[1] Univ Buenos Aires, Hosp Clin Jose San Martin, Div Inmunogenet, Fac Med, RA-1120 Buenos Aires, DF, Argentina
[2] Belfast City Hosp, No Ireland Reg Histocompatibil & Immunogenet Lab, Belfast BT9 7AD, Antrim, North Ireland
[3] Univ Ulster, Coleraine BT52 1SA, Londonderry, North Ireland