Connective tissue diseases (CTDs) such as systemic lupus erythematosus, systemic sclerosis, myositis, Sjögren’s syndrome, and rheumatoid arthritis are systemic diseases which are often associated with a challenge in diagnosis. Autoantibodies (AAbs) can be detected in these diseases and help clinicians in their diagnosis. Actually, pathophysiology of these diseases is associated with the presence of antinuclear antibodies. In the last decades, many new antibodies were discovered, but their implication in pathogenesis of CTDs remains unclear. Furthermore, the classification of these AAbs is nowadays misused, as their targets can be localized outside of the nuclear compartment. Interestingly, in most cases, each antibody is associated with a specific phenotype in CTDs and therefore help in better defining either the disease subtypes or diseases activity and outcome. Because of recent progresses in their detection and in the comprehension of their pathogenesis implication in CTD-associated antibodies, clinicians should pay attention to the presence of these different AAbs to improve patient’s management. In this review, we propose to focus on the different phenotypes and features associated with each autoantibody used in clinical practice in those CTDs.

Anti-SS-A antibodies are often sought for in autoimmune diseases diagnosis. Two different target proteins have actually been identified: Ro52 and Ro60. Clinical and immunological associations seem different depending on anti-Ro52 or anti-Ro60 antibodies presence. However, due to a heterogeneous presentation in the literature, some immunology laboratories in France have stopped providing anti-Ro52 antibody findings. We report here a new hospital study designed to determine the diagnostic utility of the separate detection of anti-Ro52 and anti-Ro60 antibodies. We conducted a retrospective, observational study, including every adult patient with positive antinuclear antibodies (ANA) tested in our immunology laboratory, and associated with anti-Ro52 and/or anti-Ro60 antibodies, between 2011 and 2014. Out of 13032 sera tested for ANA, 399 adults had antibodies to Ro52 and/or Ro60; 81.7% were female, with a mean age of 54.5 ± 17.0 years. Anti-Ro52 antibodies were found in 75.7% of the patients and anti-Ro60 antibodies in 56.9%. Among them, 43.1% were classified in the Ro52 + Ro60- group, 32.6% in the Ro52 + Ro60 + group and 24.3% in the Ro52-Ro60+ group. In the Ro52-Ro60+ group, systemic lupus was the most frequent diagnosis (48.5%), with a possible association with antiphospholipid antibodies (anti-cardiolipin antibodies: OR 2.5 (CI95 [1.0–5.0], p = 0.05) and lupus anticoagulant {OR 3.6 (CI95 [1.10–10.0] p = 0.02)}. In the Ro52+Ro60+, primary Sjögren Syndrome was the most likely (OR 4.2 95% CI [2.1–8.3] p < 10−4), especially in patients Ro52+Ro60+La+. Patients with isolated anti-Ro52 had a wider variety of diseases associated, but among auto-immune diseases they were more prone to inflammatory myositis (OR 10.5 [1.4–81.7], p = 0.02) and inflammatory rheumatism (OR 4.6 [1.6–13.8], p = 0.006) in contrast to systemic lupus (OR 0.2 [0.1–0.3], p < 10−4) or primary Sjögren's syndrome (OR 0.1 [0.06–0.2], p < 10−4). We therefore suggest that, when anti-ENA antibodies are prescribed, it should include separate anti-Ro52 and anti-Ro60 antibodies determination. To go even further, we would like to suggest a change in ENA nomenclature to avoid confusion, abandoning the anti-SS-A label in favor of the anti-Ro52/TRIM21 or anti-Ro60 antibody for a clearer designation.

Bullous Pemphigoid (BP) is an inflammatory rare autoimmune bullous dermatosis, which outcome cannot be predicted through clinical investigations. Eosinophils are the main immune infiltrated cells in BP. However, the release of Major Basic Protein (MBP), Eosinophil Derived Neurotoxin (EDN), and Eosinophil Cationic Protein (ECP) upon eosinophil activation has still not been evaluated with respect to BP development. MBP, EDN and ECP were measured by ELISA in serum (n = 61) and blister fluid (n = 20) of patients with BP at baseline, and in serum after 2 months of treatment (n = 41). Eosinophil activation in BP patients was illustrated at baseline by significantly higher MBP, EDN and ECP serum concentrations as compared with control subjects (n = 20), but without distinction according to disease severity or outcome. EDN and ECP values were even higher in the blister fluids (P < 0.01 and P < 0.05, respectively), whereas MBP values were lower (P < 0.001). ECP serum concentration decreased after 60 days of treatment in BP patients with ongoing remission but not in patients who later relapsed (P < 0.05). A reduction of at least 12.8 ng/mL in ECP concentrations provided a positive predictive value for remission of 81%, showing that ECP serum variation could be a useful biomarker stratifying BP patients at risk of relapse.

Background: DNA extracellular traps (ETs), released by neutrophils (NETs), or eosinophils (EETs), play a pathogenic role in several autoimmune disorders. However, to date, NETs have never been investigated in bullous pemphigoid (BP) with respect to clinical and immunological activities, both at baseline and at time of relapse which have been characterized with specific IL-17 and IL-23 patterns. Objective: We sought to assess whether ETs were associated with BP as well as the relative contribution of IL-17 axis cytokines to NET induction. Methods: Skin biopsy specimens were obtained from 11 patients with BP. Immuno-detection of neutrophils and eosinophils combined to DNA staining allowed us to investigate the in-situ presence of NETs and EETs using confocal scanning microscopy. NETs release was evaluated ex vivo by stimulating polymorphonuclear cells from BP patients with BP biological fluids in presence of IL-17A and IL-23 or of glucocorticoids. Results: At baseline, ETs were observed in BP lesions at the site of dermal-epidermal cleavage. Despite an important infiltrate of eosinophils, ETs were essentially associated with neutrophils in situ and were not related to BP clinical activity at diagnosis. In situ observation of NETs was associated in 6 among 8 patients with serum capacity of NET induction. Notably both blister fluid and sera from BP patients at diagnosis and at time of relapse could induce NET formation ex vivo . In contrast, a longitudinal investigation showed a decrease of NET formation with time of treatment in patients undergoing remission. Mimicking relapse, complementation of sera from BP patients with ongoing remission with either IL-17A or IL-23 increased NET formation. Conversely, IL-17A inhibited NET formation induced by serum from BP patients with relapse supplemented or not with IL-23. Finally, glucocorticoids also inhibited NET formation ex vivo in BP. Conclusion: NET formation is an associated phenomenon with BP. Furthermore, we showed that IL-23 favored NET formation, whereas the effects of IL-17A are environment dependent. Indeed, IL-17A displayed a protective effect on NET formation when associated with IL-23, showing for the first-time differential effects of these two cytokines in BP.

Checkpoint inhibitor (CPI) blockade is considered to be a revolution in cancer therapy, although most patients (70%–80%) remain resistant to this therapy. It has been hypothesized that only tumors with high mutation rates generate a natural antitumor T cell response, which could be revigorated by this therapy. In patients with no pre-existing antitumor T cells, a vaccine-induced T cell response is a rational option to counteract clinical resistance. This hypothesis has been validated in preclinical models using various cancer vaccines combined with inhibitory pathway blockade (PD-1-PDL1-2, CTLA-4-CD80-CD86). Enhanced T cell infiltration of various tumors has been demonstrated following this combination therapy. The timing of this combination appears to be critical to the success of this therapy and multiple combinations of immunomodulating antibodies (CPI antagonists or costimulatory pathway agonists) have reinforced the synergy with cancer vaccines. Only limited results are available in humans and this combined approach has yet to be validated. Comprehensive monitoring of the regulation of CPI and costimulatory molecules after administration of immunomodulatory antibodies (anti-PD1/PD-L1, anti-CTLA-4, anti-OX40, etc.) and cancer vaccines should help to guide the selection of the best combination and timing of this therapy.