title: Renal tubular acidosis in renal transplant patients: the effect of immunosuppressive drugs.
abstract: BACKGROUND
  Renal tubular acidosis (RTA) is a non-anion gap metabolic acidosis and is generally mild and asymptomatic in kidney recipients. Calcineurine inhibitors (CNIs) increase the frequency of RTA but the frequency of RTA development in kidney transplant recipients receiving mammalian target of rapamycin inhibitors (mTORi) treatment remains unclear. In this study, we aimed to investigate the frequency of RTA in kidney transplant recipients on mTORi and CNI treatment and to compare both groups.
  
  
  METHODS
  We enrolled 137 adult renal transplant patients - 82 patients on mTORi and 55 patients on CNI who had similar age, sex, posttransplant follow-up period, and graft functions. We recorded the parameters of venous blood gas analysis, including serum pH value, serum bicarbonate (HCO3) concentration, presence of metabolic acidosis defined as low HCO3 (<22 mEq/L), and serum pH value (<7.35), as well as base excess and urine pH at last follow-up. RTA was defined to be metabolic acidosis with normal serum anion gap and positive urine anion gap.
  
  
  RESULTS
  The mean age of our study population was 41.2±11.3 years. RTA frequency was 35% in the mTORi group and 41% in the CNI group. mTORi and CNI groups did not differ significantly in terms of the development of metabolic and renal tubular acidosis. Type I RTA was common in both groups. RTA was affected by duration of time since transplantation and graft functions in both groups.
  
  
  CONCLUSIONS
  The rates of RTA development in patients on long-term CNI and mTORi treatment were similar.
authors: Department of Nephrology, Izmir Tepecik Research and Training Hospital, Izmir, Turkey.
authors: Mehmet
authors: M
authors: Tanrisev
authors: Division of Nephrology, Kahramanmaras State Hospital, Kahramanmaras, Turkey.
authors: Ozkan
authors: O
authors: Gungor
authors: Division of Nephrology, Erciyes University, School of Medicine, Kayseri, Turkey.
authors: Ismail
authors: I
authors: Kocyigit
authors: Tissue Typing Laboratory, Izmir Tepecik Research and Training Hospital, Izmir, Turkey.
authors: Yusuf
authors: Y
authors: Kurtulmus
authors: Department of General Surgery, Tepecik Resarch and Training Hospital, Izmir, Turkey.
authors: Cem
authors: C
authors: Tugmen
authors: Department of Nephrology, Izmir Tepecik Research and Training Hospital, Izmir, Turkey.
authors: Hulya
authors: H
authors: Colak
authors: Division of Nephrology, Kahramanmaras State Hospital, Kahramanmaras, Turkey.
authors: Orcun
authors: O
authors: Altunoren
authors: Department of General Surgery, Izmir Tepecik Research and Training Hospital, Izmir, Turkey.
authors: Eyup
authors: E
authors: Kebapci
authors: Department of General Surgery, Izmir Tepecik Research and Training Hospital, Izmir, Turkey.
authors: Cezmi
authors: C
authors: Karaca
mesh_terms: D000141:Acidosis, Renal Tubular / Q000209:etiology*; D000328:Adult; D004791:Enzyme Inhibitors / Q000009:adverse effects* / Q000627:therapeutic use; D005260:Female; D006801:Humans; D007166:Immunosuppressive Agents / Q000009:adverse effects* / Q000627:therapeutic use; D007676:Kidney Failure, Chronic / Q000601:surgery*; D016030:Kidney Transplantation / Q000009:adverse effects* / Q000379:methods; D008297:Male; D008875:Middle Aged; D058570:TOR Serine-Threonine Kinases / Q000037:antagonists & inhibitors*; D016896:Treatment Outcome
chemical_list: D004791:Enzyme Inhibitors; D007166:Immunosuppressive Agents; C546842:MTOR protein, human; D058570:TOR Serine-Threonine Kinases