Polymorphisms in the F8 Gene and MHC-II Variants as Risk Factors for the Development of Inhibitory Anti-Factor VIII Antibodies During the Treatment of Hemophilia A: A Computational Assessment.

Polymorphisms in the F8 Gene and MHC-II Variants as Risk Factors for the Development of Inhibitory Anti-Factor VIII Antibodies during the Treatment of Hemophilia A: A Computational Assessment.

PLoS Comput Biol. 2013 May; 9(5): e1003066
Pandey GS, Yanover C, Howard TE, Sauna ZE

The development of neutralizing anti-drug-antibodies to the Factor VIII protein-therapeutic is currently the most significant impediment to the effective management of hemophilia A. Common non-synonymous single nucleotide polymorphisms (ns-SNPs) in the F8 gene occur as six haplotypes in the human population (denoted H1 to H6) of which H3 and H4 have been associated with an increased risk of developing anti-drug antibodies. There is evidence that CD4+ T-cell response is essential for the development of anti-drug antibodies and such a response requires the presentation of the peptides by the MHC-class-II (MHC-II) molecules of the patient. We measured the binding and half-life of peptide-MHC-II complexes using synthetic peptides from regions of the Factor VIII protein where ns-SNPs occur and showed that these wild type peptides form stable complexes with six common MHC-II alleles, representing 46.5% of the North American population. Next, we compared the affinities computed by NetMHCIIpan, a neural network-based algorithm for MHC-II peptide binding prediction, to the experimentally measured values and concluded that these are in good agreement (area under the ROC-curve of 0.778 to 0.972 for the six MHC-II variants). Using a computational binding predictor, we were able to expand our analysis to (a) include all wild type peptides spanning each polymorphic position; and (b) consider more MHC-II variants, thus allowing for a better estimation of the risk for clinical manifestation of anti-drug antibodies in the entire population (or a specific sub-population). Analysis of these computational data confirmed that peptides which have the wild type sequence at positions where the polymorphisms associated with haplotypes H3, H4 and H5 occur bind MHC-II proteins significantly more than a negative control. Taken together, the experimental and computational results suggest that wild type peptides from polymorphic regions of FVIII constitute potential T-cell epitopes and thus could explain the increased incidence of anti-drug antibodies in hemophilia A patients with haplotypes H3 and H4. HubMed – drug


Paclitaxel-loaded poly(glycolide-co-?-caprolactone)-b-D-?-tocopheryl polyethylene glycol 2000 succinate nanoparticles for lung cancer therapy.

Int J Nanomedicine. 2013; 8: 1947-57
Zhao T, Chen H, Dong Y, Zhang J, Huang H, Zhu J, Zhang W

In order to improve the therapeutic efficacy and minimize the side effects of lung cancer chemotherapy, the formulation of paclitaxel-loaded poly(glycolide-co-?-caprolactone)-b-D-?-tocopheryl polyethylene glycol 2000 succinate nanoparticles (PTX-loaded [PGA-co-PCL]-b-TPGS2k NPs) was prepared. The novel amphiphilic copolymer (PGA-co-PCL)-b-TPGS2k was synthesized by ring-opening polymerization and characterized by proton nuclear magnetic resonance spectroscopy and gel permeation chromatography. The PTX-loaded (PGA-co-PCL)-b-TPGS2k NPs were characterized in terms of size, size distribution, zeta potential, drug encapsulation, surface morphology, and drug release. In vitro cellular uptakes of NPs were investigated with confocal laser scanning microscopy, indicating the coumarin 6-loaded (PGA-co-PCL)-b-TPGS2k NPs could be internalized by human lung cancer A-549 cells. The antitumor effect of PTX-loaded NPs was evaluated, both in vitro and in vivo, on an A-549 cell tumor-bearing mouse model via intratumoral injection. The commercial PTX formulation Taxol was chosen as the reference. Experimental results showed that the PTX-loaded NPs possessed higher cytotoxicity and could effectively inhibit the growth of tumor. All the results suggested that amphiphilic copolymer (PGA-co-PCL)-b-TPGS2k could act as a potential biological material for nanoformulation in the treatment of lung cancer. HubMed – drug


Targeting the endothelin axis in scleroderma renal crisis: rationale and feasibility.

QJM. 2013 May 21;
Penn H, Quillinan N, Khan K, Chakravarty K, Ong VH, Burns A, Denton CP

BACKGROUND: We have studied endothelin-1 (ET-1) levels and ET-1 ligand and receptor tissue expression in scleroderma renal crisis (SRC) and undertaken a pilot open label safety study of bosentan, a non-selective ET-1 receptor antagonist, in SRC [Bosentan in Renal Disease-1 (BIRD-1)]. METHODS: Serum levels of ET-1 were measured in healthy controls (n = 20) or systemic sclerosis (SSc) (n = 80) with or without SRC, including cases of pulmonary arterial hypertension (PAH). Renal biopsies (n = 27) from patients with SRC were stained for endothelin ligand and receptors. Six cases of SRC received 6 months bosentan. Outcome measures were compared with SRC cases managed at our centre from 2000 to 2004 (n = 49). RESULTS: Serum ET-1 was elevated in SRC but less than in PAH. ET-1 and both endothelin A and endothelin B receptor expression was increased in SRC biopsies in glomeruli, interstitium and hallmark vascular lesions of SRC. In the BIRD-1 cohort, serum ET-1 was elevated in all cases at SRC (median healthy controls 0.50 pg/ml; SRC 1.48 pg/ml; P < 0.0005), and increased further with bosentan therapy (1.46 vs. 3.05 pg/ml; t-test P < 0.05). Bosentan was well tolerated with no significant drug-related serious adverse events and long-term outcomes were favourable compared with historic cases. Three patients developed rebound hypertension on withdrawal of bosentan and one appeared to further benefit from maintenance therapy. CONCLUSION: Upregulation of ET-1 ligand axis suggests that ET-1 receptor blockade is logical and treatment with bosentan appears to be safe in SRC. Future studies to assess therapeutic benefit and compare selective or non-selective receptor antagonists are justified. HubMed – drug