Cryoglobulins
Cryoglobulins Test Description Cryoglobulins are abnormal serum proteins which precipitate at low laboratory temperatures and redissolve after being warmed. When patients with cryoglobulins present in their blood are subjected to cold, they may experience vascular problems of their extremities, with Raynaud-like symptoms such as pain, cyanosis, and coldness of the fingers and toes due to the formed complexes blocking small blood vessels. The presence of cryoglobulins in the blood (cryoglobulinemia) is usually associated with immunologic disease. The test is conducted by refrigerating a serum sample at 4°C for at least 72 hours and observing for the formation of a precipitate. The reversibility of the reaction is verified by rewarming the serum sample. If the presence of cryoglobulins is thus shown, further study is done to identify the cryoglobulin components. EVIDENCE FOR PRACTICE: Evidence of renal disease in hepatitis C virus-positive individuals ...