W Chiu, E Kondeatis, CHF Nevard, R Vaughan, AG Clark

Background: Renal graft thrombosis is a major cause of graft loss in paediatric recipients, occurring in 2.6% - 12% of various series of paediatric renal transplants, especially in early graft loss. In 1993 activated protein C resistance (APCR) was identified as a common risk factor for thrombophilia and the commonest cause is the Factor V Leiden mutation (a guanine (G) to adenine (A) substitution at nucleotide (nt) 1691 of the FV gene). Whether carriage of this mutation in the kidney donor or recipient predisposes to renal graft thrombosis is unknown.

Method: Paediatric renal graft recipients in Guy's Hospital, London, during Jan 92 to Dec 96 were included in this study. Recipient and donor DNA, when available, were tested for the Factor V Leiden mutation by polymerase chain reaction using sequence-specific primers (SSP-PCR). Patients whose DNA were not available or whose DNA failed to undergo the PCR reaction were excluded, and the results analysed using the Fisher's exact test.

Results: 92 renal transplants were performed for 86 patients within the study period. 10 patients lost their grafts as a result of allograft thrombosis (10.8%). DNA for 64 recipients (of 64 transplants) and 40 donors (of 44 kidneys) were available for analysis, which included 7 recipients and 4 donors with subsequently thrombosed allografts. 5/108 samples (4.6%), were heterozygous for the mutation. None occurred in the donors or recipients of thrombosed grafts. The odds ratios for thrombosis when the recipients and donors carry the mutation were 1.480 (95% C.I. 0.065 - 33.901) and 1.286 (95% C.I. 0.057 - 29.114) respectively.

Conclusion: Heterozygosity for the Factor V Leiden mutation as determined by SSP-PCR in the kidney donor or the recipient does not appear to represent a risk factor for allograft thrombosis in children. Routine screening for the mutation before transplantation is thus not warranted.