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The Paediatric Immunology team in CHI at Crumlin are joining forces with the Irish Primary Immunodeficiency Association (IPIA) to mark Primary Immunodeficiency (PI) week from April 22nd to April 29th.

Primary Immunodeficiencies (also known as inborn errors of immunity) are inherited disorders of the immune system. Patients with PI can present with a wide variety of symptoms including severe and recurrent infection, autoimmunity, allergic disease, malignancy and inflammation. PI’s vary in severity. Some PI’s such as severe combined immunodeficiency (SCID) can present in infancy with severe infection and failure to thrive and can be life-threatening unless identified quickly. However, less severe PI’s can present at any stage of life. In total, approximately 450 PI’s have been identified to date, and with advances in genetic testing, this number continues to increase year on year. It is estimated that 70-90% of PI’s worldwide are undiagnosed. Early diagnosis and treatment can save lives, prevent complications from severe infection or undiagnosed autoimmunity, and improve quality of life. Treatments that can help patients with PI include antibiotic prophylaxis, extra vaccinations, immunoglobulin (also known as antibody) replacement therapy (IRT), medications to modulate the immune response, and on rare occasions, haematopoietic stem cell transplantation (HSCT), thymic transplantation, or autologous stem cell gene therapy.

CHI at Crumlin is the National Centre for the diagnosis, investigation, and management of children in Ireland with PI. The Paediatric Immunology team is led by Prof. Ronan Leahy, ably assisted by a team of NCHDs, and will soon be joined by Dr Aisling Flinn who has completed her training in Paediatric Immunology and HSCT in the UK. The team enjoys multidisciplinary input from Psychology (Stephanie Hardcastle, Claire Griffin), Social Work (Eilish O’Donoghue), Dietetics (Joyce Lee) and administration (Sinead Blair). Immunology Nurse Specialists Samantha Connell and Ressjinn Malazarte help newly diagnosed patients and their parents/carers to learn about their condition, manage their medications, and in particular, with the help of our nursing colleagues on the medical day unit, care for those patients who need IRT or are preparing for/recovering post-HSCT. The Paediatric Immunology team works closely with our colleagues in Paediatric Infectious Diseases, Rheumatology, and other teams to diagnose PI’s in children early. CHI at Crumlin is a documenting centre for the European Society of Immunodeficiencies. 


CHI patient Sean aged 16, Clinical Nurse Specialist Ressjinn Malazarte and Consultant Paediatric Immunologist Dr Ronan Leahy show some of the materials to mark World Immunodeficiency Week.

2022 marks a special year for Paediatric Immunology in Ireland, with the planned addition of a screen for ADA-deficiency SCID to the National Newborn Bloodspot Screening Programme in the second half of the year. Plans to expand the Newborn Screening programme to include other forms of SCID are currently undergoing evaluation by HIQA.

An information stand with key resources was held in CHI at Crumlin on April 26th. For more information about PI week activities worldwide click here. If you have a PI, or know someone who has a PI, or if you want to support patients with PI in Ireland, register with the IPIA patient support group. IPIA is the leading patient support group for patients with PI in Ireland, and a valuable source of reliable information and support for patients and their families. To learn more, click here. 


Clinical Nurse Specialist Samantha Connelly and Medical Social Worker Eilish O'Donoghue from the Infectious Diseases and Immunology Team at the information stand in CHI at Crumlin.

10 Warning Signs for a Suspected PI in Childhood

Paediatricians should consider a PI when two or more of the following are seen:
1) Four or more new ear infections within 1 year.
2) Two or more serious sinus infections within 1 year.
3) Two or more months on antibiotics with little effect.
4) Two or more pneumonias within 1 year.
5) Failure of an infant to gain weight or grow normally.
6) Recurrent, deep skin or organ abscesses.
7) Persistent thrush in mouth or fungal infection on skin.
8) Need for intravenous antibiotics to clear infections.
9) Two or more deep-seated infections including septicaemia.
10) A family history of PI.

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