24,438 research outputs found
Recommended from our members
Complement Activation in Patients With Probable Systemic Lupus Erythematosus and Ability to Predict Progression to American College of Rheumatology-Classified Systemic Lupus Erythematosus.
ObjectiveTo evaluate the frequency of cell-bound complement activation products (CB-CAPs) as a marker of complement activation in patients with suspected systemic lupus erythematosus (SLE) and the usefulness of this biomarker as a predictor of the evolution of probable SLE into SLE as classified by the American College of Rheumatology (ACR) criteria.MethodsPatients in whom SLE was suspected by lupus experts and who fulfilled 3 ACR classification criteria for SLE (probable SLE) were enrolled, along with patients with established SLE as classified by both the ACR and the Systemic Lupus International Collaborating Clinics (SLICC) criteria, patients with primary Sjögren's syndrome (SS), and patients with other rheumatic diseases. Individual CB-CAPs were measured by flow cytometry, and positivity rates were compared to those of commonly assessed biomarkers, including serum complement proteins (C3 and C4) and autoantibodies. The frequency of a positive multianalyte assay panel (MAP), which includes CB-CAPs, was also evaluated. Probable SLE cases were followed up prospectively.ResultsThe 92 patients with probable SLE were diagnosed more recently than the 53 patients with established SLE, and their use of antirheumatic medications was lower. At the enrollment visit, more patients with probable SLE were positive for CB-CAPs (28%) or MAP (40%) than had low complement levels (9%) (P = 0.0001 for each). In probable SLE, MAP scores of >0.8 at enrollment predicted fulfillment of a fourth ACR criterion within 18 months (hazard ratio 3.11, P < 0.01).ConclusionComplement activation occurs in some patients with probable SLE and can be detected with higher frequency by evaluating CB-CAPs and MAP than by assessing traditional serum complement protein levels. A MAP score above 0.8 predicts transition to classifiable SLE according to ACR criteria
A notion of selective ultrafilter corresponding to topological Ramsey spaces
We introduce the relation of "almost-reduction" in an arbitrary topological
Ramsey space R, as a generalization of the relation of "almost-inclusion" on
the space of infinite sets of natural numbers (the Ellentuck space). This leads
us to a type of ultrafilter U on the set of first approximations of the
elements of R which corresponds to the well-known notion of "selective
ultrafilter" on N, the set of natural numbers. The relationship turns out to be
rather exact in the sense that it permits us to lift several well-known facts
about selective ultrafilters on N and the Ellentuck space to the ultrafilter U
and the Ramsey space R. For example, we prove that the Open Coloring Axiom
holds in M[U], where M is a Solovay model. In this way we extend a result due
to Di Prisco and Todorcevic which gives the same conclusion for the Ellentuck
space.Comment: 24 pages; submitted to Mathematical Logic Quarterl
- …