Background About 1% of white populations are homozygous carriers of an alle
le of the gene for the CC chemokine receptor 5 (CCR5) with a 32 bp deletion
(CCR5 Delta 32), which leads to an inactive receptor. During acute and chr
onic transplant rejection, ligands for CCR5 are upregulated, and the graft
is infiltrated by CCR5-positive mononuclear cells. We therefore investigate
d the influence of CCR5 Delta 32 on renal-transplant survival
Methods Genomic DNA from peripheral-blood leucocytes of 1227 renal-transpla
nt recipients was screened by PCR for the presence of CCR5 Delta 32. Demogr
aphic and clinical data were extracted from hospital records. Complete foll
ow-up data were available for 576 recipients of first renal transplants. Gr
aft survival was analysed by Fisher's exact test and Kaplan-Meier plots com
pared with a log-rank test.
Findings PCR identified 21 patients homozygous for CCR5 Delta 32 (frequency
1.7%). One patient died with a functioning graft. Only one of the remainin
g patients lost transplant function during follow-up (median 7.2 years) com
pared with 78 of the 555 patients with a homozygous wild-type or heterozygo
us CCR5 Delta 32 genotype. Graft survival was significantly longer in the h
omozygous CCR5 Delta 32 group than in the control group (log-rank p=0.033;
hazard ratio 0.367 [95% CI 0.157-0.859]).
Interpretation Patients homozygous for CCR5 Delta 32; show longer survival
of renal transplants than those with: other genotypes, suggesting a pathoph
ysiological role for CCR5 in transplant Loss. This receptor may be a useful
target for the prevention of transplant loss.