[1] Katholieke Univ Leuven, Rega Inst Med Res, Lab Mol Immunol, B-3000 Leuven, Belgium
[2] Katholieke Univ Leuven, Rega Inst Med Res, Lab Expt Chemotherapy, B-3000 Leuven, Belgium
[3] Univ Instelling Antwerp, Lab Clin Biochem, B-2610 Wilrijk, Belgium