Sickle cell disease is an autosomal recessive genetic red cell disorder with a worldwide distribution. Growing evidence suggests a possible involvement of complement activation in the severity of clinical complications of sickle cell disease. In this study we found activation of the alternative complement pathway with microvascular deposition of C5b-9 on skin biopsies from patients with sickle cell disease. There was also deposition of C3b on sickle red cell membranes, which is promoted locally by the exposure of phosphatidylserine. In addition, we showed for the first time a peculiar “stop-and-go” motion of sickle cell red blood cells on tumor factor-α–activated vascular endothelial surfaces. Using the C3b/iC3b binding plasma protein factor Has an inhibitor of C3b cell-cell interactions, we found that factor H and its domains 19-20 prevent the adhesion of sickle red cells to the endothelium, normalizing speed transition times of red cells. We documented that factor H acts by preventing the adhesion of sickle red cells to P-selectin and/or the Mac-1 receptor (CD11b/CD18), supporting the activation of the alternative pathway of complement as an additional mechanism in the pathogenesis of acute sickle cell related vaso-occlusive crises. Our data provide a rationale for further investigation of the potential contribution of factor H and other modulators of the alternative complement pathway with potential implications for the treatment of sickle cell disease.
Sickle cell disease (SCD; ORPHA232; OMIM # 603903) is a chronic and invalidating disorder distributed worldwide, with high morbidity and mortality. Given the disease complexity and the multiplicity of pathophysiological targets, development of new therapeutic options is critical, despite the positive effects of hydroxyurea (HU), for many years the only approved drug for SCD.New therapeutic strategies might be divided into (1) pathophysiology-related novel therapies and (2) innovations in curative therapeutic options such as hematopoietic stem cell transplantation and gene therapy. The pathophysiology related novel therapies are: a) Agents which reduce sickling or prevent sickle red cell dehydration; b) Agents targeting SCD vasculopathy and sickle cell-endothelial adhesive events; c) Anti-oxidant agents.This review highlights new therapeutic strategies in SCD and discusses future developments, research implications, and possible innovative clinical trials.
Collectively, our data generate a rationale to support a larger clinical trial of early ECP program in SCD pregnancy.
Purpose: The current clinical investigation for primary aldosteronism (PA) diagnosis requires complex expensive tests from the initial suspicion to the final subtype classification, including invasive approaches; therefore, appropriate markers for subtype definition are greatly desirable. The present study performs a metabolomics analysis to further examine specific molecular signatures of PA urines Experimental design: The study considered PA subtype and gender-related differences using two orthogonal advanced UHPLC-MS metabolomics approaches. Patients with essential hypertension (n = 36) and PA (n = 50) who were referred to the outpatient hypertension clinic and matched healthy subjects (n = 10) are investigated. Results: Statistically significant changes (p < 0.05 ANOVA, Fc > 1.5) of metabolites involved in central carbon, energy, and nitrogen metabolism are identified, especially purine and pyrimidine nucleosides and precursors, and free amino acids. PLS-DA interpretation provides strong evidence of a disease-specific metabolic pattern with dAMP, diiodothyronine, and 5-methoxytryptophan as leading factors, and a sex-specific metabolic pattern associated with orotidine 5-phosphate, N-acetylalanine, hydroxyproline, and cysteine. The results are verified using an independent sample set, which confirms the identification of specific signatures. Conclusions and clinical relevance: Metabolomics is used to identify low molecular weight molecular markers of PA, which paves the way for follow-up validation studies in larger cohorts.
Aldosterone and renin measurement is a cornerstone for primary aldosteronism (PA) diagnosis, but different thresholds are used according to different assays. A fully automated chemiluminescence (CL) immunoassay for renin and aldosterone was recently proposed, showing good performance for PA screening by aldosterone to renin ratio (ARR). This study aimed to define the accuracy of this assay in the screening and in the most popular confirmatory test of autonomous aldosterone production, the intravenous saline loading test (ivSLT). We compared aldosterone results obtained by CL vs radioimmunoassay (RIA) in hypertensive patients investigated for PA (102 baseline and 85 after ivSLT). An excellent correlation was observed between RIA and CL in the entire population for aldosterone (r=0.922) and ARR (r=0.977). For ARR, Deming regression proved a good accordance between methods and, consistent with the fit model, our previous institutional ARR cut-off of 32 (pg ml)/(pg ml) corresponded to 20 pg ml mU l in CL assay. However, the correlation was weaker in the low end of aldosterone concentrations (r=0.676 for aldosterone <100 pg ml), with a concordance of ivSLT results in only 68% of patients. CL assay displays a diagnostic performance very similar to RIA for ARR screening, but it is substantially inferior in the setting of confirmatory tests of autonomous aldosterone secretion, that is, ivSLT.
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