Chronic granulomatous disease (CGD) is a rare genetic disease caused by defects in genes encoding the subunits of the nicotinamide adenine dinucleotide（NADPH）phosphate oxidase complex. In normal phagocytes peroxisome proliferator-activated receptor gamma (PPARγ) activation links NADPH oxidase activity with enhanced mitochondrial reactive oxygen species (ROS) production. There is deficient mitochondrial ROS production in CGD，due to the lack of this upstream signaling by the NADPH oxidase and PPARγ. These patients are susceptible to bacterial and fungal infections, as well as extensive tissue granuloma formation. X-chromosome-linked CGD (X-CGD) is most frequently. And it generally produces a severe phenotype, with a mortality rate of 3% to 5% per year despite state-of-the-art prophylaxis and intensive multimodal treatment.~At present the most curative treatment for patients with X-CGD is hematopoietic stem cell transplantion (HSCT). But for many patients without an HLA-matched donor and active infections/inflammatory complications still require novel approches.~PPARγ agonist such as pioglitazone, approved for type 2 diabetes, was reported to bypass the need for the NADPH oxidase for enhanced mtROS production and partially restored host defense in CGD. What's more, some animal models and several clinical cases have proved its efficacy. The investigators propose to study the efficacy and safety of the therapy with pioglitazone for children with severe infection of CGD, and its long-term effects.~Through this study the investigators hope to confirm the benefits of pioglitazone in the treatment of this rare disease especially for those patients without a prompt suitable matched donor or for whom the critical disease conditions force to postpone HSCT.
The purpose of this proposed research is to investigate the efficacy and safety of the therapy with pioglitazone for chronic granulomatous disease (CGD) patients severe infection.