Circulating Th2 cell reduction and Th1/Th2 imbalance are correlated with primary Sjogren’s syndrome-associated interstitial lung disease

• Published in: Arthritis research & therapy Vol. 24; no. 1; pp. 121 - 9
• Main Authors: Shi, Lei, Wang, Jia, Guo, Hong-Xia, Han, Xiao-Lei, Tang, Yu-Ping, Liu, Guang-Ying
• Format: Journal Article
• Language: English
• Published: London BioMed Central 23.05.2022; BioMed Central Ltd; BMC
• Subjects: Age; Antibodies; Arthritis; Blood; Complications and side effects; Connective tissue; Development and progression; Exocrine glands; Flow cytometry; Health aspects; Immunology; Interstitial lung disease (ILD); Laboratories; Lung diseases; Lung diseases, Interstitial; Lymphocytes; Measurement; Medical diagnosis; Medicine; Medicine & Public Health; Mortality; Orthopedics; Pathogenesis; Primary Sjogren syndrome (pSS); Research Article; Respiratory system; Rheumatology; Risk factors; Sjogren's syndrome; T cells; Th1/Th2 ratio; Th2 cells; China; Interstitial lung disease (ILD); Primary Sjogren syndrome (pSS); Th2 cells; Th1/Th2 ratio
• ISSN: 1478-6362; 1478-6354; 1478-6362
• DOI: 10.1186/s13075-022-02811-z

Objective Primary Sjogren’s syndrome (pSS) is a heterogeneous chronic autoimmune disorder characterized by lymphocyte infiltration of the exocrine glands and the involvement and dysfunction of multiple organs and tissues. Interstitial lung disease (ILD) is the most common type of respiratory system damage. This study ascertained the factors related to ILD in patients with pSS (pSS-ILD), such as altered levels of circulating lymphocyte subtypes. Methods Eighty healthy controls and 142 patients diagnosed with pSS were included. The pSS patients were classified into groups with pSS-ILD or pSS without ILD (pSS-non-ILD). Baseline clinical and laboratory data were collected for all subjects, including the levels of lymphocytes measured by modified flow cytometry. Results The pSS-ILD patients were older, had higher ESSDAI scores, had higher positivity rates for anti-SSB and anti-Ro52 antibodies, and had more frequent symptoms of respiratory system involvement than pSS-non-ILD patients. pSS-ILD patients had the lowest Th2 cell counts among the three groups. Although the absolute numbers of Treg and NK cells were lower in pSS patients with and without ILD than in the healthy controls, there was no significant difference between the two pSS groups. The Th1/Th2 ratio was significantly higher in patients with ILD than in patients without ILD. Further analysis showed that older age (OR=1.084), lower Th2 count (OR=0.947), higher Th1/Th2 ratio (OR=1.021), and positivity for anti-SSB (OR=3.620) and anti-Ro52 (OR=5.184) antibodies were associated with the occurrence of ILD in patients with pSS. Conclusion Decreased circulating Th2 cells and an elevated Th1/Th2 ratio may be the immunological mechanism underlying the development of ILD in pSS patients.