Tnfsf13b, also known as the gene encoding B-cell activating factor (BAFF) or tumor necrosis factor ligand superfamily member 13B, is a key regulator in the immune system. BAFF is fundamental for the survival of transitional and mature B cells [3]. It is involved in multiple autoimmune-related pathways, and its overexpression can lead to an expanded B cell compartment and autoimmunity in mice, with elevated amounts also found in the serum of autoimmune patients [3].

Polymorphisms in Tnfsf13b are associated with various diseases. In primary Sjögren's syndrome (pSS) patients, the SNP rs12583006 of Tnfsf13b was significantly related to pSS susceptibility, and polymorphisms in this gene were related to pSS vulnerability in both patients and healthy controls [1]. In rheumatoid arthritis (RA), the rs9514828 T allele and the TAT haplotype of Tnfsf13b were associated with an increased risk of developing RA, and this polymorphism was also associated with increased gene expression in RA patients [2]. In apical periodontitis, the TT genotype and T allele of Tnfsf13b rs9514828 were associated with an increased risk of primary apical periodontitis, while the minor allele T decreased the risk of secondary apical periodontitis [4]. Additionally, in pediatric severe adenovirus pneumonia, plasma Tnfsf13B levels were elevated and could potentially serve as an inflammatory indicator [5].

In conclusion, Tnfsf13b plays a crucial role in B-cell survival and is significantly associated with multiple autoimmune and inflammatory diseases such as primary Sjögren's syndrome, rheumatoid arthritis, apical periodontitis, and severe adenovirus pneumonia in pediatric patients. Understanding the functions of Tnfsf13b through studying its polymorphisms helps in uncovering the disease-related mechanisms, providing potential directions for diagnosis and treatment.

References:

1. Zheng, Anhao, Hu, Naiwen, Xu, Jing, Bai, Yanyan, Sun, Hongsheng. . Associations between TNFSF13B polymorphisms and primary Sjögren's syndrome susceptibility in primary Sjögren's syndrome patients: A meta-analysis. In Immunity, inflammation and disease, 11, e1103. doi:10.1002/iid3.1103. https://pubmed.ncbi.nlm.nih.gov/38156381/

2. Santillán-López, Enrique, Muñoz-Valle, José Francisco, Oregon-Romero, Edith, Cerpa-Cruz, Sergio, Palafox-Sánchez, Claudia Azucena. 2022. Analysis of TNFSF13B polymorphisms and BAFF expression in rheumatoid arthritis and primary Sjögren's syndrome patients. In Molecular genetics & genomic medicine, 10, e1950. doi:10.1002/mgg3.1950. https://pubmed.ncbi.nlm.nih.gov/35411715/

3. Mackay, Fabienne, Schneider, Pascal, Rennert, Paul, Browning, Jeffrey. 2001. BAFF AND APRIL: a tutorial on B cell survival. In Annual review of immunology, 21, 231-64. doi:. https://pubmed.ncbi.nlm.nih.gov/12427767/

4. Cruz, Alvaro, Gascón, Luis Gerardo, Palafox-Sánchez, Claudia Azucena, Mejía-Flores, Rocío, Salazar-Camarena, Diana Celeste. 2022. TNFSF13B rs9514828 gene polymorphism and soluble B cell activating factor levels: Association with apical periodontitis. In International endodontic journal, 56, 419-431. doi:10.1111/iej.13879. https://pubmed.ncbi.nlm.nih.gov/36508294/

5. Fan, Huifeng, Lu, Bingtai, Cao, Can, Wu, Minhao, Lu, Gen. 2021. Plasma TNFSF13B and TNFSF14 Function as Inflammatory Indicators of Severe Adenovirus Pneumonia in Pediatric Patients. In Frontiers in immunology, 11, 614781. doi:10.3389/fimmu.2020.614781. https://pubmed.ncbi.nlm.nih.gov/33542721/