Standard of Care and Treatment for AGM5

Managing Agammaglobulinemia 5 (AGM5) is a lifelong commitment to protecting your health by replacing what your immune system cannot produce on its own. Because your body lacks B cells, it cannot create the antibodies (immunoglobulins) needed to fight germs ^[1]. The goal of treatment is to provide you with immunity that helps keep you healthy and prevents long-term complications ^[2].

The Cornerstone: Immunoglobulin Replacement Therapy (IgRT)

The most important part of your care is Immunoglobulin Replacement Therapy (IgRT). This treatment uses antibodies collected from thousands of healthy donors to provide you with a broad range of protection against common viruses and bacteria ^[3].

There are two primary ways to receive this therapy, and the choice depends on your preference, your veins, and how your body reacts to the medicine:

• Intravenous Immunoglobulin (IVIG): Delivered directly into a vein, usually at a hospital or infusion center. It is typically given once every 3 to 4 weeks ^[4]. Because it provides a large dose all at once, your antibody levels will “peak” right after the infusion and slowly drop to a “trough” (the lowest level) until the next one ^[5].
• Subcutaneous Immunoglobulin (SCIG): Delivered under the skin, often at home using a small pump. These infusions are smaller and happen more frequently—usually once a week or every 1–2 weeks ^[6]. SCIG provides more consistent antibody levels without the high peaks and low troughs of IVIG ^[7].

IgRT Safety and Side Effects

Like all medical treatments, IgRT carries risks. Common side effects include headache, flu-like symptoms, and (with SCIG) local swelling or redness at the injection site. Rare but important risks include aseptic meningitis (a non-infectious inflammation around the brain), blood clots (thrombosis), hemolysis (breakdown of red blood cells), and kidney injury. Seek urgent medical care if you experience a severe headache, chest pain, difficulty breathing, or dark urine after an infusion.

Individualizing Your Dose

Your doctor will measure your IgG trough level to help guide your treatment. While general guidelines sometimes reference a trough level of 500–800 mg/dL, there is no universal AGM5-specific target ^[8][9]. Dosing is product- and patient-specific.

The most important measure of success is your clinical response. If you are still getting frequent infections, or if you have existing lung damage like bronchiectasis, your doctor may increase your dose or frequency regardless of your lab numbers ^[9][10].

Managing Infections

Even with replacement therapy, breakthrough infections can occur.

• Prompt Antibiotics: Your team should assess you promptly and start empiric antibiotics when a bacterial infection is suspected. Whenever feasible, your doctor should culture the infection (test a sample of mucus, blood, or skin) to identify the specific germ, without delaying treatment if you are seriously ill ^[11][12]. Not every fever or cough is bacterial; enteroviral infections, for example, require a different approach.
• Prophylactic Antibiotics: If you continue to get infections, your doctor may prescribe a daily low-dose antibiotic (such as azithromycin) to prevent germs from taking hold ^[13][14]. This decision is highly individualized and carries risks, including drug interactions, QT prolongation (changes to heart rhythm), hearing or gastrointestinal side effects, and antimicrobial resistance.

Important Vaccination Rules

Because your immune system functions differently, vaccination practices must be adjusted:

• Live Vaccines are Contraindicated: You should not receive live attenuated vaccines (such as MMR, oral rotavirus, or the nasal spray flu vaccine). Because you lack B cells, these weakened viruses could potentially grow unchecked and cause illness ^[15].
• Inactivated Vaccines: Vaccines like the “flu shot” or COVID-19 vaccines are generally safe and should not be dismissed. While your body cannot make antibodies in response, they may still provide partial T-cell protection ^[16][17].
• Household Contacts: People living with you should be fully vaccinated with inactivated vaccines to protect you. Your immunologist should provide specific guidance on whether your contacts can safely receive live vaccines ^[15].