Patient understanding Pi Pi stands

PI stands for primary humoral immunodeficiency disease. There are more than 450 different kinds of PI.1 With PI, part of your immune system, which is what protects you from infections and fights off diseases, is missing or doesn't function properly. As a result, your body can't protect you from germs as well as it should, so you are more likely to develop infections and be sick more often.

PI is not contagious; you can't catch it from someone else. PI is usually inherited, which means it is carried through the genes of your parents. If you have the disease, you might pass it along to your children, but you won't give it to anyone else.1

If you or someone you know has PI, you know how difficult it can be. But there is good news, too. There are FDA*-approved treatment options available, as well as lots of support. If you have PI, you are certainly not alone.

Journey to PI Diagnosis

Journey to Primary Immunodeficiency (PI) Diagnosis

UNBranded Video

Hear Joanne, a PI patient and retired registered nurse, describe her journey to getting diagnosed with PI.

Patients Understanding Pi Understanding

Understanding PI symptoms and diagnosis

The signs and symptoms of PI vary from person to person. If someone you know is experiencing any of the symptoms below, encourage them to talk to their doctor. Early detection of PI can help prevent long-term problems.

If a person is experiencing recurrent and/or chronic infections, lab testing may be necessary to detect the presence of PI. The patient's medical history and physical exam will help determine the appropriate choice of lab tests. Blood samples and DNA analysis can be used to confirm a particular diagnosis.1

Patient Understanding The

The most common symptoms1-3

  • Chronic, recurring infections that are more severe, longer lasting, and more difficult to cure, such as sinus infections, when compared to people with healthy immune systems
  • Frequently getting sick with infections, such as a common cold, that a healthy immune system would normally be able to fight off
  • Autoimmune problems, such as autoimmune lung or skin disease, which happen when the immune system attacks the body's own organs. Other issues include anemia, celiac disease, arthritis, lupus, and thyroid disorders

Patients What is What causes

What causes PI?

Overview of the immune system

The immune system is an incredible collection of cells, proteins, tissues, and organs that defends against a wide variety of germs every day.2

Patients understanding How

How does the immune system work?

patients understanding immune

The immune system in people with PI1

Usually, the immune system does a great job protecting the body from threats. But in people who have PI, the immune system doesn't work properly. In some cases, the immune system may not work at all. With a lower amount of antibodies, or antibodies that are not working properly, germs are more likley to get through your body's defenses.

Patients understanding treatment

Treatment options for PI

In addition to treating PI, it's important to deal with the disease itself, so you will be less likely to get an infection in the first place. Fortunately, there are several treatments available2:

Patients understanding xembify footnote

Other treatments may also be available.2

Patients understanding xembify

XEMBIFY is an immune globulin (IG)

IG stands for immune globulin. Immune globulin, or IG, is a medicine made from proteins from human plasma, taken from healthy donors, and contains purified antibodies. Plasma is the liquid part of the blood that contains antibodies needed to keep the body healthy.

Immune globulin is given to people with PI to replace missing or ineffective proteins to help the immune system protect against germs and other threats. It is sometimes referred to as IG replacement therapy.

Patients understanding Pi two

Two ways that IG therapy is given

If infused by IV, it is given every 3 to 4 weeks; if given subcutaneously, it can be given daily to weekly, as desired. Also, while IV infusion is administered by a healthcare professional in a clinic or home, subcutaneous infusion can be self-administered conveniently at home.

XEMBIFY is a subcutaneous IG replacement therapy used to treat patients with PI who are 2 years of age and older. Learn more about infusing XEMBIFY.

Patient What is callout

Proven for PI

Learn more about how XEMBIFY has been shown to help patients living with PI.

Starting XEMBIFY

Learn about infusing XEMBIFY with this step-by-step video.

Savings and Support

Learn more about Xembify Connexions for strong support from the start.


What is XEMBIFY®?

XEMBIFY® (immune globulin subcutaneous human–klhw) is a 20% immune globulin used in the treatment of primary humoral immunodeficiency disease (PIDD) in patients 2 years of age and older. XEMBIFY is for subcutaneous administration only.

  • Thrombosis (formation of blood clots within blood vessels) may occur with immune globulin products, including XEMBIFY. Before you take XEMBIFY, talk to your doctor if you:
    • Are older
    • Are sedentary (need to lie down or sit down) for long periods of time
    • Are taking estrogen-containing medicines (birth control pills, hormone replacement therapy)
    • Have a permanent intravenous (IV) catheter
    • Have hyperviscosity of the blood (diseases such as multiple myeloma or other causes of elevated proteins in the blood)
    • Have cardiovascular (heart) problems or previous history of stroke
  • Thrombosis may occur even if you don't have any risk factors
  • If you are at risk of thrombosis, your doctor may prescribe XEMBIFY at the minimum dose and infusion rate. Make sure you drink plenty of fluid before taking XEMBIFY. Make sure your doctor is checking you regularly for signs and symptoms of thrombosis and is checking your blood viscosity if you are at risk of hyperviscosity
Who should not use XEMBIFY?
  • XEMBIFY should not be used if you have had a severe allergic reaction to human immune globulin, or if you have been told by a doctor that you are IgA deficient and have developed antibodies to IgA and hypersensitivity after exposure to a previous plasma product
What are possible serious side effects of XEMBIFY?
  • Hypersensitivity. Severe allergic reactions may occur with immune globulin products, including XEMBIFY. If you have a severe allergic reaction, stop the infusion immediately and get medical attention. XEMBIFY contains IgA. If you have known antibodies to IgA, you may have a greater risk of developing potentially severe allergic reactions
  • Aseptic meningitis syndrome (AMS). Aseptic meningitis is a non-infectious inflammation of the membranes that cover the brain. It causes a severe headache syndrome, which may occur with human immune globulin treatment, including XEMBIFY. If you are showing signs and symptoms of AMS, your doctor may conduct a thorough neurological evaluation including spinal tap (sampling fluid which surrounds the spinal cord) to rule out other causes of meningitis. Stopping human immune globulin treatment has resulted in the end of signs and symptoms within several days. Treatment may include analgesics (pain medicines) and/or a special procedure known as a "blood patch" to stop headache
  • Kidney problems or failure. Kidney problems or failure may occur with use of human immune globulin products, especially those containing sucrose (sugar). XEMBIFY does not contain sucrose. If you have kidney disease or diabetes with kidney involvement, your doctor should perform a blood test to assess your hydration level and kidney function before beginning immune globulin treatment and at appropriate intervals thereafter. If your doctor determines that kidney function is worsening, they may discontinue treatment
  • Hemolysis. Your doctor should monitor you for symptoms of hemolysis (destruction of red blood cells causing anemia, or low red blood cell count). If your doctor suspects hemolysis, they should perform additional tests to confirm
  • Transfusion-related acute lung injury (TRALI). TRALI is a rare but serious syndrome characterized by sudden acute respiratory distress following transfusion. If your doctor suspects TRALI, they will monitor you for any other lung issues. TRALI may be managed with oxygen therapy
  • Transmissible infectious agents. Because XEMBIFY is made from human blood, it may carry a risk of transmitting infectious agents such as viruses, the variant Creutzfeldt-Jakob disease (vCJD) agent, and, theoretically, the Creutzfeldt-Jakob disease (CJD) agent. No cases of transmission of viral diseases or CJD have been associated with the use of XEMBIFY
  • Interference with lab tests. Because XEMBIFY contains a variety of antibodies, blood tests to determine antibody levels may be falsely elevated. Be sure to tell your doctor or lab technician that you are using XEMBIFY
What are other possible side effects of XEMBIFY?
  • In clinical studies of XEMBIFY, some patients experienced local side effects (at the injection site) including pain, redness, puffiness, bruising, nodules, itching, firmness, scabbing and swelling at the site on the skin where the injection occurred. Some patients experienced non-injection-site side effects including cough and diarrhea.
  • Use of XEMBIFY may interfere with the immune response to virus vaccines, such as vaccines for measles, mumps, rubella and varicella. Tell your doctor you are taking XEMBIFY before getting vaccinations

Please see full Prescribing Information for XEMBIFY.

You are encouraged to report negative side effects of prescription drugs to the FDA. Visit or call 1-800-FDA-1088.




  1. What is PI? Immune Deficiency Foundation website. Accessed January 31, 2024.
  2. Laboratory tests. Immune Deficiency Foundation website. Accessed January 12. 2024.
  3. Ballow M, Epland K, Heimall J, et al, eds. Immune Deficiency Foundation Patient & Family Handbook for Primary Immunodeficiency Diseases. 6th ed. Towson, MD: Immune Deficiency Foundation; 2019.
  4. The immune system and primary immunodeficiency. Immune Deficiency Foundation website. Accessed January 12, 2024.



PI, primary humoral immunodeficiency disease

SCIG, subcutaneous immune globulin