RHD maternal-fetal genotype incompatibility and schizophrenia: extending the MFG test to include multiple siblings and birth order

Rh incompatibility disease (ie Rh hemolytic disease of the fetus and newborn) has been implicated as a risk factor for schizophrenia. Here, we extend the maternal-fetal genotype incompatibility (MFG) test used in an earlier case-parent trio study that found significant evidence for an increased risk of schizophrenia in RHD MFG-incompatible children. We modify the MFG test for case-parent trios to include any number of siblings. This modified test enables us to use more of the available data from the earlier study. The increased sample size not only gives us greater power to test for MFG incompatibility but it also enables us to model the impact of previous RHD MFG-incompatible pregnancies on the relative risk of RHD MFG incompatibility in later-born siblings. This modeling is important, because RHD MFG incompatibility is a proxy for Rh incompatibility disease, and the risk of Rh incompatibility disease increases with the number of previous RHD MFG-incompatible pregnancies. The best-fitting models are consistent with the hypothesized effect that previous incompatible pregnancies increase the risk of schizophrenia due to RHD MFG incompatibility. There was significant evidence that the relative risk of schizophrenia in the second- and later-born RHD MFG-incompatible children is 1.7, consistent with earlier estimates. Our extension of the MFG test has general application to family-based studies of maternal-genotype and MFG interaction effects.     

Search for cognitive trait components of schizophrenia reveals a locus for verbal learning and memory on 4q and for visual working memory on 2q

Research to identify predisposing genes for complex diseases relying solely on clinical diagnosis is probably not ideal. Here, we analyzed genome-wide data for 168 schizophrenia families using neuropsychological variables associated with disease susceptibility, with the aid of SOLAR, a program for variance-component analysis. The linkage signal was greatly accentuated by application of the quantitative traits compared with diagnosis. We found evidence for a locus for verbal learning and memory on 4q21 (Z=3.01, Z(mp)=3.84 and empiric P=0.031 for delayed memory; Z=2.96, Z(mp)=3.4 and P=0.026 for verbal learning) and suggestive evidence for visual working memory on 2q36 (Z=2.80, Z(mp)=2.08 and P=0.093). In addition, some evidence emerged for a locus for recognition memory on 10p13, visual attention on 15q22 and executive function on 9p22 in the complete sample, as well as for delayed memory on 8q12, semantic clustering and intrusions on 1q42 and visual attention on 3p25 in the genealogically distinctive sample subsets. Of the loci linked to schizophrenia in diverse populations, in addition to the earlier mentioned regions, some evidence of linkage was observed for 2q, 6q, 7q, 11q, 13q, 14q, 18q and 22q. Our results reveal initial information on the effect of the loci associated with schizophrenia in multiple studies, and emphasize the value of trait components in the search for susceptibility loci for complex diseases.     

Angiodysplasia of cardia of stomach--a case report

Angiodysplasia of gastrointestinal tract is still thought to be an entity of unknown aetiology. This lesion is most commonly observed in elderly patients presenting with severe and persistent iron deficiency anaemia, following occult blood loss or acute episodes of haematemesis. In the stomach antral vascular ectasia is the most common presentation. We report an autopsy case of vascular ectasia in the cardia of stomach in a young patient with clinical symptoms of anaemia as the presentation and an associated secondary hemosiderosis of liver.     

Intragraft immunological events associated with EBV DNAemia in liver transplant patients

Epstein-Barr virus (EBV) may cause post-transplant lymphoproliferative disorder, but most EBV infections after liver transplantation (Ltx) are clinically silent reactivations. In this study, we investigated the intragraft immunological events associated with EBV DNAemia. Altogether, 105 adult Ltx patients were monitored for EBV DNAemia. Fourteen (13%) patients developed EBV DNAemia during the first year after transplantation. Liver biopsies obtained associated with EBV DNAemia, without evidence of other herpes or hepatitis viruses or rejection, were available from five patients. The numbers of lymphocytes positive for B-cell marker (CD20), T-cell markers (CD3, CD4 and CD8) and IL-2R, adhesion molecules (ICAM-1, VCAM-1 and ELAM-1) and their ligands [lymphocyte function-associated antigen-1 (LFA-1), very late antigen (VLA-4) and Sialyl Lewis X (sLeX)] were demonstrated in liver biopsies by immunohistochemistry, and zero-biopsies from donor livers were used as controls. EBV DNAemia was associated with increased number of CD20-positive (22±30, p=0.09) and significantly increased numbers of CD3 (80±16, p=0.001)-, CD4 (23±8, p=0.009)- and CD8 (38±8, p=0.001)-positive lymphocytes in the graft. ICAM-1, but not VCAM-1 or ELAM-1, was strongly expressed and the number of LFA-1-positive cells was significantly increased (48±10, p=0.0002). Low-level EBV DNAemia was associated with B- and especially T-cell infiltration of the graft, as well as an increase in ICAM-1 and the number of LFA-1-positive cells. However, EBV DNAemia or these immunological events did not have any effect on the liver transplant.     

Evaluation of STOX1 as a preeclampsia candidate gene in a population-wide sample

Preeclampsia is a common, pregnancy-specific vascular disorder characterised by hypertension and proteinuria. A recent report suggested association of the STOX1 gene on chromosome 10q22.1 with preeclampsia in the Dutch population. Here, we present a comprehensive assessment of STOX1 as a candidate gene for preeclampsia in the Finnish population by re-examining our previous genetic linkage analysis results for both chromosome 10 and paralogous loci, by genotyping representative markers in a nationwide data set, and by studying STOX1 expression in placentas from preeclamptic and uncomplicated pregnancies. In conclusion, we are unable to validate STOX1 as a common preeclampsia susceptibility gene.     

Why human pemphigoid autoantibodies do not trigger disease by the passive transfer into mice?

The recapitulation of disease features in animals by the transfer of patient autoantibodies has been used to demonstrate the autoimmune nature of several diseases. Failure of disease induction by the passive transfer of autoantibodies has been assigned to a limited cross-reactivity of the autoantibodies with the murine tissue. However, the possibility that the passively transferred "inflammatory" patient autoantibodies may not be able to unfold their pathogenic potential due to restricted Fc-dependent effector functions has not yet been systematically explored. In this study we analyze the interaction of patients' autoantibodies with murine complement and granulocytes. Bullous pemphigoid is a blistering disease associated with autoantibodies, which are thought to induce subepidermal blistering by activating complement and granulocytes. The passive transfer of patients autoantibodies failed to induce skin blistering in wild type mice. The cross-reactivity of pemphigoid autoantibodies with murine antigens was analyzed in silico, ex vivo and by the passive transfer of IgG in vivo. Complement-fixing ability of patients' autoantibodies was evaluated by complement-binding test. Granulocyte activation was assessed by reactive oxygen species production assay and the cryosection model. We have found that although pemphigoid autoantibodies bound to murine skin in vitro and in vivo, they showed a lower capacity to fix murine complement and a reduced ability to activate murine granulocytes when compared with human complement and cells, respectively. These results indicate that for disease models using the passive transfer of patient autoantibodies, their interaction with the innate factors of the host should be optimized to match the human situation.     

Mechanical verification of soft-tissue attachment on bioactive glasses and titanium implants

Soft-tissue attachment is a desired feature of many clinical biomaterials. The aim of the current study was to design a suitable experimental method for tensile testing of implant incorporation with soft-tissues. Conical implants were made of three compositions of bioactive glass (SiO(2)-P(2)O(5)-B(2)O(3)-Na(2)O-K(2)O-CaO-MgO) or titanium fiber mesh (porosity 84.7%). The implants were surgically inserted into the dorsal subcutaneous soft-tissue or back muscles in the rat. Soft-tissue attachment was evaluated by pull-out testing using a custom-made jig 8 weeks after implantation. Titanium fiber mesh implants had developed a relatively high pull-out force in subcutaneous tissue (12.33+/-5.29 N, mean+/-SD) and also measurable attachment with muscle tissue (2.46+/-1.33 N). The bioactive glass implants failed to show mechanically relevant soft-tissue bonding. The experimental set-up of mechanical testing seems to be feasible for verification studies of soft-tissue attachment. The inexpensive small animal model is beneficial for large-scale in vivo screening of new biomaterials.     

Induction of phenotype modifying cytokines by FERMT1 mutations

Kindler syndrome (KS) is a progressive skin disorder caused by FERMT1 mutations. Early in life, KS manifests as a mechanobullous disease reflecting diminished cell adhesion, but the mechanisms of its later phenotypic features, progressive poikiloderma, and mucocutaneous fibrosis, remain elusive. The FERMT1 gene product and KS protein, kindlin-1, is an epithelial-specific phosphoprotein involved in integrin beta-1 activation, without an obvious link to dermal connective tissue. Here we show how lack of intracellular kindlin-1 in epidermal keratinocytes leads to profound changes in another skin compartment, the dermis. Kindlin-1-deficient keratinocytes respond to cell stress by upregulating the expression of cytokines such as IL-20, IL-24, TGF-β2, IL1F5, PDGFB, and CTGF. These launch-via paracrine communication-an inflammatory response in the dermis, accompanied by the presence of TGF-β, IL-6, and CTGF, activation of fibroblasts and their differentiation to myofibroblasts, which secrete and deposit increased amounts of extracellular matrix proteins. These data are concordant with a model wherein repeated cycles of epidermal cell stress, cytokine secretion, dermal inflammation, and profibrotic processes underlie mucocutaneous fibrosis in KS.     

Plasmacytoid DC promote priming of autoimmune Th17 cells and EAE

EAE, an animal model for MS, is a Th17 and Th1‐cell‐mediated autoimmune disease, but the mechanisms leading to priming of encephalitogenic T cells in autoimmune neuroinflammation are poorly understood. To investigate the role of plasmacytoid DC (pDC) in the initiation of autoimmune Th17‐ and Th1‐cell responses and EAE, we depleted pDC with anti‐pDC Ag‐1 (anti‐PDCA1) mAb prior to immunization of C57BL/6 mice with myelin oligodendrocyte glycoprotein (MOG). pDC‐depleted mice developed less severe clinical and histopathological signs of EAE than control mice, which demonstrates a promoting role for pDC in the initiation of EAE. The levels of type I IFN were much lower in the sera from anti‐PDCA1‐treated mice. However, neutralization of type I IFN ameliorated the early phase of EAE but did not alter the severity of disease. Thus, only a minor part of the EAE‐promoting effect of pDC appears to be mediated by IFN‐α/β secretion. The numbers of MOG‐specific Th17 cells, but not Th1 cells, were lower in spleen from anti‐PDCA1‐treated mice compared with controls. In contrast, pDC depletion a week after MOG immunization resulted in more severe clinical signs of EAE. In conclusion, we demonstrate that pDC promote initiation of MOG‐induced Th17‐cell responses and EAE.     

Cytokines as genetic modifiers in K5–/– mice and in human epidermolysis bullosa simplex

Epidermolysis bullosa simplex (EBS) is a skin disorder caused by fully‐penetrant mutations in the keratin genes KRT5 and KRT14, leading to extensive cytolysis and cell fragility of basal keratinocytes. EBS is subject to environmental conditions and displays high intra‐ and interfamilial variability, suggesting modifying loci. Here, we demonstrate that upregulation of certain cytokines accompanies mutations in keratin 5 (K5) but not in keratin 14 (K14). We find for the first time that cytokines macrophage chemotactic protein (MCP)‐1/[chemokine (C‐C motif) ligand 2] (CCL2), macrophage inflammatory protein (MIP)‐3β/CCL19 and MIP‐3α/CCL20, all regulated by nuclear factor kappa B (NFκB) and involved in the recruitment, maturation, and migration of Langerhans cells (LCs) in the epidermis, are upregulated in the skin of K5^–/–, but not of K14^–/– mice. In neonatal K5^–/– epidermis, the number of LCs was increased two‐fold. At the same time, tumor necrosis factor alpha (TNFα) remained unaltered, demonstrating the specificity of that process. Most remarkably, enhanced LC recruitment within the epidermis was found in five EBS patients carrying mutations in the KRT5 gene but not in EBS patients with KRT14 gene mutations. In agreement with the NFκB‐dependent regulation of these cytokines, we found a decrease in p120‐catenin in the basal epidermis of K5^–/– mice. These data provide the first explanation for distinct, keratin‐type‐specific genotype–phenotype correlations in EBS and represent a rationale to investigate gene loci affecting skin pathology in EBS. Hum Mutat 0, 1–10, 2009. © 2009 Wiley‐Liss, Inc.