Urine Galectin-3 binding protein reflects nephritis activity in systemic lupus erythematosus.

BACKGROUND: Lupus nephritis (LN) is a major and severe organ involvement in systemic lupus erythematosus (SLE), whose diagnosis and treatment necessitate to perform kidney biopsy, which is an invasive procedure. Non-invasive urine biomarkers are an active area of investigation to support LN diagnosis and management. OBJECTIVE: To investigate the role of urinary galectin-3 binding protein (u-Gal-3BP) as a candidate biomarker of renal disease in biopsy proven LN. PATIENTS AND METHODS: Levels of u-Gal-3BP were investigated in a cross-sectional fashion by ELISA in 270 subjects: 86 LN patients, 63 active SLE patients with no kidney involvement, 73 SLE patients with inactive disease and 48 age and sex-matched population-based controls (PBC). Moreover, urine samples were analysed separately by ELISA for additional markers of kidney pathology: neutrophil gelatinase-associated lipocalin (NGAL), osteopontin (OPN), kidney injury molecule-1 (KIM-1) and galectin-3 (Gal-3). The concentrations of all studied molecules were normalized to urine creatinine levels. In 10 patients, post-treatment levels of the biomarkers were measured. RESULTS: Normalized u-Gal-3BP levels were higher in LN patients compared to the other groups (p < .0001). Comparing different LN classes, u-Gal-3BP levels were higher among patients with proliferative (class III/IV) and membranous (class V) as compared to mesangial (class II) forms (p = .04). In proliferative forms, u-Gal-3BP levels correlated with the activity index in renal biopsies (r = 0.42, p = .004). Moreover, in a subset of 10 patients with repeated kidney biopsy and urine sampling before and after induction treatment, a significant decrease of u-Gal-3BP was observed (p = .03). Among the other markers, KIM-1 was also able to discriminate LN from the other groups, while NGAL, OPN and Gal-3 could not in this cohort. CONCLUSION: Given its ability to discriminate LN patients from active non-renal and inactive SLE patients, the observed correlation with the activity index in renal biopsies, and its levels declining following treatment, u-Gal-3BP shows promise as a non-invasive urinary biomarker to help detecting and to monitor renal involvement in SLE patients and should be validated in larger cohorts.

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.

The binding of SLE autoantibodies to mitochondria.

Systemic lupus erythematosus (SLE) is a prototypic autoimmune disease characterized by immune complexes. Because these complexes contain mitochondrial components, we assessed the presence of antibodies to whole mitochondria (wMITO) using an ELISA in which mitochondria from mouse liver are bound to microtiter plates pre-coated with poly-l-lysine. Studies with this ELISA demonstrated that SLE plasmas contain abundant anti-wMITO activity. While digestion with DNase 1 did not affect anti-wMITO activity, adsorption of plasma on DNA affinity columns could reduce binding activity. Assay for anti-mitochondrial antibodies (AMA) by immunofluorescence and an ELISA with the M2 antigen (2-oxo-acid dehydrogenase protein complex) showed a low frequency of positivity, indicating that AMA and anti-wMITO are distinct specificities. In the study of 204 patients with SLE, the levels of anti-wMITO were higher in active SLE and correlated with levels of anti-DNA. These findings suggest that anti-wMITO can form immune complexes with mitochondria which may drive pathogenesis.

Microparticles in the blood of patients with SLE: Size, content of mitochondria and role in circulating immune complexes.

OBJECTIVE: Microparticles (MPs) are small extracellular vesicles released from apoptotic or activated cells through a blebbing process. MPs express surface molecules from their parental cells and they bind IgG to form circulating immune complexes (MP-ICs) in patients with systemic lupus erythematosus (SLE). Through investigation of MP size, IgG expression, content of nucleic acids and mitochondrial molecules, we hypothesized that unrecognized particle populations can be identified in SLE. METHODS: We investigated 327 well-characterized SLE patients and 304 controls divided into two sets (280/280 and 47/24). We measured MPs by flow cytometry using a gating strategy to encompass small (0.2-0.7 µm) and large (0.7-3.0 µm) MPs. Nucleic acids were labeled with SYTO 13 and mitochondria with MitoTracker. Expression of mitochondria markers TOM-20 and Hexokinase 1 and the presence of IgG was investigated. RESULTS: MPs staining with SYTO 13 were more frequent in 280 SLE patients compared to 280 controls. In 47 SLE patients, levels of large MPs were elevated compared to 24 controls. The majority of large MPs contained mitochondria (mitoMPs). The number of mitoMPs associated positively with high disease activity, anti-dsDNA antibodies and pro-inflammatory cytokines. Patients with active lupus nephritis had higher levels of mitoMPs and IgG-positive mitoMPs. CONCLUSION: Blood of patients with SLE contain a previously unrecognized population of circulating large MPs with bound IgG and mitochondrial proteins. Levels of these particles are related to several measures of active SLE, suggesting that these structures may have a role in disease pathogenesis.

Methotrexate in early rheumatoid arthritis: Is the anchor drug still holding?

Treat-to-target (T2T) is currently the most fashionable strategy for treatment-naïve, early rheumatoid arthritis (RA) patients. A T2T approach can lead to a complete and drug-free disease remission, whereas failure to obtain remission leads to damage early in the disease course. Hence, one should try to achieve high remission rates as early as possible, implementing the best therapeutic strategies available. Methotrexate (MTX) combined with glucocorticoid bridging is the mainstay of T2T. However, MTX is often used suboptimally in RA patients for many reasons, including poor tolerability, low compliance, and safety issues. Recent evidence has suggested that novel targeted synthetic DMARDs (tsDMARDs) such as the Janus-kinase (JAK) inhibitors in combination with glucocorticoids yielded better outcomes in early RA than conventional treatment. Such an approach may have advantages in terms of patients' outcomes, though some concerns about serious adverse events need to be addressed.