTS: At 12 months, 5 patients (14.7%) achieved complete response, 10 (29.4%) partial and 19 (55.8%) no response. Response occurred ∼6 months after RTX. At 24 months, the clinical situation was unchanged: two non-responders achieved partial response and two responders relapsed. Responders had significantly higher baseline GFR and lower anti-PLA2R antibodies compared with non-responders. Outcome was similar between one or two doses of RTX (non-responders 55.5 versus 56%, respectively) and between patients who had received previous therapy versus those receiving RTX as first-line therapy (non-responders 40 versus 68%, respectively). In the 15 patients already treated, the response to RTX was comparable to that of previous therapies. CONCLUSION: Low-dose RTX obtains remission in <50% of PMN patients. Probably, higher doses and longer treatments are needed to induce and maintain a response. The balance between the costs and benefits should guide the selection of the patient and the optimal dosage.