Which organism infection commonly triggers cold agglutinin disease?

Which organism infection commonly triggers cold agglutinin disease?

• A. Staphylococcus aureus
• B. Streptococcus pneumoniae
• C. Mycoplasma pneumoniae
• D. Haemophilus influenzae

Answer: (C)

Cold agglutinin disease is an autoimmune hemolytic anemia in which IgM antibodies bind red cells at low temperatures, activate complement, and cause hemolysis. The classic trigger is Mycoplasma pneumoniae infection, which stimulates production of anti-I antibodies that target red cells and cause agglutination in cooler parts of the body, leading to hemolysis and sometimes acrocyanosis or Raynaud-like symptoms. The other organisms listed are not typically associated with this antibody-mediated process, so they don’t fit as well as triggers.

Cold agglutinin disease is an autoimmune hemolytic anemia in which IgM antibodies bind red cells at low temperatures, activate complement, and cause hemolysis. The classic trigger is Mycoplasma pneumoniae infection, which stimulates production of anti-I antibodies that target red cells and cause agglutination in cooler parts of the body, leading to hemolysis and sometimes acrocyanosis or Raynaud-like symptoms. The other organisms listed are not typically associated with this antibody-mediated process, so they don’t fit as well as triggers.