Chronic Granulomatous Disease (CGD) is an immunodeficiency disorder affecting about 1 in 250,000 individuals. The disease is caused by a lack of superoxide production by the leukocyte enzyme NADPH oxidase. Superoxide is used to kill phagocytosed micro-organisms in neutrophils, eosinophils, monocytes and macrophages. The leukocyte NADPH oxidase is composed of five subunits, of which the enzymatic component is gp91-phox, also called Nox2. This protein is encoded by the CYBB gene on the × chromosome. Mutations in this gene are found in about 70% of all CGD patients. This article lists all mutations identified in CYBB in the X-linked form of CGD. Moreover, apparently benign polymorphisms in CYBB are also given, which should facilitate the recognition of future disease-causing mutations.

Chronic granulomatous disease (CGD) is a rare primary immunodeficiency caused by defects in the genes encoding any of the NADPH oxidase components responsible for the respiratory burst of phagocytic leukocytes. CGD is a genetically heterogeneous disease with an X-linked recessive (XR-CGD) form caused by mutations in the CYBB gene encoding the gp91(phox) protein, and an autosomal recessive (AR-CGD) form caused by mutations in the CYBA, NCF1, NCF2, or NCF4 genes encoding p22(phox) , p47(phox) , p67(phox) , and p40(phox) , respectively. Patients suffering from this disease are susceptible to severe life-threatening bacterial and fungal infections and excessive inflammation characterized by granuloma formation in any organ, for instance, the gastrointestinal and genitourinary tract. An early diagnosis of and the prompt treatment for these conditions are crucial for an optimal outcome of affected patients. To prevent infections, CGD patients should receive lifelong antibiotics and antifungal prophylaxis. These two measures, as well as newer more effective antimicrobials, have significantly modified the natural history of CGD, resulting in a remarkable change in overall survival, which is now around 90%, reaching well into adulthood. At present, hematopoietic stem cell transplantation (HSCT) is the only definitive treatment that can cure CGD and reverse organ dysfunction. Timing, donor selection, and conditioning regimens remain the key points of this therapy. In recent years, gene therapy (GT) for XR-CGD has been proposed as an alternative to HSCT for CGD patients without a matched donor. After the failure of the first trials performed with retroviral vectors, some groups have proposed the use of regulated SIN-lentiviral vectors targeting gp91(phox) expression in myeloid cells to increase the safety and efficacy of the GT protocols.

Mass SARS-Cov-2 vaccination campaign represents the only strategy to defeat the global pandemic we are facing. Immunocompromised patients represent a vulnerable population at high risk of developing severe COVID-19 and thus should be prioritized in the vaccination programs and in the study of the vaccine efficacy. Nevertheless, most data on efficacy and safety of the available vaccines derive from trials conducted on healthy individuals; hence, studies on immunogenicity of SARS-CoV2 vaccines in such populations are deeply needed. Here, we perform an observational longitudinal study analyzing the humoral and cellular response following the BNT162b2 mRNA COVID-19 vaccine in a cohort of patients affected by inborn errors of immunity (IEI) compared to healthy controls (HC). We show that both IEI and HC groups experienced a significant increase in anti-SARS-CoV-2 Abs 1 week after the second scheduled dose as well as an overall statistically significant expansion of the Ag-specific CD4+CD40L+ T cells in both HC and IEI. Five IEI patients did not develop any specific CD4+CD40L+ T cellular response, with one of these patients unable to also mount any humoral response. These data raise immunologic concerns about using Ab response as a sole metric of protective immunity following vaccination for SARS-CoV-2. Taken together, these findings suggest that evaluation of vaccine-induced immunity in this subpopulation should also include quantification of Ag-specific T cells.