The Clinical Significance of Complete Class Switching Defect in Ataxia Telangiectasia Patients Publisher Pubmed



Ghiasy S¹ ; Parvaneh L¹ ; Azizi G^{1, 2} ; Sadri G¹ ; Zaki Dizaji M¹ ; Abolhassani H^{1, 3} ; Aghamohammadi A¹
Source: Expert Review of Clinical Immunology Published:2017

Abstract

Background: Ataxia telangiectasia (AT) is a primary immunodeficiency associated with recurrent infections. We aimed to investigate clinical and immunological classification in AT patients who suffer from a different spectrum of humoral immune defects. Methods: AT patients were categorized according to the ability of class switching and patients with hyper IgM (HIgM) profile were defined as class switching defect (CSD). Results: Serum immunoglobulin profile in 66 AT patients showed normal immunoglobulin level (22.8%), IgA deficiency (37.9%) and hypogammaglobulinemia (18.1%) in the majority of patients, while 21.2% had HIgM profile revealing CSD. CSD does not affect the frequency of infections, however, the frequency of lymphoproliferation (p < 0.001), and autoimmunity (p = 0.004) were significantly higher in this group. Neurologic symptoms in CSD patients are mild or appear after recurrent infections, therefore these patients were usually misdiagnosed as HIgM syndrome. Conclusions: Although most of AT patients have reduced IgA levels or normal immunoglobulin levels, but a fraction of these patients may show CSD ensuing HIgM-profile. CSD poses affected individuals at higher risk of non-infectious complications. © 2017 Informa UK Limited, trading as Taylor & Francis Group.