Immunoglobulin D (IgD) 2 heavy and 2 light chains <1%of serum immunoglobulins Serves as a membrane receptor on B lymphocytes May play role in antigen- stimulated lymphocyte differentiation Immunoglobulin D (IgD) ◼ 2 heavy and 2 light chains ◼ <1% of serum immunoglobulins ◼ Serves as a membrane receptor on B lymphocytes ◼ May play role in antigen￾stimulated lymphocyte differentiation