BIOM-42. LONGITUDINAL IMMUNE PROFILES OF LOWER GRADE ADULT GLIOMA PATIENTS

Immune dysregulation is a known characteristic of glioma, however there is little known about the peripheral immune status of lower-grade (LrGG) glioma patients across the course of disease. Using immunomethylomic (deconvoluted blood DNA methylation) data from the UCSF Immune Profiles Study, we explore changes in patient peripheral blood immune cell profiles in newly diagnosed and recurrent LrGG patients. For patients receiving radiation (RT) and temozolomide (TMZ) (n = 75), blood is collected pre-RT/TMZ, post-RT/TMZ, before, during, and after adjuvant TMZ (if applicable). For patients followed only by MRI (n = 53) and those with other treatment plans (n = 67), blood is collected at MRIs, and if applicable, before radiation. For all patients, blood is also collected before new treatment intervention. For patients (LrGG IDH mutated) with paired pre- and post-surgery samples (n = 139), we observed a significant post-surgery increase in the count of memory B-cells (p = 1.7e-5), neutrophils (p = 0.0001), basophils (p = 8.7e-5), monocytes (p = 0.0001), and T-regulatory cells (p = 0.0001) along with a significant decrease in natural killer cells (p = 0.0003). Treatment was also associated with altered patient immune profiles. The use of dexamethasone was associated with an increased count of B-memory (p = 0.0001) and B-naïve cells (p = 0.0001), monocytes (p = 2.1e-5), and neutrophils (p = 3.7e-6) post-surgery. Patients receiving chemoradiation (n = 12) exhibited significant and temporally sustained decreases in B-memory (p < 0.0001), B-naïve (p = 0.005), CD4 naïve cells (p = 0.002), and in neutrophils (p = 0.001). Patient follow-up, data collection, and further analyses are ongoing. These results shed light on the dynamic and variable immune changes in LrGG patients and provide a guide for future prognostic and therapeutic studies.