Disclosed are methods and compositions of anti-B cell antibodies, preferably anti-CD22 antibodies, for diagnosis, prognosis and therapy of B-cell associated diseases, such as B-cell malignancies, autoimmune disease and immune dysfunction disease. In certain embodiments, trogocytosis induced by anti-B cell antibodies may determine antibody efficacy, disease responsiveness and prognosis of therapeutic intervention. In other embodiments, optimal dosages of therapeutic antibody may be selected by monitoring the degree of trogocytosis induced by anti-B cell antibodies. Other characteristics of anti-B-cell antibodies that may be monitored include inducing phosphorylation of CD22, CD79a and CD79b inducing translocation of CD22, CD79a and CD79b to lipid rafts inducing caspase-dependent apoptosis increasing pLyn, pERKs and pJNKs decreasing constitutively-active p38 or inducing mitochondrial membrane depolarization, generation of reactive oxygen species, upregulation of pro-apoptotic Bax and downregulation of anti-apoptotic Bcl-xl, Mcl-1 and Bcl-2.
