PhD Scientific Days 2023

Clinical Medicine - Posters J

Decreased Serum Level of Soluble PD-L1 in Discoid Lupus Erythematosus, but not in Subacute Cutaneous Lupus Erythematosus

Text of the abstract

Introduction
Cutaneous lupus erythematosus (CLE) is an autoimmune skin disease with various clinical forms including subtypes of discoid lupus erythematosus (DLE) and subacute cutaneous lupus erythematosus (SCLE). The altered function of the programmed cell death 1/programmed cell death ligand 1 (PD-1/PD-L1) axis might play a role in CLE pathogenesis.
Aims
We aimed to explore the soluble forms of PD-1 (sPD-1) and PD-L1 (sPD-L1) in subtypes of CLE.
Methods
Enzyme-linked immunosorbent assay was used to measure the levels of sPD-1 and sPD-L1 in serum of 21 DLE, 18 SCLE, 13 SLE patients and 20 healthy controls (HCs). Mann-Whitney U-test was used to detect any significant differences between patient groups and HCs and Spearmann’s rank correlation coefficient to detect any association between clinical activity of skin symptoms and levels of sPD-1/sPD-L1.
Results
Regarding sPD-1 no statistically significant differences were found between DLE and SCLE groups or in comparison with HCs. Concerning sPD-L1, a significantly lower serum level was found in the DLE group compared to SCLE and HC groups (p=0.027 and p=0.009, respectively). No association between clinical activity of skin symptoms and sPD-1/sPD-L1 levels was found.
Conclusion
Alterations of the inhibitory effect of sPD-L1 on T-cell activity might contribute to the pathogenesis of DLE. sPD-1 seems to play marginal role in the pathogenesis of CLE.