In multiple myeloma there is proliferation of -

Ans. is 'a' i.e., Plasma cells Multiple myelomao Multiple myeloma is a plasma cell neoplasm characterized by involvement of the skeleton at multiple sites,o Plasma cells proliferate abnormally and the proliferated plasma cells infiltrate various organs, particularly bone marrow, but can also spread to lymph nodes and extranodal sites like skin,o The proliferation and survival of myeloma cells are dependent on several cytokines, IL-6 is particularly important,o The neoplastic plasma cells secrete abnormally large amounts of immunoglobulin.o The immunoglobulin secreted by neoplastic plasma cells are quiet different form the immunoglobulin normally present in the blood.o The normal immunoglobulin consists of two heavy and two lights chains molecules and the production of both chain is tightly balanced.o The immunoglobulin secreted in this condition may be : -Isolated light chain or heavy chain.May be an intact antibody molecule of any heavy chain subclass.May be an altered antibody or fragment.