Organ Exchange Programme Based on Virtual Crossmatch Increases Access to Kidney Transplantation of Highly Sensitized Patients in Andalusia. Andalusian Work Group for Highly-Sensitized Patients
Antonia Alvarez Marquez1, Auxiliadora Mazuecos Blanca7, Corona Alonso Diaz2, Abelardo Caballero González6, Mercedes Cabello Diaz10, Carmen De Gracia Guindo8, Teresa García Alvarez7, Antonio Garrido Torres Puchol4, Francisco González Roncero11, Maria Francisca González Escribano3, Jesús Huet Ruiz-Matas1, Antonio Nieto Diaz5, Alberto Rodriguez Benot9, Manuel Alonso Gil1.
1Regional Transplant Organisation of Andalusia, Andalusian Health Service, Sevilla, Spain; 2Immunology Department, Hospital Reina Sofia, Córdoba, Spain; 3Immunology Department, Hospital Virgen del Rocio, Sevilla, Spain; 4Immunology Department, Hospital Virgen de las Nieves, Granada, Spain; 5Immunology Department, Hospital Puerta del Mar, Cádiz, Spain; 6Immunology Department, Hospital Regional de Málaga, Málaga, Spain; 7Nephrology Department, Hospital Puerta del Mar, Cádiz, Spain; 8Nephrology Department, Hospital Virgen de las Nieves, Granada, Spain; 9Nephrology Department, Hospital Reina Sofía, Córdoba, Spain; 10Nephrology Department, Hospital Regional de Málaga, Málaga, Spain; 11Nephrology Department, Hospital Virgen del Rocio, Sevilla, Spain
Introduction: Anti-HLA antibodies reduce opportunities of kidney transplantation for patients on waiting list.
Objectives: We describe the results of a kidney allocation system for highly-sensitized(HS)patients, based on Virtual-Crossmatch(VCM) and Calculated-PRA implemented in Andalusia(a region in southern Spain with a population of 8.4 million inhabitants)and comprising five andalusian kidney transplant centres.
Method: The VCM-Programme started in June 2012. A specific computer program was designed to perform an on line VCM after introducing donor HLA antigens and patients'anti-HLA antibodies. Only patients with PRA>=95% determined by Luminex© assay in two consecutive studies were included.
When a potential donor fulfils criteria, immunology laboratory performs the VCM. The software provides a list of possible candidates arranged by blood type and date of onset of dialysis, and applies criteria in case of more than one candidate. A negative crossmatch by CDC is mandatory before transplantation.
Results: 215 HS-patients with median time on waiting list of 5.2 years (1-23.5 years) were included during the first 65 months of the VCM-Programme. During this period, 2153 deceased kidney transplants were performed in Andalusia, 90 in HS-patients (4%). After being included in VCM-Program, kidney transplantation in HS-patients was performed at a median time of 267 days (1-1681 days).
Compared with our previous kidney exchange program based on sera exchange and CDC crossmatch:1165 deceased kidney transplants were performed in Andalusia during 44 months, 12 in HS-patients(1%),which means one transplant every 144 days, while with VCM-Program, 90 of 2153 cadaveric kidney transplants(4%)were performed in HS-patients (p=0.0049),one transplant every 22 days. This new system also reduces the number of positive crossmatches with a predictive negative value of 91%.
Conclusions: Kidney allocation based on VCM significantly increases access to kidney transplantation for HS-patients.
