International clinical consensus on leukocyte adhesion deficiency-I: Modified Delphi analysis.

Background: Leukocyte adhesion deficiency-I (LAD-I) is a rare autosomal-recessive inborn error of immunity caused by mutations in Objective: We sought to provide international, expert-led consensus recommendations for the diagnosis and severity classification of LAD-I; and to characterize standard of care and burden of illness for patients with severe LAD-I. Methods: Twelve geographically diverse experts (3 steering committee members and 9 Delphi participants) were recruited to participate in a modified Delphi study. Two rounds of online questionnaires were conducted, plus a virtual workshop. Final recommendations were approved by all experts. Results: Consensus was achieved across 26 recommendations regarding the diagnosis and treatment of patients with LAD-I. Experts agreed LAD-I severity classification should consider laboratory assessment in addition to clinical phenotype within a comprehensive framework. In the absence of symptoms, particularly in infancy, diagnosis and severity classification is based on flow cytometric assessments (CD18 and CD11a/CD11b expression) and molecular genetic testing or family history. Conclusion: The framework developed by the Delphi panel will aid clinicians in the diagnosis, classification, and treatment of patients with LAD-I. Recommendations support best clinical practice that can lead to improved clinical outcomes.