Health condition
X-linked agammaglobulinaemia adults
X-linked agammaglobulinaemia (XLA) is a genetic absence of B cells and antibodies in boys, now a lifelong adult condition thanks to immunoglobulin therapy - adult care centres on optimised replacement, lung protection and specific infection risks.
Why trust this guide
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Editorial team
Written by our editorial team from the UK sources listed on each page.
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Sourced from guidance
Checked against current NHS and UK specialist society guidance at the time of review.
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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.
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Caused by BTK gene defects: B cells never develop, so immunoglobulins of all classes are absent or near-absent from infancy
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Diagnosis clues: severe or recurrent bacterial infections in early childhood, absent tonsils and lymph nodes, and flow cytometry showing absent B cells
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Lifelong immunoglobulin replacement is the cornerstone; with good troughs, adults live full lives
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Specific vigilances: enteroviral infections (which replacement covers less well), mycoplasma joint infections, and bronchiectasis surveillance
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Live vaccines are contraindicated; genetic counselling matters - daughters of affected men are obligate carriers
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
BTK is the enzyme B cells need to grow up; without it the antibody arm of immunity never forms. Boys present in the first years of life once maternal antibody fades - pneumonia, ear and sinus infections, sometimes sepsis - and older diagnoses still occur where the pattern went unrecognised. The transformation wrought by immunoglobulin therapy is one of immunology's successes: a condition once fatal in childhood now fills adult clinics with men managing careers and families alongside three-weekly infusions or weekly home injections.
Diagnosis and treatment routes
Adult XLA care is maintenance done seriously: trough-guided dosing (aiming higher where lungs are damaged), annual lung function with low-threshold CT for bronchiectasis, physiotherapy and prompt antibiotics for chest symptoms, and awareness that antibody replacement imperfectly covers enteroviruses and mycoplasma - unusual neurological symptoms or a chronically inflamed joint deserve specialist attention quickly. Carrier and family counselling completes the picture. Adults whose XLA follow-up has drifted should re-engage with an immunology centre; private review is typically available within about two weeks.
Seeing a specialist
Who to see, and how quickly you can be seen.
The specialist for this condition is usually a consultant clinical 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 X-linked agammaglobulinaemia adults.
Quick, plain-English answers to what people ask us most.
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What is X-linked agammaglobulinaemia in adults?
It is a rare inherited immunodeficiency, usually diagnosed in early childhood, in which the body cannot produce mature antibody-producing cells (B cells), leading to very low antibody levels and recurrent infections; some adults live long-term with the condition through ongoing treatment.
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What causes X-linked agammaglobulinaemia?
It is caused by mutations in the BTK gene, essential for normal B cell development, inherited in an X-linked pattern, meaning it almost exclusively affects males.
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What are the symptoms in adults?
Recurrent bacterial infections, particularly of the ears, sinuses, and lungs, despite ongoing treatment, and, without adequate antibody replacement, an increased risk of more serious or chronic infections over time.
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Is X-linked agammaglobulinaemia dangerous?
Yes, without treatment, recurrent and sometimes severe infections can cause significant, cumulative organ damage, particularly to the lungs, so lifelong immunoglobulin replacement therapy and specialist monitoring are essential.
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Is X-linked agammaglobulinaemia hereditary?
Yes, it's inherited in an X-linked pattern, passed from mothers (who carry the gene without symptoms) to their sons, who are affected.
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Can X-linked agammaglobulinaemia be treated?
Yes, regular immunoglobulin replacement therapy effectively restores antibody levels and significantly reduces the frequency and severity of infections, allowing most people to lead active lives.
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How is X-linked agammaglobulinaemia managed in adults?
Management centres on regular immunoglobulin replacement (given intravenously or subcutaneously), prompt treatment of any infections, and regular monitoring, particularly of lung health, given the cumulative risk of damage from past and any breakthrough infections.
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When should I see an immunologist, and how quickly can I be seen privately?
Ongoing specialist immunology follow-up is essential for anyone with X-linked agammaglobulinaemia. NHS specialist clinics can have waits; private immunologists can often see you within about two weeks.