Interpersonal synchrony feels good but impedes self-regulation of affec

The social benefits of interpersonal synchrony are widely recognized. Yet, little is known about its impact on the self. According to enactive cognitive science, the human self for its stability and regulation needs to balance social attunement with disengagement from others. Too much interpersonal synchrony is considered detrimental for a person's ability to self-regulate. In this study, 66 adults took part in the Body-Conversation Task (BCT), a dyadic movement task promoting spontaneous social interaction. Using whole-body behavioural imaging, we investigated the simultaneous impact of interpersonal synchrony (between persons) and intrapersonal synchrony (within a person) on positive affect and self-regulation of affect. We hypothesized that interpersonal synchrony's known tendency to increase positive affect would have a trade-off, decreasing a person's ability to self-regulate affect. Interpersonal synchrony predicted an increase in positive affect. Consistent with our hypothesis, it simultaneously predicted a weakening in self-regulation of affect. Intrapersonal synchrony, however, tended to oppose these effects. Our findings challenge the widespread belief that harmony with others has only beneficial effects, pointing to the need to better understand the impact of interaction dynamics on the stability and regulation of the human self

Dynamics of complement activation in aHUS and how to monitor eculizumab therapy

Atypical hemolytic-uremic syndrome (aHUS) is associated with genetic complement abnormalities/anti-complement factor H antibodies, which paved the way to treatment with eculizumab. We studied 44 aHUS patients and their relatives to (1) test new assays of complement activation, (2) verify whether such abnormality occurs also in unaffected mutation carriers, and (3) search for a tool for eculizumab titration. An abnormal circulating complement profile (low C3, high C5a, or SC5b-9) was found in 47% to 64% of patients, irrespective of disease phase. Acute aHUS serum, but not serum from remission, caused wider C3 and C5b-9 deposits than control serum on unstimulated human microvascular endothelial cells (HMEC-1). In adenosine 5'-diphosphate-activated HMEC-1, also sera from 84% and 100% of patients in remission, and from all unaffected mutation carriers, induced excessive C3 and C5b-9 deposits. At variance, in most patients with C3 glomerulopathies/immune complex-associated membranoproliferative glomerulonephritis, serum-induced endothelial C5b-9 deposits were normal. In 8 eculizumab-treated aHUS patients, C3/SC5b-9 circulating levels did not change posteculizumab, whereas serum-induced endothelial C5b-9 deposits normalized after treatment, paralleled or even preceded remission, and guided drug dosing and timing. These results point to efficient complement inhibition on endothelium for aHUS treatment. C5b-9 endothelial deposits might help monitor eculizumab effectiveness, avoid drug overexposure, and save money considering the extremely high cost of the drug

Mitochondrial-dependent Autoimmunity in Membranous Nephropathy of IgG4-related Disease

The pathophysiology of glomerular lesions of membranous nephropathy (MN), including seldom-reported IgG4-related disease, is still elusive. Unlike in idiopathic MN where IgG4 prevails, in this patient IgG3 was predominant in glomerular deposits in the absence of circulating anti-phospholipase A2 receptor antibodies, suggesting a distinct pathologic process. Here we documented that IgG4 retrieved from the serum of our propositus reacted against carbonic anhydrase II (CAII) at the podocyte surface. In patient's biopsy, glomerular CAII staining increased and co-localized with subepithelial IgG4 deposits along the capillary walls. Patient's IgG4 caused a drop in cell pH followed by mitochondrial dysfunction, excessive ROS production and cytoskeletal reorganization in cultured podocytes. These events promoted mitochondrial superoxide-dismutase-2 (SOD2) externalization on the plasma membrane, becoming recognizable by complement-binding IgG3 anti-SOD2. Among patients with IgG4-related disease only sera of those with IgG4 anti-CAII antibodies caused low intracellular pH and mitochondrial alterations underlying SOD2 externalization. Circulating IgG4 anti-CAII can cause podocyte injury through processes of intracellular acidification, mitochondrial oxidative stress and neoantigen induction in patients with IgG4 related disease. The onset of MN in a subset of patients could be due to IgG4 antibodies recognizing CAII with consequent exposure of mitochondrial neoantigen in the context of multifactorial pathogenesis of disease