HLA-B27 in the Greek Cypriot population: distribution of subtypes in patients with ankylosing spondylitis and other HLA-B27-related diseases. The possible protective role of B*2707

The major purpose of the present study was to investigate the frequency of human leukocyte antigen (HLA)-B27 alleles in healthy controls and in patients with ankylosing spondylitis (AS) and other HLA-B27-related diseases in the Greek Cypriot population. We selected 102 HLA-B27-positive individuals (60 controls and 42 patients). Typing of the HLA-B27 alleles was performed by polymerase chain reaction amplification with sequence-specific primers. Only two alleles were detected in the patient group: B*2702 (n = 31, 73.8%) and B*2705 (n = 11, 26.2%). The HLA-B*2707 allele was detected (n = 10, 16.7%) only in the healthy controls in addition to the B*2702 (n = 31, 51.7%) and B*2705 (n = 19, 31.7%) alleles. Our results show a restricted number of HLA-B27 subtypes associated with AS and other B27-related diseases and an elevated frequency of the B*2702 allele in the AS patients. The allele B*2707 seems to have a protective role in the population studied because it was found only in the healthy controls.

Clinical course and outcome after kidney transplantation in patients with C3 glomerulonephritis due to CFHR5 nephropathy

BACKGROUND

Complement factor H-related protein 5 (CFHR5) nephropathy is an inherited renal disease characterized by microscopic and synpharyngitic macroscopic haematuria, C3 glomerulonephritis and renal failure. It is caused by an internal duplication of exons 2-3 within the CFHR5 gene resulting in dysregulation of the alternative complement pathway. The clinical characteristics and outcomes of transplanted patients with this rare familial nephropathy remain unknown.

METHODS

This is a retrospective case series study of 17 kidney transplant patients with the established founder mutation, followed-up over a span of 30 years.

RESULTS

The mean (±SD) age of patients at the time of the study and at transplantation was 58.6 ± 9.9 and 46.7 ± 8.8 years, respectively. The 10- and 15-year patient survival rates were 100 and 77.8%, respectively. Proteinuria was present in 33.3% and microscopic haematuria in 58.3% of patients with a functional graft. Serum complement levels were normal in all. 'Confirmed' and 'likely' recurrence of CFHR5 nephropathy were 16.6 and 52.9%, respectively; however, 76.5% of patients had a functional graft after a median of 120 months post-transplantation. Total recurrence was not associated with graft loss (P = 0.171), but was associated with the presence of microscopic haematuria (P = 0.001) and proteinuria (P = 0.018). Graft loss was associated with the presence of proteinuria (P = 0.025).

CONCLUSIONS

We describe for the first time the clinical characteristics and outcome of patients with CFHR5 nephropathy post-transplantation. Despite the recurrence of CFHR5 nephropathy, we provide evidence for a long-term favourable outcome and support the continued provision of kidney transplantation as a renal replacement option in patients with CFHR5 nephropathy.