Cold Agglutination

Doug had his appointment with Dr. Myers in Salida today. His blood work shows no sign of MM - praise God!

Dr. Myers said that Doug has tested positive for "cold agglutinate". This is a rare disorder where abnormal blood proteins called cold agglutinins cause red blood cells to form clumps and die, thus causing possibly severe anemia. The process is triggered by exposure to cold temperatures. Dr. Myers said that Doug needs to avoid getting chilled, so he should dress warmly in cold weather. Or spend the winters in Texas, which we had already planned to do!

Of course we had never heard of this before, so I looked it up for more detail:
Cold agglutinin disease is an autoimmune disease characterized by the presence of high concentrations of circulating antibodies, usually IgM, directed against red blood cells. It is a form of autoimmune hemolytic anemia, specifically one in which antibodies only bind red blood cells at low body temperatures, typically 28-31°C. (82 – 88 degrees F)



There are two forms of cold agglutinin disease: 1-primary and 2-secondary. (Doug's is secondary to the MM.)


• The primary form is by definition idiopathic, a disease for which no cause is known.


• Secondary cold agglutinin disease is a result of an underlying condition.


 In adults, this is typically due to a lymphoproliferative disease such as lymphoma and chronic lymphoid leukemia, or infection.


At body temperatures of 28-31°C, such as those encountered during winter months, and occasionally at body temperatures of 37°C (normal body temp, 98.6 degrees F), antibodies (generally IgM) bind to the polysaccharide region of glycoproteins on the surface of red blood cells (typically the I antigen, i antigen, and Pr antigens). Binding of antibodies to red blood cells activates the classical pathway of the complement system. If the complement response is sufficient, red blood cells are damaged by the membrane attack complex, an effector of the complement cascade. In the formation of the membrane attack complex, several complement proteins are inserted into the red blood cell membrane, forming pores that lead to membrane instability and intravascular hemolysis (destruction of the red blood cell within the blood vessels).


Individuals with cold agglutinin disease present with signs and symptoms of hemolytic anemia.

Dr. Myers said that this disease does not usually result in any significant clinical impact, so we are not too alarmed at this point. Right now the blood tests show mild anemia but that is not new. Doug's cold agglutinin test showed a dilution of 1:64. Normal is 1:32.

So just one more thing to watch -- meanwhile we continue to lead happy busy lives.

Love to all.