Plasma protein profiling using multiplex extension assay in dlbcl. a descriptive study exploring plasma protein pattern evolution in dlbcl treated with r‐chop

Background: In a previous study utilizing multiplex protein extension assay (PEA) we were able to highlight significant differences in pretreatment plasma proteins in lymphoma and leukemia patients compared to age and gender matched controls. In this study we intended to explore the pattern of changes in plasma proteins throughout the venture of treatment with R-CHOP for patients with DLBCL and possible association to clinical outcome and prognosis. Materials and methods: Frozen plasma samples from 94 DLBCL patients 41(44%) female, 53 (56%) male, median age of 64 years (27–87 years), and 60 age and gender matched controls were used. Samples were collected before the start (n = 93), midway through (n = 30), at progressive disease (n = 5) at relapse (n = 5) and after completion of chemotherapy in complete remission (n = 51). A total of 182 plasma proteins were measured using customized protein panels utilizing PEA technique. Results: Multivariate modelling using partial least square discriminant analysis revealed significant distinctions in protein patterns at diagnosis compared to controls and between samples collected at different stages of the illness. Striking differences in protein levels before and after treatment in patient who responded to treatment were evident (Figure 1). The three top proteins were TCL1A, CXCL13 and IL2RA. Moreover, particular proteins were significantly associated with established clinical risk factors such as age < versus ≥60 years (top CXCL17), A versus B-symptoms (top BLM hydrolase), Stage I+II versus III+IV (top CD163) and IPI 0–1 versus 3–5 (top BLM hydrolase). Furthermore, proteins well linked to mitogen activated protein kinase (MAPK) cascade, inflammatory response, cell differentiation were prominent when comparing pre and post treatment samples and controls. Cox regression analysis revealed multiple proteins significantly linked to overall survival, lymphoma specific survival and relapse free survival. Finally, there were profound differences between patients in CR and controls. Conclusion: Plasma protein profiling could add valuable insight to the biological changes in DLBCL patients undergoing treatment with R-CHOP and may aid the quest for biomarkers predicting response to treatment and prognosis. The intriguing differences between patients in CR and controls demands further studying. Abbreviations: DLBCL: Diffuse Large B-Cells Lymphoma RCHOP: Rituximab, Cyclophosphamide, Doxorubicin hydrochloride, Vincristine sulfate, and Prednisone PEA: protein extension assay TCL1A: T-cell leukemia/lymphoma protein 1A CXCL13: Cyclin-dependent kinase inhibitor 1 IL2RA: Interleukin-2 receptor alpha chain BLM Hydrolase: Bleomycin hydrolase CD163: Cluster of Differentiation 163 MAPK: Mitogen activated protein kinase Forest plot over proteins that differ significantly between DLBCL before and controls and between DL after versus before, but in opposite directions. Only top 10 for after versus before in each direction are shown. Keyword: diagnostic and prognostic biomarkers No conflicts of interests pertinent to the abstract.