Cryoglobulinaemia

Cryoglobulinaemia is a medical condition characterized by the presence of abnormal proteins, called cryoglobulins, in the blood. These proteins have the unique property of clumping together or precipitating when exposed to cold temperatures, typically below 37 degrees Celsius (98.6 degrees Fahrenheit). Once the blood warms, these cryoglobulins usually dissolve.

The presence of cryoglobulins can lead to a range of symptoms, often affecting the skin, joints, and nervous system. Common manifestations include Raynaud's phenomenon, where fingers and toes become numb and cold in response to cold exposure. Skin lesions, such as purpura (purple bruises) and ulcers, can also develop, particularly on the lower extremities. Joint pain and swelling, along with muscle aches, are frequently reported. Neurological symptoms may include numbness, tingling, and weakness.

Cryoglobulinaemia can be broadly classified into three types, based on the composition of the cryoglobulin. Type I is associated with monoclonal immunoglobulins, often seen in lymphoproliferative disorders like multiple myeloma or Waldenström's macroglobulinemia. Type II and Type III involve polyclonal immunoglobulins complexed with monoclonal immunoglobulins, and are commonly linked to chronic infections such as hepatitis C virus (HCV) infection, autoimmune diseases like Sjögren's syndrome or rheumatoid arthritis, and certain cancers.

Diagnosis typically involves a blood test performed at body temperature and then at a lower temperature to detect the presence and type of cryoglobulins. Further investigations are conducted to identify any underlying conditions contributing to the cryoglobulinaemia. Treatment focuses on managing the underlying cause and alleviating symptoms. This may involve avoiding cold exposure, medications to suppress the immune system, treatments for the underlying infection or malignancy, and plasmapheresis in severe cases.