Hyperviscosity syndrome is classically associated with monoclonal disease producing which immunoglobulin class?

Hyperviscosity syndrome is classically associated with monoclonal disease producing which immunoglobulin class?

• A. IgG
• B. IgA
• C. IgM
• D. IgD

Answer: (C)

Hyperviscosity occurs when there is a high concentration of a monoclonal antibody in the blood. IgM stands out because it is a pentamer, making it large and dramatically increasing plasma viscosity even at relatively lower concentrations. This is classic in Waldenström’s macroglobulinemia, where a clonal lymphoplasmacytic population overproduces IgM, leading to symptoms like visual disturbances, mucosal bleeding, and headaches from sluggish blood flow. Other immunoglobulins can contribute to viscosity only at much higher levels, while IgD isn’t typically associated with hyperviscosity.

Hyperviscosity occurs when there is a high concentration of a monoclonal antibody in the blood. IgM stands out because it is a pentamer, making it large and dramatically increasing plasma viscosity even at relatively lower concentrations. This is classic in Waldenström’s macroglobulinemia, where a clonal lymphoplasmacytic population overproduces IgM, leading to symptoms like visual disturbances, mucosal bleeding, and headaches from sluggish blood flow. Other immunoglobulins can contribute to viscosity only at much higher levels, while IgD isn’t typically associated with hyperviscosity.