Mammalian target of rapamycin inhibition counterbalances the inflammatory status of immune cells in patients with chronic granulomatous disease

The Role of NADPH Oxidase 2 in Leukocytes

NADPH oxidase (NOX) family members are major resources of intracellular reactive oxygen species (ROS). In the immune system, ROS derived from phagocytic NOX (NOX2) participate in both pathogen clearance and signaling transduction. The role of NOX2 in neutrophils and macrophages has been well studied as mutations in NOX2 subunits cause chronic granulomas disease (CGD). NOX2 is expressed across a wide range of immune cells and recent reports have demonstrated that NOX2-derived ROS play important roles in other immune cells during an immune response. In this review, we summarize current knowledge of functions of NADPH oxidase 2 in each subset of leukocytes, as well as associations of NOX2 deficiency with diseases associated specifically with autoimmunity and immune deficiency. We also discuss important knowledge gaps as well as potential future directions for NOX2 research.

Exploring the translational potential of PLGA nanoparticles for intra-articular rapamycin delivery in osteoarthritis therapy

Osteoarthritis (OA) is a prevalent joint disease that affects all the tissues within the joint and currently lacks disease-modifying treatments in clinical practice. Despite the potential of rapamycin for OA disease alleviation, its clinical application is hindered by the challenge of achieving therapeutic concentrations, which necessitates multiple injections per week. To address this issue, rapamycin was loaded into poly(lactic-co-glycolic acid) nanoparticles (RNPs), which are nontoxic, have a high encapsulation efficiency and exhibit sustained release properties for OA treatment. The RNPs were found to promote chondrogenic differentiation of ATDC5 cells and prevent senescence caused by oxidative stress in primary mouse articular chondrocytes. Moreover, RNPs were capable to alleviate metabolism homeostatic imbalance of primary mouse articular chondrocytes in both monolayer and 3D cultures under inflammatory or oxidative stress. In the mouse destabilization of the medial meniscus (DMM) model, intra-articular injection of RNPs effectively mitigated joint cartilage destruction, osteophyte formation, chondrocytes hypertrophy, synovial inflammation, and pain. Our study demonstrates the feasibility of using RNPs as a potential clinically translational therapy to prevent the progression of post-traumatic OA.

The paradox of autoimmunity and autoinflammation in inherited neutrophil disorders - in search of common patterns

Congenital defects of neutrophil number or function are associated with a severe infectious phenotype that may require intensive medical attention and interventions to be controlled. While the infectious complications in inherited neutrophil disorders are easily understood much less clear and explained are autoimmune and autoinflammatory phenomena. We survey the clinical burden of autoimmunity/autoinflammation in this setting, search for common patterns, discuss potential mechanisms and emerging treatments.

A functional role for Serum Amyloid A in the molecular regulation of autophagy in breast cancer

It has been established that the acute phase protein, Serum amyloid A (SAA), which is usually synthesized by the liver, is also synthesized by cancer cells and cancer-associated cells in the tumor microenvironment. SAA also activates modulators of autophagy, such as the PI3K/Akt and MAPK signaling pathways. However, the role of SAA in autophagy in breast cancer still remains to be elucidated. The aim of this study was to investigate the role of SAA in the regulation of signaling pathways and autophagy in in vitro and in vivo models of breast cancer. The MDA-MB-231 and MCF7 cell lines were transiently transfected to overexpress SAA1. A tumor-bearing SAA1/2 knockout mouse model was also utilized in this study. SAA1 overexpression activated ERK signaling in the MDA-MB-231 cells, downregulated the PI3K pathway protein, PKB/Akt, in the MCF7 cell line, while SAA1/2 knockout also inhibited Akt. Furthermore, SAA1 overexpression in vitro downregulated autophagy, while the expression of SQSTM1/p62 was increased in the MCF7 cells, and SAA1/2 knockout induced autophagy in vivo. SAA overexpression in the MDA-MB-231 and MCF7 cells resulted in an increase in cell viability and increased the expression of the proliferation marker, MCM2, in the MCF7 cells. Furthermore, knockout of SAA1/2 resulted in an altered inflammatory profile, evident in the decrease of plasma IL-1β, IL-6 and IL-10, while increasing the plasma levels of MCP-1 and TNF-α. Lastly, SAA1/2 knockout promoted resistance to apoptosis and necrosis through the regulation of autophagy. SAA thus regulates autophagy in breast cancer cells to promote tumorigenesis.

Heightened turnover and failed maturation of monocyte-derived macrophages in murine chronic granulomatous disease

Loss of NADPH oxidase activity leads to altered phagocyte responses and exaggerated inflammation in chronic granulomatous disease (CGD). We sought to assess the effects of Nox2 absence on monocyte-derived macrophages (MoMacs) in gp91phox-/y mice during zymosan-induced peritonitis. MoMacs from CGD and wild-type (WT) peritonea were characterized over time after zymosan injection. Although numbers lavaged from both genotypes were virtually identical, there were marked differences in maturation: newly recruited WT MoMacs rapidly enlarged and matured, losing Ly6C and gaining MHCII, CD206, and CD36, whereas CGD MoMacs remained small and were mostly Ly6C+MHCII-. RNA-sequencing analyses showed few intrinsic differences between genotypes in newly recruited MoMacs but significant differences with time. WT MoMacs displayed changes in metabolism, adhesion, and reparative functions, whereas CGD MoMacs remained inflammatory. PKH dye labeling revealed that although WT MoMacs were mostly recruited within the first 24 hours and remained in the peritoneum while maturing and enlarging, CGD monocytes streamed into the peritoneum for days, with many migrating to the diaphragm where they were found in fibrin(ogen) clots surrounding clusters of neutrophils in nascent pyogranulomata. Importantly, these observations seemed to be driven by milieu: adoptive transfer of CGD MoMacs into inflamed peritonea of WT mice resulted in immunophenotypic maturation and normal behavior, whereas altered maturation/behavior of WT MoMacs resulted from transfer into inflamed peritonea of CGD mice. In addition, Nox2-deficient MoMacs behaved similarly to their Nox2-sufficient counterparts within the largely WT milieu of mixed bone marrow chimeras. These data show persistent recruitment with fundamental failure of MoMac maturation in CGD.

The Yin and Yang dualistic features of autophagy in thermal burn wound healing

Burn healing should be regarded as a dynamic process consisting of two main, interrelated phases: (a) the inflammatory phase when neutrophils and monocytes infiltrate the injury site, through localized vasodilation and fluid extravasation, and (b) the proliferative-remodeling phase, which represents a key event in wound healing. In the skin, both canonical autophagy (induced by starvation, oxidative stress, and environmental aggressions) and non-canonical or selective autophagy have evolved to play a discrete, but, essential, “housekeeping” role, for homeostasis, immune tolerance, and survival. Experimental data supporting the pro-survival roles of autophagy, highlighting its Yang, luminous and positive feature of this complex but insufficient explored molecular pathway, have been reported. Autophagic cell death describes an “excessive” degradation of important cellular components that are necessary for normal cell function. This deadly molecular mechanism brings to light the darker, concealed, Yin feature of autophagy. Autophagy seems to perform dual, conflicting roles in the angiogenesis context, revealing once again, its Yin–Yang features. Autophagy with its Yin–Yang features remains the shadow player, able to decide quietly whether the cell survives or dies.

Molecular regulation of autophagy in a pro-inflammatory tumour microenvironment: New insight into the role of serum amyloid A

Chronic inflammation, systemic or local, plays a vital role in tumour progression and metastasis. Dysregulation of key physiological processes such as autophagy elicit unfavourable immune responses to induce chronic inflammation. Cytokines, growth factors and acute phase proteins present in the tumour microenvironment regulate inflammatory responses and alter crosstalk between various signalling pathways involved in the progression of cancer. Serum amyloid A (SAA) is a key acute phase protein secreted by the liver during the acute phase response (APR) following infection or injury. However, cancer and cancer-associated cells produce SAA, which when present in high levels in the tumour microenvironment contributes to cancer initiation, progression and metastasis. SAA can activate several signalling pathways such as the PI3K and MAPK pathways, which are also known modulators of the intracellular degradation process, autophagy. Autophagy can be regarded as having a double edged sword effect in cancer. Its dysregulation can induce malignant transformation through metabolic stress which manifests as oxidative stress, endoplasmic reticulum (ER) stress and DNA damage. On the other hand, autophagy can promote cancer survival during metabolic stress, hypoxia and senescence. Autophagy has been utilised to promote the efficiency of chemotherapeutic agents and can either be inhibited or induced to improve treatment outcomes. This review aims to address the known mechanisms that regulate autophagy as well as illustrating the role of SAA in modulating these pathways and its clinical implications for cancer therapy.

Progress in treating chronic granulomatous disease

Chronic granulomatous disease is a primary immunodeficiency due to a defect in one of six subunits that make up the nicotinamide adenine dinucleotide phosphate oxidase complex. The most commonly defective protein, gp91^phox , is inherited in an X-linked fashion; other defects have autosomal recessive inheritance. Bacterial and fungal infections are common presentations, although inflammatory complications are increasingly recognized as a significant cause of morbidity and are challenging to treat. Haematopoietic stem cell transplantation offers cure from the disease with improved quality of life; overall survival in the current era is around 85%, with most achieving long-term cure free of medication. More recently, gene therapy is emerging as an alternative approach. Results using gammaretroviral vectors were disappointing with genotoxicity and loss of efficacy, but preliminary results using lentiviral vectors are extremely encouraging.

Lower T Regulatory and Th17 Cell Populations Predicted by RT-PCR-Amplified FOXP3 and RORγt Genes Are Not Rare in Patients With Primary Immunodeficiency Diseases

Deficiencies in T regulatory (Treg) and Th17 cells attenuate peripheral tolerance and the IL-17 family of cytokines, contributing to autoimmune disorders and opportunistic (fungal) infections, respectively. Because of limited blood samples from patients with primary immunodeficiency diseases (PIDs), a positive correlation/linear relationship between Treg and Th17 cells and their respective expressions of transcription factors forkhead box P3 (FOXP3) and retinoic acid-related orphan receptor γ (RORγt) by real-time PCR (RT-PCR) amplification, was used to predict the percentages of Treg and Th17 cells in peripheral blood. Compared to glyceraldehyde 3-phosphate dehydrogenase (GAPDH) expression, the percentages of Treg and Th17 cells were calculated as the linear relationship to the 2^−ΔCT value (cycle threshold). Among 91 PIDs patients, 68 and 78 had predicted Treg and Th17 percentages below 5% of the normal ranges (0.859 and 0.734%, respectively), which expanded different categories beyond obvious T cell deficiency. Notably, FOXP3 was undetectable in one patient (CVID), RORγt was undetectable in six patients (one CVID, one CID, two neutropenia, one WAS, and one CMC), and both were undetectable in four patients (two SCID, one STAT1, and one periodic fever). In contrast, two patients with auto-IFNγ antibodies had increased susceptibility to intracellular mycobacterial infections, interrupted Th1 development and subsequent elevation in the Th17 cells. Both predicted Treg and Th17 percentages in the PIDs patients were more independent of age (months) than in the controls. The predicted Th17/Treg ratio in the PIDs patients, overall, was lower than that in the healthy controls (0.79 ± 0.075 vs. 1.16 ± 0.208; p = 0.038). In conclusion, lower predicted Treg and Th17 cell populations calculated by RT-PCR-amplified FOXP3 and RORγt in PIDs patients at diagnosis can explain the higher potential phenotypes of autoimmune disorders and opportunistic infections, although effective interventions in the early stage might have prevented such phenotypic development and caused a statistical bias in the comparisons.

Chronic Granulomatous Disease: a Comprehensive Review

Chronic granulomatous disease (CGD) is a primary immunodeficiency of phagocyte function due to defective NADPH oxidase (phox). Compared with the common types of CYBB/gp91^phox, NCF1/p47^phox, and CYBA/p22^phox deficiency, NCF4/p40^phox deficiency is a mild and atypical form of CGD without invasive bacterial or fungal infections. It can be diagnosed using serum-opsonized E.coli as a stimulus in dihydrorhodamine (DHR) assay. Patients with CYBC1/Eros deficiency, a new and rare form of CGD, present as loss of respiratory burst and gp91^phox expression in phagocytes. Neutrophils from patients with CGD are deficient in neutrophil extracellular traps (NETosis), autophagy, and apoptosis. The hyper-activation of NF-ĸB and inflammasome in CGD phagocytes also lead to long-lasting production of pro-inflammatory cytokines and inflammatory manifestations, such as granuloma formation and inflammatory bowel disease-like colitis. Patients with CGD and X-linked female carriers also have a higher incidence of autoimmune diseases. The implementation of antimicrobial, anti-fungal, and interferon-γ prophylaxis has greatly improved overall survival. Residual NADPH oxidase activity is significantly associated with disease severity and the chance of survival of the patient. New therapeutic approaches using immunomodulators for CGD-related inflammatory manifestations are under investigation, including pioglitazone, tamoxifen, and rapamycin. Hematopoietic stem cell transplantation (HSCT) is the curative treatment. Outcomes of HSCT have improved substantially over the last decade with overall survival more than 84-90%, but there are debates about designing optimal conditioning protocols using myeloablative or reduced-intensity regimens. The gene therapy for X-linked CGD using hematopoietic stem and progenitor cells transduced ex vivo by lentiviral vector encoding the human gp91phox gene demonstrated persistence of adequate oxidase-positive neutrophils in a small number of patients. Gene therapy using genome-editing technology such as CRISPR/Cas9 nucleases is a promising approach for patients with CGD in the future.

Systemic Redox Imbalance in Patients with Chronic Granulomatous Disease

The aim of our study was to evaluate redox status, enzymatic and non-enzymatic antioxidant barriers, oxidative damage of proteins, lipids and DNA, as well as concentration of coenzyme Q10 and vitamins A and E in patients with chronic granulomatous disease (CGD). The study was performed on fifteen Caucasian individuals (median age 24 years and seven months) diagnosed with CGD. The mutation in the NCF1 gene was confirmed in ten patients, and in the CYBB gene in five patients. We demonstrated high levels of total oxidant status (TOS) and oxidative stress index (OSI), lipids (↑8-isoprostanes (8-isoP), ↑4-hydroxynonenal (4-HNE)), proteins (↑advanced oxidation protein products (AOPP)) and DNA (↑8-hydroxy-2’-deoxyguanosine (8-OHdG)) oxidation products in CGD individuals as compared to sex- and age-matched healthy controls. We showed enhanced serum enzymatic activity of catalase (CAT) and superoxide dismutase-1 (SOD) and significantly decreased coenzyme Q10 concentration. Our study confirmed redox disturbances and increased oxidative damage in CGD patients, and indicated the need to compare redox imbalance depending on the type of mutation and nicotinamide adenine dinucleotide phosphate (NADPH) oxidase activity. The question regarding effectiveness of antioxidant therapy in patients with CGD is open, and the need to establish guidelines in this area remains to be addressed.

Autophagy-mediated regulation of neutrophils and clinical applications

Autophagy, an adaptive catabolic process, plays a cytoprotective role in enabling cellular homeostasis in the innate and adaptive immune systems. Neutrophils, the most abundant immune cells in circulation, are professional killers that orchestrate a series of events during acute inflammation. The recent literature indicates that autophagy has important roles in regulating neutrophil functions, including differentiation, degranulation, metabolism and neutrophil extracellular trap formation, that dictate neutrophil fate. It is also becoming increasingly clear that autophagy regulation is critical for neutrophils to exert their immunological activity. However, evidence regarding the systematic communication between neutrophils and autophagy is insufficient. Here, we provide an updated overview of the function of autophagy as a regulator of neutrophils and discuss its clinical relevance to provide novel insight into potentially relevant treatment strategies.

Inflammatory consequences of inherited disorders affecting neutrophil function

Primary immunodeficiencies affecting the function of neutrophils and other phagocytic leukocytes are notable for an increased susceptibility to bacterial and fungal infections as a result of impaired leukocyte recruitment, ingestion, and/or killing of microbes. The underlying molecular defects can also impact other innate immune responses to infectious and inflammatory stimuli, leading to inflammatory and autoimmune complications that are not always directly related to infection. This review will provide an update on congenital disorders affecting neutrophil function in which a combination of host defense and inflammatory complications are prominent, including nicotinamide dinucleotide phosphate oxidase defects in chronic granulomatous disease and β2 integrin defects in leukocyte adhesion deficiency.

The microbiome and immunodeficiencies: Lessons from rare diseases

Primary immunodeficiencies (PIDs) are inherited disorders of the immune system, associated with a considerable increase in susceptibility to infections. PIDs can also predispose to malignancy, inflammation and autoimmunity. There is increasing awareness that some aspects of the immune dysregulation in PIDs may be linked to intestinal microbiota. Indeed, the gut microbiota and its metabolites have been shown to influence immune functions and immune homeostasis both locally and systemically. Recent studies have indicated that genetic defects causing PIDs lead to perturbations in the conventional mechanisms underlying homeostasis in the gut, resulting in poor immune surveillance at the intestinal barrier, which associates with altered intestinal permeability and bacterial translocation. Consistently, a substantial proportion of PID patients presents with clinically challenging IBD-like pathology. Here, we describe the current body of literature reporting on dysbiosis of the gut microbiota in different PIDs and how this can be either the result or cause of immune dysregulation. Further, we report how infections in PIDs enhance pathobionts colonization and speculate how, in turn, pathobionts may be responsible for increased disease susceptibility and secondary infections in these patients. The potential relationship between the microbial composition in the intestine and other sites, such as the oral cavity and skin, is also highlighted. Finally, we provide evidence, in preclinical models of PIDs, for the efficacy of microbiota manipulation to ameliorate disease complications, and suggest that the potential use of dietary intervention to correct dysbiotic flora in PID patients may hold promise.

Gastrointestinal Complications in Chronic Granulomatous Disease

Almost half of patients with chronic granulomatous disease (CGD) suffer from gastrointestinal (GI) inflammation, the pathogenesis of which is complex and multifactorial. As a result, the management of CGD-associated GI inflammation remains challenging due to its chronicity and difficulty in managing the simultaneous need for immunomodulation with increased susceptibility to infection. In order to contextualize prospective treatment interventions for CGD-associated GI inflammation, we have reviewed the clinical presentation, pathogenesis and current management of this disease. Increased understanding of the role of nicotinamide adenine dinucleotide phosphate (NADPH) oxidase complex 2 (NOX2)-derived reactive oxygen species (ROS) in inflammatory bowel disease (IBD) will likely reveal novel targets for therapeutic intervention.

Rapamycin as an Adjunctive Therapy for NLRC4 Associated Macrophage Activation Syndrome

Gain of function (GOF) mutations affecting the inflammasome component NLRC4 are known to cause early-onset macrophage activation syndrome (MAS) and neonatal enterocolitis. Here we report a patient with a NLRC4 GOF mutation presenting with neonatal MAS efficiently treated with a combination of anakinra and rapamycin. Through in vitro studies, we show that rapamycin reduces both IL-1β and IL-18 secretion by the patient's phagocytic cells. The reduction of cytokine secretion is associated with a reduction of caspase-1 activation regardless of the pathogen- or danger-associated molecular patterns triggering the activation of the inflammasome. This study suggests that patients with inherited auto-inflammatory disorders could benefit from an adjunctive therapy with rapamycin.

Production of interleukin-1β related to mammalian target of rapamycin/Toll-like receptor 4 signaling pathway during Aspergillus fumigatus infection of the mouse cornea

AIM

To elucidate the effect of rapamycin on regulating the production of interleukin (IL)-1β in Aspergillus fumigatus (A. fumigatus)-induced keratitis and to verify whether the expression of IL-1β in A. fumigatus keratitis is associated with the mammalian target of rapamycin (mTOR)/Toll-like receptor 4 (TLR4) signaling pathway.

METHODS

Fungal keratitis mouse models of susceptible C57BL/6 mice were established using A. fumigatus. The mice were subsequently treated with rapamycin. The protein levels of p-mTOR, TLR4, and IL-1β in normal and infected corneal tissue were measured by Western blot. The TLR4 and IL-1β mRNA levels were determined by real-time polymerase chain reaction (PCR).

RESULTS

In C57BL/6 mice, rapamycin treatment decreased the clinical scores and production of the pro-inflammatory cytokine, IL-1β. The expression of TLR4, stimulated by A. fumigatus, was reduced as well when the mTOR signaling pathway was suppressed by rapamycin.

CONCLUSION

Rapamycin is beneficial for the outcome of fungal keratitis and has an inhibitory effect expression of the inflammatory cytokine IL-1β. The inhibitory effect on IL-1β expression can be associated with the mTOR/TLR4 signaling pathway in A. fumigatus infection in mice.

Metabolism as a Target for Modulation in Autoimmune Diseases

Metabolic pathways are now well recognized as important regulators of immune differentiation and activation, and thus influence the development of autoimmune diseases such as systemic lupus erythematosus (SLE). The mechanistic target of rapamycin (mTOR) has emerged as a key sensor of metabolic stress and an important mediator of proinflammatory lineage specification. Metabolic pathways control the production of mitochondrial reactive oxygen species (ROS), which promote mTOR activation and also modulate the antigenicity of proteins, lipids, and DNA, thus placing ROS at the heart of metabolic disturbances during pathogenesis of SLE. Therefore, we review here the pathways that control ROS production and mTOR activation and identify targets for safe therapeutic modulation of the signaling network that underlies autoimmune diseases, focusing on SLE.

Future of Care for Patients With Chronic Granulomatous Disease: Gene Therapy and Targeted Molecular Medicine

Chronic granulomatous disease is a rare and potentially fatal disorder of neutrophil function. Beyond current medical management and hematopoietic stem cell transplantation, new methods of gene therapy that use lentiviral vectors or gene editing might extend curative therapies to patients who lack a suitable transplantation donor while eliminating the risk of graft-versus-host disease. Furthermore, new therapies focused on altering the biology of phagolysosomes might offer novel targeted treatments for inflammatory complications in patients with chronic granulomatous disease.

The Potential Role of Trained Immunity in Autoimmune and Autoinflammatory Disorders

During induction of trained immunity, monocytes and macrophages undergo a functional and transcriptional reprogramming toward increased activation. Important rewiring of cellular metabolism of the myeloid cells takes place during induction of trained immunity, including a shift toward glycolysis induced through the mTOR pathway, as well as glutaminolysis and cholesterol synthesis. Subsequently, this leads to modulation of the function of epigenetic enzymes, resulting in important changes in chromatin architecture that enables increased gene transcription. However, in addition to the beneficial effects of trained immunity as a host defense mechanism, we hypothesize that trained immunity also plays a deleterious role in the induction and/or maintenance of autoimmune and autoinflammatory diseases if inappropriately activated.

NADPH Oxidase Deficiency: A Multisystem Approach

The immune system is a complex system able to recognize a wide variety of host agents, through different biological processes. For example, controlled changes in the redox state are able to start different pathways in immune cells and are involved in the killing of microbes. The generation and release of ROS in the form of an “oxidative burst” represent the pivotal mechanism by which phagocytic cells are able to destroy pathogens. On the other hand, impaired oxidative balance is also implicated in the pathogenesis of inflammatory complications, which may affect the function of many body systems. NADPH oxidase (NOX) plays a pivotal role in the production of ROS, and the defect of its different subunits leads to the development of chronic granulomatous disease (CGD). The defect of the different NOX subunits in CGD affects different organs. In this context, this review will be focused on the description of the effect of NOX2 deficiency in different body systems. Moreover, we will also focus our attention on the novel insight in the pathogenesis of immunodeficiency and inflammation-related manifestations and on the protective role of NOX2 deficiency against the development of atherosclerosis.

Inflammatory bowel disease in chronic granulomatous disease: An emerging problem over a twenty years' experience

BACKGROUND

Chronic granulomatous disease (CGD) is a primary immunodeficiency of phagocytes, characterized by life-threatening infections and hyperinflammation. Due to survival improvement, inflammatory bowel disease (IBD) is becoming increasingly relevant. Here, we report our 20 year experience.

METHODS

We retrospectively analyzed clinic, endoscopic, and histologic features, as well as the management of CGD-IBD patients referred to the Bambino Gesù Children's Hospital in Rome, Italy.

RESULTS

Of 20 patients with CGD, 9 presented with CGD-IBD at diagnosis and/or during follow-up. Symptoms occurred at a median age of 16 years (range 3.2-42), with a median delay of 6 months for endoscopic confirmation. Patients mainly complained of nonspecific diarrhea (55%), with discrepancy between symptom paucity and severe endoscopic appearance, mainly represented by extensive colonic involvement (44%). Histology revealed at least 2 characteristic features (epithelioid granulomas, pigmented macrophages, and increased eosinophils) in 78% of patients. Eight of 9 patients received oral mesalamine, and 5 required systemic steroids. One patient received azathioprine due to steroid dependence. No patient required biological therapy or surgery. Clinical remission was obtained in all patients, but the majority complained of mild relapses. Two episodes of severe infection occurred early after steroid therapy.

CONCLUSIONS

Penetrance of CGD-IBD increases with age. Clinical manifestations may be subtle, and clinicians should have a low threshold to recommend endoscopy. Treatment with NSAIDs and/or steroids achieves a good response, but relapses usually occur. Infection surveillance is mandatory during treatment, to prevent opportunistic infections. A close collaboration between pediatric immunologists and gastroenterologists is pivotal, including combined follow-up.

Recent advances in understanding and treating chronic granulomatous disease

A number of recent advances have been made in the epidemiology and treatment of chronic granulomatous disease. Several reports from developing regions describe the presentations and progress of local populations, highlighting complications due to Bacillus Calmette-Guérin vaccination. A number of new reports describe complications of chronic granulomatous disease in adult patients, as more survivors reach adulthood. The complications experienced by X-linked carriers are particularly highlighted in three new reports, confirming that infection and inflammatory or autoimmune conditions are more common and severe than previously recognised. Finally, definitive treatment with haematopoietic stem cell transplantation and gene therapy is reviewed.