COMMON VARIABLE IMMUNODEFICIENCY WITH UNUSUAL PERIPHERAL NEUROPATHY AND ASSOCIATED IL-7 RECEPTOR MUTATION

Abstract

<h3>Introduction</h3> Common variable immunodeficiency is the most common symptomatic primary immunodeficiency, characterized by hypogammaglobulinemia and presenting with a broad range of symptoms including recurrent bacterial infections, autoimmunity, and neoplastic conditions. We present a case of common variable immunodeficiency associated with peripheral neuropathy and a pathogenic heterozygous variant of interleukin-7 receptor (IL7R) gene. <h3>Case Description</h3> The patient is a thirty-eight-year-old female with a history of recurrent infections since childhood including pneumonia and sinus infections status post-tonsillectomy and sinus surgery. She subsequently developed severe left leg and lower back pain which progressed to left foot drop and decreased sensation over the leg with accompanied paresthesia. Labs showed profound hypogammaglobulinemia with scarce levels of IgG (55mg/dl) and IgM (21mg/dl) and lack of IgA (2mg/dl) and IgE (<0.3 IU/ml). Further workup included normal lymphocyte proliferation with deficient polysaccharide and protein response. The patient's lack of IgG antibody production is an important criterion for the diagnosis of common variable immunodeficiency. Genetic panel was performed and significant for a single pathogenic variant in IL7R. <h3>Discussion</h3> We present a case of recurrent sinopulmonary infections with associated peripheral neuropathy prompting further evaluation, revealing the diagnosis of common variable immunodeficiency. Mononeuropathy is a rare finding in common variable immunodeficiency, although should elicit further evaluation if the etiology is unclear. Additional workup was significant for a single pathogenic variant in IL7R. This gene is associated with autosomal recessive severe combined immunodeficiency when homozygous. Further genetic testing is indicated to determine the clinical significance of this variant.