The Usefulness of Flow Cytometry for Measuring Phosphorylated Signal Transducer and Activator of Transcription 1 to Diagnose and Manage Chronic Mucocutaneous Candidiasis: A Case Report

Abstract

ized by a chronic and recurrent mucocutaneous fungal infection [1]. Genetic mutation of the signal transducer and activator of transcription 1 (STAT1) protein has been known to cause AD-CMC [2]. The STAT1 protein is a member of the STAT family regulated by the Janus kinase (JAK), which is translocated to the nucleus and regulates the expression of genes related to STAT signaling and immune system regulation [3]. In particular, gain-of-function (GOF) STAT1 mutation disrupts interferon-γ, interleukin-17, and interleukin-22 signaling, causing defective Th1 and Th17 responses (Fig. 1A) [2, 4]. Although GOF STAT1 mutation can be identi ed by genetic testing or western blotting, both methods are laborious, time-consuming, and expensive [5]. Recently, ow cytometry (FCM) has been increasingly used to measure intracellular phosphorylatedprotein levels. Some studies have suggested that FCM could be used as a diagnostic tool to monitor the phosphorylation of INTRODUCTION Autosomal dominant chronic mucocutaneous candidiasis (AD-CMC) is a primary immunode ciency disorder (PID) character