[Transferrin microheterogeneity in patients treated by maintenance haemodialysis]

Transferrin (Tf) plays a crucial role in iron transport in the human body. In physiologically status Tf occurs in four variants. The concentration of Tf and its variants is changing in several conditions, especially during acute phase response, which may take place in end-stage renal disease (ESRD). The aim of this study was the assessment of the associations between changes of glycosylation of transferrin and selected blood cell count and iron metabolism parameters in ESRD patients treated by maintenance hemodialysis (mHD) with long lasting anaemia despite treatment by rHuEPO. Studies were carried out on a group of 55 ESRD patients treated by HD (ESRD group). The reference values were obtained from a group of 20 healthy volunteers (HV group). The Tf concentration was determined by the rocket immunoelectrophoresis according to Laurell. To estimate the microheterogenity of Tf the crossed affinoimmunoelectrophoresis according to Bog-Hansen was used. The concentration of selected hematological variables, and selected liver metabolism variables was assessed by routine laboratory tests, while the concentration of cytokines was measured by ELISA method, and selected acute phase proteins, i.e. C-reactive protein, by immunonephelometry method. Tf in studied sera was divided into four variants Tf1, Tf2, Tf3, Tf4. The percentage contents of variants in HV was Tf1=4%, Tf2=9%, Tf3=82%, Tf4=4%. In the sera of ESRD group the percentage contents of the Tf1, Tf2, Tf4 variants increased to 9%, 16%, 10% respectively, while the Tf3 variant decreased to 65%. Serum concentration of Tf was lower (1441 +/- 526 mg/L) in ESRD patients (p<0.0001) vs. 3539 +/- 955 mg/L in HV group. During this study we have revealed that the quantity and the quality of Tf is changing in ESRD patients. The observed correlations between concentration of Tf3 and selected hematological variables and also between Tf3 and rHuEPO, suggests that the decrease concentration of the Tf3 may lead to an impaired iron transport to the cells and may be one of the factors affecting anaemia in patients treated by HD and rHuEPO.