[Evaluation of the factor which has an influence on red blood cell deformability in patients with end-stage renal...

To explore the calcium homoeostasis of red blood cells (RBC) in patients with end-stage renal disease (ESRD), which plays an important role in RBC deformability and survival, we measured free calcium-ion concentration of RBC([Ca2+]i). [Ca2+]i was measured by fluorescent spectrophotometry using fura-2. The subjects constituted 5 groups; normal controls(C group), patients with diabetes mellitus(DM) without renal failure (DM group), ESRD patients with DM (HD-DM group), non-diabetic ESRD patients with lower intact parathyroid hormone (i-PTH)(HD-NDM-A group), and with higher i-PTH(HD-NDM-B group). [Ca2] i was significantly higher in the HD-NDM group than in the C group, in the HD-DM group than in the DM group, in the DM group than in the C group, in the HD-DM group than in the HD-NDM group, and in the HD-NDM-B group than in the HD-NDM-A group. There was a significant positive correlation between i PTH and [Ca2+]i, and between C-PTH and [Ca2+]i. In stepwise multivariate regression analysis, ESRD, DM, and secondary hyperparathyroidism (SHPT) appeared as independent determinants of [Ca2+]i. [Ca2+]i was significantly decreased after a hemodialysis session comparing to that of before the session. These data indicate that [Ca2+] i of RBC is elevated in ESRD probably due to uraemia, DM, and SHPT.