Cobalamin binding proteins in patients with HIV infection

Abstract: P-Cobalamins have been reported to be decreased in patients with HIV infection. Because of this, we found it of interest to examine both cobalamin-saturated binding proteins (holo-transcobalamin, holo-TC and holo-haptocorrin, holo-HC) and cobalamin unsaturated binding proteins (apo-transcobalamin, apo-TC and apo-haptocorrin, apo-HC). The results are given as range and (median). Eighteen male HIV-infected patients with plasma cobalamins below 200 pmol/1 were studied. We found low concentrations of holo-TC (37–88 (47.5) pmol/1) and holo-HC (64–184 (135.5) pmol/1). The concentration of apo-TC and apo-HC was increased (480–1730 (1025) pmol/1; 70–800 (235) pmol/1). It is concluded that, in HIV-infected patients, low plasma cobalamin does not reflect a low concentration of transcobalamin or haptocorrin. In 20 HIV-infected patients and 31 patients with malignant haematological diseases, the TC isopeptide patterns were determined. In the HIV group, an increased frequency of TC isopeptide X was found and the overall distribution of TC isopeptides was significantly different from the reference population (p < 0.05). There was no difference between the group of patients with malignant haematological diseases and the reference group.