Cross‐validation of commercial enzyme‐linked immunosorbent assay and radioimmunoassay for porcine C‐peptide concentration measurements in non‐human primate serum

Abstract

Porcine C-peptide can be reliably measured in NHP serum using the Mercodia ELISA, making this assay interchangeable with the Millipore RIA. Inherent differences in antibody affinity and calibration factors may explain the lower ELISA values as compared to the RIA; however without access to a traceable reference standard, it is not possible to determine which assay is most accurate. Regression modeling resulted in a correction factor appropriate for conversion of ELISA data to RIA-equivalent data facilitating comparison of assay results longitudinally and between groups.

The value of glycated albumin for the prediction of graft outcome in the non‐human primate porcine islet transplantation model

“…Over time, the levels of porcine C‐peptide in PITx recipients fluctuated to a greater extent than the GA levels. Considering the reported between‐assay coefficient variations for porcine C‐peptide and GA are 8%‐13% and 0.68%‐0.75%, respectively, GA may compensate for the variability of the porcine C‐peptide assay to estimate graft function. As a short‐term glycation index, 1,5‐anhydroglucitol may be a better indicator for the deterioration of islet graft function.…”

Role of Peptides in Diagnostics

“…In the 21st century, a number of peptide-based diagnostic systems has already been developed for commercial use or are on the verge of completion. There are a few examples of ELISAs with peptide-based diagnostic probes: C-peptide [25,26], gliadin [27], vasoactive intestinal peptide [28] diphtheria toxin (DTx) [29], Chlamydia trachomatis [30][31][32][33][34] human T-lymphotropic virus type I (HTLV-I) [35], human C. pneumoniae [31][32][33] and COVID 19 spike protein [36].…”

Porcine C‐peptide measurement to assess graft function in xenogeneic porcine islet transplantation; editorial commentary

“…In this issue of the journal, Gresch and colleagues in the Minneapolis group report the validation of two assays for porcine C‐peptide to assess porcine islet graft function after transplantation into cynomolgus macaques . This commentary is written to link this publication with two others in the journal on this topic, an earlier one by the Minneapolis group and a publication by Shin et al. in the Seoul group .…”

“…The Minneapolis group conducted a validation study in a matrix of porcine serum and a matrix of cynomolgus macaque serum . This may represent an irrelevant item, but actually this is not the case, especially not for assay performance in the xenotransplantation field.…”