ANTI-DONOR BLOOD TYPE ANTIBODY DOES NOT AFFECT THE OUTCOME OF ABO INCOMPATIBLE KIDNEY TRANSPLANTATION:

O73 Aims: The high titer of anti-donor blood type antibody (ADBTAB) has been considered to be a great risk for acute humoral rejection (AHR) and hyperacute rejection (HAR) in ABO incompatible kidney transplantation (ABOINCKTx). The aim of this study is to evaluate whether ADBTAB affects the outcome of ABOINCKTx. Methods: ADBTABs (IgG & IgM) were measured in 78 ABOINCKTx recipients before pre-treatment (preTr) and post-transplantation (postTx). We studied whether the titers correlated with the severity (0, 1, 2) of acute humoral rejection (AHR) based on Banff scheme and hyperacute rejection (HAR) and the graft survival. Immunoaddsorption and/or plasmapheresis and plasma exchange were performed as preTr to remove IgG and IgM. Immunosuppression consisted of steroid, MMF or azathioprine, cyclosporine or tacrolimus and ALG or basiliximab. Splenectomy was performed in 76 recipients at transplantation. No patients had plasmapheresis or exchange postTx. Results: The maximum titers of preTr IgG and IgM were significantly different in the blood type incompatible matching groups as follows. IgG : (A1 to B) < (B to A1) 5years) in preTr IgG and IgM, and postTx IgG and IgM. There was no significant difference between two groups. Graft and patient survivals are 100% up to present since January 1997 in 42 ABOINCKTx recipients irrespective of titers of ADBTABs. Conclusions: The titer of ADBTABs did not correlate with the severity of AHR and the outcome of ABOINCKTx. However the titers of ADBTABs postTx must be controlled under the threshold titer of HAR (IgG ≤x512 and IgM≤x512).