Hemophagocytic ymphohistiocytosis associated with ataxia telangiectasia

Abstract

Hemophagocytic lymphohistiocytosis (HLH) is a life-threatening inflammatory condition believed to be caused by uncontrolled activation of macrophages and histiocytes. HLH may be triggered by infections or associated with malignancy, metabolic disorders and drug toxicity, or alternatively, by a variety of genetic defects. While this disorder has been reported to be associated with a growing number of primary immunodeficiencies, especially those with significant T cell and (or) NK cell dysfunction, it has never been reported in ataxia telangiectasia (AT). AT is characterized by truncal ataxia, dilatation of blood vessels, immunodeficiency and a high predisposition to cancer. Almost all cases of AT have at least 1 or a combination of more than 1 of the following features: low immunoglobulin levels, inability to produce specific antibodies in response to vaccination, T cell lymphopenia and (or) T cell dysfunction. In this report, we describe the first case of a fatal episode of HLH in a patient with AT. The overlapping laboratory anomalies of HLH and lymphoid malignancy poses a challenge for accurate diagnosis, and awareness of the phenomenon by clinicians may result in earlier treatment and resolution of inflammation. Statement of novelty: HLH can affect various types of immunodeficiency but has never been reported in patients with AT. Here, we report the first case of a fatal episode of HLH in a patient with AT.Copyright © 2017, National Research Council Canada. All rights reserved.