ESPE Abstracts

Introduction: Generation of neutralizing antibodies (Nab) is a complication in enzyme replacement therapies and can lead to loss of treatment efficacy. Asfotase alfa (AA) was recently approved as the first replacement therapy in severe hypophosphatasia (congenital deficiency of alkaline phosphatase [TNSALP]). We report a case of neutralizing antibody mediated loss of efficacy of AA treatment in hypophosphatasia and the successful result of immune tolerance ind...

Background: Hyperphosphatemic conditions such as chronic kidney disease are associated with muscle wasting and impaired life quality. While muscle regeneration relies on myogenic progenitor recruitment, the effects of high phosphate loads on this process has not been investigated in detail. This study aims to clarify the direct effectsof hyperphosphatemic conditions on skeletal myoblast differentiation in an murine cell model system.Material and methods:...

Achondroplasia (Ach) is a skeletal disorder caused by gain-of-function mutations of FGFR3. Ach patients suffer from various complications such as short stature, foramen magnum stenosis and sleep apnea. Disease-specific treatment is not available at present, although some drugs including a C-type natriuretic peptide analogue have been developed. The mutated FGFR3, G380R, has an elevated activity of the receptor-associated tyrosine kinase, but G380R is further activated...

Multiple epiphyseal dysplasia (MED) is a chondrodysplasia characterised by delayed epiphyseal endochondral ossification, resulting in disproportionate short stature and early onset osteoarthritis. MED can be caused by heterozygous mutations in COMP, MATN3, COL9A1, COL9A2 and COL9A3, or bi-allelic mutations in SLC26A2. Human induced pluripotent stem cells (hiPSCs) are reprogrammed somatic cells which can differentiate to form all body tissues and have excellent potential for ti...

Background: Pseudohypoparathyroidism type 1b (PHP1b) is caused by epigenetic errors on the maternal GNAS allele at differentially methylated regions (DMRs) associated with exons A/B, XL, and NESP that lead to reduced production of Gαs transcripts most notably in the renal proximal tubule and thyroid follicular cells. Most PHP1b cases appear sporadically, few of which can be explained by paternal uniparental disomy involving chromosome 20q, leading to global methy...

Background: Thymus transplantation is undertaken for conditions associated with severe immunodeficiency. These comprise a number of genetic and syndromic associations including 22q deletion syndrome, CHARGE association, diabetic embryopathy, and other rarer conditions. These conditions may also be associated with hypoparathyroidism and patients are therefore at risk of severe hypocalcaemia. There are no published guidelines for calcium replacement in these patients during the ...