Removal of Methylene Blue from Plasma via an Adsorbent Filter

Abstract

OBJECTIVE: To evaluate adsorbent filtration of methylene blue (MB) and leukocytes from plasma. METHODS: Plasma (750 ml) from apheresis of 10 normal subjects was split into three aliquots: control (A), filtration (B) and MB addition (to 1 microM), phototreatment and filtration (C). Biochemical and coagulation tests were performed: units A and B were reinfused. RESULTS: Filtration reduced MB to undetectable (< 0.05 microM) levels and leukocytes by 3 log10. Biochemical analytes were unchanged. The partial thromboplastin time was prolonged with MB addition (11 +/- 13%) or filtration (26 +/- 12%, p < 0.05), but the effects were not additive. Autologous transfusion was well tolerated. CONCLUSION: Adsorbent filtration can reduce residual MB to undetectable levels and yields a component suitable for transfusion.