Common variable immunodeficiency (CVID) is defined as an immune system dysfunction typically caused by a mutation in a gene or genes, in which several of the proteins (antibodies) that help fighting infections are at low levels. People with CVID are highly susceptible to infections, particularly in the respiratory system , sinuses, and ears.. CVID is characterized by a low level of specific proteins (antibodies), also called immunoglobulin, which results in a decreasedability to fight invading microorganisms, toxins, or other foreign substances. These immunoglobulins are produced by specialized white blood cells (B cells) as they mature.
Symptoms
Signs and symptoms of CVID may appear during childhood or adolescence. The signs and symptoms of CVID include:
- Recurring ear infections
- Recurring sinus infections
- Recurring lung infections
- Pneumonia
- Recurring bronchial infections
- Gastrointestinal infections
- Painful swollen joints
- Swollen knee
- Swollen ankle
- Swollen elbow
- Swollen wrist
- Digestive symptoms
- Enlarged spleen
- Swollen glands
- Swollen lymph nodes
- Autoimmune diseases
- Sinus infections
- Ear infections
- Conjunctivitis
- Respiratory infections
- Diarrhea
- Meningitis
- Lymphadenopathy
- Low number of plasma cells in bone marrow
- T cell dysfunction
- Bronchietasis
- Chronic diarrhea
- Reduced IgA levels
- Reduced IgG levels
- Reduced IgM levels
- Lack of normal antibody levels
- Chronic recurring infections
- Presence of anti-IgA antibodies
Signs and symptoms of CVID may vary on an individual basis.
Causes
The primary cause of CVID is unknown, because of the heterogeneity of the disease. Common variable immunodeficiency is thought as a result from a combination of genetic and environmental factors. The condition may be inherited or it can be caused by the use of certain antirheumatic or antiepileptic drugs.
Risk Factors
Most patients with Common Variable Immunodeficiency get frequent bacterial infections of the ears, sinuses, bronchi, and lungs. They also commonly have an enlarged spleen and swollen glands or lymph nodes. Patients may develop painful swollen joints in the knee, ankle, elbow, or wrist and also may develop digestive disorders. Along with other autoimmune problems, some patients develop autoantibodies that attack their own blood cells. CVID patients have an increased risk of developing some cancers.
Complications
CVID patients can develop complications of different kinds, such as:
Autoimmune manifestations
Autoimmunity is the main type of complication in CVID patients: pernicious anemia, autoimmune hemolytic anemia, idiopathic thrombocytopenic purpura, psoriasis,vitiligo, rheumatoid arthritis, primary hypothyroidism, atrophic gastritis, malignancies, particularly Non-Hodgkin’s lymphoma and gastric carcinoma;
Enteropathy
Symptoms of CVID enteropathy are similar to those of celiac disease, usually accompanied by symptoms such as abdominal cramps, diarrhea, constipation and, in some cases, malabsorption and weight loss.
Lymphocytic infiltration of tissues
This condition causes swelling of the lymph nodes, enlargement of the spleen and of the liver, as well as the formation of granulomas.
Anxiety and depression may develop as well, as a result of dealing with the symptoms.
Prevention
There is no known way to prevent congenital immunodeficiency disorders. But not all individuals who inherit a gene mutation associated with CVID will develop the disease. Additional genetic or environmental factors are probably needed for the disorder to occur, because in many cases, affected children have an unaffected parent who shares the same mutation. Good nutrition may prevent acquired immunodeficiency caused by malnutrition.
