Re-evaluation of the haptoglobin reference values with the radial immunodiffusion technique

The reference values of the three main types of serum haptoglobin Hp 1-1, Hp 2-1, and Hp 2-2, as determined by radial immunodiffusion and with phenotype determination on polyacrylamide gel electrophoresis have been re-evaluated for both sexes. For that purpose about 500 serum samples were collected from normal, healthy Dutch volunteers. The relative occurrence of the three main types of serum haptoglobin in Dutch men and women was found to be comparable to that reported for other whites, with the Hp 2-1 phenotype predominating in the Dutch population and phenotype Hp 0-0 being absent. The observed overall reference range of haptoglobin for the Dutch population, irrespective of the phenotype, was 0.50-3.30 g/L serum. As reported by other investigators we found that the reference values for the three main types of haptoglobin significantly differed (Hp 1-1: 1.40 +/- 0.51; Hp 2-1: 2.10 +/- 0.76; and Hp 2-2: 1.65 +/- 0.73 g/L serum, mean +/- SD). However, in contrast to the data available in the literature, the reference values of haptoglobin for men and for women, as determined by the radial immunodiffusion technique, were not significantly different.