The incidence of elderly patients with ESRD is increasing, as is the number of elderly listed for kidney transplantation. In fact, we are transplanting more and more elderly patients over the age of 70. Studies suggest that the elderly have excellent graft survival, possibly due to a less robust immune response, but unfortunately still have a higher mortality than younger patients. This dichotomy led me to wonder what the best immunosuppression is for the elderly. Logic would suggest they need less intense induction immunosuppression to avoid infectious complications. At the same time however, perhaps more intense induction can reduce the incidence of rejection and allow reduced maintenance immunosuppression (such as steroid free or low CNI) improving both infectious and cardiac outcomes. Reviewing the literature led me to 3 interesting papers on induction immunosuppression and outcome in the elderly.
Two studies were registry analysis1,2 and one was a single center study3. The registry analysis compared 3 agents: IL-2 inhibitors (anti-CD25), antilymphocyte globulin (thymoglobulin), and alemtuzumab. They suggested worse outcome with alemtuzumab compared to thymoglobulin or anti-CD25. Although outcomes with thymoglobulin and anti-CD25 were similar, thymoglobulin had a lower incidence of rejection and surprisingly revealed a trend to better patient survival! This was especially prevalent in high risk recipients whom also enjoyed better graft survival. It is possible that this effect is due to less maintenance immunosuppression and less requirement for high doses of immunosuppression to treat rejection. The single center study evaluated different cumulative doses of Thymoglobulin and outcome within different age groups. What they found was elderly (age > 60) patients had a reduced survival if they received > 6mg/kg of Thymoglobulin.
Looks like low dose thymo induction wins again!