A new national allocation scheme for adult kidneys in the United Kingdom. United Kingdom Transplant Support Service Authority (UKTSSA) Users' Kidney Advisory Group and its Task Forces.

A new allocation scheme for kidneys from adult cadaver donors was introduced in the UK on July 1st, 1998. The new scheme is based on data from an analysis of factors influencing transplant survival instigated by the Kidney Advisory Group (KAG) of the UKTSSA. A cohort of 6,363 first cadaver allografts performed in the UK between 1986-1993 was used for the analysis with 99.6% one-year follow-up and 97.8% 5-year follow-up. HLA matching was one of a number of factors that were found to influence transplant survival, thus supporting the policy of exchange of kidneys based on matching. The new allocation scheme is based on 3 tiers in which cadaver organs are offered first in Tier 1 to patients with zero HLA antigen mismatches (000 matchgrade), in Tier 2 to favorably matched patients, (matched for HLA-DR and mismatched for a maximum of one HLA-A and one-B locus antigen -100, 010, 110 matchgrades) and remaining kidneys in Tier 3 to non-favorably matched patients. A points score devised by a subgroup of the KAG to reflect natural justice and common sense is used as a discriminator between equally matched patients. The points are based on recipient age, donor-recipient age difference, waiting time, matchability for HLA antigens, sensitization to HLA antigens and the transplant unit balance of organ exchange. The performance of the scheme will be closely monitored, but computer simulations predict that there will be an overall improvement in transplant survival as a result of an increase in well matched transplants.

Renal transplantation in highly sensitized patients: five years of the SOS Scheme.

1. One-year graft survival of 218 patients transplanted through the SOS Scheme for highly sensitized recipients was 65%. There was significant improvement in the graft survival of 135 patients transplanted from 1986 to 1988, compared to the 83 patients transplanted from 1984 to 1985 (70% vs 56% at 1 year). 2. Of the 513 patients entered into the SOS Scheme, 218 (42%) received a graft, and of those 218, 179 were transplanted within 1 year. 3. Sex and previous graft history influenced the patient's sensitization status. Males with previously failed grafts and females waiting for their first transplant appeared at greater risk of becoming highly sensitized. 4. HLA matching improved graft survival in highly sensitized patients. The effect of matching was most evident for DR and for HLA-B and DR combined. The effect of matching for HLA-A was minimal. 5. HLA-DR1-positive individuals appeared to be at lower risk of becoming highly sensitized. In addition, DR1-positive highly sensitized patients had superior graft survival compared to DR1 negative recipients.

Structure of the sidechain of lipopolysaccharide from Erwinia amylovora T.

The sidechain of lipopolysaccharide from Erwinia amylovora T was composed of D-fucose, D-galactose and D-glucose in equimolar proportions. Using NMR spectroscopy, methylation analysis, mass spectrometry, Smith degradation and optical rotation data, the repeat unit was shown to have the following most probable structure: (formula; see text)

In defense of organ sharing in kidney transplantation.

1. The risks associated with nonbeneficial matching constitute a persistent hazard to the transplant over a long period. 2. The benefits of HLA matching and CsA are separate and additive. 3. There is no evidence that beneficial matching is not relevant to all (UK) centers. 4. Contemporary typing methods are expected to improve the accuracy of typing and reduce kidney cold-ischemia times. 5. Organ sharing increases the numbers of beneficial matches. 6. Patients with easily matchable ABO-HLA phenotypes should wait for beneficially matched transplants. 7. Patients with phenotypes that are difficult to match should be intelligently mismatched after due consideration of responder status, acceptable mismatches, and cross-reactive groups. 8. Organ sharing does not prejudice graft survival. 9. Wastage is minimized with a central clearing house. 10. Organ sharing reduces the incidence of high sensitization. 11. Organ sharing is cost effective. For these reasons we repudiate the view that organ sharing is now superfluous.

Automated irregular antibody screening on a modified 15-channel blood-grouping machine.

The addition of a 15-channel blood-grouping machine of two single-channel antibody screening systems, based on the principles described by Marsh and Lalezari has produced a modified machine capable for detecting most clinically significant irregular body group antibodies with a sensitivity equal to normal manual screening tests.