Reply: The Importance of Testing Anti-IL-17 Antibodies from Different Suppliers

Abstract

We thank Yapici et al. (1) for their interest in our study (2). We agree with them that the choice of the antibody is of paramount importance in a study based on immunohistochemistry results. Our choice of the Santa Cruz antibody for the present study was based on the existing literature (3-5) and on our previous work (6). In a recent study performed on graft biopsies of transplant recipients with delayed graft function, we used the same antibody and we did not observe either any epithelial expression or colocalization with CD4 within the interstitial infiltrate (6). Indeed, in this particular set of patients, IL-17 production was mainly localized in infiltrating monocytes and neutrophils (6).In our study on antibody-mediated acute rejection, we obtained the same results on tissue samples using two independent technical approaches, immunohistochemistry and immunofluorescence coupled with confocal microscopy (2). Moreover, IL-17 expression was virtually absent in the control groups, further suggesting the specificity of the immunohistochemical staining (2). Finally, the findings of the immunofluorescence performed on cultured tubular cells were significantly correlated with the results of the ELISA performed on the supernatant of the same cells.It is well known that IL-17 is a family composed of six members (7). The conflicting results observed in some of the studies mentioned by Yapici et al. might be related to the polyclonal nature of the antibody that does not specifically recognize a single member of the IL-17 family. This observation is true also for the other antibodies from different suppliers and makes extremely hard to compare them.

Dysregulation of Interleukin 23 Receptor Expression in Kidney Allografts Associated with Composite Outcome

“…Higher infiltration of Th17 is significantly associated with the severity of allograft dysfunction and tissue injury [24]. IL-17 expression by tubular epithelial cells in renal transplant recipients with acute antibody-mediated rejection has also been observed, with IL-17 tubular expression being directly and significantly correlated with the extension of C4d deposits [25].…”