A proper designation of highly sensitized patients is crucial since it impacts the allocation. CDC-DSA is generally considered a contraindication for transplantation, whereas SPA-DSA remains controversial. The lack of consensus between centers is partly due to the heterogeneity of the HLA antibodies involved, the lack of standardization in antibody titer, the immunoglobulin (sub)class and the epitopes recognized. Until the issues are resolved, one should be careful to use the information generated in SPA for the allocation of kidneys and focus on the 'old CDC' that has shown to be effective in the past.