CASE REPORT article
Front. Immunol.
Sec. Inflammation
This article is part of the Research TopicImmune Cell Dynamics in Pulmonary Fibrosis: From Mechanisms to Therapeutic TargetsView all articles
Lymphocyte Dynamics as the Central Mediator in Osimertinib-Induced CD4+ T-Cell Depletion, Fulminant Cytomegalovirus Pneumonitis, and Progressive Pulmonary Fibrosis: A Case Report
Provisionally accepted
- The First Affiliated Hospital of Yangtze University, Jingzhou, China
Select one of your emails
You have multiple emails registered with Frontiers:
Notify me on publication
Please enter your email address:
If you already have an account, please login
You don't have a Frontiers account ? You can register here
Osimertinib-induced severe lymphocytopenia can create a profound immunodeficiency state, facilitating opportunistic infections and progressive fibrotic lung disease. A 75-year-old female with EGFR-mutant NSCLC developed respiratory failure with diffuse ground-glass opacities and profound lymphocytopenia (ALC 0.48×10⁹/L). Overreliance on BAL-NGS detection of Mycobacterium avium complex delayed diagnosis of cytomegalovirus pneumonia. Guideline-discordant erlotinib rechallenge accelerated lymphocyte depletion, culminating in high-grade CMV viremia with CD4⁺ lymphocytopenia (0.16×10⁹/L) and irreversible pulmonary fibrosis despite ganciclovir-induced virologic clearance. This case demonstrates an immune-fibrotic axis wherein TKI-induced lymphocytopenia enables CMV pneumonitis and fibrotic remodeling. Lymphocytopenia in this setting mandates urgent viral exclusion before attributing injury to drug toxicity and precludes TKI rechallenge during active infection or severe immunosuppression. BAL-NGS requires rigorous clinicoradiologic correlation.
Keywords: CD4+ T-cell, CMV pneumonia, Diagnostic error, Drug-induced lung injury, Lymphocytopenia, Osimertinib, Pulmonary Fibrosis
Received: 09 Sep 2025; Accepted: 02 Dec 2025.
Copyright: © 2025 Zhu, Peng and Lu. 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: Jinzhi Lu
Disclaimer: All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article or claim that may be made by its manufacturer is not guaranteed or endorsed by the publisher.