Lymphocytes are a type of white blood cell in the body which are crucial for fighting infections.
They consist of two general types of cells, T cells and B cells. B cells are essential for making certain chemicals or proteins called antibodies that help protect against bacterial and viral infections. Antibodies can be purified from healthy, normal blood donors and administered to children with SCID in the form of gammaglobulin infusions or injections. The exact function of NK cells is unknown, although it is thought that they may be important in rejecting donor bone marrow following the bone marrow transplant. Some patients with SCID have low to absent function of their NK cells.