The spectrum of autoantibodies in IPEX syndrome is broad and includes anti-mitochondrial autoantibodies

IPEX syndrome is a congenital disorder of immune regulation caused by mutations in the FOXP3 gene, which is required for the suppressive function of naturally arising CD4 + CD25 + regulatory T cells. In this case series we evaluated serum samples from 12 patients with IPEX syndrome for the presence of common autoantibodies associated with a broad range of autoimmune disorders. We note that 75% of patients (9/12) had 1 or more autoantibodies, an incidence far above the cumulative rate observed in the general population. The range of autoantibodies differed between patients and there was no predominant autoantibody or pattern of autoantibodies present in this cohort. Surprisingly, one patient had high-titer anti-mitochondrial antibodies (AMA) typically associated with primary biliary cirrhosis (PBC) although the patient had no signs of cholestasis. PBC is a well-characterized autoimmune disease that occurs primarily in women and includes the serological hallmarks of serum AMA and elevated IgM which were both present in this patient. PBC is virtually absent in children with the exception of one reported child with interleukin 2 receptor a (CD25) deficiency which is associated with an IPEX-like regulatory T cell dysfunction. Based on the present data and the available literature we suggest a direct role for CD4 + CD25 + regulatory T cells in restraining B cell autoantibody production and that defects in regulatory T cells may be crucial to the development of PBC. (C) 2010 Elsevier Ltd. All rights reserved.

Decreased AIRE Expression and Global Thymic Hypofunction in Down Syndrome

The Down syndrome (DS) immune phenotype is characterized by thymus hypotrophy, higher propensity to organ-specific autoimmune disorders, and higher susceptibility to infections, among other features. Considering that AIRE (autoimmune regulator) is located on 21q22.3, we analyzed protein and gene expression in surgically removed thymuses from 14 DS patients with congenital heart defects, who were compared with 42 age-matched controls with heart anomaly as an isolated malformation. Immunohistochemistry revealed 70.48 +/- 49.59 AIRE-positive cells/mm(2) in DS versus 154.70 +/- 61.16 AIRE-positive cells/mm(2) in controls (p < 0.0001), and quantitative PCR as well as DNA microarray data confirmed those results. The number of FOXP3-positive cells/mm(2) was equivalent in both groups. Thymus transcriptome analysis showed 407 genes significantly hypoexpressed in DS, most of which were related, according to network transcriptional analysis (FunNet), to cell division and to immunity. Immune response-related genes included those involved in 1) Ag processing and presentation (HLA-DQB1, HLA-DRB3, CD1A, CD1B, CD1C, ERAP) and 2) thymic T cell differentiation (IL2RG, RAG2, CD3D, CD3E, PRDX2, CDK6) and selection (SH2D1A, CD74). It is noteworthy that relevant AIRE-partner genes, such as TOP2A, LAMNB1, and NUP93, were found hypoexpressed in DNA microarrays and quantitative real-time PCR analyses. These findings on global thymic hypofunction in DS revealed molecular mechanisms underlying DS immune phenotype and strongly suggest that DS immune abnormalities are present since early development, rather than being a consequence of precocious aging, as widely hypothesized. Thus, DS should be considered as a non-monogenic primary immunodeficiency. The Journal of Immunology, 2011, 187: 3422-3430.

Increased circulating pro-inflammatory cytokines and imbalanced regulatory T-cell cytokines production in chronic idiopathic urticaria

The immunologic characterization of chronic idiopathic urticaria (CIU), mainly regarding cytokine profile needs more investigation. We examined circulating inflammatory cytokine levels, T-cell induced secretion, and cytokine mRNA expression in patients with CIU subjected to the intradermal autologous serum skin test (ASST). Increased levels of circulating pro-inflammatory cytokines, such as TNF-alpha, IL-1 beta, IL-12p70, and IL-6 have been observed in most of patients with CIU, together with an enhancement of IL-2 secretion following T-cell stimulation. Highlighting the inflammatory profile in CIU found in ASST positive, is the enhanced B-cell proliferative responsiveness and increased IL-17 secretion levels. ASST-positive patients also exhibited impaired IL-4 secretion associated with increased IL-10 production. Altered cytokine expression in patients with ASST-negative, was the down-modulation of spontaneous IL-10 mRNA expression levels in peripheral blood mononuclear cells. Our findings support the concept of immunologic dysregulation in CIU, revealing a systemic inflammatory profile associated with disturbed cytokine production by T cells, mainly related to IL-17 and IL-10 production. (c) 2008 Elsevier B.V. All rights reserved.

Oral tolerance reduces Th17 cells as well as the overall inflammation in the central nervous system of EAE mice

Multiple sclerosis (MS) is an autoimmune disease characterized by inflammatory immune response directed against myelin antigens of the central nervous system. In its murine model, EAE, Th17 cells play an important role in disease pathogenesis. These cells can induce blood-brain barrier disruption and CNS immune cells activation, due to the capacity to secrete high levels of IL-17 and IL-22 in an IL-6 + TGF-beta dependent manner. Thus, using the oral tolerance model, by which 200 mu g of MOG 35-55 is given orally to C57BL/6 mice prior to immunization, we showed that the percentage of Th17 cells as well as IL-17 secretion is reduced both in the periphery and also in the CNS of orally tolerated animals. Altogether, our data corroborates with the pathogenic role of IL-17 and IFN-gamma in EAE, as its reduction after oral tolerance, leads to an overall reduction of pro-inflammatory cytokines, such as IL-1 alpha, IL-6, IL-9, IL-12p70 and the chemokines MIP-1 beta, RANTES, Eotaxin and KC in the CNS. It is noteworthy that this was associated to an increase in IL-10 levels. Thus, our data clearly show that disease suppression after oral tolerance induction, correlates with reduction in target organ inflammation, that may be caused by a reduced Th1/Th17 response. Crown Copyright (c) 2010 Published by Elsevier B.V. All rights reserved.

Familial neuromyelitis optica

Background: Detection of aquaporin-4-specific immunoglobulin G (IgG) has expanded the spectrum of neuromyelitis optica (NMO). Rare reports of familial aggregation have suggested a component of genetic susceptibility but these reports mostly antedated the discovery of the NMO-IgG biomarker and recently updated diagnostic criteria. Methods: We report a case series describing the demographic, clinical, neuroimaging, and NMO-IgG serologic status of 12 multiplex NMO pedigrees with a total of 25 affected individuals. Results: Twenty-one patients (84%) were women. Families were Asian (n = 5), Latino (n = 4), white (n = 1), or African (n = 2). Apparent transmission was either maternal (n = 5) or paternal (n = 2). In 1 family, 3 individuals had NMO; in the others, 2 individuals were affected. Sibling pairs (n = 6), parent-child (n = 4), and aunt-niece (n = 3) pairs were observed. Nineteen patients (76%) were NMO-IgG positive. Twelve (48%) had clinical or serologic evidence of another autoimmune disease. Familial occurrence of NMO occurs in approximately 3% of patients with well-established diagnosis of NMO. Conclusions: A small proportion of patients with NMO have relatives with this condition, but familial occurrence is more common than would be expected from its frequency in the general population. Familial NMO is indistinguishable from sporadic NMO based on clinical symptoms, age at onset, sex distribution, and frequency of NMO-IgG detection. One or 2 generations were affected and affected individuals represented a small fraction of family members. Taken together, these data suggest complex genetic susceptibility in NMO. Neurology (R) 2010;75:310-315

Anti-Ro antibody and cutaneous vasculitis in systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is a complex systemic autoimmune disease with various clinical and serological manifestations. Previous studies have shown the association of SLE and anti-Ro antibody with a series of clinical manifestations. We investigated this association in Brazilian patients with SLE. Five hundred and nine consecutive patients who fulfilled the revised American College of Rheumatology criteria for the SLE were enrolled in the study from June to December 2007. All patients were from our Service of Rheumatology, School of Medicine, University of Sao Paulo, Brazil. Frequencies of a series of laboratorial and clinical manifestations were calculated. Anti-Ro antibody was associated to anti-La antibody, female, and cutaneous vasculitis. In multivariate analysis, patients with anti-Ro antibody has 1.63 (95% CI 1.07-2.50) more risk to develop cutaneous vasculitis than patients without this antibody. Our data have demonstrated that anti-Ro antibody is an independent useful serologic marker for cutaneous vasculitis.

Pediatric Antiphospholipid Syndrome: Clinical and Immunologic Features of 121 Patients in an International Registry

OBJECTIVES. The purpose of this study was to obtain data on the association of antiphospholipid antibodies with clinical manifestations in childhood and to enable future studies to determine the impact of treatment and long-term outcome of pediatric antiphospholipid syndrome. PATIENTS AND METHODS. A European registry extended internationally of pediatric patients with antiphospholipid syndrome was established as a collaborative project of the European Antiphospholipid Antibodies Forum and Lupus Working Group of the Pediatric Rheumatology European Society. To be eligible for enrollment the patient must meet the preliminary criteria for the classification of pediatric antiphospholipid syndrome and the onset of antiphospholipid syndrome must have occurred before the patient`s 18th birthday. RESULTS. As of December 1, 2007, there were 121 confirmed antiphospholipid syndrome cases registered from 14 countries. Fifty-six patients were male, and 65 were female, with a mean age at the onset of antiphospholipid syndrome of 10.7 years. Sixty (49.5%) patients had underlying autoimmune disease. Venous thrombosis occurred in 72 (60%), arterial thrombosis in 39 (32%), small-vessel thrombosis in 7 (6%), and mixed arterial and venous thrombosis in 3 (2%). Associated nonthrombotic clinical manifestations included hematologic manifestations (38%), skin disorders (18%), and nonthrombotic neurologic manifestations (16%). Laboratory investigations revealed positive anticardiolipin antibodies in 81% of the patients, anti-beta(2)-glycoprotein I antibodies in 67%, and lupus anticoagulant in 72%. Comparisons between different subgroups revealed that patients with primary antiphospholipid syndrome were younger and had a higher frequency of arterial thrombotic events, whereas patients with antiphospholipid syndrome associated with underlying autoimmune disease were older and had a higher frequency of venous thrombotic events associated with hematologic and skin manifestations. CONCLUSIONS. Clinical and laboratory characterization of patients with pediatric antiphospholipid syndrome implies some important differences between antiphospholipid syndrome in pediatric and adult populations. Comparisons between children with primary antiphospholipid syndrome and antiphospholipid syndrome associated with autoimmune disease have revealed certain differences that suggest 2 distinct subgroups. Pediatrics 2008; 122: e1100-e1107

Regulation of type 17 helper T-cell function by nitric oxide during inflammation

Type 17 helper T (Th17) cells are implicated in the pathogenesis many of human autoimmune diseases. Development of Th17 can be enhanced by the activation of aryl hydrocarbon receptor (AHR) whose ligands include the environmental pollutant dioxin, potentially linking environmental factors to the increased prevalence of autoimmune disease. We report here that nitric oxide (NO) can suppress the proliferation and function of polarized murine and human Th17 cells. NO also inhibits AHR expression in Th17 cells and the downstream events of AHR activation, including IL-22, IL-23 receptor, and Cyp1a1. Conversely, NO did not affect the polarization of Th17 cells from mice deficient in AHR. Furthermore, mice lacking inducible nitric oxide synthase (Nos2(-/-)) developed more severe experimental autoimmune encephalomyelitis than WT mice, with elevated AHR expression, increased IL-17A, and IL-22 synthesis. NO may therefore represent an important endogenous regulator to prevent overexpansion of Th17 cells and control of autoimmune diseases caused by environmental pollutants.

Protective effect of an extract from Ascaris suum in experimental arthritis models

We investigated the effect of an extract from a helminth (Ascaris suum) in zymosan-induced arthritis (ZYA) or collagen-induced arthritis (CIA). Rats and mice, respectively, received 1 mg and 0.1 mg zymosan intra-articularly (i.a.). Test groups received an A. suum extract either per os (p.o.) or intraperitoneally (i.p.) 30 min prior to i.a. zymosan. Controls received saline. Hypernociception was measured using the articular incapacitation test. Cell influx, nitrite, and cytokine levels were assessed in joint exudates. The synovia and distal femoral extremities were used for histopathology. Cartilage damage was assessed through determining glycosaminoglycan (GAG) content. DBA/1J mice were subjected to CIA. The test group received A. suum extract i.p. 1 day after CIA became clinically detectable. Clinical severity and hypernociception were assessed daily. Neutrophil influx was determined using myeloperoxidase activity. The A. suum extract, either i.p. or p.o., significantly and dose-dependently inhibited cell influx and hypernociception in ZYA in addition to reducing GAG loss and ameliorating synovitis. The A. suum extract reduced i.a. levels of NO, interleukin-1 beta (IL-1 beta), and IL-10 but not tumor necrosis factor alpha (TNF-alpha) in rats subjected to ZYA while reducing i.a. IL-10, but not IL-1 beta or TNIT-alpha, levels in mice. Clinically, mice subjected to CIA treated with the A. suum extract had less severe arthritis. Hypernociception, myeloperoxidase activity, and synovitis severity were significantly reduced. These data show that a helminth extract given p.o. protects from arthritis severity in two classical arthritis models. This A. suum effect is species independent and functions orally and parenterally. The results show clinical and structural benefits when A. suum extract is given either prophylactically or therapeutically.

Dry eye in childhood: Epidemiological and clinical aspects

Because dry eye disease is rare in children and its pathogenesis is less well known than in adults, its diagnosis is often overlooked. It can occur in association with a number of congenital, autoimmune, endocrine, and inflammatory disorders, or under certain environmental and nutritional conditions. In some cases, early detection allows the underlying cause of the dry eye to be successfully treated and eliminated. In other cases, the disease may represent a lifelong problem, whose proper management can prevent ulceration and scarring of the ocular surface. Because of the association of pediatric dry eye with other conditions, a multidisciplinary approach to diagnosis and treatment is usually required. The purpose of this review is to enhance physician awareness of dry eye in children, to describe the most frequently associated conditions, and to discuss the diagnostic and therapeutic options available.

The Immunomodulatory Action of Sialostatin L on Dendritic Cells Reveals Its Potential to Interfere with Autoimmunity

Sialostatin L (SialoL) is a secreted cysteine protease inhibitor identified in the salivary glands of the Lyme disease vector Ixodes scapularis. In this study, we reveal the mechanisms of SialoL immunomodulatory actions on the vertebrate host. LPS-induced maturation of dendritic cells from C57BL/6 mice was significantly reduced in the presence of SialoL. Although OVA degradation was not affected by the presence of SialoL in dendritic cell cultures, cathepsin S activity was partially inhibited, leading to an accumulation of a 10-kDa invariant chain intermediate in these cells. As a consequence, in vitro Ag-specific CD4(+) T cell proliferation was inhibited in a time-dependent manner by SialoL, and further studies engaging cathepsin S(-/-) or cathepsin L(-/-) dendritic cells confirmed that the immunomodulatory actions of SialoL are mediated by inhibition of cathepsin S. Moreover, mice treated with SialoL displayed decreased early T cell expansion and recall response upon antigenic stimulation. Finally, SialoL administration during the immunization phase of experimental autoimmune encephalomyelitis in mice significantly prevented disease symptoms, which was associated with impaired IFN-gamma and IL-17 production and specific T cell proliferation. These results illuminate the dual mechanism by which a human disease vector protein modulates vertebrate host immunity and reveals its potential in prevention of an autoimmune disease. The Journal of Immunology, 2009, 182: 7422-7429.

Leptin and the Immune Response An Active Player or an Innocent Bystander?

Leptin is involved in the control of energy storage by the body. Low serum leptin levels, as seen in starvation, are associated with impaired inflammatory T cell responses that can be reversed by exogenous leptin. Common variable immunodeficiency (CVID) is characterized by hypogammaglobulinemia and recurrent infections. Several defects in T cell function have also been described, and allergy, autoimmune disease, and lymphomas or other malignancies can be present. Previous studies in Brazilian CVID patients have shown that, in contrast with mononuclear cells from healthy controls, CVID cells cultured with phytohemagglutinin and added leptin increased the proliferative response and decreased activation-induced apoptosis. Interleukin (IL)-2 and especially IL-4 production also increased significantly, although the effects of exposure to leptin were not observed uniformly in CVID patients. The majority, however, responded in some degree, and some exhibited completely restored values of the four parameters. These remarkable results indicate leptin could be used to improve immune function in these patients. On the other hand, we found no specific correlation between serum leptin levels and the number of infectious events over a 24-month period, presence of autoimmunity, allergies, or cancer in these patients. The results suggest that the absolute value of serum leptin does not determine the clinical behavior of patients or responses to leptin in vitro. Of note is the divergence between serum leptin, response to leptin in vitro, and the presence of autoimmunity, indicating the need to identify the cellular and molecular players involved in the regulation of the immune response by leptin in CVID.

Allogeneic apoptotic thymocyte-stimulated dendritic cells expand functional regulatory T cells

P>Dendritic cells (DCs) play an important role in the clearance of apoptotic cells. The removal of apoptotic cells leads to peripheral tolerance, although their role is still not clear. We show that the uptake of apoptotic thymocytes by DCs converts these cells into tolerogenic DCs resistant to maturation by lipopolysaccharide, modulating the production of interleukin-12 and up-regulating the expression of transforming growth factor-beta(1) latency associated peptide. We also observed that DCs pulsed with apoptotic cells in the allogeneic context were more efficient in the expansion of regulatory T cells (Tregs), and that this expansion requires contact between DCs and the T cell. The Tregs sorted from in vitro culture suppressed the proliferation of splenocytes in vitro in a specific and non-specific manner. In the in vivo model, the transfer of CD4+ CD25- cells to Nude mice induced autoimmunity, with cell infiltrate found in the stomach, colon, liver and kidneys. The co-transfer of CD4+ CD25- and CD4+ CD25+ prevented the presence of cell infiltrates in several organs and increased the total cell count in lymph nodes. Our data indicate that apoptotic cells have an important role in peripheral tolerance via induction of tolerogenic DCs and CD4+ CD25+ Foxp3+ cells that present regulatory functions.

Reduced frequency of CD4(+)CD25(HIGH)FOXP3(+) cells and diminished FOXP3 expression in patients with Common Variable Immunodeficiency: A link to autoimmunity?

Common Variable Immunodeficiency (CVID) is a primary immunodeficiency disease characterized by defective immunoglobulin production and often associated with autoimmunity. We used flow cytometry to analyze CD4(+)CD25(HIGH)FOXP3(+) T regulatory (Treg) cells and ask whether perturbations in their frequency in peripheral blood could underlie the high incidence of autoimmune disorders in CVID patients. In this study, we report for the first time that CVID patients with autoimmune disease have a significantly reduced frequency of CD4(+)CD25(HIGH)FOXP3(+) cells in their peripheral blood accompanied by a decreased intensity of FOXP3 expression. Notably, although CVID patients in whom autoimmunity was not diagnosed had a reduced frequency of CD4(+)CD25(HIGH)FOXP3(+) cells, FOXP3 expression levels did not differ from those in healthy controls. In conclusion, these data suggest compromised homeostasis of CD4(+)CD25(HIGH)FOXP3(+) cells in a subset of CVID patients with autoimmunity, and may implicate Treg cells in pathological mechanisms of CVID. (C) 2009 Elsevier Inc. All rights reserved.

New insights into Vogt-Koyanagi-Harada disease

Vogt-Koyanagi-Harada disease (VKH), a well-established multiorgan disorder affecting pigmented structures, is an autoimmune disorder of melanocyte proteins in genetically susceptible individuals. Several clinical and experimental data point to the importance of the effector role of CD4+ T cells and Th1 cytokines, the relevance of searching a target protein in the melanocyte, and the relevance of the HLA-DRB1*0405 in the pathogenesis of the disease. Vogt-Koyanagi-Harada disease has a benign course when early diagnosed and adequatey treated. Full-blown recurrences are rare after the acute stage of Vogt-Koyanagi-Harada disease is over. On the other hand, clinical findings, such as progressive tissue depigmentation (including sunset glow fundus) and uveitis recurrence, indicate that ocular inflammation may persist after the acute phase. Additionally, indocyanine green angiography findings suggest the presence of choroidal inflammation in eyes without clinically detectable inflammation. The aim of this paper is to review the latest research results on Vogt-Koyanagi-Harada disease pathogenesis and chronic/convalescent stages, which may help to better understand this potentially blinding disease and to improve its treatment.