Alport syndrome: HLA association and kidney graft outcome.

Alport syndrome (AS) is a genetic disease of type IV collagen involving non-homogeneous patterns of inheritance characterized clinically by the presence of progressive haematuric nephritis leading to end-stage renal disease (ESRD), hearing loss and/or ophthalmologic abnormalities. The aim of this study was to investigate, in a cohort of AS patients who had undergone a kidney graft (KG) or who were still on a waiting list for a KG, (a) whether there is a correlation between AS and HLA antigen expression, and (b) long-term graft outcome in transplant patients. The AS cohort was represented by 34 ESRD patients, of whom 25 received a KG and the remaining nine were still on a waiting list. AS transplant patients represented 2.78% of 899 first KGs performed at our centre (Transplantation Department at S. Martino Hospital, Genoa) between 1983 and 2002. Grafts were procured from cadaveric donors in 18 cases and from living, related donors in seven cases. All AS transplant patients had a post-transplant follow-up period of at least 12 months. Results showed that: (i) the frequency of the HLA-DRB1*16 antigen was significantly increased in the whole AS cohort as compared to 128 healthy subjects (HS) (corrected P-value 0.0026; relative risk 7.20) as well as to 232 non-AS ESRD patients on a waiting list for KG (corrected P-values 0.0156; relative risk 4.67); (ii) 5- and 10-year graft survivals in the AS transplant patients were 80 and 73%, respectively, and did not differ from those of a control group represented by 25 non-AS KG recipients matched for sex, age, number of HLA mismatches and immunosuppressive treatment. Increased frequency of HLA-DRB1*16 in AS patients may reflect a linkage disequilibrium with genes coding for collagen synthesis.