Serum concentration of cystatin C is not affected by cellular proliferation in patients with proliferative haematological disorders

Background Recent reports have shown elevated concentrations of serum cystatin C (CC) in patients with solid tumours. The aim of our study was to investigate whether patients with proliferative haematological disorders have increased serum concentrations of CC compared with normal subjects. Methods Full blood count, serum CC, β₂-microglobulin (β₂M) and serum creatinine were determined in 27 apparently healthy subjects and 35 patients with proliferative haematological disorders. Creatinine clearance was calculated using the Cockroft-Gault formula. Results CC and β₂M showed a significant correlation with each other (r = 0·96, P < 0·0001). Serum β₂M (P = 0·001) and the serum β₂M:CC ratio (P = 0·001) were significantly higher in the patients with normal renal function than in controls, but serum CC was not significantly different (P = 0·08). CC did not show a significant correlation with blood count parameters. Discussion Compared with β₂M and the β₂M:CC ratio, serum CC is not influenced by cell proliferation in haematological disorders.