Increase of sTNF receptor levels in acute renal allograft rejection after treatment with OKT3.

The use of OKT3 is associated with severe clinical side-effects. Adverse reactions are partly attributed to release of tumour necrosis factor (TNF). TNF binds to two receptors on the outer membranes of most human cell lines. Shedding of these proteins (sTNFR-p55 and sTNFR-p75) may block biological effects of TNF. Here we show a fair correlation between serum levels of sTNFRs and renal function as measured by glomerular filtration rate (GFR). In addition we assessed levels of sTNFR-p55 and sTNFR-p75, corrected for reduced renal clearance, in renal allograft rejection and following treatment with OKT3. Corrected serum levels (CSL) of sTNFR-p55 and sTNFR-p75 were determined in 12 renal allograft patients treated for an acute rejection episode with either OKT3 or methylprednisolone (MPNS). Serum levels of CSLsTNFR-p55 and CSLsTNFR-p75 in both groups prior to anti-rejection treatment were not elevated. CSLsTNFRs peaked at 1 h after the administration of OKT3, whereas in the MPNS group CSLsTNFRs remained unchanged. We conclude that in acute renal transplant rejection CSLsTNFRs increase after treatment with OKT3. In spite of high circulating sTNFRs levels all OKT3-treated patients suffered from clinical side-effects.