Comparison of cystatin C and B eta‐2‐microglobulin kinetics in children on maintenance hemodialysis

Middle‐molecules ( MM ) are not monitored in children on hemodialysis ( HD ), but are accumulated and increase the risk of cardiovascular disease and mortality. Molecular properties of C ystatin C ( CyC ), 13 kDa, potentially make it a preferred MM marker over B eta‐2‐ M icroglobulin ( B2M ), 12 kDa. We compared CyC and B2M kinetics to investigate if CyC can be used as preferred MM marker. CyC (mg/L) and B2M (μg/mL) were measured in 21 low‐flux HD sessions in seven children. Blood samples were taken at HD start (pre), 1 and 2 hours into HD and at end of HD (post) for all sessions and 60 minutes after the first HD ( E q). PreCyC (9.85 ± 2.15) did not differ (P > 0.05) from postCyC (10.04 ± 2.83). PostB2M (38.87 ± 7.12) was higher (P 0.05), while EqB2M was lower than postB2M (36.48 ± 7.68 vs. 41.09 ± 8.99, P