OVERVIEW
Cryoglobulinemia is a systemic vasculitis characterized by the deposition of circulating immune complexes in small to medium-sized vessels. Immunoglobulins that are reversibly deposited at low temperatures are present in the patient’s serum. Cryoglobulins are usually divided into three types: type I consists of a single monoclonal Ig. It may be IgM, IgG, lgA, or Ben Jones protein; type II consists of a mixture of monoclonal lg (IgM or lgG or IgA) and polyclonal Ig (mainly IgG); and type III is a mixed polyclonal type, which accounts for about 50% of the total. It consists of multiple strains of polyclonal Ig to form complexes such as IgM-IgG, IgM-lgG-IgA, etc., all of which have RF activity. Mixed type II and type III cryoglobulinemia (MC) is associated with infectious, immunologic, and neoplastic diseases.
Symptoms.
The disease can occur in both men and women, but it is more common in women, and it occurs in young adults, with a high prevalence in those aged 25-45 years.
1. Early in the course of the disease, most patients may show Raynaud’s phenomenon and cyanosis in the fingers or toes when they are cold or in contact with cold water. Thereafter, there may be limb pain, numbness, multi-joint pain or muscle pain when exposed to cold, and even purpura or purple skin pattern.
2. Skin and mucous membrane damage: the most common is recurrent palpable non-thrombocytopenic purpura without itching, often distributed in the lower limbs, especially around the ankles, but also in the nose, ears, mouth and other exposed areas.
3. Renal damage: edema, massive proteinuria and hypertension. It manifests as acute and chronic glomerulonephritis, acute progressive nephritis, and even quickly develops into uremia.
4. Digestive system: hepatomegaly or accompanied by splenomegaly, may have abnormal liver function.
5. The disease may also involve the nervous system, manifesting as encephalopathy, motor disorders, myasthenia, myasthenia gravis and EMG abnormalities. Involvement of the heart manifests as myocarditis, coronary arteritis, transient pericarditis and arrhythmia. Lung involvement may manifest as interstitial fibrosis and mild pleurisy.
Examination
1. Blood routine and blood sedimentation
Some patients have mild anemia, and the white blood cell count may be mildly elevated or decreased. Blood viscosity is increased and red blood cells are arranged in the form of string money. Most of the patients have rapid blood sedimentation.
2. Urine routine
More than half of the patients may have proteinuria, hematuria, tubular pattern and pus cells.
3. Biochemical examination
About 2/3 of patients may have abnormal liver function, elevated serum GPT and elevated bilirubin. When renal function is involved, there may be elevated BUN, elevated blood potassium and decreased CO2CP. Protein electrophoresis shows elevated gamma globulin.
4. Immunologic examination
Serum IgG and IgM are elevated, sometimes IgA is elevated, complement is lowered, a few patients may have positive rheumatoid factor and antinuclear antibody, and some patients have low cellular immunity.
Treatment
1. General treatment: patients should prevent cold stimulation, pay attention to keep warm, and give non-steroidal anti-inflammatory drugs for arthralgia. People with lower limb purpura should avoid standing for a long time. Raynaud’s phenomenon can be given vasodilators, such as nifedipine (cardioplegia), Tolazoline and anticoagulants, such as enteric aspirin.
2. Pathogenic treatment: Targeted treatment should be given to infections, autoimmune diseases such as systemic lupus erythematosus, and tumors. Avoid taking suspected sensitizing drugs.
3. Plasma exchange.
4. Glucocorticoids and immunosuppressive drugs.
Prognosis
The prognosis of those without nephritis is good. Patients with advanced disease often die of renal failure and infection.