Nathalie Bardin

Increased expression of CD146, a new marker of the endothelial junction in active inflammatory bowel disease

Background: Crohns disease (CD) and ulcerative colitis (UC), the 2 major forms of inflammatory bowel diseases (IBD), have been associated with disturbances in vascular physiology, including permeability and angiogenesis, that are in part regulated by the endothelial intercellular junctions. These junctions are composed of several adhesion molecules including the platelet endothelial cell adhesion molecule‐1 (PECAM‐1, CD31) and the more recently described CD146 (S‐Endo1 Ag, MUC18). Aim: To study the expression of tissue and soluble form of CD146 in patients with CD or UC in relation to disease activity and location. This study was made in comparison with the soluble form of CD31 (sCD31). Results: In active disease, a high expression of CD146 was observed on endothelial cells in intestinal biopsies from both CD and UC. In addition, we observed a decrease of sCD146 in relation to active disease and extensive location of CD and UC. Lower levels of sCD31 were also detected in active and extensive location of UC, but no difference could be observed in CD. Conclusion: sCD146 is a novel marker of the endothelial intercellular junction that reflects endothelial remodeling more effectively than soluble CD31. Further studies are warranted to determine whether sCD146 will provide a serological assay reflecting alterations in vascular permeability and vessel proliferation in the inflamed IBD intestine.

Antigenic profile, prevalence, and clinical significance of antiphospholipid antibodies in women referred for in vitro fertilization.

Abstract:u2002 The aim of this prospective study was to assess the prevalence of antiphospholipid antibodies (aPL) in women who had undergone in vitro fertilization (IVF) and the relationship between aPL and IVF outcome. A total of 101 infertile women with at least three unsuccessful IVF attempts were consecutively included in this study. Samples were collected in the follicular phase of a spontaneous ovarian cycle 2 months after the last ovulation induction treatment. Age‐matched healthy fertile women (n= 160) were included as controls. All were evaluated for the presence of lupus anticoagulant (LA), antibodies (IgG, IgA, IgM) to cardiolipin (aCL), beta2‐glycoprotein I (aβ2GPI), and phosphatidylethanolamine (aPE). Out of the 101 infertile women, 40 were persistently positive for aPL, showing a prevalence significantly higher than in controls (39.6% versus 5%, P < 0.0001). Among aPL, aPE were found with a significantly higher prevalence compared with LA, aCL, and aβ2GPI (67.5% versus 0%, 15%, and 40%, respectively). Interestingly, aPE were found in 70% of the cases in the absence of the other aPL. The predominant isotype of aPL was IgA, in particular for aβ2GPI. Finally, no significant association was found between the presence of aPL and IVF outcome. This prospective study shows aPE as the most prevalent aPL in infertile women and IgA as more common than IgG and IgM. However, our results do not support an association between aPL and IVF outcome.

Mouse CD146/MCAM is a marker of natural killer cell maturation.

CD146/melanoma cell adhesion molecule is an adhesion molecule expressed by endothelial cells and by a small fraction of activated T and B lymphocytes in humans. In order to analyze the pattern of CD146 expression in mouse leukocytes at steady‐state conditions, we generated a set of novel rat anti‐mouse CD146 monoclonal antibodies. CD146 expression was undetectable on monocytes, dendritic cells, T cells or B cells, but was expressed on about 30% of neutrophils and 60% of NK cells. Within murine lymphocytes, CD146 was defined as a novel NK‐specific surface molecule. An increased percentage of CD146+ cells was found in the most mature CD27−CD11b+ NK cell subpopulation, which also displays higher expression of Ly49C/I, Ly49D and KLRG1 and lower expression of NKG2A/C/E molecules. CD146+ NK cells were found to be less cytotoxic and produce less IFN‐γ than CD146− NK cells upon stimulation with target cells or activating antibodies. These findings define CD146 as a marker of mouse NK cell maturation that may be used as an alternative to the combined use of CD27 and CD11b staining to detect final stages of NK cell maturation.

Tubular CD146 Expression in Nephropathies Is Related to Chronic Renal Failure

Background: CD146, a member of the immunoglobulin superfamily, is mainly expressed at the endothelial junction. The soluble form of CD146 is increased in the serum of patients with chronic renal failure. The aim of the study was to investigate CD146 expression on biopsies of normal kidney and nephropathies. Methods: We did an immunohistochemical analysis of 10 normal renal tissues and 126 patients with nephropathies. Results: The mean age of the patients was 47.5 ± 18 years with 65% of men. At the time of the biopsy, 73 patients (57.9%) had a renal failure and the mean proteinuria was 3.3 ± 2.9 g/24 h. Inflammatory syndrome was present in 60 (47.6%) patients. Fibrous interstitial changes from minimal lesions to diffuse lesions were seen in 105 (83.3%) biopsies; the mean glomerulosclerosis index was 16.9 ± 19.7%. Normal kidneys showed CD146 staining on endothelial cells, smooth muscle cells, and mesangium. Normal tubular cells were not stained. If endocapillary proliferation was present, the mesangial CD146 expression was higher. This mesangial expression correlated with proteinuria (p = 0.007) and not with renal failure (p = 0.07). A de novo expression on tubular cells was found in 53 patients (42%) and this expression correlated with age (p < 0.001), male sex (p = 0.04), glomerulosclerosis (p < 0.001), interstitial fibrosis (p < 0.001), and renal failure (p < 0.001). Conclusion: Renal CD146 expression is of interest for determining the pathogenesis of mesangial alterations during glomerular injuries and of tubular phenotypic changes during chronic renal failure.

Clinical Evaluation of a New Quantitative Enzyme-Linked Immunosorbent Assay for Detection of Double-Stranded DNA Autoantibodies

Abstract:u2002 The measurement of autoantibodies specific for double‐stranded DNA (anti‐dsDNA) is a useful tool for the diagnosis and the prognosis of systemic lupus erythematosus (SLE). A new quantitative enzyme‐linked immunosorbent assay (ELISA), ORG anti‐dsDNA, is recently available for the determination of anti‐dsDNA antibodies. The aim of this study was to evaluate the clinical performance of this new assay in a cohort of SLE patients. Seventy‐five sera from SLE patients were tested by two methods for anti‐dsDNA determination, ORG anti‐dsDNA, and EliA anti‐dsDNA. Normal controls were 60 sera from healthy subjects. Moreover, 37 sera from patients with non‐SLE connective tissue diseases were tested in parallel. The levels of complement components (C3, C4, CH50) were measured by nephelometry. From SLE patients, 91% were positive against 9% in non‐SLE patients and 2% in healthy subjects. The sensitivity, specificity, and Youden test for SLE were 90%, 98%, and 88%, respectively. The Yule test (1%) indicated a close association with the disease. The comparison with EliA anti‐dsDNA showed a moderate concordance between the two tests in the group of SLE (κ= 0.51) and a good concordance in the non‐SLE group (κ= 0.89). A significant inverse correlation was found with complement components levels, biological markers associated with disease activity. Our results show this new assay as sensitive and specific for the diagnosis of SLE. Moreover, the correlation with markers associated with disease activity makes it promising for clinical use.