Spectrum of different categories of Primary Immunodeficiency Disorders diagnosed at Children Hospital.

Objective: To determine the frequency and spectrum of different categories of Primary immunodeficiency disorders (PIDD). Methodology: This was a prospective, observational analytical study, conducted in the Pediatric Medicine Department, University of Child Health Sciences (UCHS) from January 2021 to January 2023.We recruited 81 patients, initially suspected based on Jeffrey Modell Foundation(JMF) warning signs, followed by detailed evaluation. Descriptive statistics were applied. Results: Male patients exceeded female (47: 31). Median age of presentation was 17 months. Median diagnostic delay was 10.5 months. Need of I/V antibiotics was the most frequent JMF warning sign (88.5%). Consanguinity, previous hospital admissions, family history and sibling death were present in 80%, 78%, 54%, 37% of cases respectively. The most conspicuous clinical feature was persistent or recurrent thrush (51%). Patients were categorized into six main groups: B-Cell defect (29.5%), SCID (24.4%), CID (14.1%), T-Cell defect (12.8 %), Phagocytic defect (11.5%) and NK deficiency (7.7%). Main bulk of patients 37 (47.4 %) were in age-group up to one year. Most common site of infection was recurrent pneumonia (76%) and the least was septic arthritis (5.1%). Conclusion: PIDD should no longer be considered a rarity. B-Cell defect is the most common while earliest to diagnose are SCID and LAD. International health authorities should advocate EQUITABLE utilization of genetic testing across the globe.