Myeloperoxidase Deficiency: Causes, Symptoms, and Treatment
Medically reviewed by Harsha Moole, MD, Internal Medicine. Last reviewed: October 2, 2026.
What kind of doctor treats Myeloperoxidase Deficiency?
A primary care doctor, such as a family medicine or internal medicine doctor, usually manages this condition. If infections are frequent or severe, the doctor may refer the patient to an immunologist or an infectious disease doctor. A direct primary care or concierge doctor can be a first stop for an evaluation and can refer you to a specialist when needed.
What it is
Myeloperoxidase deficiency is a condition where certain immune cells lack a protein called myeloperoxidase, which helps the body fight infections. The cells involved are neutrophils, white blood cells that defend against germs. Without this protein, they cannot make one of the chemicals they normally use to kill bacteria and fungi.
Most people with this condition never know they have it. Their immune systems usually handle everyday germs just fine. It is one of the most common inherited immune differences and is considered mostly harmless.
Symptoms
Most people have no symptoms. The condition is often found by accident during a routine blood test. When symptoms do happen, they usually involve infections that are more frequent or longer lasting than expected, most often fungal infections such as candida. Serious illness is rare and usually linked to another problem like diabetes.
Causes and who gets it
The condition is caused by changes in a gene that carries instructions for making myeloperoxidase. It is inherited, passed down from parents to children. Most people with the condition inherited one changed copy from each parent. It affects people of all backgrounds and both sexes.
How doctors diagnose it
Doctors usually find the condition with a blood test that checks how well neutrophils work. Special lab tests can measure the enzyme directly or look at the gene itself.
Treatment
When infections do happen, doctors treat them with medicines that fight bacteria or fungi. People with diabetes or other conditions that weaken the body's defenses may need closer follow-up.
When to see a doctor
Anyone who has infections that keep coming back should talk to a doctor. The same goes for infections that are unusual for their age or do not improve with normal treatment. Fevers that return without a clear cause also deserve a checkup.
How a direct primary care or concierge doctor fits in
A direct primary care doctor charges a flat monthly fee instead of billing insurance for visits; a concierge doctor often charges more and may work alongside a patient's insurance. These doctors have longer appointments, which makes it easier to review infection history and order the right lab tests. If infections become frequent or hard to control, the doctor will refer the patient to a specialist and stay involved in care.
Common questions
Is myeloperoxidase deficiency dangerous?
For most people, no. The vast majority of people with this condition live normal lives without unusual infections. Severe problems are rare. They tend to happen when another illness, such as diabetes, is also present.
Can it be passed to my children?
The changed gene can be passed down. But a child would usually need two changed copies, one from each parent, to have the complete condition. Genetic counseling can help families understand the chances.
Do I need antibiotics all the time?
Most people do not. Doctors prescribe medicines to treat infections when they happen. Preventive medicines are not usually needed for this condition.
Why did my blood test mention this if I feel fine?
Some lab machines flag missing myeloperoxidase automatically. If you have no unusual infections, the finding usually does not require any action.
Sources
- NIH Genetic and Rare Diseases Information Center - Myeloperoxidase deficiency
- MedlinePlus - Mannose-binding lectin deficiency: MedlinePlus Genetics
Medical Disclaimer
This content is for general educational and informational purposes only and is not medical advice. It is not a substitute for professional medical advice, diagnosis, or treatment, and reading it does not create a doctor-patient relationship. Always seek the advice of your physician or another qualified health provider with any questions about a medical condition, and never disregard or delay seeking professional advice because of something you read here. If you think you may have a medical emergency, call 911 (or your local emergency number) immediately.
