Letter: The price of blood tests

Sir, I recognise the point made by Robert Blackburn (letter, 5 December) that the patent system provides incentive for commercial research to develop marketable products that may be of value for health care. However, where the patents which result are excessively broad, this inhibits further commercial research in the area.

If broad patents are to be granted, then the liberal provision of licences by the patent holder to other manufacturers at reasonable prices is essential for optimising the development of the best possible diagnostic kits.

The reason that Murex Diagnostics' prices for anti-HCV kits were at the same general level as those of Chiron's licensees was to defray the costs of any retrospective reimbursement to Chiron for the kits that had been sold by Murex. That the price of theanti-HCV assays are at a level four times higher than for anti-HIV kits merely reflects the very high cost of the HCV licence when compared with the cost of licences for HIV.

When seen against this background, is it not reasonable to be concerned that in the absence of the pressure of wider competition provided by companies such as Murex and Organon Diagnostics, the costs of HCV kits are even less likely to fall to the more realistic levels of those of all the other viruses for which mass testing is undertaken?

Yours faithfully, JOHN BARBARA Head of Microbiology National Blood Transfusion Service London, NW9