A novel ECEL1 mutation expands the phenotype of distal arthrogryposis multiplex congenita type 5D to include pretibial vertical skin creases

Arthrogryposis multiplex congenita (AMC) is a heterogeneous disorder characterized by multiple joint contractures often in association with other congenital abnormalities. Pretibial linear vertical creases are a rare finding associated with arthrogryposis, and the etiology of the specific condition is unknown. We aimed to genetically and clinically characterize a boy from a consanguineous family, presenting with AMC and pretibial vertical linear creases on the shins. Whole exome sequencing and variant analysis revealed homozygous novel missense variants of ECEL1 (c.1163T > C, p.Leu388Pro, NM_004826) and MUSK (c.2572C > T, p.Arg858Cys, NM_005592). Both variants are predicted to have deleterious effects on the protein function, with amino acid positions highly conserved among species. The variants segregated in the family, with healthy mother, father, and sister being heterozygous carriers and the index patient being homozygous for both mutations. We report on a unique patient with a novel ECEL1 homozygous mutation, expanding the phenotypic spectrum of Distal AMC Type 5D to include vertical linear skin creases. The homozygous mutation in MUSK is of unknown clinical significance. MUSK mutations have previously shown to cause congenital myasthenic syndrome, a neuromuscular disorder with defects in the neuromuscular junction.     

Role of NFkappaB in antigen presentation and development of regulatory T cells elucidated by treatment of dendritic cells with the proteasome inhibitor PSI.

Dendritic cells (DC) are the most potent antigen-presenting cells for naive T cells, due to their high expression of MHC and costimulatory molecules, but relatively little is known about the biochemical pathways that regulate this function. We used the proteasome inhibitor N-benzyloxycarbonyl-Ile-Glu(O-tert-butyl)-Ala-leucinal (PSI) to demonstrate that DC antigen presentation is NFkappaB dependent. As PSI is not a specific inhibitor of NFkappaB, we reproduced this finding using a very specific approach, namely adenoviral gene transfer of IkappaBalpha, the naturally occurring inhibitor of NFkappaB. The mechanism for this inhibition of DC antigen presentation involves at least three aspects of antigen presenting function: down-regulation of HLA class II, down-regulation of CD86, and inhibition of the immunostimulatory cytokines IL-12 and TNF-alpha. In the light of the marked down-regulation of antigen-presentation cell function, it was of interest to investigate what effects exposure to PSI-treated DC might have on T cell function. It was found that immunological tolerance was induced, as challenge of T cells previously exposed to PSI-treated DC, with normal DC from the same donor did not restore their response, despite the presence of viable T cells. There were also changes in T cell surface markers, with down-regulation of CD3 and CD25 expression, and inhibition of the production of Th1 cytokines like IL-2 and IFN-gamma. These results demonstrates that NFkappaB is an effective target for blocking DC antigen presentation and inhibiting T cell-dependent immune responses, and this has implications for the development of therapeutic agents for use in multiple conditions, including transplantation, allergy and autoimmune diseases.     

Performance of Bordetella pertussis IS481 real-time PCR in a vaccine trial setting

A real-time PCR method targeting the Bordetella pertussis IS481 gene fragment was evaluated in a vaccine trial setting in which real-time PCR results could be validated against culture and serology results. Two commonly used DNA extraction methods, Amplicor Respiratory Preparation kit and the QIAamp DNA Mini Kit, were compared. An approximately 50-fold higher sensitivity was achieved using the Amplicor kit. 89 of 276 aspirates analysed with the IS481 real-time PCR were positive. Interestingly, six of these were culture negative and came from serology-negative patients. Defining true positive cases either as culture-positive or as PCR-positive cases that had been confirmed with a serology-positive result or verified with a newly constructed recA PCR, the sensitivity and specificity of the IS481 real-time PCR were 89% and 98%, respectively. This study confirms the specificity and high diagnostic sensitivity of IS481-based PCR methods for diagnosis of B. pertussis.     

High sustained response rate in patients with histologically mild (low grade and stage) chronic hepatitis C infection. A randomized,double blind,placebo controlled trial of interferon alpha-2b with and without ribavirin

OBJECTIVE: To evaluate the efficacy and safety of therapy for patients with histologically mild hepatitis C virus (HCV) liver disease. DESIGN: A randomized, double blind, placebo controlled trial of interferon alpha-2b with or without ribavirin. SETTING: Regional and university hospitals. PARTICIPANTS: One hundred and sixteen treatment naive patients with mild chronic HCV infection. Mild HCV infection was defined according to Knodell as a grade score of > or = 1 and < or = 6 and a stage score of < or = 1. INTERVENTIONS: Interferon alpha-2b (3 MU three times weekly) for 52 weeks in combination with either ribavirin or a matched placebo. MAIN OUTCOME MEASURES: The study endpoint was the absence of HCV RNA in plasma and liver tissue 26 weeks post-treatment. In addition, liver histology was compared pre- and post-treatment. RESULTS: Combination therapy was superior to interferon monotherapy, with a virological sustained response rate of 54% (31/57) and 20% (12/59), respectively, in both serum and liver tissue (P = 0.001). The sustained response rate was higher with combination therapy than monotherapy both in genotype non-1 (81% vs 36%) and in genotype 1 (28% vs 4%). There was a significant improvement in mean grade score in all sustained responders, irrespective of treatment arm. CONCLUSION: Combination therapy with interferon and ribavirin was safe and as effective in patients with histologically mild HCV infection as previously reported for more advanced disease.