Analysis of serum lipoprotein abnormalities in patients with nephropathy : composition of serum apolopoprotein

With polyacrylamide gel electrophoresis (PAGE) and isoelectric focusing electrophoresis, we studied the changes of serum lipoprotein (Lp) and VLDL apolopoprotein C (apoC) in 71 patients with uncomplicated primary renal desease [hemodialysis (HD) (N＝17), chronic renal failure (RF) (N＝4), nephrotic syndrome (NS) (n＝19), and other glomerulonephritis (CGN) (n＝31)], and 16 normal controls. 1) PAGE revealed increased appearance of midband in patients with renal disease : HD (94.1%), NS (78.9%), RF (75.0%), and CGN (32.6%). On the other hand, the frequency of midband in normal control was only 6.3%. Serum triglyceride concentration in each group pf HD, RF and NS was higher than that in normal control (P＜0.001, P＜0.05, P＜0.001, respectively). Serum total sholestrol concentration in the group of NS was highter than that in normal control (P＜0.001). Serum HDL-cholesterol concentration in each group of HD, NS and CGN was lower than that in normal control (P＜0.001, P＜0.01, P＜0.01, respectively). 2) VLDL apoC II/C III ratio in patients with renal disease was lower than that in normal control (P＜0.05). The group of HD with midband had the lowest VLDL apoC II/C III ratio vs. normal control (P＜0.001). VLDL apoC II/C III ratio in the group of NS with midband and that od CGN with midband were lower than that in normal control (P＜0.01, P＜0.02, respectively). These findings suggesu that the kindney may have an important relation to the metaboloism. 3) Patients in each group had different compositions of VLDL apoC III. VLDL apoC III-2＋C III-3/C III ratio and VLDL apoC III-2/C III-1 ratio in the group of HD with midband were higher than those in the group of normal control. NS with midband and CGN with midband (P＜0.001, P＜0.001, P＜0.002, respectively). VLDL apoC III-2/C III-1 ratio in the group of NS with midband was lower than that in the group of NS without midband (P＜0.02). That is, VLDL contained excess sialylated apoC III in HD with midband, whlie VLDL contained less sialylated apoC III in NS with midband. These findings may attribute to the different mechanism of midband formation in patients with NS and those with HD. 4) Serum triglyceride concentration had negative correlations with VLDL apoC III-2/C III-1 ratio and with VLDL apoC III-2＋C III-3/C III ratio, in both normal control and aoo patients with midband. Serum total cholesterol concentration had negative correlations with VLDL apoC III-2/C III-1 ratio and with VLDL apoC III-2＋C III-3/ C III ratio, only in all oatients with midband.