Delineating the immunological profile of Algerian children with Down syndrome: A case series
Linda Mokrane1, Azzeddine Tahiat1, Samira Aggoune2
1Algiers University of Health Sciences, Rouiba Hospital, Department of Medical Biology, 16000, Algiers, Algeria.
Purpose:
This study aimed to characterize the immunological profile of Algerian children with Down Syndrome (DS).
Methods:
Serum immunoglobulin (Ig) levels were measured using nephelometry, and lymphocyte subpopulations were analyzed by flow cytometry (FACSLyric™, BD Biosciences, US). The lymphocyte phenotype in DS patients was compared to that of patients with combined immunodeficiency (CID).
Results:
Our cohort included 33 patients with DS (20 males), and 40 patients with CID (24 males). All patients had a clinical history of recurrent or severe infections, including upper and lower respiratory tract infections in 25 patients (76%). Serum Ig were measured in 29 patients, with normal levels of IgG, IgA, and IgM in 83%, 73%, and 80% of patients, respectively. Elevated IgG, IgA, and IgM levels were found in 14%, 17%, and 3% of patients, while reduced levels were seen in 3%, 10%, and 17% of patients, respectively. Lymphocyte phenotype analysis revealed CD4 lymphopenia in 24 (73%) patients, CD8 lymphopenia in 19 (58%) patients, B-cell lymphopenia in 16 (48%) patients, and reduced NK cells in 7 (21%) patients. Naïve CD4+ and CD8+ T cells were analyzed in nine patients, with low percentages observed in three. Patients with DS exhibited significantly milder CD3 and CD4 lymphopenia compared to those with CID.
Conclusion:
Children with DS typically present with T- and B-cell lymphopenia, while maintaining generally normal Ig levels. T-cell lymphopenia in DS is less pronounced than in CID, and the increased susceptibility to infections stems from both immunological and non-immunological factors linked to trisomy 21.
