Banhara Pedro B, Gonçalves Renato T, Rocha Pedro T, Delgado Alvimar G, Leite Maurilo, Gomes Carlos P
Clin Nephrol. 2015 Jun;83(6):331-7. doi: 10.5414/CN108541.
Tubular dysfunction is prevalent among kidney transplant patients using calcineurin inhibitors, but our knowledge of the tubular effects of mTOR inhibitors is more limited.
60 kidney transplant outpatients using either the calcineurin inhibitor tacrolimus or the mTOR inhibitor sirolimus were investigated for renal tubular dysfunction. Proximal tubule function was assessed by quantification of albumin and β2-microglobulin, tubular reabsorption of phosphate and fractional excretion of bicarbonate. Distal tubular function was evaluated by water deprivation test and by urinary acidification test using furosemide and fludrocortisone for pH, ammonium and titratable acidity measurements.
The prevalence of distal renal tubular acidosis (dRTA) was 17% for both treatment groups. 70% of patients treated with sirolimus and 94% using tacrolimus presented with urine concentrating defect (p=0.04).
Distal RTA and urine concentrating defect were highly prevalent after kidney transplantation both in the sirolimus and tacrolimus treated patients. Acidification test was essential for the appropriate diagnosis of dRTA while dipstick urine specific gravity test was able to detect urine concentrating defect in this population.
在使用钙调神经磷酸酶抑制剂的肾移植患者中，肾小管功能障碍很常见，但我们对雷帕霉素靶蛋白（mTOR）抑制剂的肾小管作用了解较少。
对60名使用钙调神经磷酸酶抑制剂他克莫司或mTOR抑制剂西罗莫司的肾移植门诊患者进行肾小管功能障碍调查。通过定量白蛋白和β2-微球蛋白、磷酸盐的肾小管重吸收和碳酸氢盐排泄分数评估近端肾小管功能。通过禁水试验以及使用速尿和氟氢可的松进行尿液酸化试验来评估远端肾小管功能，以测量pH值、铵和可滴定酸度。
两个治疗组的远端肾小管酸中毒（dRTA）患病率均为17%。接受西罗莫司治疗的患者中有70%出现尿浓缩功能缺陷，使用他克莫司的患者中有94%出现尿浓缩功能缺陷（p=0.04）。
在接受西罗莫司和他克莫司治疗的肾移植患者中，远端RTA和尿浓缩功能缺陷非常普遍。酸化试验对于dRTA的正确诊断至关重要，而尿试纸比重试验能够检测该人群中的尿浓缩功能缺陷。
