Renal tubular acidosis after kidney transplantation--incidence, risk factors and clinical implications.
BACKGROUND
Renal tubular acidosis (RTA) is a non-anion gap metabolic acidosis and is generally mild and asymptomatic in kidney recipients. Although calcineurin inhibitors, suboptimal allograft function, donor age and acute rejection have been associated with RTA, no detailed study has been conducted to investigate the prevalence and clinical implications of RTA in long-term kidney recipients.


METHODS
In this cross-sectional study, we enrolled 109 patients (74 males, 35 females) for the study [patients with glomerular filtration rate (GFR) <30 ml/min/1.73 m(2), unstable allograft function, diarrhoea, and respiratory disease were excluded]. Thirty-six patients (33%) were found to have RTA on the basis of plasma bicarbonate, arterial pH, urine and serum anion gap measurements.


RESULTS
Deceased donor transplantation [P = 0.034, 95% confidence interval (CI): 1.10-13.27], female gender (P = 0.017, 95% CI: 1.23-8.50), and lower GFR (55.8 +/- 19.4 in RTA and 66.1 +/- 15.9 ml/min/1.73 m(2) in non-RTA, P = 0.002, 95% CI: 1.10-13.27) were independent risk factors for RTA. Also, C-reactive protein was found to be higher in the RTA group (2.7 +/- 1.5 vs 2.0 +/- 1.5 mg/dl, P = 0.03), while no difference was noticed in body mass index or serum albumin. Analysis of the prevalence of osteoporosis and osteopenia in patients with RTA and without RTA, respectively, revealed no difference in frequency of osteoporosis (33% vs 31%) or osteopenia (33% vs 47%).


CONCLUSIONS
Although long-term kidney recipients have a relatively high prevalence of RTA, it is usually mild and subclinical. Further studies are needed to clarify long-term effects of RTA in kidney recipients.
Keven
Kenan
K
Department of Nephrology, Ankara University School of Medicine, Ibni Sina Hospital, Ankara 06100, Turkey. keven@medicine.ankara.edu.tr
Ozturk
Ramazan
R
Sengul
Sule
S
Kutlay
Sim
S
Ergun
Ihsan
I
Erturk
Sehsuvar
S
Erbay
Bulent
B
D000141:Acidosis, Renal Tubular / Q000453:epidemiology* / Q000209:etiology / Q000378:metabolism; D000328:Adult; D002097:C-Reactive Protein / Q000378:metabolism; D016001:Confidence Intervals; D003430:Cross-Sectional Studies; D005260:Female; D005500:Follow-Up Studies; D005919:Glomerular Filtration Rate; D006801:Humans; D006863:Hydrogen-Ion Concentration; D015994:Incidence; D016030:Kidney Transplantation / Q000009:adverse effects*; D008297:Male; D011188:Potassium / Q000097:blood; D011379:Prognosis; D012189:Retrospective Studies; D012307:Risk Factors; D012709:Serum Albumin / Q000378:metabolism; D017678:Sex Distribution; D013997:Time Factors; D014184:Transplantation, Homologous; D014421:Turkey / Q000453:epidemiology; D014556:Urine / Q000737:chemistry
D012709:Serum Albumin; D002097:C-Reactive Protein; D011188:Potassium