Tph and Tfh cells as biomarkers and targets in rheumatic diseases.

The role of B cell-helper T cells, including T follicular helper cells (Tfh), T peripheral helper cells (Tph), and others, in autoimmune rheumatic diseases is reviewed, focusing on clinical applications. A case is presented where the presence of B helper T cells could help decide the next medication to use in a patient with rheumatoid arthritis refractory to TNF inhibitors. The review covers topics including the biology of B cell and T cell interactions, the origin and function of B cell-helper T cells, disease associations, B cell-helper T cells as a marker of disease phenotype and treatment response, and therapeutic approaches. B cell-helper T cells are a subset of CD4+ T cells that are specialized to aid in B cell development and affinity maturation. B cell-helper T cells, including Tfh and Tph cells, are positively correlated with increased disease activity and lymphoid aggregate-associated phenotypes in multiple autoantibody-associated immune conditions. Higher numbers of circulating Tfh and Tph cells are also associated with greater likelihood of response to certain biologics in rheumatoid arthritis. In the future, Tfh and Tph cell levels may be used as both biomarkers of disease activity and targets to treat multiple autoantibody-associated rheumatic diseases, leading to a new era of personalized medicine.