Lipoprotein-associated Phospholipase A2: A New Biomarker for Lymphoma Development in Sjögren’s Syndrome

Adrianos Nezos¹, Eleni Kotsifaki¹, Charalampos Skarlis², Konstantinos Markakis¹, Haralampos Moutsopoulos³, Michael Koutsilieris¹, Clio Mavragani¹ and Anna Psarrou¹, ¹National & Kapodistrian University of Athens, Athens, Greece, ²National &Kapodistrian University of Athens, Athens, Greece, ³National & Kapodistrian University of Athens/ Academy of Athens, Athens, Greece

Meeting: ACR Convergence 2020

Keywords: autoimmune diseases, Biomarkers, Gene Expression, macrophages, Sjögren's Syndrome

Session Information

Date: Friday, November 6, 2020

Title: Genetics, Genomics & Proteomics Poster

Session Type: Poster Session A

Session Time: 9:00AM-11:00AM

Background/Purpose: B-cell non-Hodgkin’s lymphoma (B-NHL) is one of the major complications of primary Sjögren’s syndrome (SS). Chronic inflammation and macrophages in SS minor salivary glands have been previously suggested as significant predictors for lymphoma development among SS patients. Extracellular lipoprotein-associated phospholipase A2 (Lp-PLA2) -a product of tissue macrophages- is found in the circulation associated with lipoproteins and has been previously involved in cardiovascular, autoimmune and malignant diseases, including lymphoma.

The purpose of the current study was to investigate the role of Lp-PLA2 as a potential biomarker for the development of B-NHL in the setting of primary SS.

Methods: Lp-PLA2 activity in serum samples collected from 50 primary SS patients with no lymphoma (SS-nL), 9 primary SS patients with lymphoma (SS-L) and 42 healthy controls (HC) was determined by detection of [³H]PAF degradation products by liquid scintillation counter (Cohort 1). Additionally, sera from an independent cohort of 50 SS-nL, 30 SS-L and 32 HC were tested for Lp-PLA2 activity using a commercially available ELISA kit (Cohort 2). Lp-PLA2 mRNA and protein expression in minor salivary gland (MSG) tissue samples from SS-nL, SS-L patients included in the 2 cohorts and sicca controls (SC) were analyzed by real-Time PCR, western blot and immunohistochemistry.

Results: Serum Lp-PLA2 activity was significantly increased in SS-L compared to both SS-nL and HC in the two independent cohorts included in the study [mean±SD (nmol/min/ml): 62.0±13.4 vs 47.6±14.4 vs 50.7±16.6, p-values: 0.003 and 0.04, respectively (Cohort 1) and 19.0±4.7 vs 15.3±3.2 vs 14.5±3.0, p-values: 0.0005 and 0.0001, respectively (Cohort 2)]. Lp-PLA2 expression in MSG tissues was also increased in SS-L compared to SS-nL and SC at both mRNA and protein level. No significant difference in either serum Lp-PLA2 activity or MSG tissue expression was observed between SS-nL and HC.

Conclusion: Lp-PLA2 serum activity and MSG tissue mRNA/protein expression could serve as a novel biomarker for B-cell lymphoproliferation in the setting of SS.

Disclosure: A. Nezos, None; E. Kotsifaki, None; C. Skarlis, None; K. Markakis, None; H. Moutsopoulos, None; M. Koutsilieris, None; C. Mavragani, None; A. Psarrou, None.

To cite this abstract in AMA style:

Nezos A, Kotsifaki E, Skarlis C, Markakis K, Moutsopoulos H, Koutsilieris M, Mavragani C, Psarrou A. Lipoprotein-associated Phospholipase A2: A New Biomarker for Lymphoma Development in Sjögren’s Syndrome [abstract]. Arthritis Rheumatol. 2020; 72 (suppl 10). https://acrabstracts.org/abstract/lipoprotein-associated-phospholipase-a2-a-new-biomarker-for-lymphoma-development-in-sjogrens-syndrome/. Accessed .

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