In hemolytic diseases, such as sickle cell disease (SCD), intravascular hemolysis results in the release of hemoglobin, heme, and heme-loaded membrane microvesicles in the bloodstream. Intravascular hemolysis is thus associated with inflammation and organ injury. Complement system can be activated by heme in vitro.
View Article and Find Full Text PDFIntravascular erythrocyte destruction, accompanied by the release of pro-oxidative and pro-inflammatory components hemoglobin and heme, is a common event in the pathogenesis of numerous diseases with heterogeneous etiology and clinical features. A frequent adverse effect related to massive hemolysis is the renal injury and inflammation. Nevertheless, it is still unclear whether heme--a danger-associated molecular pattern--and ligand for TLR4 or upstream hemolysis-derived products are responsible for these effects.
View Article and Find Full Text PDFPurposeWe aimed to identify the genetic cause to a clinical syndrome encompassing hypohidrosis, electrolyte imbalance, lacrimal gland dysfunction, ichthyosis, and xerostomia (HELIX syndrome), and to comprehensively delineate the phenotype.MethodsWe performed homozygosity mapping, whole-genome sequencing, gene sequencing, expression studies, functional tests, protein bioinformatics, and histological characterization in two unrelated families with HELIX syndrome.ResultsWe identified biallelic missense mutations (c.
View Article and Find Full Text PDFBackground: Amelogenesis imperfecta (AI) is a group of genetic diseases characterised by tooth enamel defects. AI was recently described in patients with familial hypercalciuria and hypomagnesaemia with nephrocalcinosis (FHHNC) caused by CLDN16 mutations. In the kidney, claudin-16 interacts with claudin-19 to control the paracellular passage of calcium and magnesium.
View Article and Find Full Text PDFClaudin-16 protein (CLDN16) is a component of tight junctions (TJ) with a restrictive distribution so far demonstrated mainly in the kidney. Here, we demonstrate the expression of CLDN16 also in the tooth germ and show that claudin-16 gene (CLDN16) mutations result in amelogenesis imperfecta (AI) in the 5 studied patients with familial hypomagnesemia with hypercalciuria and nephrocalcinosis (FHHNC). To investigate the role of CLDN16 in tooth formation, we studied a murine model of FHHNC and showed that CLDN16 deficiency led to altered secretory ameloblast TJ structure, lowering of extracellular pH in the forming enamel matrix, and abnormal enamel matrix protein processing, resulting in an enamel phenotype closely resembling human AI.
View Article and Find Full Text PDFThe study of immunoglobulin G subtypes constituting immune deposits present in membranous nephropathy is useful to guide diagnosis. IgG4 deposits are more often seen in primitive forms of membranous nephropathy due to autoantibody (anti-phospholipase A2 receptor in a majority of cases). These deposits are polytypic.
View Article and Find Full Text PDFA 39-year-old female patient was admitted to explore chronic renal failure. Clinical history included silicone breast implants. Clinical examination was normal.
View Article and Find Full Text PDFLoss-of-function mutations of CYP24A1, the enzyme that converts the major circulating and active forms of vitamin D to inactive metabolites, recently have been implicated in idiopathic infantile hypercalcemia. Patients with biallelic mutations in CYP24A1 present with severe hypercalcemia and nephrocalcinosis in infancy or hypercalciuria, kidney stones, and nephrocalcinosis in adulthood. We describe a cohort of 7 patients (2 adults, 5 children) presenting with severe hypercalcemia who had homozygous or compound heterozygous mutations in CYP24A1.
View Article and Find Full Text PDFDense deposit disease is characterized by dense deposits in the glomerular and tubular basement membranes. We report 3 cases with long-term follow-up differing in histologic pattern and clinical evolution. Clinical and histologic data were collected between 1976 and 2012.
View Article and Find Full Text PDFBackground/aims: Calcium homeostasis requires regulated cellular and interstitial systems interacting to modulate the activity and movement of this ion. Disruption of these systems in the kidney results in nephrocalcinosis and nephrolithiasis, important medical problems whose pathogenesis is incompletely understood.
Methods: We investigated 25 patients from 16 families with unexplained nephrocalcinosis and characteristic dental defects (amelogenesis imperfecta, gingival hyperplasia, impaired tooth eruption).
We report a case of a kidney and pancreas transplanted patient, hospitalized for septic hip arthritis. The whole diagnostic work-up including synovial and bone biopsies remained negative. After inefficient empirical anti-bacterial antibiotic treatment, femoral head resection was performed and tissue analysis revealed Aspergillus fumigatus hyphae.
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