Compromiso renal en vasculitis asociadas a anticuerpos anticitoplasma de neutrófilos. Recomendaciones de consenso de las Sociedades Chilenas de Nefrología y Reumatología / Renal involvement in antineutrophil cytoplasmic antibodies (ANCA) associated vasculitides. Recommendations of the Chilean Societies of Nephrology and Rheumatology

Renal involvement is a frequent complication in antineutrophil cytoplasmic antibodies (ANCA)associated vasculitides, adding morbidity and mortality, such as chronic kidney disease and the need for renal replacement therapy. With the aim of reaching a consensus on relevant issues regarding the diagnosis, treatment and follow-up of patients with these diseases, the Chilean Societies of Nephrology and Rheumatology formed a working group that, based on a critical review of the available literature and their experience, raised and answered consensually a set of questions relevant to the subject. This document includes aspects related to the clinical diagnosis, the histological characteristics, the therapeutic alternatives to induce and maintain the remission of the disease, relapse surveillance strategies and complementary therapies.

Cyclosporin A-treated Dendritic Cells may affect the outcome of organ transplantation by decreasing CD4+CD25+ regulatory T cell proliferation

One of the mechanisms for generation of tolerance involves immature dendritic cells (DCs) and a subpopulation of regulatory CD4+ CD25+ T lymphocytes (T REG). The purpose of this work was to analyze how Cyclosporine A (CsA), a widely used immunosuppressive drug, may affect T REG proliferation. Purified and activated murine DCs obtained from bone marrow precursors differentiated with rGMCSF were co-cultured with purified CFSE-labeled T REG from OTII mice, and their phenotype and proliferation analyzed by flow cytometry. Our data indicate that DCs differentiated in the presence of CsA show an altered phenotype, with a lower expression of MHC-II and a lower activating capacity. Additionally, these CsA-treated DCs show decreased production of IL-2 and IL-12 and increased IL-10 secretion when stimulated with LPS, indicating an effect on the polarization of the immune response. Interestingly, CsA-treated DCs show an anti-tolerogenic effect since they reduce the proliferation of T REG cells from 72 to 47 percent. Further inhibition to a 24 percent of T REG proliferation was obtained as a direct effect of CsA on T REG. In conclusion, the anti-tolerogenic effect of CsA should be considered in the planning of immunosuppression in the context of clinical transplantation.

La detección antígeno-específica de linfocitos T y sus aplicaciones clínicas / Clinical applications of antigen-specific detection of T lymphocytes

The important role that T lymphocytes play during the immune response against pathogens and tumor cells has encouraged the development of technologies aimed to detect these immune cells in an antigen-specific fashion. Recently, a methodology consisting of the production of soluble ligands that bind the T lymphocyte receptor was developed. Such ligands consist of molecules from the Major Histocompatibility Complex loaded with either pathogen or tumor derived peptides. These molecular complexes are tetramerized to enhance the binding efficiency to the T cell receptor (TCR), which improves the detection sensitivity of antigen specific T lymphocytes. This new technology is currently used successfully during the follow up patients that were vaccinated against certain tumor antigens, to evaluate the expansion of tumor specific T lymphocytes. This methodology is also promising for the detection and specific deletion of autoreactive T lymphocytes as a treatment for autoimmune disorders. In this article we review the molecular components involved in antigen recognition by T lymphocytes, and the potential benefits for Biomedicine that could result from the detection of these cells by soluble specific ligands (Rev MÚd Chile 2004; 132: 371-80).