Diagnostic performance of a new vimentin-derived ACPA (CCP high ă sensitive) in patients with rheumatoid arthritis

International audienceAutoantibodies are a common feature of rheumatoid arthritis (RA), and ă their detection is used as a diagnostic tool in medical practice. ă Rheumatoid factor (RF) and/or anti-citrullinated protein antibodies ă (ACPA) detection in patients' sera are now included in 2010 ACR/EULAR ă criteria for RA diagnosis. In this study, we evaluated a new ă vimentin-derived ACPA ELISA, the anti-cyclic citrullinated peptide high ă sensitive (CCP hs) test, and we compared its performance with the RF IgM ă and anti-CCP3 tests on a French multicenter cohort of 84 RA patients, ă 107 non-RA patients and 100 healthy controls. Sensitivities for RA ă diagnosis were 71.4, 84.5 and 64.3 % and specificities were 88.4, 86.9 ă and 87.3 % for CCP hs, CCP3 and RF IgM, respectively. There was a ă moderate correlation between CCP hs and CCP3 titers (Pearson's r = 0.43; ă p < 0.0001). These results support the contention that anti-CCP hs ă antibodies are new reliable ACPA with high specificity for RA

Heterogeneous clinical spectrum of anti-SRP myositis and importance of the methods of detection of anti-SRP autoantibodies: a multicentric study

International audienceAnti-signal recognition particle (SRP) antibodies are important serological markers for the diagnosis and the prognosis of idiopathic inflammatory myopathy (IIM), especially to distinguish immune-mediated necrotizing myopathy (IMNM). This study was set up to investigate the phenotype associated with anti-SRP antibodies and to evaluate the methods for detecting these antibodies. Clinical and biological data were retrospectively obtained from 60 adult patients with anti-SRP antibodies detected by a dot immunoassay from 12 centers. Thirty-six (60 %) out of these 60 patients suffered from an IIM, and among them, 21 patients were diagnosed as IMNM. Among patients with a definite IIM, proximal weakness and myalgia were prominent symptoms at the time of diagnosis. Only few patients displayed severe extra-muscular symptoms such as cardiac involvement or severe myositis. Mean creatine kinase levels were high for all patients except for two of them. When testing by indirect immunofluorescence (IIF) on HEp2 cells, the fraction of patients displaying the typical anti-SRP fine speckled staining of the cytoplasm was higher in patients with IIM (30/36) (83 %) than in patients with non-IIM (3/24) (12.5 %) (p < 0.0001). Thirty (91 %) out of 33 patients with a positive immunodot and a characteristic IIF cytoplasmic staining suffered from a clinical definite myositis, whereas only 6 (22 %) out of 27 patients with a positive immunodot but a negative cytoplasmic pattern suffered from a myositis (p < 0.00001). This series highlights the strong heterogeneity of anti-SRP positivity that encompassed IMNM and non-IMNM and supports the necessity of considering both IIF and dot immunoassay to confirm the diagnosis of anti-SRP-associated myositis

THE BOVINE ANTERIOR HYPOTHALAMUS: CHARACTERIZATION OF THE VASOPRESSIN-OXYTOCIN CONTAINING NUCLEUS AND CHANGES IN RELATION TO SEXUAL DIFFERENTIATION

In an effort to systematically describe the neurochemical anatomy of the bovine anterior hypothalamus, we used a series of immunocytochemical markers such as Acetylcholine Esterase (AChE), Arginine-Vasopressin (AVP), Calbindin (Calb), Galanin (Gal), Neuropeptide-Y (NPY), Oxytocin (OXT), Somatostatin (SST) and Vasoactive Intestinal Peptide (VIP). We also investigated the potential sex difference present in the suprachiasmatic nucleus (SCN) and the vasopressin-oxytocin containing nucleus (VON) of 6 males and 6 female Bos taurus. Our study revealed that the cytochemical structure of the cattle anterior hypothalamus follows the blueprint of other mammals. The VON, which was never described before in cattle, showed a sex difference with a 33.7% smaller volume and 23.2% fewer magnocellular neurons (approximately 20-30 \u3bcm) in the male. The SCN also did show a sex difference in VIP neurons and volume with a 36.1% larger female nucleus with 28.1% more cells. Additionally, we included 5 heifers with freemartin syndrome as a new animal model relevant for sexual differentiation in the brain. This is to our knowledge the first freemartin study in relation to the brain. Surprisingly, the SCN of freemartin heifers was 32.5% larger than its control male and female counterparts with 29% more VIP cells. Conversely, the freemartin VON had an intermediary size between male and female. To analyze our data, a classical statistical analysis and a novel multivariate and multi-aspect approach were applied. These findings shed new light on sexual dimorphism in the bovine brain and present this species with freemartins as a valuable animal model in neuroscience. This article is protected by copyright. All rights reserved