Which immunoglobulin concentration is significantly increased in patients with Waldenstrom's macroglobulinemia?

In Waldenstrom's macroglobulinemia, the hallmark is the overproduction of a specific type of immunoglobulin known as IgM. This condition is characterized by a proliferation of B lymphocytes that secrete large amounts of IgM, leading to elevated serum levels of this particular immunoglobulin. The clinical manifestation of the disease is often related to the effects of high IgM levels, such as hyperviscosity syndrome, which can cause significant symptoms due to the thickening of the blood.

The focus on IgM in Waldenstrom's macroglobulinemia distinguishes it from other conditions like multiple myeloma, which typically involves increased production of IgG or IgA. Understanding this specificity in immunoglobulin elevation helps in diagnosing and managing the condition effectively, making IgM a critical marker in the clinical setting of Waldenstrom's macroglobulinemia.