Abnormally elevated serum transcobalamin II levels in patients with cerebral malaria.

Transcobalamin II (TCII) levels have been reported to be elevated in patients with many clinical conditions including proliferative reticuloendothelial system. As reactive macrophage hyperplasia frequently occurs in patients with malaria, the objective of the present study was to determine TCII in patients with Plasmodium falciparum with cerebral symptoms. The studies were performed on 14 cerebral malaria patients as well as 60 normal subjects. The mean values of serum vitamin B12 and TCII levels were significantly higher in the patient group and 6 and 7 patients had serum vitamin B12 and TCII levels higher than the normal values. There was direct relationship between serum TCII levels and BUN or creatinine levels. These findings indicated that raised serum TCII level occurred only in patients with renal insufficiency. A decreased glomerular fiLtration rate reduced the amount of vitamin B12 and TCII-B12 that filtered through the glomeruli resulting in the reduced proximal tubular cells uptake and its degradation of TCII. This reduced lysosomal enzyme activity, therefore, prolongs the intravascular TCII survival and increased secretion of TCII into the circulation. Therefore, serum TCII levels were elevated in these cerebral malaria patients.