Network analysis to determine association between immuno-related toxicities and immune soluble profile in patients treated with anti-PD-1

Background: Immune checkpoint inhibitors (ICIs) have peculiar, immune-related adverse events (irAEs), as a consequence of interfering with self-tolerance mechanisms. The incidence of irAEs varies by ICI class, administered dose and treatment schedule. The aim of the study was to define a baseline (T0) immune profile (IP) predictive of irAE development. Methods: A prospective, multicenter study evaluating the IP of 79 patients with advanced cancer, treated with anti-PD-1drugs as a first- or second-line setting was performed. The results were then correlated with irAEs onset. The IP was studied by means of multiplex assay, evaluating circulating concentration of 12 cytokines, 5 chemokines, 13 soluble immune checkpoints and 3 adhesion molecules. IDO levels were evaluated through a modified liquid chromatography–tandem mass spectrometry. Data were first pre-processed by performing logarithmic transformation and Shapiro-Wilk-test. A connectivity heatmap was obtained by calculating Spearman correlation coefficients. Two different networks of connectivity were constructed, based on the toxicity profile. Results: Toxicity was predominantly of low/moderate grade. High-grade irAEs were relatively rare, while cumulative toxicity was high (23%). A positive and statistically significant correlation between the cumulative toxicity and IP10 and IL8, sLAG3, sPDL-2 sHEVM, sCD137, sCD27 and sICAM1 was found. Moreover, patients who experienced irAEs had a markedly different connectivity pattern characterized by disruption of most of the paired connections between cytokines (all the connections of the cytokine IL8, most of the connections between the pro-inflammatory chemokines, or all the connections of CD137, CD27, and CD28), while sPDL-2 pair-wise connectivity values seemed to be intensified. Network connectivity analysis identified a total of 187 statistically significant interactions in patients without toxicity and a total of 126 interactions in patients with toxicity. Ninety-eight interactions were common to both networks, while 29 were specifically observed in patients with toxicity. Conclusions: A peculiar pattern of immune dysregulation in patients who develop irAEs was defined. This immune serological profile could lead to the design of a personalized therapeutic strategy in order to prevent, monitor and treat irAEs at an early stage.