RESUMO
The blood-CSF barrier inhibits permeation of most chemotherapeutic agents into the central nervous system (CNS). The influence of systemic chemotherapy and prohylactic CNS irradiation on the permeability of the blood-CSF barrier was studied in 49 children treated for acute lymphoblastic leukemia (ALL) or non-Hodgkin's lymphoma. To study the permeability of the blood-CSF barrier under treatment according to BFM-ALL protocols, nephelometric determinations of albumin, immunoglobulin G (IgG), and alpha-2-macroglobulin in serum and CSF and total protein in CSF were performed at several time intervals during chemotherapy and prophylactic cranial irradiation. During systemic induction chemotherapy, no significant changes of blood-CSF barrier could be observed. In contrast, in the course of prophylactic CNS irradiation and intrathecal methotrexate application, a significant elevation of albumin, alpha-2-macroglobulin and total protein in CSF, and a significant decrease of blood:CSF ratios for albumin and alpha-2-macroglobulin were observed. IgG did not change significantly. After prophylactic CNS treatment and during maintenance chemotherapy protein concentrations and blood:CSF ratios gradually returned to normal range. This normalization was accelerated by cortisone treatment during the reinduction period.