Association between high molecular weight apolipoprotein isoforms and lipoprotein levels in advanced chronic kidney disease and the effect of hemodialysis

To explore the association between high molecular weight apo(a) isoforms and lipoprotein(a) [Lp(a)] in chronic kidney disease (CKD) and the effect of maintenance hemodialysis (MHD), plasma Lp(a) and apo(a) isoforms were determined in age and sex-matched CKD stage 4 and stage 5 patients (repeated after 4 weeks of MHD) and healthy controls (n = 18). Median Lp(a) increased with severity of CKD. Upon HMW apo(a) isoform stratification, Lp(a) in S(2) isoform group was 37.6 mg/dl in CKD stage 4 and 64.0 mg/dl in stage 5 (P < 0.024 and P < 0.001 vs. controls), whereas in S(3) + S(4) group there was no significant increase. Following MHD, Lp(a) also decreased significantly only in the S(2) group. Increase in Lp(a) in CKD patients with HMW apo(a) isoforms is mainly restricted to S(2) isoform group, furthermore, decrease in Lp(a) levels in response to MHD is also seen in this group only.