In clinical studies of CGD [23–30], the disorder has presented most often with pneumonia, infectious dermatitis, osteomyelitis, and recurrent or severe abscess formation in the skin and organs of the reticuloendothelial Fulvestrant system. Tissue examination typically shows microscopic granulomas [31]. Infections are caused generally by bacteria such as Staphylococcus aureus and gram-negative bacilli, and fungi such as Aspergillus and Candida [22, 29]. Unusual pathogens characteristic of CGD include Burkholderia cepacia, Chromobacterium violaceum, Nocardia and invasive Serratia marcescens.

The management of CGD includes prophylactic antibiotics, antifungals and IFN-γ, along with aggressive and prolonged treatment of infections as they occur [22, 32]. Prophylactic trimethoprim/sulfamethoxazole (5 mg/kg/day based on trimethoprim) reduces the frequency of major infections from about once every year to once every 3.5 years, preventing staphylococcal and

skin infections without increasing the frequency of serious fungal infections. Itraconazole prophylaxis showed marked efficacy in the prevention of fungal Compound Library infection in CGD (100 mg daily for patients <13 years or <50 kg; 200 mg daily for those ≥13 years or ≥50 kg). IFN-γ reduces the frequency of severe infections and the length of hospitalization for infections and is well tolerated [33], although not all centres use the drug. Therefore, the current recommendations include prophylaxis with trimethoprim/sulfamethoxazole, itraconazole and IFN-γ (50 μg/m2) in CGD [22]. Bone marrow transplantation and gene therapy offer through potential cure of CGD, although with considerable risk and toxicity. Several transplant approaches are in

use, ranging from full myeloablation resulting, when successful, in complete engraftment, to non-myeloablative conditioning regimens, leading to stable hematopoietic chimerism [22]. Gene therapy for CGD has shown marking of cells in the periphery for several months, but clinical benefit has been elusive, presumably because of the low numbers of corrected cells in the circulation (<0.01%). In contrast to severe combined immunodeficiency, where the growth advantage of corrected cells enables small numbers to fill the T-cell compartment, restoring the NADPH oxidase in neutrophils does not seem to offer any apparent selective growth advantage to these cells, making it more difficult for CGD gene therapy to achieve long-term correction [22]. However, even temporary correction of a small proportion of cells can provide short-term clinical benefit [34, 35]. A multinational group has achieved successful gene therapy in patients with X-linked CGD, using liposomal busulfan conditioning followed by infusion with autologous CD34+ peripheral blood stem cells transduced with a retroviral vector, in which gp91phox expression is driven by the spleen focus-forming virus long terminal repeat [36–38].