Introduction. Leukocyte adhesion deficiency (LAD-1) is an inborn error of immunity characterized by a defect in leukocyte trafficking. Approximately, 300 patients with LAD-1 have been reported worldwide up to 2022. The main objectives of this research were to analyze the cases of LAD-1 in the Mexican population during the period 2011-2023.
Methods. Patients with clinical suspicion of LAD-1 were referred to our institution. Complete blood counts, and flow cytometric analysis (to identify the expression of CD18, CD11b and the lymphocyte population phenotyping) were performed. Statistical analyses were then carried out.
Results. We report clinical manifestations and immunological findings of 6 Mexican patients diagnosed with LAD-1. The diagnosis was based on typical clinical presentation, combined with laboratory demonstration of leukocytosis, significant reduction or near absence of CD18 and its associated molecules CD11a, CD11b, and CD11c on leukocytes. We found atypical manifestations, not described in other countries, such as early-onset autoimmunity or infections caused by certain microorganisms.
Conclusions. Patients with LAD-1 may present with atypical manifestations, making flow cytometry an indispensable tool to confirm the diagnosis. We present the first report on the experience of a Latin American country in these patients.