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Updated: Aug 5, 2026
Longitudinal In Vivo Imaging and Quantification of Human Pancreatic Islet Grafting and Contributing Host Cells in the Anterior Eye Chamber
Published on: June 11, 2020
Day-Zero Serum FTIR Spectroscopy Identifies a Biochemical Signature Associated with Functional Pancreas Graft
Emanuel Vigia1,2,3,4, Luís Ramalhete2,3,5, Rúben Araújo2,6
1Hepatobiliopancreatic and Transplantation Centre, Curry Cabral Hospital, Unidade Local De Saúde De São José, R. Da Beneficência 8, 1050-099 Lisbon, Portugal.
Background:
Simultaneous pancreas-kidney (SPK) transplantation can restore renal function and insulin independence, but non-technical pancreas graft dysfunction remains difficult to anticipate.
Methods:
We conducted an exploratory single-centre retrospective biomarker-modelling study to determine whether day-zero recipient serum Fourier-transform infrared (FTIR) spectra are associated with subsequent loss of insulin independence after SPK transplantation.
Results:
Among 104 screened recipients, 51 met predefined sample-availability, spectral-quality, data-linkage and endpoint-adjudication criteria; 30 maintained pancreas graft function and 21 developed dysfunction. Cases dominated by early technical surgical failure were excluded. Clinical-only, FTIR-only and FTIR-clinical Naïve Bayes models were evaluated using leave-one-out cross-validation with Fast Correlation-Based Filter feature selection. In locked-feature internal validation, the best FTIR-only model used second-derivative spectra with vector normalization and nine selected wavenumbers, achieving AUC 0.997 (95% CI 0.985-1.000) and accuracy 0.961 (95% CI 0.902-1.000). A fixed-feature permutation analysis exceeded label-randomized performance (empirical p = 0.001). The secondary Group 1 versus Group 3 analysis suggested discrimination of pancreas dysfunction despite preserved kidney function (AUC 0.992; accuracy 0.930).
Conclusions:
Given the small cohort, high-dimensional input, non-nested feature selection, selection-bias risk and absence of external validation, serum FTIR should be considered a candidate risk-enrichment platform requiring prospective multicentre validation.
