The probiotic Lactobacillus rhamnosus mimics the dark-driven regulation of appetite markers and melatonin receptors' expression in zebrafish (Danio rerio) larvae: Understanding the role of the gut microbiome.

The use of probiotics has been recently considered a novel therapeutic strategy to prevent pathologies such as obesity; however, the specific mechanisms of action by which probiotics exert their beneficial effects on metabolic health remain unclear. The aim of the present study was to investigate the short-term effects of a probiotic Lactobacillus rhamnosus supplementation (PROB) on appetite regulation, growth-related markers, and microbiota diversity in zebrafish (Danio rerio) larvae, compared to a group subjected to a constant darkness photoperiod (DARK), as well as to evaluate the effects of both treatments on melatonin receptors' expression. After a 24 h treatment, both PROB and DARK conditions caused a significant increase in leptin a expression. Moreover, mRNA abundances of leptin b and proopiomelanocortin a were elevated in the PROB group, and DARK showed a similar tendency, supporting a negative regulation of appetite markers by the treatments. Moreover, both PROB and DARK also enhanced the abundances of melatonin receptors transcript (melatonin receptor 1 ba and bb) and protein (melatonin receptor 1) suggesting a potential involvement of melatonin in mediating these effects. Nevertheless, treatments did not exhibit a significant effect on the expression of most of the growth hormone/insulin-like growth factor axis genes evaluated. Finally, only the DARK condition significantly modulated gut microbiota diversity at such short time, altogether highlighting the rapid effects of this probiotic on modulating appetite regulatory and melatonin receptors' expression, without a concomitant variation of gut microbiota.

Algorithm for antinuclear antibodies in subjects with clinical suspicion of autoimmune diseases.

OBJECTIVES: Antinuclear antibodies (ANA) are fundamental in the diagnosis of systemic autoimmune rheumatic diseases (SARDs). Different assays for ANA screening are available, such as indirect immunofluorescence (IIF) on HEp-2 cells and Multiplex fluorescent immunoassay (MFI). This study aimed to clarify the importance of ANA detected only by IIF in the future development of SARDs and to recommend a laboratory algorithm that integrates the available diagnostic approaches to optimise the diagnosis of ANA IIF+MFI- subjects. METHODS: A total of 9,291 subjects with clinical suspicion of SARDs were evaluated for ANA by IIF and MFI. One hundred and ninety-eight subjects (2.1%) were ANA IIF+MFI-, who were followed up for 2 years. ANA were evaluated using IIF on HEp-2 cells and MFI on the BioPlex 2200. RESULTS: The ANA IIF+MFI- cohort included 106 subjects with SARDs, 26 subject with other autoimmune diseases (not-SARDs) and 66 subjects with minor symptoms or ANA requested in check-ups. Only 94 subjects underwent re-evaluation. After a 2-year follow-up, most re-evaluated subjects (51 patients) became ANA negative for both assays (mainly rheumatoid arthritis, polymyalgia and inflammatory bowel disease patients) and 35 subjects remained ANA IIF+MFI- (principally systemic sclerosis and systemic lupus erythematosus patients). A new algorithm for ANA evaluation was suggested. CONCLUSIONS: According to the proposed algorithm, ANA IIF+MFI- subjects should be screened by an alternative solid-phase assay such as line-immunoassay or ELISA.

Incidence of thromboembolic events in asymptomatic carriers of IgA anti ß2 glycoprotein-I antibodies.

BACKGROUND: The antiphospholipid syndrome (APS) is defined by simultaneous presence of vascular clinical events and antiphospholipid antibodies (aPL). The aPL considered as diagnostics are lupus anticoagulant and antibodies anticardiolipin (aCL) and anti-ß2 glycoprotein-I (aB2GP1). During recent years, IgA aB2GP1 antibodies have been associated with thrombotic events both in patients positive, and mainly negative for other aPL, however its value as a pro-thrombotic risk-factor in asymptomatic patients has not been well defined. OBJECTIVE: To test the role of IgA anti B2GP1 as a risk factor for the development of APS-events (thrombosis or pregnancy morbidity) in asymptomatic population with a 5-year follow-up. METHODS: 244 patients isolated positive for anti-beta2-glycoprotein I IgA (Group-1 study) and 221 negative patients (Group-2 control) were studied. All the patients were negative for IgG and IgM aCL. RESULTS: During the follow-up, 45 patients (9.7%) had APS-events, 38 positive for IgA-aB2GP1 and 7 negative (15.6% vs 3.2%, p<0.001). The incidence rate of APS-events was 3.1% per year in IgA-aB2GP1 positive patients and 0.6% per year in the control group. Arterial thrombosis were the most frequent APS-events (N = 25, 55%) and were mainly observed in Group-1 patients (21 vs 4, p = 0.001). Multivariate analysis were shown as independent risk-factors for the development of APS-events, age, sex (men) and presence of IgA-aB2GP1 (odds ratio 5.25, 95% CI 2.24 to 12.32). CONCLUSION: The presence of IgA-aB2GP1 in people with no history of APS-events is the main independent risk factor for the development of these types of events, mainly arterial thrombosis.

Circulating Immune Complexes of IgA Bound to Beta 2 Glycoprotein are Strongly Associated with the Occurrence of Acute Thrombotic Events.

AIM: Antiphospholipid syndrome (APS) is characterized by recurrent thrombosis and/or gestational morbidity in patients with antiphospholipid autoantibodies (aPL). Over recent years, IgA anti-beta2-glycoprotein I (B2GPI) antibodies (IgA aB2GPI) have reached similar clinical relevance as IgG or IgM isotypes. We recently described the presence of immune complexes of IgA bounded to B2GPI (B2A-CIC) in the blood of patients with antecedents of APS symptomalology. However, B2A-CIC's clinical associations with thrombotic events (TEV) have not been described yet. METHODS: A total of 145 individuals who were isolate positive for IgA aB2GPI were studied: 50 controls without any APS antecedent, 22 patients with recent TEV (Group-1), and 73 patients with antecedents of old TEV (Group-2). RESULTS: Mean B2A-CIC levels and prevalence in Group-1 were 29.6±4.1 AU and 81.8%, respectively, and were significantly higher than those of Group-2 and controls (p＜0.001). In a multivariable analysis, positivity of B2A-CIC was an independent variable for acute thrombosis with a 22.7 odd ratio (confidence interval 5.1-101.6, 95%, p＜0.001). Levels of B2A-CIC dropped significantly two months after the TEV. B2A-CIC positive patients had lower platelet levels than B2A-CIC-negative patients (p＜0.001) and more prevalence of thrombocytopenia (p＜0.019). Group-1 had no significant differences in C3 and C4 levels compared with other groups. CONCLUSION: B2A-CIC is strongly associated with acute TEV. Patients who did not develop thrombosis and were B2A-CIC positive had lower platelet levels, which suggest a hypercoagulable state. This mechanism is unrelated to complement-fixing aPL. B2A-CIC could potentially select IgA aB2GPI-positive patients at risk of developing a thrombotic event.

Isolated IgA anti- ß2 glycoprotein I antibodies in patients with clinical criteria for antiphospholipid syndrome.

Seronegative antiphospholipid syndrome (SNAPS) is an autoimmune disease present in patients with clinical manifestations highly suggestive of Antiphospholipid Syndrome (APS) but with persistently negative consensus antiphospholipid antibodies (a-PL). IgA anti-ß 2 Glycoprotein I (aB2-GPI) antibodies are associated with APS. However, they are not currently considered to be laboratory criteria due to the heterogeneity of published works and the use of poor standardized diagnostic systems. We have aimed to assess aPL antibodies in a group of patients with clinical manifestations of APS (C-APS) to evaluate the importance of the presence of IgA aB2GPI antibodies in APS and its relation with other aPL antibodies. Only 14% of patients with C-APS were positive for any consensus antibody, whereas the presence of isolated IgA aB2GPI antibodies was found in 22% of C-APS patients. In patients with arterial thrombosis IgA aB2GPI, antibodies were the only aPL antibodies present. Serologic profile in primary APS (PAPS) is different from systemic autoimmune disorders associated APS (SAD-APS). IgA aB2GPI antibodies are more prevalent in PAPS and IgG aB2GPI antibodies are predominant in SAD-APS. The analysis of IgA aB2GPI antibodies in patients with clinical manifestations of PAPS might avoid underdiagnosed patients and provide a better diagnosis in patients with SAD-APS. Laboratory consensus criteria might consider including analysis of IgA aB2GPI for APS diagnosis.