Semi‐xenotransplantation: the regenerative medicine‐based approach to immunosuppression‐free transplantation and to meet the organ demand

Although xenografts have always held immeasurable potential as an inexhaustible source of donor organs, immunological barriers and physiological incompatibility have proved to be formidable obstacles to clinical utility. An exciting, new regenerative medicine‐based approach termed “semi‐xenotransplantation” (SX) seeks to overcome these obstacles by combining the availability and reproducibility of animal organs with the biocompatibility and functionality of human allografts. Compared to conventional xenotransplantation wherein the whole organ is animal‐derived, SX grafts are cleansed of their antigenic cellular compartment to produce whole‐organ extracellular matrix scaffolds that retain their innate structure and vascular channels. These scaffolds are then repopulated with recipient or donor human stem cells to generate biocompatible semi‐xenografts with the structure and function of native human organs. While numerous hurdles must be still overcome in order for SX to become a viable treatment option for end‐stage organ failure, the immense potential of SX for meeting the urgent needs for a new source of organs and immunosuppression‐free transplantation justifies the interest that the transplant community is committing to the field.     

Detection of a recurring mutation in the human growth hormone-releasing hormone receptor gene

OBJECTIVE: Mutations in the gene encoding for the GH-releasing hormone receptor (GHRHR) have been recently described in patients with familial isolated GH deficiency (IGHD) type IB. To date, all reported mutations have been found in kindreds sharing common ancestors. The only exception is a T to A transversion which causes a substitution of histidine for leucine in codon 144 (L144H) and creates a DraIII restriction site. This mutation was described in two families with different ethnic background residing in two different continents (Europe and North America). DESIGN: We searched for GHRHR mutations in a new family with IGHD from a third continent (South America) and found the affected individuals to be homozygous for the same L144H change. We performed linkage analysis with intra- and para-genic polymorphisms to determine if the three families carrying the L144H allele are related. RESULTS: Linkage analysis studies demonstrated that one of the three families does not share the same para- and intragenic GHRHR polymorphisms with the other two. CONCLUSIONS: The L144H mutation has arisen at least twice and should be considered for initial genetic analysis in patients with familial IGHD in whom the a GHRHR mutation is suspected.     

Lanreotide extended-release aqueous-gel formulation, injected by patient, partner or healthcare provider in patients with acromegaly in the United States: 1-year data from the SODA registry

Lanreotide depot (LD; commercial name Somatuline^® Depot) is an injectable, extended-release formulation of the synthetic somatostatin analog (SSA) lanreotide. In recent clinical trials, LD was found to be suitable for self or partner administration, avoiding the need to travel to a medical facility. The Somatuline^® Depot for Acromegaly (SODA) study is an ongoing, multicenter, observational study in the US investigating the efficacy, safety, convenience and symptom relief provided by LD in patients with acromegaly. Sub-analyses explore outcomes according to who administered the injection: patient, partner, healthcare provider (HCP) or a combination. Data reported here reflect one year of patient experience. Patients are eligible for inclusion if they have a diagnosis of acromegaly, are treated with LD and can give signed informed consent. Baseline data include patient demographics, previous acromegaly treatment and investigations, GH and IGF-I levels, LD dose and dose adjustment frequency. Symptom frequency, injection pain and treatment convenience are assessed using patient-reported questionnaires. As of 18 April 2012, 166 patients had enrolled in SODA. Most (72 %) achieved normal IGF-I levels after 12 months of LD treatment. Disease control was similar in self or partner injectors and in patients who received injections from their HCP, although self or partner injecting was deemed more convenient. LD was well-tolerated irrespective of who performed the injection. Self injection led to more injection-site reactions, but this did not increase the rate of treatment interruption. Acromegaly symptoms remained stable. Biochemical, safety and convenience data support the clinical validity of injecting LD at home.     

Excessive daytime sleepiness and fatigue in neurological disorders

Sleep and Breathing - Excessive daytime sleepiness (EDS) and fatigue are some of the most frequent symptoms in neurological diseases and could impact on quality of life by increasing the risk of...     

p.H282N and p.Y191H: 2 novel CYP21A2 mutations in Italian congenital adrenal hyperplasia patients

More than 90% of all cases of congenital adrenal hyperplasia (CAH) result from steroid 21-hydroxylase gene (CYP21A2) mutations. The CYP21A2 gene is located in the human leukocyte antigen (HLA) class III region on the short arm of chromosome 6p21.3, along with an inactive pseudogene, CYP21A1P, that is 98% homologous in its coding sequence with CYP21A2. Most CYP21A2 mutations result from intergenic recombinations between CYP21A2 and the closely linked CYP21A1P pseudogene. Rare mutations not generated by gene conversion account for only 5% to 10% of 21-hydroxylase deficiency alleles. However, detection of these rare and spontaneous mutations has continued to expand worldwide. We identified 2 novel CYP21A2 missense mutations (p.H282N and p.Y191H) in 2 Italian patients with simple-virilizing and nonclassic CAH forms. Functional analysis of these CYP21A2 mutations was performed. Functional in vitro assay for mutagenized CYP21A2 enzymes was performed in transiently transfected mammalian cells to test the residual enzyme activity and the apparent kinetic values. The residual activities obtained allowed us to classify the p.H282N and p.Y191H variants as simple-virilizing and nonclassic CAH associated mutations, respectively. These results correlate with the rate of severity of the patients' disease. This finding provides a further contribution for assisting in the diagnosis of CAH patients.