Narrative review discusses CD40/CD40L signaling regulation in rheumatoid arthritis and other autoimmune conditions

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Frontiers in Medicine Published May 18, 2026 Medically reviewed May 18, 2026 DOI ↗ By Dr. Amelia Tan, PhD · Internal Medicine & Chronic Disease

Key Takeaway

Note that safer CD40/CD40L targeting requires selectivity regarding cell-specific signaling and Fc-mediated effects.

This narrative review focuses on the role of CD40/CD40L signaling regulation in the context of rheumatoid arthritis, systemic lupus erythematosus, and Sjogren's syndrome. The publication does not report a specific study population, sample size, or setting. Instead, it synthesizes existing knowledge regarding this biological pathway in these autoimmune conditions.

The authors highlight that thromboembolic complications were observed with early CD40/CD40L-targeted biologics. No specific rates or numbers for these events were provided in the source text. The review does not include data on serious adverse events, discontinuations, or general tolerability beyond this specific observation.

The authors suggest that achieving safer therapeutic targeting of this pathway will require greater selectivity. This selectivity is particularly important with respect to cell-specific signaling and Fc-mediated adverse effects. The review acknowledges limitations inherent in narrative synthesis and does not provide pooled effect sizes or confidence intervals. Practice relevance is framed cautiously, noting the need for improved specificity in future drug development.

Study Details

Study typeSystematic review

EvidenceLevel 1

PublishedMay 2026

View Original Abstract ↓

The CD40–CD40L axis is a central costimulatory pathway that links innate and adaptive immunity and contributes to autoimmune inflammation. However, CD40 signaling does not operate in the same way across cell types, and these differences are relevant to both therapeutic efficacy and safety. In this review, we discuss the molecular features of CD40 and CD40L, the TRAF-dependent signaling pathways activated downstream of CD40, and the distinct cellular responses observed in B cells, dendritic cells, and macrophages. We also examine how dysregulated CD40/CD40L signaling contributes to key pathological features of Rheumatoid arthritis, Systemic lupus erythematosus, and Sjögren’s syndrome, including ectopic germinal center reactions, pathogenic autoantibody production, and chronic tissue inflammation. Platelet-derived CD40L and CD40 expression on vascular cells may also help explain the thromboembolic complications observed with early CD40/CD40L-targeted biologics. Current evidence suggests that safer therapeutic targeting of this pathway will require greater selectivity, particularly with respect to cell-specific signaling and Fc-mediated adverse effects.