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 requires early nephrologic
consultation. Renal disease may exist in the absence of active hepatitis. The most
common renal disease found in these patients is membrane proliferative glomerulonephritis,
which may be associated with cryoglobulinemia. Testing for complement levels and the
presence of cryoglobulins may be initiated prior to referral.
Normal Values:
Negative
Possible Meanings of Abnormal Values:
Positive
Chronic infection
Chronic lymphocytic leukemia
Cytomegalovirus infection
Hepatitis C
Hodgkin’s disease
Infectious mononucleosis
Infective endocarditis
Leprosy
Lymphoma
Mixed essential cryoglobulinemia
Multiple myeloma
Polymyalgia rheumatica
Poststreptococcal glomerulonephritis
Primary biliary cirrhosis
Raynaud’s disease
Rheumatoid arthritis
Scleroderma
Sjögren’s syndrome
Systemic lupus erythematosus
Tropical splenomegaly syndrome
Viral infection
Waldenström’s macroglobulinemia
Interventions/Implications:
Pretest
• Explain to the patient the purpose of the test and the need for a blood sample to be
drawn.
• Fasting for 8 hours is required prior to the test.
Procedure
• A 10-mL blood sample is drawn in a collection tube containing a silicone gel prewarmed
to 37°C.
• Gloves are worn throughout the procedure.
Posttest
• Apply pressure at venipuncture site. Apply dressing, periodically assessing for continued
bleeding.
• Label the specimen and transport it to the laboratory.
• Report abnormal findings to the primary care provider.
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