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Updated: May 11, 2026
Multiplexed Immunofluorescence Analysis and Quantification of Intratumoral PD-1+ Tim-3+ CD8+ T Cells
Published on: February 8, 2018
Prognostic and predictive value of IDO expression in metastatic melanoma treated with Ipilimumab
Dagmar von Bubnoff1, Christina Schmitt2, Simone M Goldinger3
1Department of Dermatology, University Hospital Lübeck, Lübeck, Germany.
Background:
The tumor microenvironment is crucial for prognosis and response to immunotherapy in several tumor entities.
Methods:
In a multicenter retrospective study, a total of 86 tumor samples from patients with metastatic melanoma were evaluated for baseline expression of indoleamine 2,3-dioxygenase (IDO) and programmed death ligand 1 (PD-L1). Expression patterns of IDO and PD-L1 on tumor cells and antigen-presenting cells (APCs) as determined by immunohistochemical (IHC) staining of paraffin-embedded tissue sections were correlated with response to ipilimumab and overall survival (OS). Statistical analysis was performed using the Spearman correlation, the Mann-Whitney test and Kaplan-Meier estimator.
Results:
IDO expression in tumor cells or APCs was not predictive for treatment response. The median OS was 26 months in IDO-positive and IDO-negative patients, regardless of IDO expression in tumor cells or APCs. A correlation of IHC expression scores of IDO and PD-L1 could not be documented.
Conclusion:
The exact role of IDO in creating an immunosuppressive tumor environment and its reversal needs to be further elucidated.
