CAD is a type of autoimmune hemolytic anemia (AIHA) in which autoantibodies (cold agglutinins) at temperatures below 30°C bind to RBC antigens and can cause agglutination of the RBCs and extravascular hemolysis. It happens more in the age of 55. A cold environment may start acute hemolysis with hemoglobinemia and hemoglobinuria.
Panel Test:
● Direct Coombs (Anti-Human Globulin) 
● Cold Agglutinins 
● Complement Components 3 and 4 
● Complement Activity 
● Immunoglobulins (IgA, IgG, IgM), 
● CBC and Automated Differential 
● Reticulocytes, Percent and Number 
● Bilirubin, Direct, 
● Lactate Dehydrogenase,
References
1. Berentsen S. How I manage cold agglutinin disease. Br J Haematol 2011; 153:309.
2. Berentsen S, Ulvestad E, Langholm R, et al. Primary chronic cold agglutinin disease: a population based clinical study of 86 patients. Haematologica 2006; 91:460.
3. Swiecicki PL, Hegerova LT, Gertz MA. Cold agglutinin disease. Blood 2013; 122:1114.