külmreaktsioonid

Külmreaktsioonid, also known as cold agglutinin disease (CAD), is a rare autoimmune disorder characterized by the presence of autoantibodies that attack red blood cells at low temperatures. These antibodies, called cold agglutinins, bind to the surface of red blood cells and cause them to clump together, a process known as agglutination. When the body temperature returns to normal, the antibodies may detach, but the red blood cells can be damaged or destroyed, leading to a type of anemia called hemolytic anemia.

The symptoms of cold agglutinin disease are typically triggered by exposure to cold. Patients may experience pain, numbness, and discoloration of the extremities, particularly the fingers, toes, ears, and nose, as the agglutinated red blood cells block blood flow in these areas. In more severe cases, this can lead to gangrene. Hemolytic anemia can manifest as fatigue, pallor, jaundice, and shortness of breath. The severity of symptoms can vary widely among individuals.

The exact cause of cold agglutinin disease is not fully understood, but it is often associated with underlying infections, such as Mycoplasma pneumoniae pneumonia or viral infections like infectious mononucleosis. It can also be a primary autoimmune disorder or secondary to lymphoproliferative disorders like lymphomas or chronic lymphocytic leukemia. Diagnosis is usually made through blood tests that detect the presence and activity of cold agglutinins.

Treatment aims to prevent cold exposure and manage the symptoms of anemia and hemolysis. Avoiding cold temperatures, wearing warm clothing, and keeping the environment warm are crucial. Medications may be prescribed to suppress the immune system or improve blood flow. In some cases, treatments that target the underlying cause, such as antibiotics for infection or chemotherapy for lymphoproliferative disorders, may be beneficial. Blood transfusions may be necessary to treat severe anemia.