Iron overload in kidney transplants: prospective analysis of biochemical and genetic markers.
BACKGROUND
The prevalence of iron overload and the influence of mutations in the HFE and TRF2 gene on biochemical markers of iron overload among renal transplant patients is unknown.


METHODS
Serum iron, ferritin, transferrin saturation (TSAT), and liver function parameters were analyzed in a cohort of 438 renal transplants. In patients with iron overload, the time course of biochemical markers of iron status as well as the influence of iron loading mutations was investigated during a time period of 5 years.


RESULTS
Of 438 renal transplant patients 41 (9.4%) presented with an iron loading phenotype (TSAT above 40% and/or ferritin above 800 ng/mL). Mutations in the HFE gene were present in 12 of 33 (36.3%) patients with iron overload. Among these one patient was homozygous for HFE C282Y, and two patients were compound heterozygous for HFE C282Y/H63D. No individual tested positive for nine other mutations in HFE as well as theTRF2 Y250X mutation. Over time we observed a decrease of mean iron and ferritin levels, and of mean TSAT in our study sample. In patients with mutations in HFE this decrease was less pronounced as compared to patients without mutations. We found an independent positive association between the presence of mutations in HFE and serum alanine-aminotransferase levels at follow-up (P= 0.003).


CONCLUSIONS
Our study demonstrates that iron overload is frequently present in renal transplant patients and shows a continuous decrease over time. This decrease is possibly impaired by the HFE C282Y and HFE H63D mutations. Furthermore, mutations in HFE may influence liver function as reflected by increased alanine-aminotransferase concentrations.
Lorenz
Matthias
M
Division of Nephrology and Dialysis, Department of Medicine III, Clinical Institute of Medical and Chemical Laboratory Diagnostics, Medical University Vienna, Vienna, Austria.
Kletzmayr
Josef
J
Huber
Andrea
A
Hörl
Walter H
WH
Sunder-Plassmann
Gere
G
Födinger
Manuela
M
D000328:Adult; D000368:Aged; D015415:Biomarkers; D005260:Female; D000071020:Hemochromatosis Protein; D015395:Histocompatibility Antigens Class I / Q000235:genetics; D006801:Humans; D019190:Iron Overload / Q000235:genetics* / Q000378:metabolism*; D016030:Kidney Transplantation; D008107:Liver Diseases / Q000401:mortality; D008297:Male; D008565:Membrane Proteins / Q000235:genetics; D008875:Middle Aged; D009154:Mutation; D011446:Prospective Studies; D035341:Telomeric Repeat Binding Protein 2 / Q000235:genetics; D014168:Transferrin / Q000378:metabolism
D015415:Biomarkers; C103673:HFE protein, human; D000071020:Hemochromatosis Protein; D015395:Histocompatibility Antigens Class I; D008565:Membrane Proteins; D035341:Telomeric Repeat Binding Protein 2; D014168:Transferrin