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Cryoglobulins are antibodies that precipitate at 4 degrees Celsius. Thus precipitated, they are deposited in the wall of blood vessels, which in turn leads to their inflammation. Characteristic for cryoglobulinemia are: general weakness, hemorrhagic diathesis, numbness and sensory disturbances.
Cryoglobulins – definition
Cryoglobulins are antibodies that build up in the walls of blood vessels when they precipitate in the blood (below 4 degrees Celsius). As a consequence, it not only leads to inflammation of the blood vessels, but also to greater permeability to blood cells and the formation of blood clots obstructing the microcirculation. In healthy people, these types of antibodies are not detected in the blood as their presence is associated with numerous diseases. e.g. cirrhosis, RA, HBV or HCV viral infection, lymphoma or lymphocytic leukemia. Cryoglobulin is associated with cryoglobulin, typically associated with:
- skin changes (hemorrhagic diathesis),
- bone pain,
- general weakness,
- sensory disorders and paraesthesia,
- numbness
- kidney and liver damage.
In the most dangerous cases, the patient may even suffer from respiratory failure due to bleeding into the alveoli. There is also damage to the digestive tract due to acute ischemia.
Cryoglobulins – when do we perform the test?
The most common indications for a cryoglobulin test are listed below.
1. Suspicion of neoplastic disease of the lymphatic system (myeloma, Waldenstrom’s macroglobulinemia).
2. Suspicion of autoimmune diseases.
3. Diagnosis of viral hepatitis.
4. Diagnosis of infectious diseases.
5. Diagnostics of haematuria, proteinuria and glomerulonephritis.
Cryoglobulins – a study
Material for the study of cryoglobulins: serum.
Preparation for the cryoglobulin test: on an empty stomach (at least 8 hours).
The course of the study: One-time collection of blood from a vein in the arm into a heated syringe. The collected blood is stored in an incubator at 37 degrees and at 4 degrees. The reactions taking place in both test tubes are observed. A positive result means a precipitation at 4 degrees. The test complications are the same as for any other type of test that requires venous blood collection.
Time to wait for the result: 1 Day.
Standard: 20 –100 mg/l.
Comments: There are three types of cryoglobulins, each in the IgG and IgM classes. Type II and III cryoglobulins activate complement. Under normal conditions, at a temperature of 4 degrees, no serum precipitation occurs. Precipitation indicates the presence of cryoglobulins. The gels produced under their influence dissolve when heated.
A positive test result is an indication for further laboratory tests. Immunoelectrophoresis and immunoblotting are performed to help identify the types of antibodies that are causing the symptoms.
Cryoglobulinemia and vasculitis
ZNK, or vasculitis associated with cryoglobulinemia, is a systemic disease of the connective tissue that results from the tissue reaction to the presence of antibodies (cryoglobulins) that build up in tiny blood vessels. Cryoglobulins cause symptoms in response to infection with certain types of hepatitis virus: hepatitis C, hepatitis B, and HIV, as well as bacterial and parasitic infections.
Cryoglobulins also occur in the course of diseases such as: multiple myeloma, systemic lupus erythematosus, RA, systemic scleroderma and Sjögren’s syndrome.
Vasculitis associated with cryoglobulinemia is rare. Most often it affects people between 40 and 50 years of age, more often women. The most common incidence is recorded in the poor countries of southern Europe, where hygiene rules are relatively low. Cryoglobulins are present in over half of patients infected with hepatitis C, while vasculitis develops in less than 5% of patients.
Vasculitis – symptoms
Vasculitis is characterized by general weakness and skin changes in the form of red spots that can be easily felt when touched. In addition, most patients suffer from joint pain and neurological disorders, such as numbness of the lower limbs, sometimes they are speech disorders. These symptoms persist despite the use of painkillers. Dry mouth and eyes are observed in some group of patients.
Given that cryoglobulinemia-related vasculitis is directly related to hepatitis C infection, a large number of patients develop impaired liver function (e.g. cirrhosis, hepatocellular carcinoma). In 1/3 of patients, vasculitis is observed Raynaud’s phenomenonfingers and toes turning pale or bluish in response to a cold temperature. Attack by kidney disease leads to:
- nausea,
- vomiting
- decreased urine output.
In extreme cases, extensive vasculitis and multi-organ failure develop, which is a threat to the patient’s life. In such a case, hospital treatment is necessary. Unfortunately, over 80% of cases of the disease are diagnosed only when it is life-threatening.
People who may have been exposed to hepatitis C or B virus infection (intravenous drug use, sex with casual partners, surgery, tattoo made) should be particularly vigilant. The appearance of symptoms of vasculitis associated with cryoglobulinemia in this group of people is an indication for determining whether the patient has been infected with hepatitis C or B. Based on the results of these tests, a diagnosis is made. This should happen promptly to avoid the development of extensive vasculitis or other dangerous complications. This requires the cooperation of several specialists: a rheumatologist, an infectious disease doctor, hepatologist, gastroenterologist, hematologist and nephrologist.
Diagnosis and treatment of vasculitis associated with cryoglobulinemia
The diagnosis of the disease is based primarily on the medical history as well as the patient’s symptoms and laboratory test results. To determine the severity of vasculitis, it is necessary to perform functional liver tests, including plasma bilirubin levels, aspartate and alanine aminotransferase levels. In some patients, ultrasound of the abdominal cavity is also performed. However, thanks to the assessment of creatinine and urea concentrations and a general urinary examination, it is possible to assess the renal function.
Note: Patients diagnosed with the disease should be alert to the possible symptoms of cancer that are common in this type of vasculitis.
The mainstay of treatment of vasculitis associated with cryoglobulinemia is rheumatological therapy, which is based on the use of glucocorticosteroids, administered at intervals of several days. However, the side effects resulting from this type of treatment should be considered, e.g. cataracts, diabetes or high blood pressure. In addition to corticosteroids, patients are also taking immunosuppressants such as azathioprine. Such treatment would not be applicable to people with blood cryoglobulins but without symptoms of vasculitis.
For joint pain, it is recommended to use non-steroidal inflammatory drugs, e.g. paracetamol. A diet that restricts the type of meat to turkey only works well for skin ailments. It is necessary to exclude products containing preservatives, dairy products and eggs from the diet.
Don’t forget about causal treatment, i.e. inhibiting viral hepatitis. In patients with hepatitis, the infectious disease doctor recommends ribavirin and peginterferon alfa. Patients whose liver virus infection has receded still require rheumatic care, as symptoms of vasculitis may persist.
To avoid contracting cryoglobulin vasculitis, you should prevent hepatitis B or C infections.