Dysregulated CD38 Expression on Peripheral Blood Immune Cell Subsets in SLE

Given its uniformly high expression on plasma cells, CD38 has been considered as a therapeutic target in patients with systemic lupus erythematosus (SLE). Herein, we investigate the distribution of CD38 expression by peripheral blood leukocyte lineages to evaluate the potential therapeutic effect of CD38-targeting antibodies on these immune cell subsets and to delineate the use of CD38 as a biomarker in SLE. We analyzed the expression of CD38 on peripheral blood leukocyte subsets by flow and mass cytometry in two different cohorts, comprising a total of 56 SLE patients. The CD38 expression levels were subsequently correlated across immune cell lineages and subsets, and with clinical and serologic disease parameters of SLE. Compared to healthy controls (HC), CD38 expression levels in SLE were significantly increased on circulating plasmacytoid dendritic cells, CD14++CD16+ monocytes, CD56+ CD16dim natural killer cells, marginal zone-like IgD+CD27+ B cells, and on CD4+ and CD8+ memory T cells. Correlation analyses revealed coordinated CD38 expression between individual innate and memory T cell subsets in SLE but not HC. However, CD38 expression levels were heterogeneous across patients, and no correlation was found between CD38 expression on immune cell subsets and the disease activity index SLEDAI-2K or established serologic and immunological markers of disease activity. In conclusion, we identified widespread changes in CD38 expression on SLE immune cells that highly correlated over different leukocyte subsets within individual patients, but was heterogenous within the population of SLE patients, regardless of disease severity or clinical manifestations. As anti-CD38 treatment is being investigated in SLE, our results may have important implications for the personalized targeting of pathogenic leukocytes by anti-CD38 monoclonal antibodies.

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POS0420 DYSREGULATED CD38 EXPRESSION ON PERIPHERAL BLOOD IMMUNE CELL SUBSETS IN SLE

Annals of the Rheumatic Diseases ◽

10.1136/annrheumdis-2021-eular.3883 ◽

2021 ◽

Vol 80 (Suppl 1) ◽

pp. 439.1-439

Author(s):

M. Burns ◽

L. Ostendorf ◽

A. Grützkau ◽

F. Hiepe ◽

T. Alexander ◽

...

Keyword(s):

Immune Cells ◽

Peripheral Blood ◽

Plasma Cells ◽

Immune Cell ◽

Target Cells ◽

Type I ◽

Expression Levels ◽

Cd38 Expression ◽

Adaptive Immune Cells ◽

Hla Dr

Background:Systemic lupus erythematosus (SLE) is a chronic autoimmune disease characterized by pathogenic antinuclear autoantibodies, which are secreted by autoreactive plasma cells. Among novel plasma cell-depleting strategies, CD38 has been identified as promising target. The monoclonal anti-CD38 antibody daratumumab is approved for treatment of multiple myeloma and provided a therapeutically relevant depletion of plasma cells in patients with SLE1.Objectives:Beyond plasma cells, CD38 is widely expressed across innate and adaptive immune cells and additional cellular targets of anti-CD38 treatment, especially in patients with SLE, are largely unknown. Therefore, this study aimed to systematically characterize the expression of CD38 in peripheral blood leukocytes to identify potential target cells of CD38-directed therapies that may contribute to or limit therapeutic benefits in SLE.Methods:We analyzed the expression of CD38 on peripheral blood leukocytes in two different cohorts, comprising a total of 56 SLE patients and 39 healthy controls, by flow and mass cytometry. CD38 expression levels across major immune cells were analyzed for changes between controls and SLE, as well as for correlation across immune cell lineages, and with clinical and serological disease parameters.Results:We detected increased CD38 expression levels on circulating NK cells, plasmacytoid dendritic cells, CD4+ and CD8+ memory T cells, as well as IgD-CD27- and marginal zone-like B cells in SLE compared to healthy controls. In myeloid and NK cells, CD38 expression was associated with an activated cellular phenotype, reflected by co-expression of molecules such as HLA-DR, CD11c or Syk. In the B cell compartment, IgA- plasmablasts and plasma cells expressed more CD38 than their IgA+ counterparts. Also, HLA-DRhigh plasmablasts showed higher CD38 expression compared to HLA-DRlow plasma cells. The strongest differences in CD38 expression between controls and SLE were found in CD8+ central and effector memory T cells. Additionally, we detected an expansion in CD38high and CD38int cells in the T cell memory compartment, with some patients showing distinctly increased expression values. We observed a high intra-individual correlation of CD38 expression across immune cell lineages, yet without correlation of CD38 expression levels with clinical activity (SLEDAI-2K), serological markers of SLE or the type I interferon surrogate marker CD169 (SIGLEC-1).Conclusion:Our data indicate that not only pathogenic plasma cells are potential target cells of CD38-targeting antibodies. The highly dysregulated CD38 expression across innate and adaptive immune cells in SLE could be of pathophysiological importance with respect to the potential efficacy and side effects of such therapies. Since CD38 expression did not correlate with disease activity, it may be assumed that it is not a response protein solely induced and modulated by type I interferons. Nevertheless, our comprehensive characterization of CD38 expression in the immune system might have important implications for personalized approaches with emerging CD38-directed therapeutics.References:[1]Ostendorf, L. et al. Targeting CD38 with Daratumumab in Refractory Systemic Lupus Erythematosus. N. Engl. J. Med. 383, 1149–1155 (2020).Disclosure of Interests:None declared

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POS0174 IMMUNOPHENOTYPE OF SJÖGREN´S SYNDROME AND SYSTEMIC LUPUS ERYTHEMATOSUS PATIENTS IDENTIFIED TWO ENDOTYPES WITH POTENTIAL THERAPEUTIC IMPLICATIONS

Annals of the Rheumatic Diseases ◽

10.1136/annrheumdis-2021-eular.2434 ◽

2021 ◽

Vol 80 (Suppl 1) ◽

pp. 300.1-300

Author(s):

L. Martin-Gutierrez ◽

J. Peng ◽

G. Robinson ◽

M. Naja ◽

H. Peckham ◽

...

Keyword(s):

Machine Learning ◽

Systemic Lupus Erythematosus ◽

Disease Activity ◽

Lupus Erythematosus ◽

Immune Cell ◽

T Cell Subsets ◽

Systemic Lupus ◽

Immune Cell Subsets ◽

Group 2 ◽

Group 1

Background:Primary Sjögren’s syndrome (pSS) and systemic lupus erythematosus (SLE) are chronic autoimmune rheumatic diseases (ARDs) that share a strong female gender bias, as well as genetic, clinical and serological characteristics.Although significant progress has been made in improving treatment and patient related outcomes in pSS and SLE, there is a need for improved early diagnosis, adequate therapy monitoring, treatment of refractory manifestations and strategies to address co-morbidities.However, the results of many clinical trials are disappointing, and nobiologic treatments are licensedin pSS, while few are available for SLE patients with refractory disease.Objectives:Identifying shared immunological features between patients with pSS and SLE that could lead to better treatment selection using a stratification approach.Methods:Immune-phenotyping of 29 immune-cell subsets in peripheral blood from patients with pSS (n=45), SLE (n=29) and secondary SS associated with SLE (SLE/SS) (n=14) with low disease activity or in clinical remission, and sex-matched healthy controls (n=31), was performed using flow cytometry. Data were analysed using logistic regression and multiple t-tests andsupervised machine learning (balanced random forest-BRF, sparse partial least squares discriminant analysis-sPLS-DA). Patients were stratified by k-means clustering. Clinical trajectories were analysed over 5 year follow-up.Results:Comparing the immune profile of pSS and SLE patients using a variety of statistical and machine learning (ML) approaches, identified very few statistically significant differences between the two cohorts despite patients having a different clinical presentation and diagnosis. Thus, we hypothesised that immune-based subtypes could be shared between pSS, SLE and SLE/SS patients. Unsupervised k-means clustering was applied to the immunological features of the combined patient cohorts and two distinct patient endotypes, were identified: Group-1 (n=49; pSS=24, SLE=19, SLE/SS=6) and Group-2 (n=39; pSS=21, SLE=10, SLE/SS=8). Significant differences in immune-cell phenotypes across B-cell and T-cell subsets were identified by logistic regression, BRF (AUC=0.9942, assessed by 10-fold cross-validation) and sPLS-DA analysis. Comparison of the multiple analysis approaches identified eight common immune-cell subsets, including total and memory CD4+ and CD8+ T-cell subsets but no B-cell subsets. Using this common immune-signature the stratification between the groups was maintained and slightly improved (AUC=0.9979 and accuracy 96.16%). Interestingly, patients in Group-2 had elevated disease activity measures at baseline and over a 5-year trajectory compared to Group-1. Finally, correlation analysis identifed correlations between disease activity markers and the top ranked immune features from the ML models.Conclusion:The identified immune-cell signatures could reflect the underlying disease pathogenesis that spans diagnositc criteria and could be used to select patients for targeted therapeutic approaches.Acknowledgements:LM-G is supported by a project grant from The Dunhill Medical Trust (RPGF1902\117); JP is supported by Versus Arthritis (21226). GAR is supported by Lupus UK, The Rosetrees Trust (M409) and Versus Arthritis (21593). MN is supported by NIHR UCLH Biomedical Research Centre (BRC525/III/CC/191350). HP has a Versus Arthritis PhD studentship (22203). This work was performed within the Centre for Adolescent Rheumatology Versus Arthritis at UCL UCLH and GOSH supported by grants from Versus Arthritis (21593 and 20164), GOSCC, and the NIHR-Biomedical Research Centres at both GOSH and UCLH.We would like to thank Mr Jamie Evans for expert support with flow cytometry analysis and Ms Eve McLoughlin for support with patient recruitment.Disclosure of Interests:None declared

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Association of microRNA-125a with the clinical features, disease activity and inflammatory cytokines of juvenile-onset lupus patients

Lupus ◽

10.1177/09612033211010328 ◽

2021 ◽

pp. 096120332110103

Author(s):

Eman Eissa ◽

Botros Morcos ◽

Rania Fawzy Mahmoud Abdelkawy ◽

Hanan H Ahmed ◽

Naglaa M Kholoussi

Keyword(s):

Disease Activity ◽

Inflammatory Cytokines ◽

Lupus Erythematosus ◽

Plasma Levels ◽

Clinical Manifestations ◽

Juvenile Onset ◽

Expression Levels ◽

Ifn Γ ◽

Chronic Autoimmune Disease ◽

Normal Controls

Background Systemic lupus erythematosus (SLE) is a chronic autoimmune disease with marked variation in its clinical presentation. Juvenile-onset SLE (jSLE) exhibits an aggressive clinical phenotype and severe complications. Dysregulated expression of microRNAs (miRs) in immune cells from patients with SLE has been found. We aim to evaluate the association of miR-125a with the clinical and laboratory characteristics, disease activity and inflammatory cytokines of jSLE patients. Methods 60 jSLE patients and 25 normal controls were involved in the study. The expression pattern of miR-125a was determined in plasma of all subjects using qRT-PCR. In addition, plasma levels of IL-17 and IFN-γ were examined using ELISA. The correlation of miR-125a expression with the clinical manifestations and disease activity of jSLE patients was analyzed. Also, its association with the inflammatory cytokines was investigated in jSLE patients. Results Our findings showed that miR-125a expression levels were significantly reduced in jSLE patients compared to normal controls ( p < 0.01) and these expression levels differed based on the clinical variability of patients. In addition, plasma levels of IL-17 and IFN-γ in jSLE patients were significantly higher than healthy controls ( p < 0.01). Finally, miR-125a expression had significant negative associations with each of SLEDAI-2K ( p < 0.01), SLICC ( p < 0.01), ESR ( p < 0.05), proteinuria ( p < 0.01) and IL-17 levels ( p < 0.01) in jSLE patients. Conclusion Our findings postulate that miR-125a could act as a candidate therapeutic target for its possible regulation of inflammation in jSLE patients.

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