What Is Common Variable Immunodeficiency (CVID)?

Medically Reviewed by Brunilda Nazario, MD on June 22, 2023
Written by Shishira Sreenivas
4 min read

Common variable immunodeficiency (CVID) is a type of genetic condition called primary immunodeficiency disease (PIDD) that causes low levels of antibodies (protective proteins) in your body. This weakens your immune system – the mechanism that helps your body fight off germs and prevent infections. 

Basically, if you have CVID, you’re more likely to get repeated infections such as ear, sinus, or lung infections. You also have a higher risk for more serious conditions like gut problems, blood and autoimmune disorders, and cancer. 

Doctors also refer to CVID by other medical terms such as adult-onset agammaglobulinemia, late-onset hypogammaglobulinemia, and acquired agammaglobulinemia.

Here’s a look at what causes CVID, signs to watch for, and how you can get help. 

 

Compared to other primary immune system disorders, CVID is more common.  About 1 in 25,000 people get it. Anybody can get this condition, but it mostly occurs in adults. While children and teens can develop CVID, they’re usually not diagnosed until they reach adulthood. 

You’re more likely to be diagnosed with this condition between ages 20 and 50. That’s because usually, your immune system develops as you grow older.

But research shows that about 2 in 10 people with CVID were found to be immunodeficient (having a weak immune system due to lack of proteins) during childhood.

 

 

 

 

Doctors aren’t exactly sure what causes most CVID cases. But for 1 in 10 people with CVID, the cause can be pinpointed to a hereditary genetic mutation in your DNA. This means it’s passed down from your family members. 

You can also get CVID if you have genetic defects in your immune system. This means there might be added or missing information in your DNA. The defects can cause your immune system to produce very low levels of antibodies in your blood called immunoglobulins and immunoglobulin G (IgG) – the proteins that help your body fight infections. 

You can also develop CVID later in your life. 

 

 

CVID symptoms may be different for each person and can range from mild to severe. That’s because it depends on how weak your immune system is. 

Symptoms can include:

  • A persistent cough
  • Breathing problems
  • Diarrhea
  • Nausea
  • Vomiting 
  • Weight loss
  • Ear infections
  • Sinus infections
  • Repeated lung infections. This could lead to bronchitis or pneumonia. 
  • Bad reactions to vaccines
  • Liver function issues
  • Low blood flow to the liver
  • A low platelet count
  • Swollen joints such as knees, elbows, and wrists.
  • Joint pain
  • An enlarged spleen

 

 

 

If you’ve noticed repeated infections in your ears, sinuses, or lungs, or have a bad reaction to recommended vaccines, tell your doctor. This might prompt your doctor to look into whether you have CVID.

To confirm the diagnosis, they’ll ask for a detailed family and medical history. They’ll order blood tests. This can help your doctor check for signs of CVID, such as a low antibody count, and how well your immune system works. 

Your doctor also might give you a vaccine for another condition to see if you’ll have a normal boost in antibodies against the vaccine.

There’s no cure for CVID. But there are ways to manage the condition. 

Once you’ve been diagnosed with CVID, to prevent repeated infections, your doctor may give your immunoglobulin (IgG) replacement therapy. It’s a blood-based treatment. Doctors take IgG proteins that are collected from healthy blood donors and give them to you to boost your antibody levels and immune function.

The therapy is delivered as an IV directly into a vein through a needle once a month or as a shot under the skin (subcutaneously) once a week or every other week. 

To keep CVID under check, you’ll need IgG replacement therapy for the rest of your life. 

Most people have no issues with this form of therapy. But it may cause side effects such as headaches or allergic reactions. Talk to your doctor about what form of therapy works best for you. 

Your doctor may also prescribe antibiotics or antiviral medications to help you clear germs from repeated infections. 

Since it’s a genetic condition that’s often passed down from other family members, there’s no way to prevent CVID. 

But because you’re more prone to infections due to a weaker immune system, it's important to maintain good hygiene, such as washing your hands regularly, to avoid germs. Getting an early diagnosis can also help you get the right therapy to keep CVID symptoms in check. 

 

When your immune system doesn’t function as it should, you’re more likely to have serious, sometimes life-threatening conditions than people who don't have CVID. 

This can include:

Autoimmune diseases. With this group of conditions, your immune system mistakenly attacks your own healthy cells. If you have CVID, you're more likely to have conditions like autoimmune hemolytic anemia (the body destroys healthy red blood cells), rheumatoid arthritis, or thrombocytopenia (a low platelet count). 

About 1 in 4 people with CVID tend to get an autoimmune condition.

Cancer. CVID increases your risk for specific cancers like lymphoma or stomach cancer.

Bronchiectasis. Repeated lung infections can damage the tubes in your lungs and widen them to create pouch-like nooks. This causes you to cough up pus a lot and makes it harder for you to get rid of built-up mucus. 

Granulomas. These tiny clusters of white blood cells often form around an infected area, usually on the skin, in your lungs, or in other organs.