Abstract 2683: Serum multiplex analysis of tertiary lymphoid structure-associated chemokines/cytokines in melanoma patients
Authors: Karapetyan Lilit , Yang Xi , Wang Hong , Sander Cindy , Karunamurthy Arivarasan , Kirkwood John M. , Storkus Walter J. 
Published: July 2021

Background: The presence of tertiary lymphoid structures(TLS) in the melanoma microenvironment has been reported to represent a biomarker of superior patient prognosis and responsiveness to immunotherapy. Pro-inflammatory chemo-/cytokines supportive of TLS development have also been previously reported to be elevated in the serum of autoimmune patients exhibiting TLS in active sites of disease. The current study was performed to investigate serum levels of TLS-associated chemo-/cytokines as biomarkers of disease-associated variables in melanoma patients.

Experimental Design: Serum concentrations of APRIL, BAFF, CCL19, CCL21, CXCL10, CXCL13, CX3CL1, lymphotoxin-alpha (LTA) were simultaneously measured by Luminex Multiplex Assay in patients with melanoma vs. healthy age/gender-matched control donors. Spearman rank correlation coefficient was used to examine the association between analytes and analytes vs. continuous variables. Wilcoxon rank-sum or Kruskal-Wallis, and Wilcoxon sign rank tests were used to evaluate associations between analyte levels and categorical variables, and treatment-induced changes, respectively. The association between target analytes and overall survival were examined using Cox proportional hazards models.

Results: In total, 79 patients with melanoma and 18 healthy donors were included in the analysis. Overall, 89%, 92%, and 82% of patients exhibited serum levels of BAFF, CX3CL1 and LTA below the assay detection limit. Serum levels of CCL19 were positively correlated with APRIL and CXCL13, and CXCL10 levels were positively correlated with disease stage. In comparison to healthy controls, melanoma patients displayed significantly higher levels of serum APRIL and CCL19 but not other analytes. Males had significantly higher levels of serum CXCL10 and CXCL13 vs. females. Serum levels of APRIL and CXCL10 increased with age. Patients with a history of autoimmune disease had higher levels of serum CXCL13. In comparison to patients with superficial spreading and nodular melanoma, mucosal melanoma patients had significantly higher levels of serum CXCL10. Serum levels of TLS-associated chemokines/cytokines did not vary amongst patients with tumors exhibiting brisk, non-brisk vs. absent levels of infiltrating lymphocytes. Treatment with immunotherapy resulted in increased serum levels of APRIL, CCL19, and CXCL13, but these changes did not reach statistical significance. Using a univariate Cox model, elevated serum levels of APRIL, CCL19, and CXCL10 were associated with worse survival amongst patients with advanced-stage melanoma.

Conclusion: Serum profiling of TLS-associated chemo-/cytokines revealed correlations with patient age, gender, and underlying autoimmune disease, but a lack of association with histopathologically-defined immune infiltration/organization in the limited series of melanoma sections thus far sampled.

Citation Format: Lilit Karapetyan, Xi Yang, Hong Wang, Cindy Sander, Arivarasan Karunamurthy, John M. Kirkwood, Walter J. Storkus. Serum multiplex analysis of tertiary lymphoid structure-associated chemokines/cytokines in melanoma patients [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 2683.