A small protein called CD24, which is glycosyl-phosphoinositol-anchored and sends T cells costimulatory signals, has been linked to the onset of autoimmune illness. According to a recent study published in the Annals of Medicine, soluble CD24 (sCD24) may serve as a biomarker of inflammation in patients with rheumatoid arthritis (RA), particularly in early and seronegative RA patients.
Between 2013 and 2018, Zheng and colleagues collected sera samples from the Department of Rheumatology and Immunology, Peking University People’s Hospital from 269 RA patients, 59 primary Sjogren’s syndrome (SS) patients, 81 SLE patients, 76 osteoarthritis (OA) patients, and 97 healthy individuals during patient routine care. A significantly elevated level of serum sCD24 was found in patients with RA compared to SS, SLE, OA, and healthy individuals (2970 ± 5780 pg/mL vs. 380 ± 490 pg/mL, 460 ± 590 pg/mL, 520 ± 1090 pg/mL and 320 ± 490 pg/mL; p < 0.001). In early RA patients (66.67%) and seronegative RA patients (61.11%), sCD24 levels were increased. Additionally, a significant correlation was noted between sCD24 and both inflammatory indicators and disease duration.
CD24 initially discovered in 1978, serves as a co-stimulatory factor that enhances T cell proliferation. It plays a critical role in ensuring the survival of autoreactive T cells during the negative selection process that takes place in the thymus. In addition, the marker holds pivotal importance, guiding B cell maturation and facilitating the removal of specific precursor B cells within the bone marrow. The growing body of evidence has revealed a robust connection between CD24 and autoimmune diseases. Genetic variations in the CD24 gene have been associated with susceptibility to various autoimmune conditions.
The present study findings have the potential to aid in the early diagnosis of RA, especially in cases of seronegative RA. The accumulation of circulating CD24 in RA serum and its association with disease activity suggest its involvement in the disease onset, rendering it a promising novel therapeutic target for RA. However, the pathogenic role of CD24 in the development of RA warrants further in-depth research.
Reference
Zheng X, Wang P, Song J, Tang Y, Xie Y, Jin X, et al. Soluble CD24 is an inflammatory biomarker in early and seronegative rheumatoid arthritis. Ann Med. 2023;55(2):2246370.