<unk>  <unk>  is a rare autoimmune<unk>  characterized by the presence of high concentrations of circulating<unk>  sensitive antibodies, usually IgM and autoantibodies that are also active at temperatures below , directed against red blood cells, causing them to agglutinate and undergo lysis. It is a form of autoimmune hemolytic anemia, specifically one in which antibodies bind red blood cells only at low body temperatures, typically 28–31 °C. When affected people's blood is exposed to<unk>  temperatures ( to ), certain proteins that normally attack bacteria (IgM antibodies) attach themselves to red blood cells and bind them together into clumps (agglutination). This eventually causes red blood cells to be prematurely destroyed (hemolysis) leading to anemia and other associated signs and symptoms.<unk>  can be primary (unknown cause) or secondary, due to an underlying condition such as an infection, another autoimmune<unk> , or certain cancers. Treatment depends on many factors including the severity of the condition, the signs and symptoms present in each person, and the underlying cause.<unk>  was first described in 1957.
Cold agglutinin disease
Atypical hemolytic uremic syndrome
MERRF syndrome
Serum sickness
Cold autoimmune hemolytic anemia
Michels Caskey syndrome
Hennekam syndrome
Uddanam nephropathy