Circulating extracellular vesicles and small non-coding RNAs cargo in idiopathic inflammatory myopathies reveal differences across myositis subsets.

OBJECTIVE: To investigate the epigenetic footprint of idiopathic inflammatory myopathies (IIM) through characterization of circulating extracellular vesicles (EVs) and the expression of EV-derived small non-coding RNAs (sncRNAs). METHODS: In this cross-sectional study, EVs were isolated by size-exclusion chromatography from plasma of patients with IIM and age- and sex-matched healthy donors (HD). EV-derived sncRNAs were sequenced and quantified using Next-Generation Sequencing (NGS). Following quality control and normalization, filtered count reads were used for differential microRNA (miRNA) and piwi-interacting RNA (piRNA) expression analyses. Putative gene targets enriched for pathways implicated in IIM were analyzed. Patients' clinical and laboratory characteristics at the time of sampling were recorded. RESULTS: Forty-seven IIM patients and 45 HD were enrolled. MiR-486-5p (p < 0.01), miR-122-5p, miR-192-5p, and miR-32-5p were significantly upregulated (p < 0.05 for all), while miR-142-3p (p < 0.001), miR-141-3p (p < 0.01), let-7a-5p (p < 0.05) and miR-3613-5p (p < 0.05) downregulated in EVs from IIM patients versus HD. MiR-486-5p was associated with raised muscle enzymes levels. Several target genes of up/downregulated miRNAs in IIM participate in inflammation, necroptosis, interferon and immune signaling. Six piRNAs were significantly dysregulated in IIM EVs versus HD (p < 0.05). Within IIM, miR-335-5p was selectively upregulated and miR-27a-5p downregulated in dermatomyositis (n = 21, p < 0.01). Finally, plasma EV levels were significantly increased in cancer-associated myositis (CAM, n = 12) versus non-CAM IIM (n = 35, p = 0.02) and HD (p < 0.01). EVs cargo in CAM was significantly enriched of let-7f-5p and depleted of miR-143-3p. CONCLUSION: Through an unbiased screening of EV-derived sncRNAs, we characterize miRNAs and piRNAs in the EVs cargo as potential biomarkers and modifiers of diverse IIM phenotypes.

The SLE-DAS provides an accurate and feasible flare tool in the clinical setting: a validation study.

OBJECTIVE: To assess the criterion validity of the SLE disease activity score (SLE-DAS) flare tool and compare its performance in identifying flares against other instruments. METHODS: Patients with SLE fulfilling SLE-DAS low disease activity at baseline were included from two academic lupus clinics. During follow-up, flares were identified by the senior attending clinician, applying the expert-consensus-based definition as gold-standard. The first clinical flare from flaring patients, and the first visit after baseline in patients without flares were analysed. In each no flare/flare visits, we assessed flares by SLE-DAS (score increase ≥1.72), classic-SELENA Flare Index (c-SELENA FI), revised-SELENA FI (r-SELENA FI), and SLEDAI-2K (score increase ≥4). We estimated the sensitivity, specificity, and Cohen's Kappa agreement of each flare tool against the gold-standard. RESULTS: A total of 442 patients were included and followed-up for 22.9 (14.2) months. Incidence of flares was 8.19/100 patient-years, with 69 patients experiencing flares. The SLE-DAS identified 96.6% of the expert-defined flares implying a treatment change and classified 28.0% of those as moderate/severe. Sensitivity and specificity for the gold-standard flare definition were: SLE-DAS 97.1% and 97.3%, c-SELENA FI 88.4% and 98.1%, r-SELENA FI 88.4% and 96.8%, SLEDAI-2K 56.5% and 99.2%, respectively. Kappa coefficients of these instruments were 0.902 (95% CI: 0.847, 0.957), 0.870 (95% CI: 0.805, 0.935), 0.832 (95% CI: 0.761, 0.903), and 0.663 (95% CI: 0.557, 0.769), respectively. The number of flare misclassifications was lowest with the SLE-DAS, and highest with the SLEDAI-2K. CONCLUSION: The SLE-DAS accurately identifies and categorizes flares as mild or moderate/severe. It is feasible and, thus, may help the physicians' treatment decisions in the clinical practice setting.

Anifrolumab In Refractory Systemic Lupus Erythematosus: A Real-Life, Multicenter Study.

OBJECTIVE: To report the real-world experience on the use of ANI in refractory SLE. METHODS: Multicenter retrospective study involving 9 Italian SLE referral centers participating in a compassionate use program for the use of ANI in active adult SLE patients in whom all the available treatment choices failed, were not tolerated or contraindicated.At baseline, at 1, 3, 6, 9 and 12 months of treatment, overall and organ specific disease activity, flares, daily glucocorticoid (GC) dose, and adverse events were recorded. RESULTS: A total of 26 patients were enrolled. At 4 weeks after starting ANI, a significant decrease in SLEDAI-2K (p=0.005), SLEDAS (p=0.005) and PGA (p=0.001) was recorded, and the same trend was maintained over time. A significant reduction in CLASI-activity (p<0.001) and in tender (p=0.026) and swollen (p=0.017) joint count was also recorded. At 3 months of follow-up, 33% of patients already achieved a remission state, while 46% were in LLDAS; at 6 months, 50% were in remission and 80% in LLDAS. A significant reduction in the mean GC daily dose was observed, starting from week 4 (p=0.04). A total of 4 disease flares according to the SELENA-SLEDAI Flare Index were recorded (three mild-moderate and one severe). Overall, 4 out of 20 patients with at least 24 weeks of follow-up (20%) were considered "non responders". CONCLUSION: This study provides a real-world experience on the use of ANI in refractory SLE patients, confirming its rapid effectiveness and an overall acceptable safety profile.

MicroRNAs in idiopathic inflammatory myopathies: state-of-the-art and future perspectives.

PURPOSE OF REVIEW: Idiopathic inflammatory myopathies (IIMs) are a group of rare autoimmune disorders characterized by muscle weakness and inflammation. MicroRNAs (miRNAs) are the main class of small noncoding RNAs regulating a wide range of physiological and pathological processes and play a role in mediating autoimmunity and inflammation. In this review, we summarize the latest knowledge on the role of miRNAs in systemic autoimmune diseases with particular focus on IIMs. RECENT FINDINGS: Study on miRNA expression in IIMs is helping in understanding the pathogenetic basis of the disease at a tissue and systemic level. Several miRNAs, even with a muscle-specific expression (myomiRs), have been shown to be involved in immune and nonimmune mechanisms of myofiber damage. MiRNAs modulate and orchestrate the local inflammatory infiltrate and could be used as potential biomarkers as they correlate with disease activity and response to therapy. SUMMARY: IIMs comprise different clinical phenotypes and still little is known about the molecular signature of each subset. Further research about miRNA profiling will provide additional insights in the disease characterization with an expected impact on the therapeutic strategies.

New onset and flare of rheumatic diseases following COVID-19 vaccination are mild and respond well to treatment: 9-month follow-up data from a single centre cohort.

OBJECTIVES: Anti-COVID-19 vaccines have proved to be effective and well tolerated. Great attention is now being paid to the characterisation of possible adverse events associated to their administration. We report a case series of suspected rheumatic diseases (RDs) following anti-COVID-19 vaccination. METHODS: We included patients evaluated at first-aid rheumatologic consultancy and at rheumatologic outpatient and inpatient clinic at Padova University Hospital between May and September 2021 presenting with a RD within 30 days after an anti-COVID-19 vaccine dose. Our selection was in accordance with the World Health Organisation guidelines for adverse event following immunisation (AEFI) surveillance. Patients were regularly re-evaluated by telemedicine or face-to-face visit. RESULTS: We identified 30 cases of RD following vaccination: 24 (80.0%) new onsets and 6 (20.0%) flares. Most of patients (76.6%) received the BNT162b2 vaccine. The mean time to RD onset/flare was 12±9 days. The most common manifestations were inflammatory arthritis (40.0%), rheumatic polymyalgia (33.3%) and adult-onset Still's disease (13.3%). At the last FU visit (9.6±2.2 months), 83.3% of patients showed complete response to first- or second-line therapy, 13.3% a partial response and one patient (3.3%) was still experiencing an active disease. CONCLUSIONS: Considering the amount of vaccine doses administered during the evaluation period we overall detected a limited number of cases. We noted a clear prevalence of autoinflammatory conditions and seronegative manifestations. The great majority of patients had mild features and showed a good response to therapy.

Size-Exclusion Chromatography Combined with Ultrafiltration Efficiently Isolates Extracellular Vesicles from Human Blood Samples in Health and Disease.

There is still a need for an efficient method for the isolation of extracellular vesicles (EVs) from human blood that provides a reliable yield with acceptable purity. Blood is a source of circulating EVs, but soluble proteins and lipoproteins hamper their concentration, isolation, and detection. This study aims to investigate the efficiency of EV isolation and characterization methods not defined as "gold standard". EVs were isolated from human platelet-free plasma (PFP) of patients and healthy donors through size-exclusion chromatography (SEC) combined with ultrafiltration (UF). Then, EVs were characterized using transmission electron microscopy (TEM), imaging flow cytometry (IFC), and nanoparticle tracking analysis (NTA). TEM images showed intact and roundish nanoparticles in pure samples. IFC analysis detected a prevalence of CD63+ EVs compared to CD9+, CD81+, and CD11c+ EVs. NTA confirmed the presence of small EVs with a concentration of ~1010 EVs/mL that were comparable when stratifying the subjects by baseline demographics; conversely, concentration differed according to the health status across healthy donors and patients affected with autoimmune diseases (130 subjects in total, with 65 healthy donors and 65 idiopathic inflammatory myopathy (IIM) patients). Altogether, our data show that a combined EV isolation method, i.e., SEC followed by UF, is a reliable approach to isolate intact EVs with a significant yield from complex fluids, which might characterize disease conditions early.

Characterization of Serum Cytokine Profiles of Patients with Active Lupus Nephritis.

Cytokines contribute to the pathogenesis of lupus nephritis (LN), yet their value as prognostic biomarkers is still debated. We aimed to describe the serum cytokines' profiles and prospectively assess correlations with disease features and renal response in a multicentric cohort of consecutive adult patients with biopsy-proven active LN. Cytokine associations with clinical and serological data were performed at LN diagnosis (T0), and at 3 (T3) and 6 months (T6) of follow up. Renal response according to EULAR definition was assessed at T3, T6 and T12. BAFF and interleukin (IL)-37 were measured by ELISA; IL-2, IL-10, IL-17A and IL-18 by a bead-based multiplex cytokine assay (Luminex). Thirty-nine patients with active LN (age 40.5 ± 15.6 years; F 71.8%; 84.6% proliferative LN) were enrolled, of whom twenty-nine displayed complete longitudinal records. At T0, we observed higher levels of IL-37 and IL-17 in proliferative vs. non-proliferative LN (IL-37: 0.0510 (0.0110-0.2300) vs. 0.0000 (0.0000-0.0397) ng/mL, p = 0.0441; IL-17: 2.0920 (0.5125-17.9400) vs. 0.0000 (0.0000-0.6025) pg/mL, p = 0.0026, respectively), and positive correlations between IL-10 and 24 h proteinuria (r = 0.416, p = 0.0249) and anti-dsDNA levels (r = 0.639, p = 0.0003). BAFF was higher in patients with low complement (p < 0.0001). We observed a sustained correlation between BAFF and IL-10 throughout T6 (r = 0.654, p = 0.0210). Higher baseline IL-37 and BAFF levels were associated with renal response at T3 and T6, respectively, while baseline IL-18 levels were higher in patients achieving response at T12. Our study highlights the complexity of the cytokine network and its potential value as a marker of active LN and renal response.

Anti-MDA5 dermatomyositis: an update from bench to bedside.

PURPOSE OF REVIEW: This review summarizes the recent developments about anti-MDA5 antibody positive dermatomyositis with a focus on its pathogenesis, clinical features and treatment options of rapidly progressive interstitial lung disease, its most ominous complication. RECENT FINDINGS: Anti-MDA5+ dermatomyositis has a heterogeneous clinical spectrum with different patient subsets exhibiting widely different outcomes; severe acute interstitial lung disease is the main factor impacting prognosis. The pathogenetic role of anti-MDA5 antibodies is an active area of investigation. SUMMARY: Anti-MDA5+ dermatomyositis has a wider spectrum of manifestations than previously thought. A high index of suspicion is needed not to miss atypical presentations. In the setting of acute interstitial lung involvement, once a confident diagnosis is made, an aggressive approach with early combined immunosuppression affords the best chances of survival.

Immunosuppressive therapy withdrawal after remission achievement in patients with lupus nephritis.

OBJECTIVES: Whether immunosuppressive therapy may be safely withdrawn in lupus nephritis (LN) is still unclear. We assessed rate and predictors of flare after IS withdrawal in patients with LN in remission. METHODS: Patients with biopsy-proven LN treated with immunosuppressants (IS) between 1980 and 2020 were considered. Remission was defined as normal serum creatinine, proteinuria <0.5 g/24 h, inactive urine sediment, and no extra-renal SLE activity on stable immunosuppressive and/or antimalarial therapy and/or prednisone ≤5mg/day. IS discontinuation was defined as the complete withdrawal of immunosuppressive therapy, flares according to SLEDAI Flare Index. Predictors of flare were analysed by multivariate logistic regression analysis. RESULTS: Among 513 SLE patients included in our database, 270 had LN. Of them, 238 underwent renal biopsy and were treated with IS. Eighty-three patients (34.8%) discontinued IS, 46 (30) months after remission achievement. During a mean (s.d.) follow-up of 116.5 (78) months, 19 patients (22.9%) developed a flare (8/19 renal) and were re-treated; 14/19 (73.7%) re-achieved remission after restarting therapy. Patients treated with IS therapy for at least 3 years after remission achievement had the lowest risk of relapse (OR 0.284, 95% CI: 0.093, 0.867; P = 0.023). At multivariate analysis, antimalarial maintenance therapy (OR 0.194, 95% CI: 0.038, 0.978; P = 0.047), age at IS discontinuation (OR 0.93, 95% CI: 0.868, 0.997; P = 0.040), remission duration >3 years before IS discontinuation (OR 0.231, 95% CI: 0.058, 0.920; P = 0.038) were protective against disease flares. CONCLUSIONS: Withdrawal of IS is feasible in LN patients in remission for at least 3 years and on antimalarial therapy. Patients who experience flares can re-achieve remission with an appropriate treatment.

B Cell Kinetics upon Therapy Commencement for Active Extrarenal Systemic Lupus Erythematosus in Relation to Development of Renal Flares: Results from Three Phase III Clinical Trials of Belimumab.

Renal flares constitute major determinants of poor prognosis in people living with systemic lupus erythematosus (SLE). The aim of the present study was to investigate changes in B cell subsets in relation to renal flares upon initiation of standard therapy (ST) plus belimumab or placebo in patients with SLE. Using data from the BLISS-76, BLISS-SC, and BLISS Northeast Asia trials, we investigated associations of relative to baseline rapid (through week 8) and early (through week 24) percentage changes in circulating CD19+ B cell subsets characterised through flow cytometry, anti-dsDNA antibodies, and complement levels with the occurrence of renal flares over one year. Patients who developed renal flares showed more prominent rapid decreases in CD19+CD20+CD138+ short-lived plasma cells (-50.4% vs. -16.7%; p = 0.019) and CD19+CD20-CD27bright plasmablasts (-50.0% vs. -29.9%; p = 0.020) compared to non-flaring patients, followed by a subsequent return. Less prominent rapid reductions in CD19+CD27-CD24brightCD38bright transitional B cells (-42.9% vs. -75.0%; p = 0.038) and CD19+CD20-CD138+ peripheral long-lived plasma cells (-11.3% vs. -29.2%; p = 0.019) were seen in belimumab-treated-but not placebo-treated-patients who developed renal flares compared to belimumab-treated patients who did not. Rapid and early changes in anti-dsDNA or complement levels showed no clear association with renal flares. In summary, a rapid drop followed by a subsequent return in circulating short-lived plasma cells and plasmablasts upon treatment for active extra-renal SLE portended renal flares, indicating a need for therapeutic adjustments in patients showing such B cell patterns. Rapid decreases in transitional B cells and peripheral long-lived plasma cells upon belimumab therapy commencement may signify a greater protection against renal flares. B cell kinetics may prove useful in early drug evaluation.

Lymphocyte immunophenotyping in inflammatory myositis: a review.

PURPOSE OF REVIEW: This is a comprehensive review of the current knowledge on predominant immune cell phenotypes involved in idiopathic inflammatory myopathies (IIM). RECENT FINDINGS: Major circulating immune cell subpopulations described in IIM encompass the lymphocyte compartment. An unbalance in T cell subsets seems to consistently affect the peripheral and muscle compartment, with a predominance of CD4+ T and B cells in dermatomyositis, CD8+ T cells in polymyositis/inclusion body myositis (IBM) and novel findings highlighting novel proinflammatory T subsets, that is, CD8+Tbet+ and CD28- T cells across different IIM subsets. On the other hand, an impairment in Treg cells number and function has been described especially across polymyositis/dermatomyositis and IBM. Total T follicular helper (Tfh) cells, increased in immune-mediated necrotizing myopathy, skewed toward Tfh2 and Tfh17 in dermatomyositis, polymyositis, and juvenile dermatomyositis. B cell compartment is more rarely described in IIM, yet an unbalance in this pool is as well likely. Evidence of plasma cells increased in polymyositis, dermatomyositis, IBM, and Bregs decreased in dermatomyositis have been reported. Perturbations in the memory and naïve subsets are common in dermatomyositis/polymyositis and antisynthetase syndrome. SUMMARY: Protean immune cell abnormalities characterize different IIM subsets, reflecting the complexity of these autoimmune conditions. A deeper understanding of B-cell and T-cell immunophenotyping may promote early diagnosis and identification of new potential therapeutic targets.

IgG anti-Pentraxin 3 antibodies are a novel biomarker of ANCA-associated vasculitis and better identify patients with eosinophilic granulomatosis with polyangiitis.

OBJECTIVE: To investigate prevalence of anti-Pentraxin 3 (PTX3) antibodies in sera of anti-neutrophil cytoplasmic antibodies (ANCA)-associated vasculitis (AAV) patients. METHODS: Anti-PTX3 and PTX3 levels were analysed by enzyme-linked immunosorbent assays in sera from unselected patients with AAV and compared with patients with systemic lupus erythematosus (SLE, n = 130), other connective tissue diseases (CTDs, n = 97) and matched healthy controls (n = 97). Optical density (OD) cut-off for positive anti-PTX3 antibodies was determined by ROC curve analysis and set as 0.234. Indirect immunofluorescence (IIF) on fixed human granulocytes was used to analyze the fluorescence pattern of anti-PTX3 antibodies. Liquid-phase inhibition tests were conducted to assess potential interferences. RESULTS: We included 101 AAV patients (females 58%, median age 60[51-69] years) affected either with granulomatosis with polyangiitis (GPA, n = 51), microscopic polyangiitis (MPA, n = 12) or eosinophilic granulomatosis with polyangiitis (EGPA, n = 38). Anti-PTX3 antibodies were detected in 29.7% AAV patients, being significantly higher than in healthy controls (p < 0.001) and CTDs (p = 0.030) but lower than in SLE (p = 0.004). Anti-PTX3 antibody prevalence was 44.7% in EGPA, 25% in MPA and 19% in GPA (p = 0.034). Among ANCA negative patients, 35.7% displayed positive anti-PTX3 antibodies. Anti-PTX3 were associated with a lower prevalence of systemic (p = 0.002), ear-nose-throat (p = 0.006) and renal manifestations (p = 0.016). Anti-PTX3 antibodies were characterized by a specific IIF pattern on fixed granulocytes. PTX3 serum levels resulted lower in AAV than healthy controls (p < 0.001). PTX3 inhibited anti-PTX3 binding in a dose-dependent manner. CONCLUSIONS: Anti-PTX3 autoantibodies appear a promising novel biomarker of AAV, especially EGPA.

Durable renal response and safety with add-on belimumab in patients with lupus nephritis in real-life setting (BeRLiSS-LN). Results from a large, nationwide, multicentric cohort.

BACKGROUND: Belimumab was recently approved for treatment of lupus glomerulonephritis (LN). AIM: To evaluate renal response and its predictors in LN patients receiving belimumab in real-life. PATIENTS AND METHODS: We considered all patients fulfilling the SLEDAI-2K renal items and/or having estimated glomerular filtration rate (eGFR)≤60 ml/min/1.73 m2, with positive anti-dsDNA and/or low C3/C4 enrolled in the multicentre Italian lupus cohort BeRLiSS (BElimumab in Real LIfe Setting Study), treated with monthly IV Belimumab 10 mg/kg over standard treatment. Primary efficacy renal response (PERR), defined as proteinuria ≤0.7 g/24 h, eGFR≥60 ml/min/1.73 m2 without rescue therapy, was considered as primary outcome. Complete renal response (CRR; proteinuria <0.5 g/24 h, eGFR≥90 ml/min/1.73 m2) was considered as secondary outcome. Prevalence and predictors of PERR were evaluated at 6, 12, 24 months by multivariate logistic regression. RESULTS: Among the 466 SLE patients of BeRLiSS, 91 fulfilled the inclusion criteria, 79 females, median age 41.0 (33.0-47.0) years, median follow-up 22.0 (12.0-36.0) months. Sixty-four (70.3%) achieved PERR, of whom 38.4% reached CRR. Among patients achieving PERR at 6 months, 86.7% maintained response throughout the follow-up. At multivariable analysis, hypertension (OR [95%CI]: 0.28 [0.09-0.89], p = 0.032), high baseline serum creatinine (0.97 [0.95-0.99], p = 0.01) and high baseline proteinuria (0.37, [0.19-0.74], p = 0.005) negatively predicted PERR. Positive predictors of PERR at 12 and 24 months were baseline anti-Sm positivity (OR [95%CI]: 6.2 [1.21-31.7], p = 0.029; 19.8 [2.01-186.7], p = 0.009, respectively) and having achieved PERR at 6 months (14.4 [3.28-63.6]; 11.7 [2.7-48.7], p = 0.001 for both). CONCLUSIONS: Add-on therapy with belimumab led to durable renal response in patients with LN in a real-life setting.

Prevalence, outcome and management of patients with SLE and secondary antiphospholipid antibody syndrome after aPL seroconversion.

OBJECTIVE: The withdrawal of oral anticoagulation (OAC) in patients with SLE and secondary aPL syndrome (SAPS) who become seronegative has not been clearly investigated to date. Our aim was to evaluate the prevalence of aPL seroconversion and the prognosis of SLE patients with SAPS who withdrew OAC after aPL negativization. METHODS: We retrospectively analysed data of all SLE patients (ACR criteria) with SAPS (Sydney criteria) prospectively followed-up in our clinic. aPL seroconversion was defined as negativization of lupus anticoagulant, aCL, and anti-ß2glycoprotein-1 antibodies on two or more consecutive measurements, at least 12 weeks apart. OAC discontinuation was defined as the definitive withdrawal of all anticoagulants. RESULTS: Fifty-five out of 513 (10.7%) SLE patients had vascular SAPS. Sixteen patients (29.1%) became aPL seronegative during follow-up. Immunosuppressive therapy predicted aPL negativization (odds ratio 5.211, 95%CI 1.341, 20.243), whereas APS diagnosis prior to that of SLE (odds ratio 0.078, 95%CI 0.008, 0.799) and triple-positive profile (odds ratio 0.264, 95%CI 0.115, 0.609) were negative predictors of aPL negativization. OAC was discontinued in 13/55 patients (23.6%), after a median follow-up of 45 months (range 1-276) from aPL seroconversion. SLE-related modifiable risk factors for thrombosis were observed in 10/13 patients (77%) at the time of the thrombotic event. No thrombotic recurrences were observed during a mean follow-up time of 44 (19) months from OAC discontinuation. CONCLUSIONS: Our results suggest that OAC can be safely discontinued in SLE patients who became persistently seronegative for aPL, at least when aPL-related thrombotic events occurred in presence of other thrombotic risk factors.

Nonimmune mechanisms in idiopathic inflammatory myopathies.

PURPOSE OF REVIEW: This review encompasses the main novelties regarding nonimmune mechanisms implicated in the pathogenesis of idiopathic inflammatory myopathies (IIM). RECENT FINDINGS: In recent years, growing data support a role for endoplasmic-reticulum (ER) stress as a propagator of muscular damage, together with the release of interferon type I and reactive oxygen species in hypoxemic muscle fibers. Other studies evaluating the relationship between autophagy and Toll-like receptors (TLRs) in IIM subtypes have shown increased TLR3 and TLR4 expression in fibers of IIM patients and colocalization with LC3, an autophagy marker, submitting autophagy as a likely player in IIM pathogenesis. Most novel evidences concern the potential role of denervation of the neuromuscular junction in IIM, possibly connected to hyperexpression of MHC-I, and trafficking of extracellular vesicles, which may represent a connection between nonimmune and immune-mediated mechanisms of muscle inflammation and damage. SUMMARY: Nonimmune mechanisms contribute to the pathogenesis of IIM, likely cooperating with immune-mediated inflammation. Consistent data were released for ER stress, autophagy, mitochondrial dysfunction and hypoxia; in addition to, neuromuscular denervation and extracellular vesicles have been proposed as thoughtful links between muscle inflammation, damage and atrophy. Further understanding of nonimmune abnormalities and potential reversible pathways is needed to improve the management of IIM.

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.

Remission in systemic lupus erythematosus: testing different definitions in a large multicentre cohort.

OBJECTIVES: Remission in systemic lupus erythematosus (SLE) is defined through a combination of 'clinical SLE Disease Activity Index (cSLEDAI)=0', 'physician's global assessment (PGA) <0.5' and 'prednisone (PDN) ≤5 mg/day'. We investigated the performance of these items, alone or in combination, in defining remission and in predicting SLICC/ACR Damage Index. METHODS: We tested seven potential definitions of remission in SLE patients followed-up for ≥5 years: PDN ≤5 mg/day; PGA <0.5; cSLEDAI=0; PGA <0.5 plus PDN ≤5 mg/day; cSLEDAI=0 plus PGA <0.5; cSLEDAI=0 plus PDN ≤5 mg/day; cSLEDAI=0 plus PDN ≤5 mg/day plus PGA <0.5. The effect of these definitions on damage was evaluated by Poisson regression analysis; the best performance was identified as the lowest Akaike and Bayesian information criterion (AIC and BIC). Positive and negative predictive values in identifying no damage increase were calculated. RESULTS: We included 646 patients (mean±SD disease duration 9.2±6.9 years). At multivariate analysis, ≥2 consecutive year remission according to all definitions protected against damage (OR, 95% CI: PGA <0.5 0.631, 0.444 to 0.896; cSLEDAI=0 0.531, 0.371 to 0.759; PGA <0.5 plus PDN ≤5 mg/day 0.554, 0.381 to 0.805; cSLEDAI=0 plus PGA <0.5 0.574, 0.400 to 0.826; cSLEDAI=0 plus PDN ≤5 mg/day 0.543, 0.376 to 0.785; cSLEDAI=0 plus PDN ≤5 mg/day plus PGA <0.5 0.532, 0.363 to 0.781, p<0.01 for all), except PDN ≤5 mg/day, which required four consecutive years (OR 0.534, 95% CI 0.325 to 0.877, p=0.013). Positive and negative predictive values were similar; however, cSLEDAI=0 showed the best performance (AIC 1082.90, BIC 1109.72, p<0.0001). Adding PGA <0.5 and/or PDN ≤5 mg/day to cSLEDAI=0 decreased remission duration (-1.8 and -1.5 year/patient, respectively) without increasing cSLEDAI=0 performance in predicting damage accrual. CONCLUSIONS: cSLEDAI=0 is the most attainable definition of remission, while displaying the best performance in predicting damage progression in the short-to-mid-term follow-up.

Immunization with Pentraxin3 prevents transition from subclinical to clinical lupus nephritis in lupus-prone mice: Insights from renal ultrastructural findings.

BACKGROUND: Pentraxin3 (PTX3) is an emerging player in lupus nephritis (LN). Anti-PTX3 antibodies showed to delay LN occurrence in vivo. AIM: To evaluate renal changes following immunization with PTX3 in a murine model of LN. MATERIALS AND METHODS: Twenty-two lupus-prone New Zealand Black/White (NZB/W)F1 mice were divided into two groups (n = 11) and subcutaneously injected with human recombinant (hr)PTX3 100 µg or phosphate buffer saline (PBS) 200 µl, three times 3 weeks apart, starting before development of proteinuria. Five mice from each group were scheduled for sacrifice at week 22 and 6 from each group at week 29. Renal lesions included electron-dense deposits (EDD), glomerular deposition of IgG, complement and PTX3 as markers of renal inflammation. They were evaluated by immunofluorescence (IF), confocal and immunoelectron microscopy (IEM). Validated semiquantitative scores were used when available to score renal lesions. Chi-squared test with Fisher exact test was used for comparison. RESULTS: Nineteen out of 22 mice were sacrificed as scheduled. Only hrPTX3-immunized mice developed anti-PTX3 antibodies. Compared to PBS-injected mice, they displayed a dramatic decrease in glomerular deposits of IgG, C1q and PTX3, as well as in the amount of EDD (p = 0.006) and podocyte effacement (p = 0.043). Importantly, PTX3 was pinpointed inside the EDD and co-localized with nuclear material. CONCLUSIONS: Immunization with PTX3 prevented progression from the preclinical to the clinical stage of LN, inciting anti-PTX3 antibodies and preventing renal PTX3 deposition. PTX3 is a novel component of EDD, submitting it as one initiating autoantigen in LN and as potential target for early treatment.

Lupus nephritis: clinical presentations and outcomes in the 21st century.

Lupus nephritis (LN) is a frequent and severe manifestation of SLE. Along the decades, the epidemiology of LN and its clinical presentation have been changing. However, even though retrospective cohort studies report a decreased mortality rate and an improvement in the disease prognosis, the percentage of patients progressing into end stage renal disease (ESRD) keeps steady despite the improvements in therapeutic strategies. Current in-use medications have been available for decades now, yet over the years, regimens for optimizing their efficacy and minimizing toxicity have been developed. Therapeutic research is now moving towards the direction of precision medicine and several new drugs, targeting selectively different pathogenetic pathways, are currently under evaluation with promising results. In this review, we address the main changes and persistent unmet needs in LN management throughout the past decades, with a focus on prognosis and upcoming treatments.

Prevalence and predictors of flare after immunosuppressant discontinuation in patients with systemic lupus erythematosus in remission.

OBJECTIVES: Patients with SLE are often exposed to prolonged immunosuppression since few data on flare recurrence in remitted patients who discontinued immunosuppressants are available. We aimed to assess the rate and predictors of flare after immunosuppressant withdrawal in SLE patients in remission. METHODS: SLE patients diagnosed between 1990 and 2018 (according to the ACR criteria), ever treated with immunosuppressants and currently in follow-up were considered. Immunosuppressant discontinuation was defined as complete withdrawal of any immunosuppressive drug. Reasons for discontinuation were remission, defined as clinical SLEDAI-2K = 0 on a stable immunosuppressive and/or antimalarial therapy and/or on prednisone ⩽5 mg/day, or poor adherence/intolerance. Flares were defined according to the SLEDAI Flare Index. Predictors of a subsequent flare were analysed by multivariate logistic regression. RESULTS: There were 319 eligible patients out of 456 (69.9%). Of the 319 patients, 139 (43.5%) discontinued immunosuppressants, 105 (75.5%) due to remission, 34 (24.5%) due to poor adherence/intolerance. The mean (s.d.) follow-up time after immunosuppressant withdrawal was 91 (71) months (range 6-372). Among the patients who discontinued immunosuppressants, 26/105 remitted (24.7%) and 23/34 unremitted patients (67.6%) experienced a flare (P < 0.001) after a median (range) follow-up of 57 (6-264) and 8 months (1-72), respectively (P = 0.009). In patients who discontinued immunosuppressants due to remission, maintenance therapy with antimalarials (OR 0.243, 95% CI 0.070, 0.842) and the duration of remission at immunosuppressant discontinuation (OR 0.870, 0.824-0.996) were independent protective factors against disease flare. CONCLUSION: SLE flares are not uncommon after immunosuppressant discontinuation, even in remitted patients; however, antimalarial therapy and durable remission can significantly reduce the risk of flare.