More patients should be excluded from being tissue donors

Editor—In their editorial, Allan and Tuft note the United Kingdom’s criteria aimed at preventing patients with Creutzfeldt-Jakob disease from becoming corneal donors.¹ In the United Kingdom, as elsewhere, discrepancies occur in practice between groups excluded as blood donors and as corneal (and other) graft donors. Among these discrepancies is the fact that relatives of patients with Creutzfeldt-Jakob disease are excluded from donating blood but not necessarily corneas. Asymptomatic relatives of the 10-15% of patients with hereditary Creutzfeldt-Jakob disease (which often occurs without a clear family history) may share the same dominant genetic defect and have a theoretical potential for transmitting the disease in the presymptomatic stage of their illness.

We recommend that blood relatives of patients with Creutzfeldt-Jakob disease or the related hereditary conditions Gerstmann-Sträussler-Scheinker disease and fatal familial insomnia should be added to the list of those excluded as corneal donors. Ideally, it would be advisable to ensure the absence of Creutzfeldt-Jakob disease by histological examination of a small piece of frontotemporal cortex from any cadaver used as a source of tissue grafts (a requirement soon to be enacted for dura mater grafts in the United States, according to the transcript of the meeting of the transmissible spongiform encephalopathy advisory committee on 6 October 1997). However, the large number of corneal transplant operations that are performed each year, coupled with the exceptional rarity of recognised transmission of Creutzfeldt-Jakob disease from contaminated grafts, make this proposal a legitimate subject for argument.