Role of serum tumour necrosis factor alpha and its soluble receptors in predicting acute renal allograft rejection

Abstract

Tumour necosis factor alpha (TNF-α) is known to be involved in pathogenesis of acute renal allograft rejection. However, measurement of cytokine serum levels alone are not a reliable index of acute rejection episodes. TNF-α induces the release of soluble receptors (TNF-SR55 and TNF-SR75) that have an inhibitory activity and catabolized by the kidney. Twenty nine transplant recepients were studied and compared to ten healthy controls. TNF-α, TNF-SR55 and TNF-SR75 were measured before and after renal transplantation. The mean pre-transplantation values were 26.3 9.7 pg/ml, 28.2 8.3 and 42.5 11.1 ng/ml respectively. According to post-transplant course patients were divided into 3 groups. Group I (stable transplant group: no= 17): The mean level of TNF-α value was 7.5 4.6 pg/ml, TNF-SR55 6.4 4.7 and TNF-SR75 12.5 8 ng/ml (p NS). Group II (acute allograft rejection group: no = 8): The mean values were 37.2 16.2 pg/ml, 16.9 9.6 and 30.9 13.4 ng/ml respectively (p0.05). Thus, TNF-α and its soluble receptor levels might be of diagnostic value in renal allograft rejection. In conclusion: 1) TNF-α and its soluble receptors are highly increased during hemodialysis. 2) There is no significant difference between healthy controls and patients with stable grafts. 3)There is highly significant increase of TNF-α and its receptors during acute rejection episodes and the day (R-2) prerejection in contrast to internal controls. 4) There is insignificant decrease of TNF-α during CS nephrotoxicity with highly significant increase of TNF-SR55, TNF-SR75 when compared to internal controls. 5) The ratios of TNF-α to SR55 & SR75 showed highly significant increase during acute rejection episodes and insignificant decrease during CS nephrotoxicity when compared to internal controls.

Keywords

• acute allograft rejection
• cyclosporine nephrotoxicity
• renal transplantation
• tumour necrosis factor