Elevated cerebrospinal fluid fibronectin concentration at diagnosis indicates poor prognosis in children with acute lymphoblastic leukemia.

We investigated whether the concentration of fibronectin (FN) in the cerebrospinal fluid (CSF) could be used for identifying patients with subclinical blast-cell infiltration in the central nervous system (CNS) and an increased risk of CNS relapse later in the course of their leukemia. Our series comprised 36 children with newly diagnosed acute lymphoblastic leukemia (ALL). The mean follow-up time was 54 months (range 5 to 96 months). The median concentration of CSF-FN at diagnosis was 2.24 mg/l (range 0.78 to 7.04 mg/l). The 3-year continuous complete remission rate for the 16 patients with CSF-FN concentrations less than or equal to 2 mg/l was 93% as compared with 37% for the 19 patients with CSF-FN greater than 2 mg/l (p = 0.001). When multivariate analysis was performed, the CSF-FN concentration retained its prognostic significance. When all relapses were considered as failures, the relative risks of relapse for patients with CSF-FN less than or equal to 2 mg/l and greater than 2 mg/l were I and 15.8 (95% confidence limits 1.8-135.6, p less than 0.02), respectively. If only CNS relapses (isolated and combined) were considered as failures, relative risks for the above-mentioned groups were I and 11.6 (1.4-99.5, p less than 0.05), respectively. We conclude that determination of the CSF-FN concentration may provide a new means of evaluating the CSF in children with ALL and may prove to be a sensitive indicator of leukemic CNS infiltration.