A population-based investigation of the autoantibody profile in mothers of children with atrioventricular block

The objective of the study was to investigate the antigen specificity and occurrence of individual autoantibodies in mothers of children diagnosed with atrioventricular (AV) block in a nation-wide setting. Patients with AV block detected before 15 years of age were identified using national quality registries as well as a network of pediatric and adult cardiologists and rheumatologists at the six university hospitals in Sweden. Patients with gross heart malformations, surgically or infectiously induced blocks were excluded. Blood samples were obtained from the mothers and maternal autoantibody profile, including the occurrence of antibodies against Ro52, Ro60, La, SmB, SmD, RNP-70k, RNP-A, RNP-C, CENP-C, Scl-70, Jo-1, ribosomal RNP and histones was investigated in 193 mothers of children with AV block by immunoblotting and ELISA. Autoantibody reactivity was detected in 48% (93/193) of the mothers of children with AV block. In autoantibody-positive mothers, the vast majority, 95% (88/93), had antibodies against Ro52, while 63% (59/93) had autoantibodies to Ro60 and 58% (54/93) had autoantibodies to La. In addition, 13% (12/93) of the autoantibody-positive mothers had antibodies to other investigated antigens besides Ro52, Ro60 and La, and of these anti-histone antibodies were most commonly represented, detected in 8% (7/93) of the mothers. In conclusion, this Swedish population-based study confirms that maternal autoantibodies may associate with heart block in the child. Further, our data demonstrate a dominant role of Ro52 antibodies in association with AV block.

Development and independent validation of a prognostic assay for stage II colon cancer using formalin-fixed paraffin-embedded tissue

PURPOSE

Current prognostic factors are poor at identifying patients at risk of disease recurrence after surgery for stage II colon cancer. Here we describe a DNA microarray-based prognostic assay using clinically relevant formalin-fixed paraffin-embedded (FFPE) samples.

PATIENTS AND METHODS

A gene signature was developed from a balanced set of 73 patients with recurrent disease (high risk) and 142 patients with no recurrence (low risk) within 5 years of surgery.

RESULTS

The 634-probe set signature identified high-risk patients with a hazard ratio (HR) of 2.62 (P < .001) during cross validation of the training set. In an independent validation set of 144 samples, the signature identified high-risk patients with an HR of 2.53 (P < .001) for recurrence and an HR of 2.21 (P = .0084) for cancer-related death. Additionally, the signature was shown to perform independently from known prognostic factors (P < .001).

CONCLUSION

This gene signature represents a novel prognostic biomarker for patients with stage II colon cancer that can be applied to FFPE tumor samples.

Development of heart block in children of SSA/SSB-autoantibody-positive women is associated with maternal age and displays a season-of-birth pattern

OBJECTIVE

Congenital heart block may develop in the fetuses of Ro/SSA-positive and La/SSB-positive mothers. Recurrence rates of only 10-20% despite persisting maternal antibodies indicate that additional factors are critical for the establishment of heart block. The authors investigated the influence of other maternal and fetal factors on heart block development in a Swedish population-based cohort.

METHODS

The influence of fetal gender, maternal age, parity and time of birth on heart block development was analysed in 145 families, including Ro/La-positive (n=190) and Ro/La-negative (n=165) pregnancies.

RESULTS

There was a recurrence rate of 12.1% in Ro/La-positive women, and no recurrence in Ro/La-negative women. Fetal gender and parity did not influence the development of heart block in either group. Maternal age in Ro/La-positive pregnancies with a child affected by heart block was, however, significantly higher than in pregnancies resulting in babies without heart block (p<0.05).Seasonal timing of pregnancy influenced the outcome. Gestational susceptibility weeks 18-24 occurring during January-March correlated with a higher proportion of children with heart block and lower vitamin D levels during the same period in a representative sample of Swedish women and a corresponding higher proportion of children with heart block born in the summer (p<0.02). Maternal age or seasonal timing of pregnancy did not affect the outcome in Ro/La-negative pregnancies.

CONCLUSION

This study identifies maternal age and seasonal timing of pregnancy as novel risk factors for heart block development in children of Ro/La-positive women. These observations may be useful for counselling when pregnancy is considered.

FOXP3 and survival in urinary bladder cancer

OBJECTIVE

To investigate the possible impact of FOXP3 expression in T-cells, as well as in tumour cells, on long-term survival in patients with urinary bladder cancer (UBC) invading muscle.

PATIENTS AND METHODS

In a retrospective study, tumour specimens from 37 patients cystectomized for T1-T4 UBC during 1999-2002 at the Karolinska University Hospital were examined by immunohistochemistry for tumour expression and/or infiltration of immune cells expressing FOXP3 as well as CD3. The results obtained were correlated with clinicopathological parameters, where the primary and secondary outcomes investigated were overall survival and progression-free survival, respectively.

RESULTS

Infiltration of CD3(+) and FOXP3(+) lymphocytes (≥3 cells per high-power field) were both correlated with better survival, and this relationship persisted throughout the whole study period (all P < 0.05). Patients with FOXP3(+) tumour cells had decreased long-term survival compared to those patients with FOXP3(-) tumours (P < 0.05). Despite a limited amount of patient material, the results of the present study indicate that FOXP3 expression, in both lymphocytes and tumour cells, is an important prognostic factor in UBC.

CONCLUSIONS

FOXP3 expression in UBC cells is associated with decreased long-term survival and thus may be a novel negative prognostic factor in UBC invading muscle. By contrast, the presence of FOXP3(+) tumour-infiltrating lymphocytes was correlated with a positive prognosis. Because FOXP3 is up-regulated upon activation in human T-cells, FOXP3 may serve more as an activation marker than as a regulatory T-cell indicator in this case. These results support the need for larger prospective studies aiming to confirm the results obtained and to examine the underlying mechanisms in detail.

FOXP3 and survival in urinary bladder cancer

OBJECTIVE

To investigate the possible impact of FOXP3 expression in T-cells, as well as in tumour cells, on long-term survival in patients with urinary bladder cancer (UBC) invading muscle.

PATIENTS AND METHODS

In a retrospective study, tumour specimens from 37 patients cystectomized for T1-T4 UBC during 1999-2002 at the Karolinska University Hospital were examined by immunohistochemistry for tumour expression and/or infiltration of immune cells expressing FOXP3 as well as CD3. The results obtained were correlated with clinicopathological parameters, where the primary and secondary outcomes investigated were overall survival and progression-free survival, respectively.

RESULTS

Infiltration of CD3(+) and FOXP3(+) lymphocytes (≥3 cells per high-power field) were both correlated with better survival, and this relationship persisted throughout the whole study period (all P < 0.05). Patients with FOXP3(+) tumour cells had decreased long-term survival compared to those patients with FOXP3(-) tumours (P < 0.05). Despite a limited amount of patient material, the results of the present study indicate that FOXP3 expression, in both lymphocytes and tumour cells, is an important prognostic factor in UBC.

CONCLUSIONS

FOXP3 expression in UBC cells is associated with decreased long-term survival and thus may be a novel negative prognostic factor in UBC invading muscle. By contrast, the presence of FOXP3(+) tumour-infiltrating lymphocytes was correlated with a positive prognosis. Because FOXP3 is up-regulated upon activation in human T-cells, FOXP3 may serve more as an activation marker than as a regulatory T-cell indicator in this case. These results support the need for larger prospective studies aiming to confirm the results obtained and to examine the underlying mechanisms in detail.

The mode of actions of the Adacolumn therapeutic leucocytapheresis in patients with inflammatory bowel disease: a concise review

Patients with active inflammatory bowel disease (IBD) have elevated and activated myeloid leucocytes which infiltrate the colonic mucosa in vast numbers. Myeloid leucocytes such as the CD14(+) CD16(+) monocytes are major sources of tumour necrosis factor (TNF)-α, and therefore selective granulocyte/monocyte (GM) adsorption (GMA) should promote remission or enhance efficacy of pharmacological therapy. However, studies in IBD have reported both impressive as well as disappointing efficacy outcomes, indicating that patients' demographic factors might determine responders or non-responders to GMA. Nonetheless, this non-drug intervention has an excellent safety profile, and therapeutic GMA is expected to expand. In this review, attempts have been made to compile an update on the mode of actions (MoA) of the Adacolumn GMA. The MoA of GMA appears to be more than adsorption of excess neutrophils and TNF-producing CD14(+) CD16(+) monocytes per se. Adsorbed GMs release interleukin (IL)-1 receptor antagonist, hepatocyte growth factor and soluble TNF receptors, which are anti-inflammatory. Additionally, a sustained increase in lymphocytes including the regulatory CD4(+) CD25(+) T cells (lymphocyte sparing) is seen post-GMA. The impact of GMA on the immune system is potentially very interesting in the context of treating immune-related diseases. Future studies are expected to add intriguing insights to the MoA of GMA.

The mode of actions of the Adacolumn therapeutic leucocytapheresis in patients with inflammatory bowel disease: a concise review

Patients with active inflammatory bowel disease (IBD) have elevated and activated myeloid leucocytes which infiltrate the colonic mucosa in vast numbers. Myeloid leucocytes such as the CD14(+) CD16(+) monocytes are major sources of tumour necrosis factor (TNF)-α, and therefore selective granulocyte/monocyte (GM) adsorption (GMA) should promote remission or enhance efficacy of pharmacological therapy. However, studies in IBD have reported both impressive as well as disappointing efficacy outcomes, indicating that patients' demographic factors might determine responders or non-responders to GMA. Nonetheless, this non-drug intervention has an excellent safety profile, and therapeutic GMA is expected to expand. In this review, attempts have been made to compile an update on the mode of actions (MoA) of the Adacolumn GMA. The MoA of GMA appears to be more than adsorption of excess neutrophils and TNF-producing CD14(+) CD16(+) monocytes per se. Adsorbed GMs release interleukin (IL)-1 receptor antagonist, hepatocyte growth factor and soluble TNF receptors, which are anti-inflammatory. Additionally, a sustained increase in lymphocytes including the regulatory CD4(+) CD25(+) T cells (lymphocyte sparing) is seen post-GMA. The impact of GMA on the immune system is potentially very interesting in the context of treating immune-related diseases. Future studies are expected to add intriguing insights to the MoA of GMA.

Maternal MHC regulates generation of pathogenic antibodies and fetal MHC-encoded genes determine susceptibility in congenital heart block

Congenital heart block develops in fetuses of anti-Ro52 Ab-positive women. A recurrence rate of 20%, despite the persistence of maternal autoantibodies, indicates that there are additional, yet unidentified, factors critical for development of congenital heart block. In this study, we demonstrate that besides the maternal MHC controlling Ab specificity, fetal MHC-encoded genes influence fetal susceptibility to congenital heart block. Using MHC congenic rat strains, we show that heart block develops in rat pups of three strains carrying MHC haplotype RT1(av1) (DA, PVG.AV1, and LEW.AV1) after maternal Ro52 immunization, but not in LEW rats (RT1(l)). Different anti-Ro52 Ab fine specificities were generated in RT1(av1) versus RT1(l) animals. Maternal and fetal influence was determined in an F(2) cross between LEW.AV1 and LEW strains, which revealed higher susceptibility in RT1(l) than RT1(av1) pups once pathogenic Ro52 Abs were present. This was further confirmed in that RT1(l) pups more frequently developed heart block than RT1(av1) pups after passive transfer of RT1(av1) anti-Ro52 sera. Our findings show that generation of pathogenic Ro52 Abs is restricted by maternal MHC, whereas the fetal MHC locus regulates susceptibility and determines the fetal disease outcome in anti-Ro52-positive pregnancies.

Evidence for immunosurveillance in intestinal premalignant lesions

The immunosurveillance theory argues that the immune system recognizes tumour-specific antigens expressed by transformed cells, which results in the destruction of cancer precursors before they become clinically manifest. As a model for the development of cancer, we set out to study premalignant lesions and immune responses in sentinel lymph nodes from patients with long-standing ulcerative colitis and progression of mucosal dysplasia. Mesenteric lymph nodes draining dysplastic and normal intestinal segments were identified by sentinel node technique during surgery in 13 patients with ulcerative colitis who were subjected to colectomy because of intestinal dysplasia. T cells were extracted from the lymph nodes and analysed by flow cytometry, and lymphocyte proliferation assays were set up in the presence of extracts from dysplastic and normal intestinal mucosa. Increase in CD4/CD8 ratio was observed in sentinel lymph nodes draining dysplastic epithelium compared to normal mucosa. The increase in CD4(+) T cells in relation to CD8(+) T cells correlated with the degree of dysplasia reflected by a significant increase in the ratio against low-grade dysplasia compared to indefinite dysplastic lesions. The T-cell response was specific to antigens from dysplastic epithelial lining as seen in proliferation assays. The observation suggests an important surveillance role for the immune system against premalignant intestinal lesions in patients with long-standing ulcerative colitis.

AIRE deficiency leads to impaired iNKT cell development

Autoimmune Polyendocrine Syndrome type I (APS I) is caused by mutations in the Autoimmune Regulator gene (AIRE), and results in the immunological destruction of endocrine organs. Herein we have characterized the CD1d-restricted invariant NKT cells (iNKT) and NK cells in APS I patients and Aire(-/-) mice, two cell populations known to play a role in the regulation of autoimmune disease. We show that the frequency of circulating iNKT cells is reduced in APS I patients compared to healthy controls. In accordance with this, iNKT cells are significantly reduced in the thymus and peripheral organs of Aire(-/-) mice. Bone marrow transfer from wild type donors into lethally irradiated Aire(-/-) recipients led to a decreased iNKT cell population in the liver, suggesting an impaired development of iNKT cells in the absence of Aire expression in radio-resistant cells. In contrast to the iNKT cells, both conventional NK cells and thymus-derived NK cells were unaffected by Aire deficiency and differentiated normally in Aire(-/-) mice. Our results show that expression of Aire in radio-resistant cells is important for the development of iNKT cells, whereas NK cell development and function does not depend on Aire.

Pilot study of sentinel-node-based adoptive immunotherapy in advanced colorectal cancer

Background

Despite optimal surgical treatment and modern adjuvant therapies, 50% of patients diagnosed with colorectal cancer die within 5 years. Immunotherapy offers an appealing complement to traditional chemotherapy, with possible long-term protection against tumor recurrences through immunological memory. We have conducted a pilot study of a novel adoptive immunotherapy, using autologous, in vitro expanded lymphocytes isolated from the tumor-draining sentinel lymph node.

Study Design

Sentinel nodes were recovered from 16 patients with disseminated or locally advanced, high-risk colorectal cancer. Single-cell suspensions of sentinel-node-acquired lymphocytes were clonally expanded in vitro in the presence of autologous tumor extract and returned as a transfusion. Patients were followed with clinical and radiological evaluations. Long-term survival was compared with traditionally treated controls.

Results

Sentinel-node-acquired CD4⁺ Th1-lymphocytes could be clonally expanded in vitro and safely administered to all 16 patients without side-effects. In four out of nine stage IV patients, complete tumor regression occurred. Median survival time in the stage IV patients (n = 9) was 2.6 years, as compared with 0.8 years in conventionally treated controls. A dose-dependent effect with regards to reduced tumor burden and long-term survival was observed.

Conclusion

Sentinel-node-based adoptive immunotherapy is feasible; the method has shown no apparent side-effects and appears to convey therapeutic antitumor effects. Further studies are justified to determine its efficacy and precise role in the treatment of colorectal cancer.

Autoimmune adrenal insufficiency: recognition and management

The main cause of Addison's disease is an autoimmune organ-specific destruction of the cells in the adrenal cortex by an autoreactive process of activated immune cells directed against the steroid-synthesising enzyme 21-hydroxylase. The diagnosis of Addison's disease is suspected in a patient presenting with symptoms of fatigue, bodyweight loss, anorexia, salt craving, and signs of low blood pressure and hyperpigmentation of the skin. Laboratory findings include electrolyte disturbances, and typically an elevated serum potassium level and sometimes a low serum sodium level is found together with low plasma levels of basal and corticotropin-stimulated hydrocortisone (cortisol). An aetiological diagnosis can rapidly be made using commercially available assays demonstrating the presence of autoantibodies directed against 21-hydroxylase. Determination of 21-hydroxylase autoantibodies also permits early diagnosis before a complete adrenocortical destruction has occurred. Thus, a window of opportunity for an early immunomodulatory intervention therapy may exist. Patients presenting with an acute adrenocortical crisis should be treated with 100mg of hydrocortisone and saline intravenously without awaiting laboratory results. Maintenance therapy includes substitution of glucocorticoid and mineralocorticoid steroids, using divided and lower total dosages of glucocorticoids than previously used.

SOCS2 influences LPS induced human monocyte-derived dendritic cell maturation

Dendritic cells (DCs) are highly specific antigen presenting cells, which link innate and adaptive immune responses and participate in protecting hosts from invading pathogens. DCs can be generated in vitro by culturing human monocytes with GM-CSF and IL-4 followed by LPS induced DC maturation. We set out to study the suppressor of cytokine signaling (SOCS) proteins during maturation and activation of human monocyte-derived DCs from peripheral blood in vitro. We found that the expression of SOCS2 mRNA and protein is dramatically up-regulated during DC maturation. Silencing of SOCS2 using siRNA, inhibited DC maturation as evidenced by a decreased expression of maturation markers such as CD83, co-stimulatory molecules CD40, CD86 and HLA-DR. Furthermore, silencing of SOCS2 decreased LPS induced activation of MAP kinases (SAKP/JNK, p38, ERK), IRF3, decreased the translocation of the NF-kappaB transcription factor and reduced downstream gene mRNA expression. These results suggest a role for SOCS2 in the MyD88-dependent and -independent TLR4 signaling pathways. In conclusion, our results demonstrate that SOCS2 is required for appropriate TLR4 signaling in maturating human DCs via both the MyD88-dependent and -independent signaling pathway.

IL-18 skews the invariant NKT-cell population via autoreactive activation in atopic eczema

Atopic eczema (AE) is a chronic relapsing inflammatory skin disease where the commensal yeast Malassezia can act as a microbial trigger factor. Malassezia activates human DC to produce IL-18, an innate cytokine that is elevated in serum of AE patients; however, the precise role of IL-18 in human AE etiology is unknown. Herein, we investigated the effect of IL-18 on the human invariant NKT (iNKT) cell compartment in AE. We found that IL-18 was a potent activator of human iNKT-cells and promoted a pro-inflammatory CD1d-dependent response, even in the absence of exogenous ligands. Chronic activation via IL-18 on the other hand was inhibitory and skewed the iNKT-cell pool by selectively suppressing CD4(+) iNKT-cells. This was mimicked in AE patients where the proportion of CD4(+) iNKT-cells was reduced in peripheral blood and coincided with elevated plasma levels of IL-18. Furthermore, a reduced CD4(+) iNKT-cell pool was associated with elevated IgE levels in plasma, and the plasma levels of IL-18 correlated with both total IgE and disease severity in the AE patients. Based on these findings, we propose that IL-18-mediated activation and subsequent dysregulation of the CD1d-restricted iNKT-cells plays a role in the pathogenesis of human AE.

Serologic follow-up of children born to mothers with Ro/SSA autoantibodies

Neonatal lupus erythematosus (NLE) develops in foetuses of mothers with Ro/SSA and La/SSB antibodies and may include foetal atrioventricular block and dermatologic manifestations. In this study, we investigated postnatal Ro and La IgG, IgA and IgM antibody levels up to 1 year of age in 32 children born to Ro/SSA positive mothers. Antibody levels were correlated with NLE manifestations, and the role of breast feeding in transfer of autoantibodies from mother to child was evaluated. Ro52, Ro60 and La IgG antibodies all transferred from the mothers to their foetus in utero and were present in the infant at birth as detected by enzyme-linked immunosorbent assay using recombinant antigens and a synthetic peptide. A significant decrease in Ro52, Ro60 and La IgG autoantibody levels of the infants was observed from birth to 4-5 weeks of age (P < 0.05, P < 0.05 and P < 0.01). Ro- and La-specific IgA and IgM antibodies were detected in the serum from a subset of mothers. However, Ro- and La-specific IgA and IgM antibody levels were low or non-detectable in children raised both with and without breastfeeding. Furthermore, NLE skin lesions developed independently of breastfeeding. Our findings support a role for placental materno-foetal transfer of IgG autoantibodies in the pathogenesis of NLE and indicate that refraining from breastfeeding does not protect from NLE skin involvement.

Loss of the lupus autoantigen Ro52/Trim21 induces tissue inflammation and systemic autoimmunity by disregulating the IL-23-Th17 pathway

Ro52/Trim21 is targeted as an autoantigen in systemic lupus erythematosus and Sjögren's syndrome. Polymorphisms in the Ro52 gene have been linked to these autoimmune conditions, but the molecular mechanism by which Ro52 may promote development of systemic autoimmune diseases has not been explored. To address this issue, we generated Ro52-null mice (Ro52^−/−), which appear phenotypically normal if left unmanipulated. However, Ro52^−/− mice develop severe dermatitis extending from the site of tissue injury induced by ear tags. The affected mice further develop several signs of systemic lupus with hypergammaglobulinemia, autoantibodies to DNA, proteinuria, and kidney pathology. Ro52, which was recently identified as an E3 ligase, mediates ubiquitination of several members of the interferon regulatory factor (IRF) family, and the Ro52-deficient mice have an enhanced production of proinflammatory cytokines that are regulated by the IRF transcription factors, including cytokines involved in the Th17 pathway (interleukin [IL] 6, IL-12/IL-23p40, and IL-17). Loss of IL-23/IL-17 by genetic deletion of IL-23/p19 in the Ro52^−/− mice conferred protection from skin disease and systemic autoimmunity. These data reveal that the lupus-associated Ro52 protein is an important negative regulator of proinflammatory cytokine production, and they provide a mechanism by which a defective Ro52 function can lead to tissue inflammation and systemic autoimmunity through the IL-23–Th17 pathway.

At the crossroads of T helper lineage commitment-Epigenetics points the way

The immune system has the capacity to respond to various types of pathogens including bacteria, viruses, tumors and parasites. This requires a flexible immune system, which in part depends on the development of alternative effector T helper cells, with different cytokine repertoires that direct the overall immune response. The reciprocal effects of the T helper subtypes Th1 and Th2 are well documented, but the mechanisms involved in alternative cytokine expression and silencing are less well defined. Introduction of advances within the field of chromatin folding and epigenetic regulation of transcription has begun to explain some of the fundamental principles of T helper cell development. In addition, epigenetic regulation has proven essential also for the more recently discovered T helper cell subtypes; regulatory T cells and the Th17 lineage. As the importance of proper epigenetic regulation becomes evident, attention is also focused on the potential harmfulness of epigenetic dysregulation. Autoimmunity and allergy are two clinical situations that have been implicated as results of imperfect cytokine silencing. This review will address recent advances in the field of epigenetic regulation of T lymphocytes and their maturation from naive cells into different effector T cell lineages. In particular, epigenetic involvement in regulation of key effector cytokines and specific transcription factors determining the CD4(+) T lymphocyte lineage commitment will be discussed.

AIRE regulates T-cell-independent B-cell responses through BAFF

Autoimmune polyendocrine syndrome type I (APS I) results in multiple endocrine organ destruction and is caused by mutations in the autoimmune regulator gene (AIRE). APS I is characterized by circulating tissue-specific autoantibodies, and the presence of these antibodies is often predictive of organ destruction. The importance of AIRE in ensuring central tolerance by regulating the negative selection of autoreactive T cells has been shown clearly. However, in Aire(-/-) mice the phenotype (i.e., autoantibodies, liver infiltrates of B cells, splenomegaly, and marginal zone B-cell lymphoma) is predominantly B-cell mediated, suggesting an exaggerated activation of B cells. We have studied T-cell-independent B-cell responses in the absence of AIRE and found that Aire(-/-) mice have an increased response against T-cell-independent type II antigens. We linked this exaggerated response to the elevated serum levels of the B-cell-activating factor of the TNF family (BAFF) that were found both in APS I patients and in Aire(-/-) mice. Transfer of Aire(-/-) bone marrow into irradiated nude mice resulted in increased percentage of BAFF-expressing antigen-presenting cells compared with wt bone marrow, suggesting a T-cell-independent mechanism behind our findings. Furthermore, in vitro experiments showed that AIRE-deficient murine bone marrow-derived dendritic cells produced significantly more BAFF than wt cells when stimulated with IFN-gamma but not when stimulated with IL-10. Our results suggest a cell-intrinsic role for AIRE in peripheral dendritic cells by regulating IFN-gamma-receptor signaling and point toward complementary mechanisms by which AIRE is involved in maintaining tolerance.