Genome Canada precision medicine strategy for structured national implementation of epitope matching in renal transplantation.

Advances in immunology support the understanding that precise structural epitopes on the antibody-accessible region of the HLA molecule determine antigenicity and challenge the need for identity across the full HLA molecule to minimize graft immunogenicity. Retrospective studies confirm that quantitative measurement of epitope-level mismatching between donor and recipient is an informative marker of graft rejection and survival and suggest that prospective allocation of donor organs based on this principle may improve graft survival. Here we describe the process for rigorous prospective evaluation of this hypothesis in a formal national proof-of-concept program for epitope-based matching. This encompasses broad societal consultation to engage the public, patients and providers; the development of clear allocation policies with strategies to support candidates who may be difficult to match; molecular and sequencing methods and web-based calculators enabling rapid epitope typing and recipient selection; precise immunological monitoring of the graft response; information systems permitting real-time monitoring of clinical outcomes; and assessment of health benefit and economic cost. The results of this objective evaluation can then be provided to payers and policy-makers for review, and adoption if of proven benefit.

RNA integrity in post mortem human variant Creutzfeldt-Jakob disease (vCJD) and control brain tissue.

AIMS: To determine premortem and post mortem factors affecting quality and yield of RNA isolated from the unique archived brain material in the UK National Creutzfeldt-Jakob Disease Surveillance Unit Brain and Tissue Bank and to compare this to control brain tissue with no neurological disease. METHODS: In parallel and in replicate, RNA was prepared from the frontal parasagittal or subfrontal cortex of samples dissected from half brains (frozen intact) or from brain samples snap frozen or placed in RNALater. A total of 350 RNA samples from 78 human autopsy cases, 21 variant Creutzfeldt-Jakob disease, 26 other neurological diseases and 31 non-neurological diseases were studied. RESULTS: There was no difference in the quality or yield of RNA isolated from variant Creutzfeldt-Jakob disease, other neurological disease and non-neurological disease brains. RNA preparations from archived frozen half brains or snap frozen autopsy samples were generally of poor quality (RNA integrity number<5). There was a highly significant negative correlation between the number of times frozen half brains had been sampled and the quality of RNA. Samples stored in RNALater provided higher-quality RNA (RNA integrity number>5). Age at death, gender, post mortem interval and freezer storage time had no effect on RNA quality. CONCLUSION: Reasonable-quality RNA can be isolated from samples dissected from archived frozen human half brains but repeated sampling results in RNA degradation. Better-quality RNA is obtained from samples placed in RNALater than from snap frozen samples. The quality and yield of RNA are not affected by age at death, gender, post mortem interval of >6 h or freezer storage time.