Delayed graft function (DGF) is a common post renal transplant complication occurring in 38% of recipients. There are no available or known investigation that can predict which recipient will develop DGF. NO is essential to the kidney milieu, involved in renal patho-physiology and plays a role in process of renal transplantation, acute and chronic rejection. One of the known physiological functions of NO is vasodilatation with a significant effect on the haemodynamics of the kidneys. It plays an important role in the regulation of glomerular capillary blood pressure, glomerular blood flow and glomerular capillary ultrafiltration coefficient (Morrissey 1994). In ESRF, NO production is inhibited but successful renal transplant can restore the normal NO metabolism. Therefore pre-transplant serum NO levels may play a role in the early function of the renal transplant. High levels of serum NO may favor immediate graft function while low levels favors delayed graft function.
We recruited 43 consecutive renal recipients between 2003 and 2004. Ethical committee approval and patient consent obtained. There were no exclusion criteria. Fasting blood sample was collected on admission and following renal replacement therapy. Blood sample was immediately centrifuged and serum analysis was done. We used Greiss reaction to measure the stable end-product of NO, nitrate.
Blood sample were processed immediately. It is centrifuged at 800 for 40 minutes, serum collected and stored at -80˚ C. On the day of analysis, blood sample diluted 2-fold with Reaction Buffer and vortexed, and then 400 μmol of the prepared mixture pippetted out into a micro-centrifuge filter. We used ultrafree®-MC microcentrifuge filters (NMWL 10,000 Dalton, supplied by Sigma-Aldrich) to deproteinise the serum. This centrifuged at 8000 G for 40 minutes, yielding 100 microml of serum which was used in NO assay. For every new assay a new sample is thawed, diluted and filtered. NO is unstable molecule and within 30 second is converted to nitrate and nitrite. However, serum nitrate is the most stable end products of NO. Therefore we measured serum nitrate as an indirect measurement of NO. We measured serum nitrate using Greiss reaction (R&D System).
Delayed graft function defined as the need for dialysis in the first week after renal transplantation.
We used SPSS version 11. Results expressed by median and
Out of the 43 recipients, 33 had immediate graft function (IGF) and 10 had DGF. In IGF group, the median serum nitrate was 68 µmol/l in DGF while in DGF group, the mean serum nitrate was 47 µmol/l. There was a significant difference between both groups (P 0.013) using Mann-Whittney test. Using binary logistic regression, there was no significant difference with age, sex or type of renal replacement therapy.
Serum NO can predict DGF. Recipients with pre-transplant low serum NO will most likely develop DGF while...