Immunological disturbances associated with Prader-Willi syndrome in Egyptian patients

Background: Prader-Willi Syndrome (PWS) is a rare complex genetic disorder resulting from the loss of expression of paternal genes in the PWS critical region on the chromosome 15 q11-q13. PWS affects multiple body systems. The most consistent major manifestations include hypotonia, mild mental retardation, hypogonadism, growth hormone insufficiency and short stature. Other manifestations involve early childhood onset of hyperphagia and obesity, characteristic craniofacial appearance, immunological, behavioural, and sometimes psychiatric disturbances. Objectives: The aim of this study is to evaluate cell mediated as well as humoral immunity in children with PWS. Participants and methods: This study included eleven Egyptian children with PWS diagnosed clinically and confirmed by the FISH technique and 25 non-PWS controls matching age and sex. CD3, CD16, CD19, CD4, and CD8 were estimated using flow cytometry. Serum immunoglobulin levels were measured using immunonephelometry. Interleukin 33 (IL-33), Human Leukocyte Antigen G (HLA-G), Procalcitonin and Human Obestatin (OB) were assessed by ELISA. Measurements of T-cell receptor excision circles (TREC) and k-deleting recombination excision circles (KREC) were performed using real-time PCR technique. Results: The karyotype analysis in all patients was normal, FISH technique showed 15q11.2 deletion in two patients in chromosome 15. The immune cell-count results revealed statistically significant higher total lymphocyte count and lower absolute cytotoxic T lymphocyte (CD8) count in PWS patients compared to controls (pequivalent 0.02405 and 0.01343 respectively). Comparing the immunoglobulin results of the PWS patients with that of control subjects, disclosed statistically significant elevation in IgG and IgM (pequivalent0.0099 and 0.0040 respectively). Furthermore, IL-33 level was significantly increased while procalcitonin was significantly decreased in PWS patients in comparison to controls (pequivalent 0.0009 and 0.0006 respectively). In addition, KREC expression showed statistically significant elevation in PWS patients in comparison to the healthy controls (pequivalent 0.0107). Conclusion: The present work sheds light on the importance of the implementation of flow cytometric measurement of lymphocyte subsets, cytokines evaluation, and immunoglobulins quantification to elucidate the immunological disturbances in PWS patients.