Common Variable Immunodeficiency (CVID) FAQS

When I was first diagnosed with CVID, I had never heard of it! Here are some popular Common Variable Immunodeficiency (CVID) FAQS. These are also the questions I had at first.

1. What is Primary Immunodeficiency (PI)? I’ve never even heard of it!

Per the Immune Deficiency Foundation Website, here is their official explanation of PI:

Primary immunodeficiency diseases are a group of more than 350 rare, chronic disorders in which part of the body’s immune system is missing or functions improperly.

While not contagious, these diseases are caused by hereditary or genetic defects, and, although some disorders present at birth or in early childhood, the disorders can affect anyone, regardless of age or gender. Some affect a single part of the immune system; others may affect one or more components of the system. And while the diseases may differ, they all share one common feature: each results from a defect in one of the functions of the body’s normal immune system.

Because one of the most important functions of the normal immune system is to protect us against infection, patients with PI commonly have an increased susceptibility to infection. The infections may be in the skin, the sinuses, the throat, the ears, the lungs, the brain or spinal cord, or in the urinary or intestinal tracts, and the increased vulnerability to infection may include repeated infections, infections that won’t clear up or unusually severe infections.

People with PI live their entire lives more susceptible to infections–enduring recurrent health problems and often developing serious and debilitating illnesses. Fortunately, with proper medical care, many patients live full and independent lives.

2. What is Common Variable Immunodeficiency Disorder (CVID)? (The Most Commonly Asked of the CVID FAQS!)

CVID FAQS – Short Version:

CVID is complex and so is explaining it! in my opinion, Wikipedia’s definition is the easiest to understand for those non-medical folks like me!

Common variable immunodeficiency (CVID) is an immune disorder characterized by recurrent infections and low antibody levels, specifically in immunoglobulin (Ig) types IgG, IgM and IgA.[1] Generally symptoms include high susceptibility to foreign invaders, chronic lung disease, and inflammation and infection of the gastrointestinal tract.[1] However, symptoms vary greatly between people. CVID is a lifelong disease…Treatment options are limited, and usually include lifelong immunoglobulin replacement therapy.[4] This therapy is thought to help reduce bacterial infections. This treatment alone is not wholly effective, and many people still experience other symptoms like lung disease and noninfectious inflammatory symptoms.

CVID FAQS – Long Version (according to the Immune Deficiency Foundation):

Common Variable Immune Deficiency (CVID) is one of the most frequently diagnosed primary immunodeficiencies, especially in adults, characterized by low levels of serum immunoglobulins and antibodies, which causes an increased susceptibility to infection. While CVID is thought to be due to genetic defects, the exact cause of the disorder is unknown in the large majority of cases.

Compared to other human immune defects, CVID is a relatively frequent form of primary immunodeficiency, found in about 1 in 25,000 persons; this is the reason it is called “common.” The degree and type of deficiency of serum immunoglobulins, and the clinical course, varies from patient to patient, hence, the word “variable.” In some patients, there is a decrease in both IgG and IgA; in others, all three major types of immunoglobulins (IgG, IgA and IgM) are decreased. In still others there are defects of the T-cells, and this may also contribute to increased susceptibility to infections as well as autoimmunity, granulomata and tumors.

Further, More Detailed Information

To be sure that CVID is the correct diagnosis, there must be evidence of a lack of functional antibodies and other possible causes of these immunologic abnormalities must be excluded. Frequent and/or unusual infections may first occur during early childhood, adolescence or adult life. Patients with CVID also have an increased incidence of autoimmune or inflammatory manifestations, granulomata and an increased susceptibility to cancer when compared to the general population. Sometimes it is the presence of one of these other conditions that prompts an evaluation for CVID.

The medical terms for absent or low blood immunoglobulins are agammaglobulinemia and hypogammaglobulinemia, respectively. Due to the late onset of symptoms and diagnosis, other names that have been used in the past include “acquired” agammaglobulinemia, “adult onset” agammaglobulinemia, or “late onset” hypogammaglobulinemia. The term “acquired immunodeficiency” refers to a syndrome caused by the AIDS virus (HIV) and should not be used for individuals with CVID, as these disorders are very different.

3. What are the Symptoms of CVID?

This is one of the most difficult Common Variable Immunodeficiency (CVID) FAQS to answer. Because CVID symptoms are specific to each patient’s immune system, they can range widely. According to My Ig Source, symptoms can include:

  • Recurring ear, sinus, and bronchi (breathing tubes) infections
  • Severe, repeated infections of the lungs (respiratory tract) that can result in permanent widening and scarring of the bronchi, a condition called bronchiectasis
  • Enlarged lymph nodes in the neck, chest, or abdomen
  • Enlarged spleen, an organ related to the immune system
  • Enlargement of Peyer’s patches, which are collections of lymphocytes in the walls of the intestine
  • Collections of inflammatory cells called granuloma can be found in the lungs, lymph nodes, liver, skin, or other organs in some cases
  • Painful swelling of the joints, a condition called polyarthritis, can also develop. People with CVID who develop arthritis usually experience issues in the larger joints like the knees, ankles, elbows, and wrists
  • Gastrointestinal complaints, such as abdominal pain, bloating, nausea, vomiting, diarrhea, and weight loss
  • Greater risk of cancer, especially cancers of the lymphoid system and gastrointestinal tract

4. How is CVID Diagnosed?

According to the Immune Deficiency Foundation, CVID should be suspected in children or adults who have a history of recurrent bacterial infections involving ears, sinuses, bronchi and lungs. The characteristic laboratory features include low levels of serum immunoglobulins, including IgG, often IgA and sometimes IgM. Another part of the diagnosis of CVID is to determine if there is a lack of functional antibody. This is done by measuring serum levels of antibody, against vaccine antigens such as tetanus or diphtheria, measles, mumps, or rubella, haemophilus or pneumococcal polysaccharide.

Patients with CVID have very low or absent antibody levels to most of these vaccines. Immunization with killed vaccines is used to measure antibody function, and this functional testing is crucial prior to beginning treatment. These tests also help the physician decide if the patient will benefit from immunoglobulin replacement therapy and can be key in obtaining insurance authorization for this therapy. The number of B- and T-lymphocytesinfo-icon may also be determined and their function tested in tissue cultures.

5. What Causes CVID?

Of all the CVID FAQS, I wanted to know the answer to this one. I mistakenly thought I caused my CVID. I am here to tell you that is not the case! Do not blame yourself.

Genetics and Inheritance of Common Variable Immune Deficiency (per the Immune Deficiency Foundation)

Patients with CVID usually have normal numbers of the cells that produce antibody (B-lymphocytesinfo-icon), but these cells fail to undergo normal maturation into plasma cells, the cells capable of making the different types of immunoglobulins and antibodies for the blood stream and secretions. The genetic causes of CVID are largely unknown, although recent studies have shown the involvement of a small group of genes in a few patients. These include inducible co-stimulatory (ICOS) and a few other proteins on B-cells. These appear to be causes of autosomal recessiveinfo-icon CVID.

Mutations in a cell receptor (TACI) needed for normal growth and regulation of B-cells have also been found in about 8% of patients with CVID. However, a causative role of TACI mutations in this immune defect is not yet clear, since some of these mutations can be found in people with normal immunoglobulins. As these are very rare gene defects for the most part, genetic testing is not yet required or indicated for the diagnosis of CVID.


6. What is the Treatment for CVID?

CVID is treated with immunoglobulin replacement therapy (IRT). IRT treatments must be given regularly and are life-long. IRT treatment involves liquid medicine made from donated plasma containing healthy immune proteins. It is either administered through an IV or through SCIG. In SCIG, the medicine can be pumped into the subcutaneous fat of the body. Often, antibiotics are used to treat infections. However, they might be used as a proactive method or in higher or longer durations.

Antibiotics are used to treat most infections that result from CVID though patients may need treatment for a longer duration than a healthy individual.

7. Why are CVID patients called Zebras?

This might be one of those weird, yet most commonly asked CVID FAQS! Yes, zebras are those black and white striped, horse-like animals, that you see at the zoo. However, Zebra, is the term (description even) that has been adopted as the mascot of CVID patients. Here’s the official explanation of how we came to be called Zebras:

Nominated for the Most Weird of all the CVID FAQS!

Per the Ehlers-Danlos Support UK website:

When you hear the sound of hooves, think horses, not zebras.”

This phrase is taught to medical students throughout their training.

In medicine, the term “zebra” is used in reference to a rare disease or condition.  Doctors are taught to assume that the simplest explanation is usually correct to avoid patients being misdiagnosed with rare illnesses. Doctors learn to expect common conditions.

But many medical professionals seem to forget that “zebras” DO exist and so getting a diagnosis and treatment can be more difficult for sufferers of rare conditions. Ehlers-Danlos syndrome is considered a rare condition and so EDS sufferers are known as medical zebras.  This identity has now been adopted across the world through social media to help bring our community together.

Of course, this is not a comprehensive list of the questions you might have. That is why I compiled a list of credible resources that will provide for information. If you think any FAQS should be added, please email me at

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Though DIVA as she may be, her path to success was not easy and is always evolving. Go here to read about her journey in “Becoming the CVIDiva.” If you want to send Susan Alynne a quick message, then visit her contact page here.