Prevalence of hemochromatosis among first-time and repeat blood donors in Norway

Background/Aims: The observed prevalence of hemochromatosis has ranged considerably from 0.05 to 0.37% in studies requiring liver biopsy. We aimed to study the prevalence of genetic hemochromatosis among Norwegian blood donors. Methods: We studied 10552 healthy blood donors (5312 women and 5240 men) using serum ferritin as a screening parameter. If serum ferritin concentration was ≥100 μg/l in women and ≥200 μg/l in men, serum iron and transferrin (measured as total iron binding CAPACITY=TIBC) were measured. Blood donors who repeatedly had a transferrin saturation above 40% and a ferritin concentration above these limits were referred to a hepatologist (H.B.). Resilts: Serum ferritin was ≥100μg/l in 94/5312 (1.8%) women and ≥200μl in 79/5240 (1.5%) men. Of these, 37 persons had a serum ferritin concentration above 100 μg/l (females) or above 200 μg/l (males) and a transferrin saturation above 40%. Nineteen of them (13 men and 6 women, median age 36 years, range 28–68) were identified as having hemochromatosis on the basis of increased hepatic iron index. Serum ferritin ranged from 111 to 1980 μg/l (median357 μg/l and transferrin saturation from 50 to 100% (median 92%), hepatic iron from 48 to 471 μmol.g dry weight (median 118 μmol/g) and hepatic iron index from 1.5 to 12.1 (median 3.0). One person had cirrhosis and none had diabetes. The prevalence of hemochromatosis was significantly higher among first-time blood donors (12 out of 3500 [3.4/1000]) compared with repeat donors (7 out of 7052 [1/1000]). p<0.005. Conclusions: The observed prevalence of hemochromatosis in Norwegian first-time blood donors of 0.34% is comparable to recently observed prevalences in other studies. However, the use of serum ferritin as a first-step screening tool may have failed to detect hemochromatosis in the early stage where iron overload has not yet occurred.