Rare Diseases What Is Common Variable Immunodeficiency? By Sarah Bence Sarah Bence Sarah Bence, OTR/L, is an occupational therapist and freelance writer. Learn about our editorial process Published on November 05, 2021 Medically reviewed Verywell Health articles are reviewed by board-certified physicians and healthcare professionals. Medical Reviewers confirm the content is thorough and accurate, reflecting the latest evidence-based research. Content is reviewed before publication and upon substantial updates. Learn more. by Anju Goel, MD, MPH Medically reviewed by Anju Goel, MD, MPH LinkedIn Anju Goel, MD, MPH, is a board-certified physician who specializes in public health, communicable disease, diabetes, and health policy. Learn about our Medical Review Board Print Table of Contents View All Table of Contents Symptoms Causes Diagnosis Treatment Prognosis Common variable immunodeficiency (CVID) is an immune system disorder that causes low antibodies, which reduces the body’s ability to fight off infections. As a result, people with CVID are highly susceptible to frequent and sometimes severe infections, as well as complications from these infections. This article provides an overview of CVID, including symptoms, causes, diagnosis, and treatment. Hiraman / Getty Images Symptoms The hallmark symptom of CVID is recurrent and potentially severe viral or bacterial infections. The precise symptoms will differ based on what type of infection the person has. For example, different types of infections (e.g., upper respiratory tract infections, gastrointestinal infections, ear infections) will all present with very different symptoms. However, it is the frequent recurrence of these infections that indicates a warning sign for CVID, rather than any exact symptoms of the infection itself. Some symptoms of CVID might include: Chronic cough, sometimes producing phlegm Runny nose Swollen lymph nodes Breathing issues Fever Ear pain Diarrhea Nausea or vomiting Pneumonia Due to the frequency and/or severity of infections, a person with CVID is also at risk for certain complications. The most common CVID complications include: Septic arthritis Autoimmune disorders, particularly cytopenias Abnormal liver function Bronchiectasis Granulomas Poor vaccine response Certain cancers, particularly lymphoma Prevalence of CVID CVID is the most common primary immunodeficiency, but this does not mean it is a common disorder. Estimates vary, but it is thought that CVID occurs in anywhere from one in 10,000 to one in 50,000 people. Causes CVID is thought to be caused by mutations in certain genes that impact the immune system—in particular, mutations in the genes that influence the production, maturation, and function of B-cells. B-cells are a type of white blood cell that produces antibodies. Antibodies are the Y-shaped proteins that help us fend off infections. CVID causes a deficiency in these antibodies. Over 20 different genetic mutations have been identified so far as either causing CVID or increasing a person’s risk of developing CVID. The most common are mutations in the TNFRSF13B gene (approximately 8% of CVID cases) and the NFKB1 gene. Most of these genetic mutations occur sporadically, but some may be passed down through families. This can occur through both dominant and recessive inheritance. However, it is important to note that identified genetic mutations only explain 10% to 20% of CVID cases. For the majority of people with CVID, there is no identifiable cause. This leads researchers to believe that environmental factors play a role in causing CVID, although we do not know at this time what these environmental factors might be. There are also likely many other genes that cause CVID that have yet to be identified. Causes and Risk Factors of Common Variable Immunodeficiency Diagnosis After gathering a health history of recurrent infections, CVID can be diagnosed through a series of blood tests. These include tests such as: Serum immunoglobulin tests Complete blood count (CBC) C-reactive protein test Liver function tests Kidney function tests Vaccine antibody tests To be diagnosed with CVID, a person must have low immunoglobulins (antibodies). This includes low IgG and either IgM or IgA. It also requires a poor response to vaccines and the absence of any other disorder that causes an immunodeficiency. Diagnostic Delay Getting diagnosed with CVID can be challenging in multiple ways: A person may become accustomed to their frequent infections and think of them as a “fact of life,” and subsequently delay seeking medical care.As a relatively rare disorder, many health providers do not know enough about CVID to properly diagnose it.CVID mimics other conditions and, as a diagnosis of exclusion, can only be diagnosed once these conditions are ruled out, which can complicate diagnosis.Finally, in the past even experts had disagreed on the diagnostic criteria for CVID, such as whether a poor vaccine response is required to have CVID. As a result, diagnosis can be delayed from four to nine years after symptoms begin. This is a significant issue, because the longer CVID goes untreated, the more complications can form, which can impact life expectancy. Therefore, it’s essential to receive a timely, accurate diagnosis if you have symptoms of CVID. Treatment The mainstay treatment for CVID is immunoglobulin (antibody) replacement therapy. This uses the blood donations from healthy individuals and essentially restores the antibodies in a person’s body to a normal level so they can better fight off infections. Immunoglobulin replacement therapy can be given either through intravenous (IV) infusions or subcutaneous injections. The exact frequency and dosage should be determined individually, based on the person’s antibody level response. Treatment is lifelong. Another aspect of CVID treatment is treating any active infections. Even with immunoglobulin replacement therapy, a person with CVID may experience more infections than the average person. This treatment will depend on what kind of specific infection the person has, but may include antibiotics, antivirals, over-the-counter (OTC) therapies, and more. Prognosis The good news is that life expectancy for those who have CVID has significantly improved in the last 30 years, from just 12 years post-diagnosis to over 50 years. This is thanks, in large part, to the pioneering of immunoglobulin replacement therapy as a CVID treatment. However, some factors may reduce a person’s life expectancy. These include: Higher age at diagnosisLower B-cellsLower baseline IgG at diagnosisComplications such as structural lung damage (bronchiectasis or granulomas), chronic hepatitis, lymphoma, or chronic gastrointestinal diseases As a result, it’s important to receive a prompt diagnosis of CVID to prevent these complications. The majority of people receiving immunoglobulin replacement therapy find they have fewer infections and a higher quality of life. Summary Common variable immunodeficiency is a disorder of the immune system that is characterized by low antibodies. It reduces the body’s ability to fight off infections, so frequent and recurring infections occur. The main treatment option is immunoglobulin (antibody) replacement therapy, but any infections that result from CVID must be treated as well. A Word From Verywell It’s possible to live a full and active life with CVID, but it will take some adjustments. These include regular treatment with immunoglobulin replacement therapy, as well as lifestyle modifications to prevent infections. Finding a healthcare provider to help with either diagnosing or managing your CVID is an important first step in living with this condition. Was this page helpful? Thanks for your feedback! Sign up for our Health Tip of the Day newsletter, and receive daily tips that will help you live your healthiest life. Sign Up You're in! Thank you, {{form.email}}, for signing up. There was an error. Please try again. What are your concerns? Other Inaccurate Hard to Understand Submit 13 Sources Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy. National Institute of Allergy and Infectious Diseases. Common variable immunodeficiency (CVID). Updated April 23, 2019. Saikia B, Gupta S. Common variable immunodeficiency. Indian J Pediatr. 2016;83(4):338-344. doi:10.1007/s12098-016-2038-x American Academy of Allergy Asthma & Immunology. Common variable immunodeficiency: symptoms and diagnosis. Salzer U, Warnatz K, Peter HH. Common variable immunodeficiency - an update. Arthritis Research & Therapy. 2012;14(5):223. doi:10.1186/ar4032 Ameratunga R, Longhurst H, Steele R, et al. Common variable immunodeficiency disorders, T-cell responses to SARS-CoV-2 vaccines, and the risk of chronic COVID-19. 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