978 resultados para LUPUS ANTICOAGULANT
Resumo:
Wolves in Italy strongly declined in the past and were confined south of the Alps since the turn of the last century, reduced in the 1970s to approximately 100 individuals surviving in two fragmented subpopulations in the central-southern Apennines. The Italian wolves are presently expanding in the Apennines, and started to recolonize the western Alps in Italy, France and Switzerland about 16 years ago. In this study, we used a population genetic approach to elucidate some aspects of the wolf recolonization process. DNA extracted from 3068 tissue and scat samples collected in the Apennines (the source populations) and in the Alps (the colony), were genotyped at 12 microsatellite loci aiming to assess (i) the strength of the bottleneck and founder effects during the onset of colonization; (ii) the rates of gene flow between source and colony; and (iii) the minimum number of colonizers that are needed to explain the genetic variability observed in the colony. We identified a total of 435 distinct wolf genotypes, which showed that wolves in the Alps: (i) have significantly lower genetic diversity (heterozygosity, allelic richness, number of private alleles) than wolves in the Apennines; (ii) are genetically distinct using pairwise F(ST) values, population assignment test and Bayesian clustering; (iii) are not in genetic equilibrium (significant bottleneck test). Spatial autocorrelations are significant among samples separated up to c. 230 km, roughly correspondent to the apparent gap in permanent wolf presence between the Alps and north Apennines. The estimated number of first-generation migrants indicates that migration has been unidirectional and male-biased, from the Apennines to the Alps, and that wolves in southern Italy did not contribute to the Alpine population. These results suggest that: (i) the Alps were colonized by a few long-range migrating wolves originating in the north Apennine subpopulation; (ii) during the colonization process there has been a moderate bottleneck; and (iii) gene flow between sources and colonies was moderate (corresponding to 1.25-2.50 wolves per generation), despite high potential for dispersal. Bottleneck simulations showed that a total of c. 8-16 effective founders are needed to explain the genetic diversity observed in the Alps. Levels of genetic diversity in the expanding Alpine wolf population, and the permanence of genetic structuring, will depend on the future rates of gene flow among distinct wolf subpopulation fragments.
Resumo:
As B-cells are crucial for the production of antibodies and also in antigen presentation, they can play an important role in autoimmune connective tissue disease. B-cell surface antigens and receptors which are capable of activating B-cell function have been proposed as targets for therapy in these diseases. Anti-B cell treatments have been used recently in SLE and primary Sjogren's syndrome in a number of open studies, notably anti-CD20 (rituximab), with encouraging results. An anti-BAFF antibody (belimumab) has been tested in patients with SLE and also showed positive results in patients with increased levels of autoantibodies. In contrast, anti-TNF therapy in connective tissue disease and in RA can increase the levels of autoantibodies. Further studies are needed to define the place of these novel treatments in the management of autoimmune connective tissue diseases.
Resumo:
The antiphospholipid syndrome was initially described in 1986. To reassess the validity of antiphospholipid antibodies in systemic lupus erythematosus (SLE), 95 patients with SLE were studied. Their antiphospholipid antibody profile was analysed and correlated with clinical findings such as thrombosis, abortions, or thrombocytopenia. A low prevalence of these antibodies was found (13 patients; 14%) with a high specificity for thrombosis (92%) and abortions (92%). The importance of anticardiolipin antibodies as a risk factor for thrombosis or abortions, or both, in patients with SLE is reaffirmed by this work.
Resumo:
INTRODUCTION: Patients with arterial disease receiving antiplatelet agents may develop venous thromboembolism (VTE) and need anticoagulant therapy, although concomitant use of these drugs may increase bleeding risk. We analyzed RIETE data and compared clinical outcomes depending on decision to discontinue or maintain antiplatelet therapy at VTE diagnosis. METHODS: Consecutive patients with acute VTE were enrolled in RIETE. Only patients receiving antiplatelet therapy at baseline were included in this analysis. Primary outcomes were: rate of subsequent ischemic events, major bleeding or death during anticoagulation course. RESULTS: 1178 patients who received antiplatelet drugs at VTE diagnosis were included. Antiplatelet therapy was discontinued in 62% of patients. During anticoagulation course, patients also receiving antiplatelet therapy had higher rates of lower limb amputations (2.28 vs. 0.21 events per 100 patients-years; p<0.01), any ischemic events (5.7 vs. 2.28 events per 100 patients-years; p<0.05) or death (23.6 vs. 13.9 deaths per 100 patients-years; p<0.01). No differences in the rate of major bleeding or recurrent VTE were revealed. In matched analysis, patients on antiplatelet therapy were found to have a significantly higher rate of limb amputations (odds ratio: 15.3; 95% CI: 1.02-229) and an increased number of composite outcomes including all-cause deaths, arterial and VTE events (odds ratio: 1.46; CI: 1.03-2.06), with no differences in major bleeding rate. CONCLUSION: Concomitant anticoagulant and antiplatelet therapy in patients with VTE and arterial disease is not associated with increased risk for bleeding, recurrent VTE or death. The worse outcome observed in patients who continued antiplatelet therapy requires further investigations.