Triiodothyronine (T3) reflects renal graft function after renal transplantation

OBJECTIVEAbnormalities in thyroid function are observed in patients with end stage renal disease. However, there are no data available evaluating sequential changes of thyroid function after renal transplantation. Therefore, we have studied thyroid hormone function in the immediate post‐operative period after renal transplantation in order to determine the relationship between improving renal function and changes in thyroid hormone economy. DESIGN AND PATIENTSThyroid function was evaluated in 22 patients before and on days 1, 3, 7 and 15 after renal transplantation. All patients received prednisone and cyclosporin as immunosuppressive therapy. Twelve patients with normal renal function undergoing comparable surgical procedures served as a control group. MEASUREMENTSSerum creatinine and thyroid hormone parameters (total T4, total T3, free T4, free T3, Thyroxin binding globulin (TBG), reverse T3, T3 sulphate and TSH) were measured. RESULTSAccording to post‐operative kidney function after renal transplantation, patients could be subdivided into three groups: five patients had primary graft function (group I); seven patients had delayed graft function because of acute renal failure (group II); 10 patients had delayed graft function requiring high doses of prednisone and some also of OKT3 because of acute rejection (group III). There was a significant fall in T3 and T4 concentrations with a concomitant rise in reverse T3 in all patients up to 3 days after renal transplantation. However, only patients in group I reached pre‐operative values on day 15 after renal transplantation (serum creatinine 167±52 μm), whereas patients in group II (creatinine 609±118 μm) and group III (creatinine 839±71 μm) continued to have T3 concentrations well in the hypothyroid range (group I, 1.68±0.28 nm) vs 0.87 ± 0.09 nm in group II and 0.76 ± 0.10 nm in group III; P