M-ficolin in children with cancer

Abstract

Objectives M-ficolin (ficolin-1) is a complement-activating pattern-recognition molecule structurally related to mannan-binding lectin. It is produced by monocytes and neutrophils, and is found in serum. Its biological role is largely unknown. We assessed M-ficolin concentration in serum from pediatric cancer patients. The aim of this study was to explore association of M-ficolin with clinical and hematological parameters, and to investigate whether the risk of chemotherapy-related infections was related to M-ficolin concentrations in serum. Methods M-ficolin was measured by time-resolved immunofluorometric assay in serum taken at cancer diagnosis and was correlated with peripheral blood counts and bone marrow examinations performed at the same time. Results Median M-ficolin concentration in 94 children with cancer was 1.6 μg/mL (interquartile range, 0.57–2.7; range, 0.055–25.8), and was not different from age-matched controls (median, 1.7 μg/mL; p = 0.92). M-ficolin was strongly associated with absolute counts of neutrophils (Spearman's rho, 0.45; 95%-CI, 0.26–0.65; p < 0.001), monocytes (0.34; 0.12–0.55; p < 0.001), and thus phagocytes (0.42; 0.20–0.63; p < 0.001) in peripheral blood. Similarly, M-ficolin correlated strongly with neutrophils (0.36; 0.14–0.59; p = 0.002) and phagocytes (0.31; 0.08–0.54; p = 0.009) in bone marrow. Low serum M-ficolin (≤0.5 μg/mL) was not associated with an increased incidence of fever in neutropenia during chemotherapy (multivariate Poisson rate ratio, 1.04; 95%-CI, 0.68–1.60; p = 0.85). Conclusions The concentration of M-ficolin in serum from children with cancer was strongly associated with neutrophil and monocyte counts in blood and bone marrow. These results suggest that M-ficolin concentrations in serum reflect the pool of phagocytes.