Cellular polarization induced by chemokines: a mechanism for leukocyte recruitment?

Chemokines are known to induce leukocyte adhesion to the endothelium and emigration into tissues. Here, Miguel Angel del Pozo and colleagues discuss how these molecules also appear to regulate the redistribution of cell adhesion receptors. Recruitment of adhesion molecules towards a cellular uropod in response to chemokines may represent a novel cooperative mechanism in the recruitment of leukocytes to sites of inflammation.

Anti-CD69 antibodies enhance phorbol-dependent glucose metabolism and Ca2+ levels in human thymocytes. Antagonist effect of cyclosporin A

The human activation antigen CD69 is an early inducible surface glycoprotein acquired by T cells in the thymus at the stage of positive selection and during activation of mature lymphoid cells both in vivo and in vitro. We have studied the regulatory influence of CD69 activation pathway on the glycolytic process and transduction signals of thymocytes. Treatment of human thymocytes with different anti-CD69 monoclonal antibodies (mAbs), in the presence of submitogenic doses of phorbol ester, produced an enhanced release of lactate without significant alterations in Fru 2,6-P2 levels or phosphofructokinase-2 (PFK-2) and pyruvate kinase activities. A small increase in phosphofructokinase-1 (PFK-1) activity was also detected. Furthermore, anti-CD69 mAb increased the glucose detritiation from [2-3H] and [3-3H]glucose, thus indicating an enhanced flux through hexokinase and PFK-1 steps. In addition, de novo synthesis of diacylglycerol and intracellular Ca2+ levels increased after anti-CD69 mAb treatment. The stimulatory effects of anti-CD69 mAb on both glycolysis and Ca2+ levels were inhibited by cyclosporin A. Because CD69 molecules are present in certain subset populations of immature thymocytes, the ability of anti-CD69 mAb to stimulate the glycolysis, the synthesis of diacylglycerol and the intracellular Ca2+ levels suggest that the activation signals delivered through CD69 molecules could play a role in the thymus cells maturation.

AB0422 DIAGNOSTIC PERFORMANCE OF THE ACR/EULAR 2013 CLASSIFICATION CRITERIA FOR SYSTEMIC SCLEROSIS IN A ROUTINE CARE SETTING

Background:

An ACR/EULAR task force released new criteria in 2013 to classify patients with systemic sclerosis (SSc).

Objectives:

This study evaluates the diagnostic performance of these criteria in a multidisciplinary care setting.

Methods:

Patients with an active follow-up in a Systemic Autoimmune Diseases Unit with a clinical diagnosis of SSc were matched by age and gender with consecutive patients referred to a capillaroscopy clinic. The classification criteria were tested on discrimination and diagnostic accuracy between both groups of patients defined as cases-SSc and controls. Receiver operating characteristic (ROC) curve and the area under the curve (AUC) was calculated for the global score to define the best cut off to classify the patients as having SSc.

Results:

A total of 130 patients with SSc and 130 matched-controls were included in this analysis, 90% women, with a mean age of 61.5. Main diagnosis for the control groups were primary Raynaud´s phenomenon (34.6%), undiferentiated connective tissue disease (13.1%), and mixed connective tissue disease (9.2%). The 92% and 8% of patients in the SSc-cases and control groups met the 2013 ACR/ EULAR SSc classification criteria respectively. Sensitivity and specificity of the criteria were 81.5% and 93.7%, respectively. The best cut offs for the total score were 8 and 9, and the AUC (95%CI) was 0.962 (0.939-0.985). The individual items with a better discriminatory capacity were abnormal capillaroscopy, telangiectasia and anticentromere antibody positivity.

Table 1.

Demographic data and ACR/ EULAR SSc classificacion criteria of SSC patients and controls.

Cases-SSc, n= 130Controls, n= 130pAge, mean (SD)62.4 (16.0)61.3 (14.8)0.58Female, %90.590.80.92Disease duration from onset of symptoms, mean (SD)7.5 (6.4)7.8 (6.7)0.73% Patients with individual ACR/EULAR 2013 Criteria ItemsSkin thickening15.80.7<0.001Sclerodactily45.56.1<0.001Puffy fingers27.71.5<0.001Digital tip ulcers30.25.3<0.001Fingertip pitting scars18.84.60.001Telangiectasia51.56.1<0.001Abnormal nailfold capillaries79.40.8<0.001Pulmonary Arterial Hypertension16.33.80.001Pulmonary fibrosis18.86.20.002Raynaud´s phenomenon90.766.9<0.001Anticentromere antibody60.718.9<0.001Scl7012.00<0.001Total Score12.5 (4.8)3.4 (2.9)<0.0001Figure 1.

ROC curve for global score of the ACR/EULAR2013 SSc classification criteria.

Conclusion:

The ACR/EULAR 2013 criteria showed good diagnostic properties in this cohort reflecting daily practice. Individual items showing the highest discriminatory capacity were abnormal capillaroscopy, telangiectasia and anticentromere antibody positivity.

References:

[1]van den Hoogen F, Khanna D, Fransen J, et al. 2013 classification criteria for systemic sclerosis: an American college of rheumatology/European league against rheumatism collaborative initiative. Annals of the Rheumatic Diseases 2013;72:1747-1755.

Disclosure of Interests:

None declared

AB0030 INCREASED CIRCULATING CD19+CD24HICD38HI REGULATORY B CELLS ARE BIOMARKERS OF RESPONSE TO METHOTREXATE IN EARLY RHEUMATOID ARTHRITIS

Background:

The protagonism of regulatory B cells seems to vary along the course of the disease in murine models of inflammatory conditions. Decreased numbers of circulating regulatory CD19+CD24hiCD38hi transitional B cells (cTrB) have been described in patients with longstanding RA.

Objectives:

To examine the frequency and evolution of cTrB cells in the peripheral blood of early RA (ERA) patients.

Methods:

Freshly isolated PBMCs from 48 steroid and DMARD-naïve ERA patients with a disease duration below 24 weeks and 48 healthy controls (HC) were examined by flow cytometry. Cocultures of isolated memory B cells were established with autologous T cells, in the absence or presence of TrB cells.

Results:

As compared with HC, ERA patients demonstrated an increased frequency of cTrB cells. cTrBs of ERA and HC displayed an anti-inflammatory cytokine profile and were able to downregulate T cell IFNγ and IL-21 production, together with ACPA secretion in autologous B/T cell cocultures. Basal frequencies of cTrBs above the median value observed in HC were associated with a good EULAR response to MTX at 12 months (RR=2.91; 95% CI, 1.37-6.47). A significant reduction of cTrBs was observed 12 months after initiating MTX, when the cTrB cell frequency was no longer elevated but decreased, and this was independent of the degree of clinical response or the intake of prednisone.

Conclusion:

An increased frequency of regulatory cTrB cells is apparent in untreated ERA, and the baseline cTrB cell frequency is associated with the clinical response to MTX at 12 months.

References:

[1]Matsushita T, et al. J Clin Invest. 2008;118:342. Flores-Borja F, et al. Sci Transl Med. 2013;5:173ra23.

Disclosure of Interests:

Paula Fortea-Gordo Grant/research support from: BMS, Alejandro Villalba: None declared, Laura Nuño: None declared, Maria-Jose Santos-Bornez Grant/research support from: BMS, Diana Peiteado: None declared, Irene Monjo: None declared, Amaya Puig-Kröger: None declared, Paloma Sanchez-Mateos: None declared, Emilio Martín-Mola Grant/research support from: BMS, Roche, Alejandro Balsa Grant/research support from: BMS, Roche, Consultant of: AbbVie, Gilead, Lilly, Pfizer, UCB, Sanofi, Sandoz, Speakers bureau: AbbVie, Lilly, Sanofi, Novartis, Pfizer, UCB, Roche, Nordic, Sandoz, Maria-Eugenia Miranda-Carus Grant/research support from: BMS, Roche