[1] Rijnstate Hosp, Dept Gastroenterol, NL-6800 TA Arnhem, Netherlands
[2] Rijnstate Hosp, Dept Endocrinol, NL-6800 TA Arnhem, Netherlands
[3] Rijnstate Hosp, Dept Pathol, NL-6800 TA Arnhem, Netherlands
[4] Rijnstate Hosp, Lab Biochem, NL-6800 TA Arnhem, Netherlands
[5] Rijnstate Hosp, Lab Biochem & Immunol, NL-6800 TA Arnhem, Netherlands
[6] Vrije Univ Amsterdam, Med Ctr, Lab Immunogenet, NL-1007 MB Amsterdam, Netherlands
[7] Univ Hosp Maastricht, Dept Internal Med, NL-6229 HX Maastricht, Netherlands