The synthesis by fine-needle aspiration biopsy cultures of IL-7, IL-16 and IL-18 is significantly associated with acute rejection in kidney transplants.

Background: T-cell activation, the key event in the development of acute allograft rejection, depends on co-stimulatory signals delivered by antigen-presenting cells (APC). APC-derived cytokines may provide co-stimulation and modulate alloimmune reaction. We have studied cytokine synthesis by fine-needle aspiration biopsy (FNAB) culture and we found significant differences for interleukin (IL)-2, IL-6, IL-10, M-CSF and IL-1ra on comparing acute rejection versus stable kidney transplant patients. We report our findings on FNAB cultures synthesis of IL-7, IL-15, IL-16, IL-17, IL-18 and RANTES (regulated upon activation, normal T-cell expressed and secreted), all potential modulators of anti-graft reaction.

Patients And Methods: Kidney transplants (KTX) treated with CsA-AZA-Pred from the beginning, were divided into four groups. Group I: day 7 post-KTX, stable; II: day 7 post-KTX, 6.5 +/- 5.5 days before acute rejection; III: first day of acute rejection; IV: day 14 post-KTX, stable. Patients from I and IV remained rejection-free for the first 6 months, at least. All rejection episodes were confirmed by classical core renal biopsy. FNAB samples were cultured according to our published methodology and culture supernatants were collected at 48 h and analysed by ELISA for IL-7, IL-15, IL-16, IL-17, IL-18 and RANTES.

Results: Group III synthesized significantly higher amounts of IL-7, IL-16 and IL-18 than stable patients (groups I and IV). RANTES production did not show significant differences among the four groups. We did not find any trace of IL-15.

Conclusions: IL-18 may play the activation role that has been attributed to IL-12 which previously, we did not find to correlate significantly with acute rejection in KTX. IL-16 seems to play an activation role rather than an inhibition of anti-graft reaction. We confirm that RANTES is not significantly associated with acute rejection in KTX.