Evaluation of Leukocytes, B and T Lymphocytes, and expression of CD200 and CD23 on B lymphocytes in Patients with Atopic Dermatitis on Dupilumab Therapy-Pilot Study

The association between expression of CD200 on B lymphocytes and the count of eosinophils and basophils in atopic dermatitis patients with and without dupilumab therapy - Pilot study

BACKGROUND

Eosinophils and basophils are implicated in allergic reactions, and the molecule CD200 on B cells may have regulatory functions. Assessing the associations between the expression of CD200 on B lymphocytes and eosinophils and basophils helps unravel the complex immune interactions in atopic dermatitis, aiding in targeted therapeutic approaches.

OBJECTIVE

The aim of our study is to evaluate the association between the count of eosinophils, basophils, CD16+ eosinophils, CD203+ basophils, the expression of activation marker CD200 on B cells and on their subsets in patients suffering from atopic dermatitis with and without dupilumab and in control group.

MATERIALS AND METHODS

Altogether we examined 75 subjects: 45 patients suffering from atopic dermatitis -32 patients without dupilumab treatment, 13 patients with dupilumab treatment and 30 subjects as a control group. Immunophenotype was examined by flow cytometry in which monoclonal antibodies with fluorescent molecules were used. For statistical analysis we used non-parametric Kruskal-Wallis one-factor analysis of variance with post-hoc by Dunn's test with Bonferroni modification and the Spearman's rank correlation coefficient with calculation of R2 (%, percent of Variation Explained).

RESULTS

In patients with dupilumab therapy we confirmed the association between absolute eosinophils and expression of molecule CD200 on total B lymphocytes (in 23.9 %), non-switched (in 27.2 %), naive (in 25 %) and memory (in 20.3 %) B lymphocytes and between relative eosinophils and expression of CD200 on total B lymphocytes (in 22.8 % %), non-switched (in 29 %), naive (in 21.3 %) and memory (in 22.3 %) B lymphocytes. This association is low in AD patients without dupilumab and even non linear in control healthy subjects.

CONCLUSION

The higher association between eosinophils and expression of CD200 molecule on memory, naive and non switched B lymphocytes in AD patients under dupilumab therapy suggests that activation of B lymphocytes is caused by IL-4, whose production involves eosinophils and the CD200 molecule on B lymphocytes.

The dichotomy of regulatory B cells in cancer versus allergic disease

Regulatory B cells (Bregs) are an immunosuppressive cell phenotype that affects the immune system by limiting the inflammatory cascade. Dysregulation of Bregs can interestingly play a dichotomous role in the pathophysiology of many diseases and is especially highlighted when examining cancer pathology compared to allergic disease. This study reviews the existing literature on Bregs and compares their role in allergic disease in contrast to cancer development. Upregulation of Bregs in cancer states has been associated with poor prognostic outcomes across various cancer types, and Breg proliferation was associated with chronic interferon signaling, activation of the BCR-BTK (B cell receptor-Bruton's tyrosine kinase) pathway, and release of C-X-C motif ligand 13. In contrast, Breg dysfunction has been identified as a key mechanism in many allergic diseases, such as allergic asthma, allergic rhinitis, atopic dermatitis, and contact dermatitis. Development of Breg-targeted immunotherapies is currently at the preclinical level, but strategies differentially focus on Breg depletion in cancer versus Breg stimulation in allergy. Our review highlights the divergent functions that Bregs play in cancer compared to allergy. We conclude that natural homeostasis hinges on a fine balance between the dichotomous role of Bregs-over or underactivation can result in a pathological state.

IL4Rα and IL17A Blockade Rescue Autoinflammation in SOCS1 Haploinsufficiency

By inhibition of JAK-STAT signaling, SOCS1 acts as a master regulator of the cytokine response across numerous tissue types and cytokine pathways. Haploinsufficiency of SOCS1 has recently emerged as a monogenic immunodysregulatory disease with marked clinical variability. Here, we describe a patient with severe dermatitis, recurrent skin infections, and psoriatic arthritis that harbors a novel heterozygous mutation in SOCS1. The variant, c.202_203delAC, generates a frameshift in SOCS1, p.Thr68fsAla*49, which leads to complete loss of protein expression. Unlike WT SOCS1, Thr68fs SOCS1 fails to inhibit JAK-STAT signaling when expressed in vitro. The peripheral immune signature from this patient was marked by a redistribution of monocyte sub-populations and hyper-responsiveness to multiple cytokines. Despite this broad hyper-response across multiple cytokine pathways in SOCS1 haploinsufficiency, the patient's clinical disease was markedly responsive to targeted IL4Rα- and IL17-blocking therapy. In accordance, the mutant allele was unable to regulate IL4Rα signaling. Further, patient cells were unresponsive to IL4/IL13 while on monoclonal antibody therapy. Together, this study reports a novel SOCS1 mutation and suggests that IL4Rα blockade may serve as an unexpected, but fruitful therapeutic target for some patients with SOCS1 haploinsufficiency.