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ORIGINAL RESEARCH article

Front. Immunol.

Sec. Cancer Immunity and Immunotherapy

This article is part of the Research TopicEfficacy of Neoadjuvant Immunotherapy and Analysis of Immunomodulation in Head and Neck Squamous Cell CarcinomaView all 6 articles

Immunotherapy-induced Sialadenitis: Sjögren's syndrome or a New Sialadenitis

Provisionally accepted
Shuyuan  SongShuyuan SongZhentao  LaoZhentao LaoRuotong  YuRuotong YuShan  YuShan YuPeiyao  LiPeiyao LiYumeng  YanYumeng YanLe  YangLe YangGuiqing  LiaoGuiqing Liao*Yan  WangYan Wang*Sien  ZhangSien Zhang*
  • Hospital of Stomatology, Guanghua School of Stomatology, Sun Yat-sen University, Guangzhou, China

The final, formatted version of the article will be published soon.

Objective: Although immune checkpoint inhibitors (ICIs) have improved survival in head and neck squamous cell carcinoma (HNSCC), associated adverse events, such as sialadenitis, remain poorly characterized. This study aimed to define the clinicopathological features, establish the causal pathogenic mechanism, and validate a therapeutic target for ICI-associated sialadenitis. Methods: This study integrated three complementary approaches. First, a prospective cohort of 25 HNSCC patients underwent functional assessment of salivary and lacrimal glands before and after ICI therapy. Second, salivary gland tissues from separate cohorts of ICI-treated (n=30) and untreated control (n=30) patients were subjected to comprehensive analysis, including histology, multi-platform immunophenotyping (immunohistochemistry, multiplex immunofluorescence, flow cytometry), and cytokine quantification at both transcript and protein levels. Finally, a preclinical mouse model was established to confirm causality and validate the therapeutic efficacy of IL-17A blockade. Results: Following ICI treatment, patients showed significantly reduced salivary and lacrimal secretion (P < 0.05). Histopathological analysis revealed extensive lymphocytic infiltration, marked periductal fibrosis, and substantial loss of acinar structures. The immune infiltrate was dominated by CD4⁺ T cells, particularly the Th17 subset, with corresponding upregulation of IL-17A both at transcriptional and protein levels. Crucially, we established a mouse model of anti-PD-1-induced sialadenitis and demonstrated that therapeutic blockade of IL-17A restores salivary function. Conclusion: This study establishes ICI-associated sialadenitis as a distinct pathological entity characterized by CD4⁺T cell-driven inflammation mediated through the Th17/IL-17 axis, which differs from Sjögren syndrome, predominantly involving B cells and from IgG4 related sialadenitis. By demonstrating therapeutic efficacy in a preclinical model, our findings provide the first preclinical validation of the IL-17 axis as an actionable therapeutic target for this condition.

Keywords: CD4+T cells, Chronic sialadenitis, Head and neck squamous cell carcinoma (HNSCC), immune checkpoint inhibitors, Th17/IL-17 axis

Received: 27 Nov 2025; Accepted: 09 Feb 2026.

Copyright: © 2026 Song, Lao, Yu, Yu, Li, Yan, Yang, Liao, Wang and Zhang. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

* Correspondence:
Guiqing Liao
Yan Wang
Sien Zhang

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