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Health condition

IgA deficiency

Selective IgA deficiency - absent or near-absent IgA with normal IgG and IgM - is the commonest primary immune deficiency, and most people who have it never know: many need no treatment, while a minority have infections, allergies or associated autoimmune conditions worth understanding.

Why trust this guide

  • 01

    Editorial team

    Written by our editorial team from the UK sources listed on each page.

  • 02

    Sourced from guidance

    Checked against current NHS and UK specialist society guidance at the time of review.

  • 03

    Current for 2026

    Reviewed on 2026-09-27 with the next review scheduled for 2027-09-27.

Key facts

The essentials at a glance.

The symptoms to recognise, when to seek help, which specialist to see, and what treatment usually involves.

  • Frequency and silence: roughly 1 in 500-700 people of European descent; the majority are asymptomatic lifelong and discovered incidentally (often via coeliac screening, where IgA deficiency invalidates the standard test)

  • The symptomatic minority: recurrent sinopulmonary infections (especially with coexisting IgG subclass deficiency), higher rates of coeliac disease, other autoimmune conditions and atopy

  • Practical flags: coeliac testing needs IgG-based assays; a historical caution exists around reactions to blood products containing IgA in those with anti-IgA antibodies - worth documenting, though modern transfusion practice manages this routinely

  • Specialist: a consultant immunologist for the infection-prone; there is no replacement therapy for IgA itself - management targets infections, associated conditions and monitoring for the small group who evolve towards broader deficiency

Understanding the condition

What it is and what happens next.

What causes it, how it is diagnosed, and the treatment routes available in the UK.

What it is and how it feels

IgA is the antibody of surfaces - secreted across the linings of the respiratory and digestive tracts as a first-line barrier - and its selective absence is the immune system's commonest inborn variation, tolerated so well by most carriers that the usual route to diagnosis is accidental: a coeliac screen that comes back with absent IgA (invalidating the standard tissue transglutaminase-IgA test and mandating IgG-based alternatives - the single most practically important fact about the condition), a pre-donation screen, or an immunology panel run for something else. Redundancy explains the silence: secretory IgM and other defences cover much of IgA's beat, and the deficiency's clinical weight emerges mainly through its associations - a modestly raised likelihood of recurrent respiratory and sinus infections (particularly when IgG2 subclass deficiency travels alongside), giardia susceptibility in the gut, and a well-documented autoimmune neighbourhood: coeliac disease at several times the background rate, thyroid autoimmunity, and others.

Diagnosis and treatment routes

Assessment therefore establishes the full immunoglobulin and subclass picture, screens for coeliac disease with the correct IgG-based serology, and calibrates follow-up to phenotype: the asymptomatic majority need documentation, the coeliac-testing caveat explained, and awareness of the transfusion consideration - anti-IgA antibodies in a subset have historically caused reactions to IgA-containing blood products, information worth carrying even though contemporary practice handles it smoothly - while the infection-prone minority earn immunology review, vaccination optimisation, prompt and adequate antibiotic treatment of bacterial infections, prophylactic strategies where winters prove repeatedly costly, and periodic monitoring, since a small fraction evolve towards common variable immunodeficiency over the years, a transition that scheduled immunoglobulin checks catch early. IgA cannot be replaced therapeutically - infused immunoglobulin is overwhelmingly IgG - so management is precisely this: knowledge deployed at the right moments, rather than any daily treatment. In many parts of the UK, routine NHS referrals for this kind of problem currently take 20-45+ weeks, whereas an initial appointment with a private consultant is typically available within around two weeks.

Seeing a specialist

Who to see, and how quickly you can be seen.

The specialist for this condition is usually a consultant immunologist. Your GP can refer you on the NHS, or you can arrange a private consultation directly.

A quiet reminder

This guide is for information, not medical advice.

Your GP knows your history and can tell you which parts apply to you. If in doubt, see them - and seek urgent care for any of the emergency symptoms described above.

Frequently asked

Common questions about IgA deficiency.

Quick, plain-English answers to what people ask us most.

  • Can you explain what IgA deficiency is?

    IgA deficiency is a health condition that affects how part of the body functions, and can range in severity from mild to significant depending on the individual. A clinician can assess your specific situation and explain what it means for you. Understanding the basics helps you ask the right questions at your appointment.

  • What causes igA deficiency?

    There are usually several contributing factors behind igA deficiency, and it's not always possible to pin down a single cause without proper assessment. Your doctor will consider your symptoms, history, and any relevant investigations to build a clearer picture. This helps make sure treatment is targeted appropriately.

  • How would I know if I have igA deficiency?

    Symptoms can vary from mild and barely noticeable to more significant and disruptive, depending on severity and individual factors. Common features often include changes that affect comfort, function, or general wellbeing in the affected area or system. If you're experiencing symptoms that concern you, it's worth having them assessed rather than guessing.

  • How worried should I be about igA deficiency?

    Most cases can be managed effectively once properly assessed and treated, though how serious it is depends on individual circumstances and how early it's picked up. Getting a professional opinion helps rule out anything more concerning and puts your mind at ease either way. Don't hesitate to seek advice if something feels wrong.

  • Is igA deficiency hereditary or genetic?

    Some cases have a genetic or family component, while others are linked more to lifestyle, environment, or other health conditions. Having a family history may increase your risk slightly, but it doesn't mean you'll definitely develop it. A clinician can advise whether genetic factors seem relevant in your particular case.

  • Is there a cure for igA deficiency?

    Treatment can often reduce symptoms significantly and, in some cases, resolve the underlying problem entirely, though this isn't guaranteed for everyone. Prevention strategies, where they exist, usually focus on managing risk factors and general health. A tailored discussion with your doctor will give you the clearest picture for your circumstances.

  • How is igA deficiency treated?

    Treatment options range from conservative measures such as lifestyle changes, medication, or physiotherapy through to more involved interventions in more severe or persistent cases. The right approach depends on the underlying cause, severity, and how it's affecting you. Your specialist will talk through the pros and cons of each option that's relevant to you.

  • What is the typical recovery time for igA deficiency?

    Some people recover within a matter of weeks, while others find it becomes a longer-term or recurring issue that needs ongoing management. Following your treatment plan closely tends to support the best possible recovery. Ask your specialist for a realistic timeline based on your own results and progress.

  • When is a specialist opinion or surgery needed for igA deficiency?

    A specialist opinion is generally recommended if symptoms persist despite initial treatment, if they're severe, or if there's uncertainty about the diagnosis. Surgery or more invasive treatment is usually reserved for cases where conservative measures haven't worked. Your GP can refer you on if they feel a specialist review would be helpful.

  • When is it worth getting igA deficiency checked by a specialist?

    See a doctor if symptoms are persistent, worsening, or affecting your daily life, or sooner if you have any red-flag symptoms your GP has warned you about. Waiting times through the NHS often run to 20-45+ weeks for a routine referral, whereas a private specialist can usually see you within roughly 2 weeks.