Clinical and immunological characteristics of 69 leukocyte adhesion deficiency‐I patients.

Background: In order to support the comprehensive classification of Leukocyte Adhesion Deficiency‐I (LAD‐I) severity by simultaneous screening of CD11a/CD18, this study assessed clinical, laboratory, and genetic findings along with outcomes of 69 LAD‐I patients during the last 15 years. Methods: Sixty‐nine patients (40 females and 29 males) with a clinical phenotype suspected of LAD‐I were referred to Immunology, Asthma, and Allergy research institute, Tehran, Iran between 2007 and 2022 for further advanced immunological screening and genetic evaluations as well as treatment, were enrolled in this study. Results: The diagnosis median age of the patients was 6 months. Delayed umbilical cord separation was found in 25 patients (36.2%). The median diagnostic delay time was 4 months (min–max: 0–82 months). Forty‐six patients (66.7%) were categorized as severe (CD18 and/or CD11a: below 2%); while 23 children (33.3%) were in moderate category (CD18 and/or CD11a: 2%–30%). During the follow‐ups, 55.1% of children were alive with a mortality rate of 44.9%. Skin ulcers (75.4%), omphalitis (65.2%), and gingivitis (37.7%) were the most frequent complaints. Genetic analysis of the patients revealed 14 previously reported and three novel pathogenic mutations in the ITGB2 gene. The overall survival of patients with and without hematopoietic stem cell transplantation was 79.3% and 55.6%, respectively. Conclusion: Physicians' awareness of LAD‐I considering delayed separation of umbilical cord marked neutrophilic leukocytosis, and variability in CD11 and CD18 expression levels, and genetic analysis leads to early diagnosis and defining disease severity. Moreover, the prenatal diagnosis would benefit families with a history of LAD‐I. [ABSTRACT FROM AUTHOR]