The immune system protects the body against infectious agents and other foreign substances in the environement. It is composed of innate and acquired immunity. B-cell is one of the cells of acquired immunity. It serves as a primary source of cells responsible for humoral response. B-cell develops ensuring that a diverse repertoire of different immunoglobulin molecules is produced.The adaptive immune response provides an efficient defense against infection but if turned against self can cause severe tissue damage. There are number of checkpoints at which auto-reactive B cells are eliminated ensuring its tolerance. Breakdown of tolerance will result in B cells escaping control measures and begin to produce pathological auto-antibodies causing several rheumatic diseases.Our study demonstrated the central role of B lymphocytes in the pathogenesis of different diseases and this brings us to a conclusion that their elimination may be of highly beneficial therapeutic goal in a variety of diseases.