Tubular Functions in Subjects after Orthotopic Liver Transplantation

Summary

Renal function after orthotopic liver transplantation (OTL) is very frequently reduced and itslevel exerts a significant effect on the morbidity and mortality of these subjects. One of the mainfactors with a negative impact on renal function after OTL is the nephrotoxic action of cyclosporinA (CsA). Renal function after OTL is usually evaluated on the basis of glomerular filtration(GF). As chronic nephrotoxicity of CsA is manifested in the histological picture by significanttubulointerstitial affection, in 75 subjects after OTL the spontaneous concentrating and acidifyingcapacity of the kidneys was investigated. The value of urine osmolality (UOSM) assessed afternoctural withdrawal of fluids was in 72.7 % lower than in healthy subjects and did not reach 600mOsm/kg H2O, although the serum creatinine concentration (Scr) was still within the normalrange. The pH value of the morning urine did not reach in 38.2 % the required value of 6.0although Scr was within the normal range. Between values of UOSM after nocturnal liquid withdrawaland GF assessed on the basis of inulin clearance (Cin) was a significant direct relationship,however the scatter of values was considerable (r = 0.226, p < 0.05). Between pH values of themorning urine and Cin no correlation was found. The assembled results support the idea that theconcentrating activity of the kidneys in subjects after OTL treated with CsA is reduced. Thisreduced concentrating capacity is already apparent on the basis of UOSM of morning urine afternocturnal fluid withdrawal. Although this defect is also frequent in subjects with a normal Scrvalue, the authors assume that the use of this simple evaluation of the concentrating capacity (itdoes not burden the patient nor the attending staff) could be useful in the early diagnosis oftubulointerstitial affection.

Key words:
Orthotopic liver transplantation - Tubulointerstitial affection - Examination of tubularfunctions