Serum unsaturated vitamin B12 proteins in adult patients with sickle cell anaemia (HbSS)

The unsaturated vitamin B12 binding capacity (UBBC) of serum, the three transcobalamins (TC I, TC II, TC III) and serum cobalamin have been studied in adult sickle cell patients with Hb SS. An increase in the level of the binding capacities of TC I and TC III resulting in an increase in UBBC was observed in these patients. There was no difference in the level of the binding capacity of TC II, while there was a significant reduction in the level of serum cobalamin. These changes in the pattern of these binding proteins are discussed in relation to the changes of these binding proteins in paediatric sickle cell patients with Hb SS. The results indicate that the pattern of these binding proteins changes with age among sickle cell patients resulting in an increased level of the binding capacities of TC I and TC III. These increases lend support to the view that these two similar binding proteins are involved in the defence mechanism of the body.