Clinical Laboratory Science Practice Exam

Plasma cells come from the B lymphocytes, which are part of the lymphoid lineage in hematopoiesis. In the bone marrow, hematopoietic stem cells produce lymphoid progenitors that mature into B cells; when these B cells are activated, they differentiate into plasma cells that secrete antibodies. The other lineages—myeloid giving granulocytes, monocytes, erythrocytes and platelets, and the erythroid path leading to red blood cells—do not produce antibody-secreting cells. So, the origin is the lymphoid (B-cell) branch.