[1] Univ Helsinki, Cent Hosp, Dept Surg 2, FIN-00014 Helsinki, Finland
[2] Univ Helsinki, Cent Hosp, Haartman Inst & HD Diagnost, Dept Bacteriol & Immunol, FIN-00014 Helsinki, Finland
[3] Univ Helsinki, Cent Hosp, Dept Med, FIN-00014 Helsinki, Finland
[4] Jorvi Hosp, Dept Pathol, Espoo, Finland