Abstract: Bruton's tyrosine kinase (BTK) is an essential protein for B cell receptor (BCR) signaling and plays a key role in B cell differentiation and proliferation. It is also expressed in myeloid cells such as mast cells and basophils. Since the discovery that BTK mutations cause X-linked agammaglobulinemia, the research and development of BTK inhibitors has undergone an important leap from cancer treatment to immune disease treatment. At present, BTK inhibitors have demonstrated significant efficacy in B-cell malignancies and are gradually being extended to autoimmune diseases such as chronic spontaneous urticaria, systemic lupus erythematosus and multiple sclerosis. This article systematically reviews the research and development process of BTK inhibitors, their molecular optimization strategies, and the progress of their application in the field of immune diseases, and analyzes their advantages and challenges at the mechanism and clinical levels.

Key words: Bruton's tyrosine kinase, BTK inhibitors, urticaria, autoimmunity