Heavy Chain Disease, also known as Franklin disease or α-chain disease, is a rare immunoproliferative disorder characterized by the overproduction of abnormal immunoglobulin heavy chains. It is classified as a subtype of monoclonal gammopathy.
In this condition, abnormal heavy chains of immunoglobulins are produced instead of the normal light and heavy chains that together form an intact antibody. These abnormal heavy chains lack the light chain component and are unable to bind to antigens effectively, compromising the immune system's ability to fight infections. Consequently, affected individuals may experience recurrent infections and exhibit signs of immunodeficiency.
Heavy Chain Disease is divided into three distinct types based on the specific heavy chain isotype involved: α-heavy chain disease, γ-heavy chain disease, and μ-heavy chain disease. α-Heavy chain disease is the most common subtype, characterized by the production of truncated α-heavy chains. γ-Heavy chain disease is characterized by truncated γ-heavy chains, while μ-heavy chain disease involves the production of truncated μ-heavy chains.
Symptoms of Heavy Chain Disease vary depending on the subtype and may include weakness, fatigue, weight loss, anemia, enlarged liver and spleen, and gastrointestinal manifestations such as diarrhea. Diagnosis is achieved through laboratory tests, including serum protein electrophoresis and immunofixation electrophoresis.
The treatment approach for Heavy Chain Disease involves a combination of therapies, including chemotherapy, corticosteroids, and immunosuppressive drugs. In severe cases, stem cell transplantation may be considered. Regular monitoring and management of infections are essential for individuals living with Heavy Chain Disease.
