A reverse translational study on the effect of rituximab, rituximab plus belimumab, or bortezomib on the humoral autoimmune response in SLE.

OBJECTIVES: SLE is a severe autoimmune disease characterized by autoreactive B cells and IC formation, which causes systemic inflammation. B cell-targeted therapy could be a promising treatment strategy in SLE patients; nevertheless, randomized clinical trials have not always been successful. However, some groups have demonstrated beneficial effects in severe SLE patients with off-label rituximab (RTX) with belimumab (BLM), or bortezomib (BTZ), which targeted different B cells subsets. This study assembled sera from SLE cohorts treated with RTX+BLM (n = 15), BTZ (n = 11) and RTX (n = 16) to get an in-depth insight into the immunological effects of these therapies on autoantibodies and IC formation. METHODS: Autoantibodies relevant for IC formation and the avidity of anti-dsDNA were determined by ELISA. IC-mediated inflammation was studied by complement levels and ex vivo serum-induced neutrophil extracellular trap formation. RESULTS: Reductions in autoantibodies were observed after all approaches, but the spectrum differed depending upon the treatment. Specifically, only RTX+BLM significantly decreased anti-C1q. Achieving seronegativity of ≥1 autoantibody, specifically anti-C1q, was associated with lower disease activity. In all SLE patients, the majority of anti-dsDNA autoantibodies had low avidity. RTX+BLM significantly reduced low-, medium- and high-avidity anti-dsDNA, while RTX and BTZ only significantly reduced medium avidity. IC-mediated inflammation, measured by C3 levels and neutrophil extracellular trap formation, improved after RTX+BLM and RTX but less after BTZ. CONCLUSION: This study demonstrated the impact of different B cell-targeted strategies on autoantibodies and IC formation and their potential clinical relevance in SLE.

Validation of the Systemic Lupus International Collaborating Clinics classification criteria in a cohort of patients with full house glomerular deposits.

In 2012, the Systemic Lupus International Collaborating Clinics (SLICC) presented a new classification for systemic lupus erythematosus (SLE). In this classification, biopsy-confirmed lupus nephritis with positive antinuclear or anti-double-stranded DNA antibodies became a stand-alone criterion. Because of the unknown diagnostic performance among patients from nephrology clinics, we aimed to test the validity of the SLICC classification, compared with the American College of Rheumatology classification, in a cohort of patients whose renal biopsies would raise the clinicopathologic suspicion of lupus nephritis. All patients with a renal biopsy showing full house glomerular deposits and clinical follow-up in our center were included and reevaluated, after which clinicians and a pathologist reached a consensus on the reference-standard clinical diagnosis of SLE. The diagnostic performance and net reclassification improvement were assessed in 149 patients, 117 of whom had clinical SLE. Compared with the American College of Rheumatology classification, the SLICC classification had better sensitivity (100 vs. 94%); although, this was at the expense of specificity (91 vs. 100%; net reclassification improvement -0.03). Excluding the stand-alone renal criterion, the specificity of the SLICC classification reached 100%, with a significant net reclassification improvement of 0.06 compared with the American College of Rheumatology classification. The SLICC classification performed well in terms of diagnostic sensitivity among patients with full house glomerular deposits; whereas, the stand-alone renal criterion had no additional value and compromised the specificity. Thus, presumed patients with lupus nephritis in nephrology clinics reflect a distinct SLE disease spectrum warranting caution when applying SLE classification criteria.

Idiopathic non-lupus full-house nephropathy is associated with poor renal outcome.

Background: Full-house immunofluorescence in combination with various histopathologic lesions in the renal biopsies of patients without overt systemic lupus erythematosus (SLE) poses a diagnostic challenge. In this setting, the biopsy findings are sometimes termed non-lupus 'full-house nephropathy' (FHN). It is presently unknown whether idiopathic non-lupus FHN is clinicopathologically and prognostically distinct from lupus FHN. Methods: We included non-lupus FHN patients and lupus FHN controls (four or more American College of Rheumatology or Systemic Lupus International Collaborating Clinics criteria) who were biopsied between 1968 and 2014 at the Leiden University Medical Centre. Non-lupus FHN patients were studied for progression to SLE and/or the presence of other conditions with FHN. The clinicopathologic characteristics and prognosis of idiopathic non-lupus FHN patients were compared with those of lupus FHN patients. Results: Of 149 included patients, 32 had non-lupus FHN. During the median follow-up of 20 years, no non-lupus FHN patients developed SLE. In all, 20 non-lupus FHN patients had idiopathic non-lupus FHN, and in 12 patients, secondary non-lupus FHN was considered due to membranous nephropathy (anti-PLA2R-positive, n = 1; cancer-associated, n = 3), IgA nephropathy ( n = 4), infection-related glomerulonephritis ( n = 2) or anti-neutrophil cytoplasmic antibody-associated glomerulonephritis ( n = 2). Idiopathic non-lupus FHN patients were more often male (P < 0.001) than lupus FHN patients and their renal biopsies more often showed a mesangial (P = 0.04) or membranous pattern of injury (P = 0.02) and less intense C1q staining (P = 0.002). Clinically, they presented with lower-range erythrocyturia (P = 0.04), more proteinuria (P < 0.01) and less complement consumption in the classical pathway (P < 0.001) than lupus FHN patients. By multivariable Cox regression analysis of patients with a lupus nephritis class III/IV pattern of injury, idiopathic non-lupus FHN compared with lupus FHN was an independent risk factor for end-stage renal disease [hazard ratio 5.31 (95% confidence interval 1.47-19.24)]. Conclusions: Our results show that the clinical recognition of idiopathic non-lupus FHN as a diagnostic category is critical.

N-octanoyl dopamine inhibits the expression of a subset of κB regulated genes: potential role of p65 Ser276 phosphorylation.

BACKGROUND AND PURPOSE: Catechol containing compounds have anti-inflammatory properties, yet for catecholamines these properties are modest. Since we have previously demonstrated that the synthetic dopamine derivative N-octanoyl dopamine (NOD) has superior anti-inflammatory properties compared to dopamine, we tested NOD in more detail and sought to elucidate the molecular entities and underlying mechanism by which NOD down-regulates inflammation. EXPERIMENTAL APPROACH: Genome wide gene expression profiling of human umbilical vein endothelial cells (HUVECs) was performed after stimulation with TNF-α or in the combination with NOD. Confirmation of these differences, NFκB activation and the molecular entities that were required for the anti-inflammatory properties were assessed in subsequent experiments. KEY RESULTS: Down regulation of inflammatory genes by NOD occurred predominantly for κB regulated genes, however not all κB regulated genes were affected. These findings were explained by inhibition of RelA phosphorylation at Ser276. Leukocyte adherence to TNF-α stimulated HUVECs was inhibited by NOD and was reflected by a diminished expression of adhesion molecules on HUVECs. NOD induced HO-1 expression, but this was not required for inhibition of NFκB. The anti-inflammatory effect of NOD seems to involve the redox active catechol structure, although the redox active para-dihydroxy benzene containing compounds also displayed anti-inflammatory effects, provided that they were sufficiently hydrophobic. CONCLUSIONS AND IMPLICATIONS: The present study highlighted important mechanisms and molecular entities by which dihydroxy benzene compounds exert their potential anti-inflammatory action. Since NOD does not have hemodynamic properties, NOD seems to be a promising candidate drug for the treatment of inflammatory diseases.

N-octanoyl-dopamine is a potent inhibitor of platelet function.

Dopamine (DA) is a co-agonist for platelet activation; yet, donor DA treatment is associated with improved transplantation outcome in renal and heart recipients. Recently, N-octanoyl-dopamine (NOD) was developed which displays superior effects compared to DA in terms of graft protecting properties. Whereas DA is a known platelet co-agonist, the effect of NOD on platelet function is unknown. This is a hypothesis generating study with the aim to assess the effects and molecular mechanisms of NOD and NOD-like compounds on platelet function. The influence of DA, NOD, and NOD-like compounds on platelet responses to classical agonists (adenosine 5'-diphosphate (ADP), U46619) was investigated in six healthy donors by applying whole blood aggregometry (Multiplate®) and flow cytometry for Pac-1, CD62P, and CD63 expression. Changes in platelet cAMP concentrations were assessed by ELISA. While DA showed synergy in platelet activation by ADP and U46619, NOD caused significant inhibition of platelet function both in whole blood aggregometry and flow cytometry. The inhibitory effect of NOD was not mediated via cAMP levels. The nonredox-active NOD-analog N-octanoyl-tyramine had no effects on platelet function. Acetylated NOD conferred to NOD by intracellular esterases showed similar inhibitory effects as NOD. In contrast to DA, NOD is a potent inhibitor of platelet function most likely through intracellular redox-active processes. This adds to the overall protective effect of NOD on pre-transplantation injury and makes NOD an attractive candidate compound for donor or organ conditioning prior to transplantation.