About Cold Agglutinin Disease
Cold agglutinin disease is a distinct subtype of autoimmune hemolytic anemia characterized by IgM autoantibodies (cold agglutinins) that bind to I or i antigens on red blood cell surfaces at cold temperatures, leading to complement C3 deposition and subsequent C1-mediated intravascular hemolysis and extravascular hemolysis in the liver. Primary CAD is a clonal lymphoproliferative disorder of the bone marrow producing monoclonal IgM cold agglutinins, while secondary CAD is associated with infections (Mycoplasma pneumoniae, EBV) or lymphoma. Cold temperatures trigger or exacerbate hemolysis, acrocyanosis, and Raynaud-like phenomena, significantly impairing quality of life.
Common Clinical Features
Clinical Trial Eligibility Tips
What to know before applying to Cold Agglutinin Disease trials.
Cold agglutinin titer (measured at 4 degrees Celsius with monospecific anti-IgM serum) above 1:64 and DAT positive for C3d only (IgG negative) are diagnostic requirements for most CAD trials; bring laboratory documentation from a reference laboratory.
Complement pathway inhibitor trials (targeting C1s, C1q, or C3) are the most active therapeutic area in CAD; prior rituximab response and current hemoglobin level and transfusion frequency determine eligibility.
Bone marrow biopsy documenting underlying clonal lymphoproliferative disorder distinguishes primary CAD from secondary CAD and affects trial eligibility; bring biopsy and immunohistochemistry results.
Patient Resources
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