Multispectral imaging for quantitative and compartment-specific immune infiltrates reveals distinct immune profiles that classify lung cancer patients

Abstract

Semiquantitative assessment of immune markers by immunohistochemistry (IHC) has significant limitations for describing the diversity of the immune response in cancer. Therefore we evaluated a fluorescence-based multiplexed IHC method in combination with a multispectral imaging system to quantify immune infiltrates in situ in the environment of non-small cell lung cancer (NSCLC). A tissue microarray including 57 non-small cell lung cancer (NSCLC) cases was stained with antibodies to CD8, CD20, CD4, FOXP3, CD45RO and for pan-cytokeratin and immune cells were quantified in epithelial and stroma compartments. The results were compared to conventional IHC and related to corresponding RNAseq expression values. We found a strong correlation between the visual and digital quantification of lymphocytes for CD45RO (correlation coefficient: r=0.52), FOXP3 (0.87), CD4 (0.79), CD20 (0.81) and CD8 cells (0.90). The correlation with RNAseq data was comparable or better for digital (0.35-0.65) rather than visual (0.38-0.58) quantification. By combining the signals of the five immune markers, further subpopulations of lymphocytes were identified and localized. Specific pattern of immune cell infiltration based either on the spatial distribution (distance between regulatory CD8+ T and cancer cells) or the relation of lymphocyte subclasses to each other (e.g. cytotoxic/regulatory cell ratio) were associated with patient prognosis.

In conclusion, the fluorescence multiplexed IHC method, based on only one tissue section, provided a reliable quantification and localization of immune cells in cancer tissue. The application of this technique on clinical biopsies can provide a basic characterization of immune infiltrates to guide clinical decisions in the era of immunotherapy.

from #ORL-AlexandrosSfakianakis via ola Kala on Inoreader http://ift.tt/2CggDjT