Clinical significance and discriminatory performance of the serum KL-6 level as a biomarker for severe Chlamydia pneumoniae infection in children
- 1Department of Clinical Laboratory, Children’s Hospital of Wujiang District , ,
- 2Department of Clinical Laboratory, The Fifth People’s Hospital of Suzhou , ,
- 3Department of Clinical Laboratory, The Affiliated Suzhou Hospital of Nanjing Medical University , ,
Abstract
Objective: To characterize the expression and evaluate the clinical utility for assessing disease severity of the serum Krebs von den Lungen-6 (KL-6) level in children with mild and severe acute Chlamydia pneumoniae (C. pneumoniae) infection.
Methods: A total of 68 hospitalized children with acute lower respiratory tract infection caused by C. pneumoniae (48 mild cases and 20 severe cases) who were admitted to Children’s Hospital of Wujiang District from May 2024 to April 2025 were enrolled, with 19 healthy children included in the control group. Serum KL-6 levels, C. pneumoniae-IgM levels, and routine laboratory indicators were measured. The correlation between the KL-6 level and clinical features was analyzed, and discriminatory performance of the KL-6 level for identifying severe C. pneumoniae infection was assessed using ROC curves.
Results: Serum KL-6 levels were significantly higher in the severe group than in the mild group [303.00 (227.75, 328.25) U/mL vs. 146.50 (133.50, 164.25) U/mL, P < 0.001]. Binary logistic regression analysis indicated that KL-6 was independently associated with severe C. pneumoniae infection in children (P < 0.001), and the area under the curve (AUC) for differentiating severe infection from mild infection was 0.951 (95%CI=0.880-0.997, P<0.001). Further analysis revealed that the KL-6 level was positively correlated with the number of pulmonary lesions, the number of hospitalization days, and C. pneumoniae-IgM levels but not with other indicators.
Conclusion: The serum KL-6 level can effectively reflect the degree of pulmonary parenchymal injury in children with C. pneumoniae infection and can serve as an independent biomarker for severe C. pneumoniae infection. It demonstrates high discriminatory ability for identifying severe cases and may serve as an auxiliary biomarker for assessing pulmonary parenchymal injury.
Related
- Combined Effects of Chlamydia pneumoniae Infection and Hypoxia on Glial Metabolism and Alzheimer’s Disease-Related Pathways
- Validation of the discriminatory performance of the iPREFACE score for clinically significant fetal acidemia: an outcome-enriched nested case–control study
- Evaluation and performance of the β-hCG discriminatory zone and targeted ultrasound findings for early pregnancy diagnosis in a high-risk population: a retrospective cohort study at a US safety-net hospital.
- Association and discriminatory performance of body roundness index for dysglycemia among adults in Ethiopia
- Associations and Discriminatory Performance of Anthropometric and Body-Shape Indices for Identifying Hypertension in Adults with Type 2 Diabetes in Malawi: A Cross-Sectional Study.
BibTeX
@article{ding2026clinical,
title = {{Clinical significance and discriminatory performance of the serum KL-6 level as a biomarker for severe Chlamydia pneumoniae infection in children}},
author = {Lei Ding and Sufang Chen and Huafeng Song and Shuting Cheng and Meng Shao and Hongyan Zhang and Jun Hua and Fei Gao and Junchi Xu},
journal = {Frontiers in cellular and infection microbiology},
year = {2026},
month = oct,
doi = {10.3389/fcimb.2026.1791097},
url = {https://europepmc.org/article/PMC/PMC13719359},
note = {CC BY},
}
RIS
TY - JOUR
TI - Clinical significance and discriminatory performance of the serum KL-6 level as a biomarker for severe Chlamydia pneumoniae infection in children
AU - Lei Ding
AU - Sufang Chen
AU - Huafeng Song
AU - Shuting Cheng
AU - Meng Shao
AU - Hongyan Zhang
AU - Jun Hua
AU - Fei Gao
AU - Junchi Xu
PY - 2026
DA - 2026/10/16
JO - Frontiers in cellular and infection microbiology
DO - 10.3389/fcimb.2026.1791097
UR - https://europepmc.org/article/PMC/PMC13719359
AB - Objective: To characterize the expression and evaluate the clinical utility for assessing disease severity of the serum Krebs von den Lungen-6 (KL-6) level in children with mild and severe acute Chlamydia pneumoniae (C. pneumoniae) infection. Methods: A total of 68 hospitalized children with acute lower respiratory tract infection caused by C. pneumoniae (48 mild cases and 20 severe cases) who were admitted to Children’s Hospital of Wujiang District from May 2024 to April 2025 were enrolled, with 19 healthy children included in the control group. Serum KL-6 levels, C. pneumoniae-IgM levels, and routine laboratory indicators were measured. The correlation between the KL-6 level and clinical features was analyzed, and discriminatory performance of the KL-6 level for identifying severe C. pneumoniae infection was assessed using ROC curves. Results: Serum KL-6 levels were significantly higher in the severe group than in the mild group [303.00 (227.75, 328.25) U/mL vs. 146.50 (133.50, 164.25) U/mL, P < 0.001]. Binary logistic regression analysis indicated that KL-6 was independently associated with severe C. pneumoniae infection in children (P < 0.001), and the area under the curve (AUC) for differentiating severe infection from mild infection was 0.951 (95%CI=0.880-0.997, P<0.001). Further analysis revealed that the KL-6 level was positively correlated with the number of pulmonary lesions, the number of hospitalization days, and C. pneumoniae-IgM levels but not with other indicators. Conclusion: The serum KL-6 level can effectively reflect the degree of pulmonary parenchymal injury in children with C. pneumoniae infection and can serve as an independent biomarker for severe C. pneumoniae infection. It demonstrates high discriminatory ability for identifying severe cases and may serve as an auxiliary biomarker for assessing pulmonary parenchymal injury.
SN - 2235-2988
ER -