Frequently Asked Questions

What is the difference between Cold Agglutinin Disease (CAD) and Cold Agglutinin Syndrome (CAS)?

Unlike cold agglutinin syndrome, Cold Agglutinin Disease is not secondary to bacterial or viral infections, overt malignancies, or autoimmune disorders.1-3

CAD, also known as primary CAD, is a well-defined and well-characterized disease that is defined by classical complement-dependent chronic hemolysis and a B-cell expansion that is nonprogressive and clinically non-malignant. CAS, formerly known as Cold Agglutinin Syndrome, exists due to an underlying disorder, such as a viral infection (eg, Mycoplasma pneumoniae or Epstein-Barr virus), autoimmune disorder, or lymphoid malignancy.1-3

CAS is usually self-remitting when the underlying condition resolves. In contrast, CAD is a chronic condition.1-3

CAD=Cold Agglutinin Disease; CAS=cold agglutinin syndrome.
References: 1. Berentsen S, Tjønnfjord GE. Diagnosis and treatment of cold agglutinin mediated autoimmune hemolytic anemia. Blood Rev. 2012;26(3):107-115. doi:10.1016/j.blre.2012.01.002 2. Berentsen S, Randen U, Tjønnfjord GE. Cold agglutinin-mediated autoimmune hemolytic anemia. Hematol Oncol Clin North Am. 2015;29(3):455-471. doi:10.1016/j.hoc.2015.01.002 3. Röth A, Barcellini W, D’Sa S, et al. Sutimlimab in cold agglutinin disease. N Engl J Med. 2021;384(14):1323-1334. doi:10.1056/NEJMoa2027760