Chronic granulomatous disease associated with atypical Kawasaki disease

Kawasaki Disease and Inborn Errors of Immunity: Exploring the Link and Implications

The exact etiopathogenesis of Kawasaki disease (KD), the most common childhood vasculitis, remains unknown; however, an aberrant immune response, possibly triggered by an infectious or environmental agent in genetically predisposed children, is believed to be the underlying pathogenetic mechanism. Patients with inborn errors of immunity (IEI) are predisposed to infections that trigger immune dysregulation due to an imbalance in various arms of the immune system. KD may develop as a complication in both primary and secondary immunodeficiencies. KD may occur either at disease presentation or have a later onset in IEIs. These include X-linked agammaglobulinemia (XLA), selective IgA deficiency, transient hypogammaglobulinemia of infancy; Wiskott-Aldrich syndrome (WAS), hyper IgE syndrome (HIES); chronic granulomatous disease (CGD), innate and intrinsic immunity defects, and autoinflammatory diseases, including PFAPA. Hitherto, the association between KD and IEI is confined to specific case reports and case series and, thus, requires extensive research for a comprehensive understanding of the underlying pathophysiological mechanisms. IEIs may serve as excellent disease models that would open new insights into the disease pathogenesis of children affected with KD. The current review highlights this critical association between KD and IEI supported by published literature.

Kawasaki disease and immunodeficiencies in children: case reports and literature review

Kawasaki disease (KD) has features that appear supporting an infectious cause with a secondary deranged inflammatory/autoimmune response. The association of KD in adults with human immunodeficiency virus infection and the presence of KD in patients with immunodeficiency disorders support the infectious theory. We present four KD patients associated with immunodeficiencies: one with X-linked agammaglobulinemia, one with HIV infection, and two with leukemia; one of these patients also had Down syndrome. We did a literature search to find out all reported cases of immunodeficiency with KD in children. In immunodeficiency disorders, the inability of the immune system to eradicate the pathogens coupled to an exaggerated inflammatory response, especially in chronic granulomatous disease, may lead to the development of KD. The study of patients with immunodeficiencies complicated with KD may shed light into the etiopathogenesis of the disease.

A child with X-linked agammaglobulinemia and Kawasaki disease: an unusual association

An association of X-linked agammaglobulinemia (XLA) with Kawasaki disease (KD) is very uncommon. Only two case reports are available so far in pediatric literature. Patients with XLA have recurrent infections and physical examination have absent lymph nodes and tonsils. Laboratory investigations reveal hypogammaglobulinemia and reduced or absent B cells on flow cytometry. KD is a medium vessel vasculitis. Here, we report a 12 year old boy with X-linked agammaglobulinemia on regular replacement intravenous immunoglobulin who developed KD on follow-up. This is an uncommon occurrence.

Phagocyte NADPH oxidase and specific immunity

The phagocyte NADPH oxidase NOX2 produces reactive oxygen species (ROS) and is a well-known player in host defence. However, there is also increasing evidence for a regulatory role of NOX2 in adaptive immunity. Deficiency in phagocyte NADPH oxidase causes chronic granulomatous disease (CGD) in humans, a condition that can also be studied in CGD mice. Clinical observations in CGD patients suggest a higher susceptibility to autoimmune diseases, in particular lupus, idiopathic thrombocytopenic purpura and rheumatoid arthritis. In mice, a strong correlation exists between a polymorphism in a NOX2 subunit and the development of autoimmune arthritis. NOX2 deficiency in mice also favours lupus development. Both CGD patients and CGD mice exhibit increased levels of immunoglobulins, including autoantibodies. Despite these phenotypes suggesting a role for NOX2 in specific immunity, mechanistic explanations for the typical increase of CGD in autoimmune disease and antibody levels are still preliminary. NOX2-dependent ROS generation is well documented for dendritic cells and B-lymphocytes. It is unclear whether T-lymphocytes produce ROS themselves or whether they are exposed to ROS derived from dendritic cells during the process of antigen presentation. ROS are signalling molecules in virtually any cell type, including T- and B-lymphocytes. However, knowledge about the impact of ROS-dependent signalling on T- and B-lymphocyte phenotype and response is still limited. ROS might contribute to Th1/Th2/Th17 cell fate decisions during T-lymphocyte activation and might enhance immunoglobulin production by B-lymphocytes. In dendritic cells, NOX2-derived ROS might be important for antigen processing and cell activation.

Reactive oxygen species deficiency induces autoimmunity with type 1 interferon signature

AIMS

Chronic granulomatous disease (CGD) is a primary immunodeficiency caused by mutations in the phagocyte reactive oxygen species (ROS)-producing NOX2 enzyme complex and characterized by recurrent infections associated with hyperinflammatory and autoimmune manifestations. A translational, comparative analysis of CGD patients and the corresponding ROS-deficient Ncf1(m1J) mutated mouse model was performed to reveal the molecular pathways operating in NOX2 complex deficient inflammation.

RESULTS

A prominent type I interferon (IFN) response signature that was accompanied by elevated autoantibody levels was identified in both mice and humans lacking functional NOX2 complex. To further underline the systemic lupus erythematosus (SLE)-related autoimmune process, we show that naïve Ncf1(m1J) mutated mice, similar to SLE patients, suffer from inflammatory kidney disease with IgG and C3 deposits in the glomeruli. Expression analysis of germ-free Ncf1(m1J) mutated mice reproduced the type I IFN signature, enabling us to conclude that the upregulated signaling pathway is of endogenous origin.

INNOVATION

Our findings link the previously unexplained connection between ROS deficiency and increased susceptibility to autoimmunity by the discovery that activation of IFN signaling is a major pathway downstream of a deficient NOX2 complex in both mice and humans.

CONCLUSION

We conclude that the lack of phagocyte-derived oxidative burst is associated with spontaneous autoimmunity and linked with type I IFN signature in both mice and humans.

Kawasaki disease in a girl with Turner syndrome: a remarkable association

We describe a girl with Turner syndrome, a genetic disorder of the X chromosome in a phenotypic female at increased risk of autoimmune and immunological diseases, who developed Kawasaki disease at the age of four years.

Given the possible relationship between these two disorders, we recommend suspecting Kawasaki disease in patients with Turner syndrome who present with persistent fever of unknown origin and who are not responsive to antibiotic therapy. Attention should be given to this phenomenon, as patients with Turner syndrome are themselves at higher risk of cardiovascular defects. Further studies are needed to better clarify this issue.

Kawasaki's disease: An unusual presentation

Atypical presentations of Kawasaki's disease have been described in the form of intestinal pseudo-obstruction, tonsillitis, hemorrhagic serous effusions, thrombocytopenia, and non-fulfillment of all criteria for diagnosis of Kawasaki's disease. However, presentation of Kawasaki's disease with shock and need for ionotropic support have been rarely described. We present a 4-year-old girl with Kawasaki's disease who presented with anasarca, oliguria, shock, and presence of dilated coronary arteries within 5 days of fever and responded to intravenous immunoglobulin (IVIG) and inotropic support.

Atypical and incomplete Kawasaki disease

Kawasaki disease (KD) is the most common systemic vasculitis in childhood after Henoch-Schonlein purpura, and the most common cause of acquired heart disease among children living in Western countries. Its diagnosis relies on clinical findings; laboratory tests are useful to rule out other causes of unexplained fever but are not specific for the diagnosis of KD. Numerous efforts to produce a diagnostic algorithm have been made, but without success. Expert opinion is therefore required in doubtful cases, especially those that lack classical criteria (the so-called atypical or incomplete cases). Renal, gastrointestinal, neurologic, pulmonary and ocular involvements have all been described. Infants may be at higher risk of complications since recognising manifestations of the disease might be more difficult in this group. Approaches to treatment and follow-up of KD are changing in parallel with changes in concepts of what constitutes classical and incomplete KD. Guiding this evolution is the probability that the diagnosis is actually KD, the duration of the child's illness and the desired effects of therapy. Until a gold standard for diagnosing KD is available, these therapeutic decisions will continue to be made on an individual basis.

X-linked primary immunodeficiencies as a bridge to better understanding X-chromosome related autoimmunity

Recent studies indicate that genes located on the X-chromosome play a major and unique role in autoimmunity. The fact that most X-linked primary immune deficiencies carry significant autoimmune manifestations greatly supports this notion. Autoimmunity and immune deficiency have been considered two opposite extremes resulting from immune dysregulation and failure of immune development and/or function, respectively. Growing evidence has been accumulating to indicate that autoimmune phenomena occur in patients suffering from primary immune deficiency (PID), and the molecular and cellular mechanisms that interconnect these conditions are being unraveled. The study of rare single-gene disorders associated with significant autoimmunity may shed light on the pathophysiology of more complex multifactorial and polygenic autoimmune disorders. In this regard, primary immunodeficiencies represent unique "experiments of Nature" that illustrate the critical role played by single-gene products in the development, function and homeostasis of the immune system. In this review we will focus on the clinical features and on the cellular and molecular pathophysiology of the known X-linked PID in which autoimmune manifestations are more common, in the attempt to understand what single-gene defects can teach us on the role that key immune pathways and cellular processes may play to prevent autoimmunity.

NADPH oxidase controls phagosomal pH and antigen cross-presentation in human dendritic cells

The phagocyte NADPH oxidase (NOX2) is critical for the bactericidal activity of phagocytic cells and plays a major role in innate immunity. We showed recently that NOX2 activity in mouse dendritic cells (DCs) prevents acidification of phagosomes, promoting antigen cross-presentation. In order to investigate the role of NOX2 in the regulation of the phagosomal pH in human DCs, we analyzed the production of reactive oxygen species (ROS) and the phagosomal/endosomal pH in monocyte-derived DCs and macrophages (M(diameter)s) from healthy donors or patients with chronic granulomatous disease (CGD). As expected, we found that human M(diameter)s acidify their phagosomes more efficiently than human DCs. Accordingly, the expression of the vacuolar proton ATPase (V-H(+)-ATPase) was higher in M(diameter)s than in DCs. Phagosomal ROS production, however, was also higher in M(diameter)s than in DCs, due to higher levels of gp91phox expression and recruitment to phagosomes. In contrast, in the absence of active NOX2, the phagosomal and endosomal pH decreased. Both in the presence of a NOX2 inhibitor and in DCs derived from patients with CGD, the cross-presentation of 2 model tumor antigens was impaired. We conclude that NOX2 activity participates in the regulation of the phagosomal and endosomal pH in human DCs, and is required for efficient antigen cross-presentation.

Inflammatory manifestations in chronic granulomatous disease (CGD)

Chronic granulomatous disease (CGD) is a genetically heterogeneous disease characterized by recurrent life-threatening infections with bacteria and fungi as well as dysregulated inflammatory mechanisms. CGD is caused by defects in the NADPH oxidase, the enzyme complex responsible for generation of superoxide and other reactive oxygen species (ROS) in phagocytic cells. In this review we will focus our attention on those particular inflammatory manifestations associated with CGD, their frequencies and the underlying immunologic mechanisms favoring it occurrence.