Primary Immunodeficiency Disorders: Genetic Conditions Impacting Immune System Function

Primary immune deficiencies (PIDs) are a group of genetic disorders that impair the development and function of the immune system. Children with these conditions are more prone to infections, autoimmune diseases, and cancer. Diagnosing PIDs can be challenging for paediatricians because symptoms can appear at any time from birth to adolescence. Unfortunately, many cases remain undiagnosed, leading to severe disease, high morbidity, and mortality.

Early detection and patient-specific therapy can significantly improve the lives of individuals with PIDs. World Primary Immunodeficiency Awareness Week, celebrated from April 22nd to April 29th, aims to increase awareness and improve public access to information about these diseases.

Immunodeficiency diseases are rare genetic disorders that weaken or malfunction the immune system. There are around 450 different forms of primary immunodeficiency, varying in severity and affecting different types of immune cells, including B-cells, T-cells, and granulocytes. Children with PIDs struggle to fight off infections, which may affect their skin, lungs, ears, intestines, and other parts of the body. Symptoms can manifest anytime from the newborn period to childhood, with most cases occurring in infants or early childhood. However, symptoms can also appear in adulthood.

In India, the estimated prevalence of PIDs is around 1 in 10,000 live births, significantly higher than the global average of 1 in 25,000 to 1 in 50,000 live births. Despite this higher prevalence, awareness and diagnosis of PIDs remain low. Studies suggest that up to 70% of PID cases in India go undiagnosed, contributing to increased morbidity and mortality rates. This is partly due to a lack of awareness among healthcare providers and the public, as well as limited access to specialized diagnostic facilities.

Parents should be alert to the following signs that may indicate an underlying immune defect: recurrent or prolonged fever, recurrent ear infections or serious sinus infections, recurrent pneumonia, recurrent diarrhoeas or colitis, recurrent deep skin abscesses, infections in internal organs like the liver, brain, or bones, persistent thrush in the mouth or fungal infections on the skin, rash or eczema, enlarged liver, spleen, or lymph nodes, the need for repeated intravenous antibiotics to clear infections, failure of an infant to gain weight or grow normally, the development of autoimmune disorders at a young age, unexplained swelling of hands, feet, or neck, family history of similar illness or deaths due to infections, and complications from certain vaccines, such as the BCG vaccine.

Treatment of primary immunodeficiency disorders aims to prevent and manage infections and replace missing or defective immune system components. The exact approach depends on the type of PID but may involve rapid and aggressive antibiotic treatment, antimicrobials to prevent bacterial or fungal infections, therapies such as immunoglobulin therapy, G-CSF, interferon-gamma, and fresh frozen plasma, hematopoietic stem cell transplantation, and gene therapy. In India, access to these treatments can be challenging, with only a few specialized centres offering comprehensive care for PIDs.

Precautions for children with PIDs include following doctor’s instructions on vaccinations, taking medications regularly with good compliance, maintaining a nutritious, well-balanced diet, engaging in regular exercise to promote overall fitness, practising good hygiene habits, refraining from close contact with individuals exhibiting severe coughs or infections, and consulting a doctor immediately for any new symptoms.

Increasing awareness can improve early detection and treatment, allowing children with PIDs to lead active, healthy lives. If your child experiences frequent, recurrent, or severe infections, consult a paediatric immunologist for evaluation and tailored treatment. In India, increased awareness and better healthcare infrastructure are essential to improve the outcomes for children with primary immunodeficiency disorders

By Dr Anjani Gummadi, Consultant Paediatric Rheumatologist and Immunologist, Ankura Hospital for Women and Children