Multiple myeloma most commonly involves which class of immunoglobulin?

Multiple myeloma most commonly involves which class of immunoglobulin?

• A. IgG
• B. IgA
• C. IgM
• D. IgE

Answer: (A)

Multiple myeloma is driven by a clone of malignant plasma cells that secretes a single type of immunoglobulin, called a monoclonal protein or M-protein. The most common heavy-chain class produced by these malignant plasma cells is IgG, so the typical M-protein in the majority of patients is an IgG immunoglobulin. This makes IgG the leading answer because it represents the largest proportion of monoclonal immunoglobulins seen in this disease. IgA is the next most common, IgM is relatively rare, and some cases involve only light chains without a heavy chain.

Multiple myeloma is driven by a clone of malignant plasma cells that secretes a single type of immunoglobulin, called a monoclonal protein or M-protein. The most common heavy-chain class produced by these malignant plasma cells is IgG, so the typical M-protein in the majority of patients is an IgG immunoglobulin. This makes IgG the leading answer because it represents the largest proportion of monoclonal immunoglobulins seen in this disease. IgA is the next most common, IgM is relatively rare, and some cases involve only light chains without a heavy chain.