RESUMEN
BACKGROUND: Microchimerism detected after solid organ transplatnation has been reported to be associated with improved graft survival with some controversies. However, the effect of pretransplantation microchimerism on the graft survival has not been studied to date. The aim of this study was to investigate the effect of pretransplantation fetomaternal microchimerism on the graft survival in renal transplantation. METHODS: A total of 27 cases of renal transplantation performed between mother and child pairs during the period from 1996 to 2004 at the Seoul National University Hospital were studied retrospectively. Presence of pretransplantation fetomaternal microchimerism was detected using DNA samples extracted from peripheral blood collected before the operation. Microchimerism for the HLA-DRB1 gene of non-inherited maternal antigen was detected using nested PCR-single strand conformation polymorphism (SSCP) method. The function and survival of allograft was compared between the groups with and without microchimerism. RESULTS: Microchimerism was detected in 10 (37%) of the 27 cases. In the group with microchimerism, serum creatinine levels at one and three years after transplantation tended to be lower in the patients with microchimerism than in those without microchimerism (one year, 1.1 vs 1.3 mg/dL, P=0.133; three years, 1.2 vs 1.5 mg/dL, P=0.083). The rejection free survival tended to be longer in the patients with microchimerism than in those without microchimerism (113.5 vs 72.5 months, P=0.146). CONCLUSIONS: This study was limited by small number of cases, and an extended study on a larger number of patients is needed to clarify the role of pretransplantation fetomaternal microchimerism on allograft survival.