Differential expression and phosphorylation of BTK protein domain in X-linked agammaglobulinemia

Document Type: Original Article

Authors

1 Research Center for Immunodeficiencies, Pediatrics Center of Excellence, Children's Medical Center, Tehran University of Medical Science, Tehran, Iran

2 Research Center for Immunodeficiencies, Pediatrics Center of Excellence, Children's Medical Center, Tehran University of Medical Sciences, Tehran, Iran

3 Department of Immunology, School of Public HealthTehran University of Medical SciencesTehranIran

4 Department of Medical Immunology, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran.

5 Research Center for Immunodeficiencies, Children's Medical Center , Tehran University of Medical Science , Tehran , Iran

Abstract

Background: X-linked (Bruton’s) agammaglobulinemia (XLA) is a rare congenital disorder with defects in early B cell development caused by mutations in the gene encoding BTK (Bruton tyrosine kinase). The aim of this study was to investigate the expression and phosphorylation of BTK protein domain in these patients.
Materials and Methods: A total of 19 patients with mutations in BTK gene were analyzed for the expression and phosphorylation of BTK protein through immunoblotting. The correlations between BTK expression and the results of immunoblotting as well as clinical and immunologic phenotypes were evaluated.
Results: Six patients showed normal expression of protein and phosphorylation of BTK and two patients had normal phosphorylation while no expression was observed. There was a significant difference between the groups of patients with normal expression of protein and those without it (p=0.01).
Conclusion: Since we identified 6 patients with normal expression and phosphorylation of BTK, and two patients with normal phosphorylation but no expression, thus more studies should be done in order to explore other aspects of the disease. Although there was not any significant correlation between the severity of clinical manifestations and BTK expression, further investigations are necessary to determine the compensatory mechanisms in XLA patients.

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