Detection of IgE-autoantibodies to nuclear antigens in patients with systemic sclerosis and analysis of their clinical relevance.

OBJECTIVES: Antinuclear antibodies (ANA) of the IgE-type have been described in several connective tissue disorders (CTD) but not yet in systemic sclerosis (SSc). Aim of the study was, therefore, to establish an ELISA for the demonstration of IgE-autoantibodies to topoisomerase-I (topo-I) and the centromeric proteins A and B (CENP-A/B), to assess their prevalence and reactivity in SSc and to analyse their clinical relevance. METHODS: One hundred fifty-one patients with SSc and 88 with CREST-syndrome, 291 patients with other CTD, and 23 patients with fibromyalgia syndrome (FM) as a control collective were included into the study. Patients' sera were analysed by an in-house-ELISA for IgE autoantibodies against topo-I and CENP-A/B using recombinant antigens. Patients were assessed for median Rodnan skin score(mRSS), different organ and cutaneous manifestations. RESULTS: Of the patients with CREST syndrome, 67% had IgE-anti-CENP-A- and 77% IgE-anti-CENP-B-antibodies. IgE-anti-topo-I antibodies were found in 56% of patients with SSc. Prevalence and reactivity were significantly higher in CREST and SSc, respectively, than in other CTD or FM. IgE-reactivity strongly correlated with IgG-antibody reactivity. In CRESTsyndrome, IgE-anti-CENP-A (but not CENP-B)-antibodies were significantly higher and more prevalent in patients with skin ulcers, high mRSS, and more than four organ manifestations. They did not correlate with blood eosinophil counts. In contrast, for IgE-anti-topo-I antibodies no correlation with clinical manifestations was observed. CONCLUSIONS: IgE-autoantibodies against CENP-A/B and topo-I occur in SSc underlining the concept that SSc may be a T helper cell type 2 mediated disease. IgE-anti-CENP-A-antibodies correlated with disease activity, but this has to be confirmed in larger studies.

Clinical impact of antibodies to Sp100 on a bacterial infection in patients with primary biliary cholangitis.

BACKGROUND: A specific antinuclear antibody for primary biliary cholangitis (PBC) is anti-Sp100, which was recognized as a serological marker of concurrent urinary tract infection. We sought to determine the clinical characteristics of PBC patients who had anti-Sp100. PATIENTS AND METHODS: Fifty-one patients with PBC and 10 healthy controls (HCs) were enrolled. Anti-Sp100 were determined with an ELISA method. Lipopolysaccharide-binding protein (LBP) was measured as a serological hallmark for bacterial infection. The correlations of anti-Sp100 with demographic, laboratory, and pathological parameters were investigated. RESULTS: Six of the 51 (11.8%) PBC patients had anti-Sp100, whereas none of the HCs did. There was no significant difference in the frequency of antimitochondrial antibodies (AMAs) between PBC patients with and without anti-Sp100 (67% vs. 82%, p = 0.5839). Biochemical and immunological parameters were not associated with the emergence of anti-Sp100 in these patients. The clinical stage by Scheuer classification was not correlated with the existence of anti-Sp100. No significant difference in the serum LBP levels was found between PBC patients with and without anti-Sp-100, although serum LBP levels were significantly higher in PBC patients with anti-Sp100 than in HCs (8.30 ± 2.24 ng/ml, vs. 5.12 ± 2.48 ng/ml, p = 0.0022). The frequency of granuloma formation was higher in the liver specimens of PBC patients with anti-Sp100 than in those without anti-Sp100 (67% vs 29%, p = 0.0710). CONCLUSION: anti-Sp100 does not become a complementary serological marker for PBC in AMA-negative patients. A bacterial infection may trigger the production of anti-Sp100. Another factor is required to initiate the autoantibody production.

The Speckled Protein (SP) Family: Immunity's Chromatin Readers.

Chromatin 'readers' are central interpreters of the epigenome that facilitate cell-specific transcriptional programs and are therapeutic targets in cancer and inflammation. The Speckled Protein (SP) family of chromatin 'readers' in humans consists of SP100, SP110, SP140, and SP140L. SPs possess functional domains (SAND, PHD, bromodomain) that dock to DNA or post-translationally modified histones and a caspase activation and recruitment domain (CARD) to promote multimerization. Mutations within immune expressed SPs associate with numerous immunological diseases including Crohn's disease, multiple sclerosis, chronic lymphocytic leukemia, veno-occlusive disease with immunodeficiency, as well as Mycobacterium tuberculosis infection, underscoring their importance in immune regulation. In this review, we posit that SPs are central chromatin regulators of gene silencing that establish immune cell identity and function.

Validation of immunogenic PASD1 peptides against HLA-A*24:02 colorectal cancer.

Colorectal cancer is the third commonest malignancy in Asia including Malaysia. The immunogenic cancer-testis antigens, which are expressed in a variety of cancers but with limited expression in normal tissues except the testis, represent an attractive approach to improve treatment options for colorectal cancer. We aimed to validate four PASD1 peptides as the immunotherapeutic targets in colorectal cancer. First, PASD1 mRNA and protein expression were determined via real-time polymerase chain reaction (RT-PCR) and immunohistochemistry. The PASD1 peptides specific to HLA-A*24:02 were investigated using IFN-y-ELISpot assay, followed by the cytolytic and granzyme-B-ELISpot assays to analyze the cytolytic effects of CD8+ T cells. Gene and protein expressions of PASD1 were detected in 20% and 17.3% of colorectal cancer samples, respectively. PASD1(4) peptide was shown to be immunogenic in colorectal cancer samples. CD8+ T cells raised against PASD1(4) peptide were able to lyze HLA-A*24:02+ PASD1+ cells. Our results reveal that PASD1(4) peptide represents a potential target for colorectal cancer.

Clinical use of anti-DFS70 autoantibodies.

The dense fine speckled (DFS) nuclear pattern is one of the most common indirect immunofluorescence (IIF) patterns detected during routine anti-nuclear antibody (ANA) screening. There is a negative association between anti-DFS70 status and systemic autoimmune rheumatic disease (SARD), especially in the absence of concomitant SARD-specific autoantibodies. The purpose of this study was to determine the need for confirming anti-DFS70 status when a DFS pattern is observed in IIF-ANA. The frequency of anti-DFS70 detection on Western blot and the positive rate of connective tissue disease (CTD)-related autoantibody screening with a fluorescence-based enzyme immunoassay was evaluated in DFS (n = 182) and non-DFS (n = 359) groups. Specific autoantibodies against 15 autoantigens were identified by line immunoassay. We evaluated the frequency of cases of DFS mistaken for non-DFS and non-DFS cases mistaken for DFS, as well as the clinical impacts of these misinterpretations. Among cases of IIF-ANA with an observable DFS pattern, 68.1% had only anti-DFS70 without CTD-related autoantibodies, 20.3% were false positive for IIF-ANA, and the remaining 11.5% had CTD-related autoantibodies independent of anti-DFS70 status. These results indicated that CTD-related autoantibodies may be present with or without anti-DFS70 even if a DFS pattern is observed in IIF-ANA. Among patients who are ANA negative or have a low probability of SARD, an anti-DFS70 confirmation test has no clinical benefit and cannot replace specific tests for detecting CTD-related autoantibodies. Specific tests to detect CTD-related autoantibodies should be performed instead of anti-DFS70 confirmation tests when a DFS pattern is observed in IIF-ANA.

Antigens under cover-The preservation and demasking of selected antigens for successful poststaining immunocytochemistry of effusion, brain smears, and lymph node aspirates.

BACKGROUND: In clinical cytology, the applicability of an ancillary test such as immunocytochemistry is too often limited by low sample volume, poor cell representation, and sample preservation. Diagnosticians often read Romanowsky-stained cytology, although specific techniques such as immunocytochemistry are often essential for a definitive diagnosis. OBJECTIVES: The goal of the present study aimed to investigate if immunocytochemistry on previously-stained cytologic specimens was possible. Different pretreatments were examined to determine which treatment preserved antigenicity best. METHODS: One hundred and twenty-two impression smears and 64 fine-needle aspirate preparations of brain and lymph nodes were processed and evaluated microscopically. The impact of staining cytologic preparations with a modified Wright's stain, using a destaining method, performing a coverslipping and decoverslipping process, and subjecting smears to a microwave treatment (MWT) were examined for the immunolabeling of selected nuclear, cytoplasmic, and plasmalemmal antigens, as well as intracellular feline coronavirus (FCoV). Biotinylated secondary antibodies were used, and the bound primary antibody was visualized using an ABC amplification kit. RESULTS: Cellular antigens were reliably detected with immunocytochemistry after smears were stained with a Romansky stain and were coverslipped early after staining and stayed coverslipped until immediately before immunolabeling. The staining intensity reached the same levels as that of the controls if the films underwent MWT in citrate buffer. In contrast, FCoV antigen detection was abolished after any physicochemical interference. CONCLUSIONS: Poststaining immunocytochemistry represents a practical tool for additional investigations on prestained cytologic specimens when searching for cellular antigens. Paired untreated samples should be kept in case the workup requires testing for more vulnerable viral antigens.

Non-specific interstitial pneumonia and features of connective tissue disease: What are the consequences of a different point of view?

Patients with Interstitial Lung Disease (ILD) without a definitive diagnosis of connective tissue diseases (CTD) were historically described as Undifferentiated Connective Tissue Disease (UCTD-ILD). Recently a new classification, Interstitial Pneumonia with Autoimmune Features (IPAF), has been proposed. Aim of this study was to describe the prevalence, clinical characteristics and prognostic factors of UCTD and IPAF subjects in a cohort of Non-Specific Interstitial Pneumonia (NSIP) patients. This retrospective, observational study enrolled 102 adult patients characterized by NSIP pattern on High Resolution Computed Tomography, without a specific diagnosis of CTD. Three groups were identified according to patients' characteristics: IPAF, UCTD or idiopathic NSIP (iNSIP). Forty percent, 27% and 55% of patients showed diagnostic criteria for IPAF, UCTD and iNSIP, respectively. No significant differences in age, gender, smoking habit, pulmonary function tests and three-year survival rate were observed among study groups. IPAF patients with antisynthetase antibodies positivity, in comparison to IPAF without antisynthetase antibodies positivity, showed more frequently an acute onset (44% vs 9%, p<0.012). The presence of autoimmune features seems not to be associated with better outcomes in NSIP patients. IPAF criteria seem to be more representative than UCTD criteria in identifying patients with autoimmune features. Further studies are needed to verify if IPAF should include patients with positive antisynthetase serology.

Dying cells expose a nuclear antigen cross-reacting with anti-PD-1 monoclonal antibodies.

Checkpoint molecules such as programmed death 1 (PD-1) dampen excessive T cell activation to preserve immune homeostasis. PD-1-specific monoclonal antibodies have revolutionized cancer therapy, as they reverse tumour-induced T cell exhaustion and restore CTL activity. Based on this success, deciphering underlying mechanisms of PD-1-mediated immune functions has become an important field of immunological research. Initially described for T cells, there is emerging evidence of unconventional PD-1 expression by myeloid as well as tumor cells, yet, with cell-intrinsic functions in various animal tumor models. Here, we describe positive PD-1 antibody staining of various murine immune and tumour cells that is, unlike for T cells, not the PD-1 receptor and restricted to cells with low forward scatter characteristics. Based on flow cytometry and various approaches, including two established murine anti-PD-1 antibody clones, CRISPR/Cas9 genome editing and confocal imaging, we describe a staining pattern assigned to a nuclear antigen cross-reacting with anti-PD-1 monoclonal antibodies. Lack of PD-1 expression was further underlined by the analysis of PD-1 expression from B16-F10-derived 3D cultures and ex vivo tumours. Thus, our data provide multiple lines of evidence that PD-1 expression by non-T cells is unlikely to be the case and, taking recent data of PD-1 tumour cell-intrinsic functions into account, suggest that other antibody-mediated pathways might apply.

STAG2 deficiency induces interferon responses via cGAS-STING pathway and restricts virus infection.

Cohesin is a multi-subunit nuclear protein complex that coordinates sister chromatid separation during cell division. Highly frequent somatic mutations in genes encoding core cohesin subunits have been reported in multiple cancer types. Here, using a genome-wide CRISPR-Cas9 screening approach to identify host dependency factors and novel innate immune regulators of rotavirus (RV) infection, we demonstrate that the loss of STAG2, an important component of the cohesin complex, confers resistance to RV replication in cell culture and human intestinal enteroids. Mechanistically, STAG2 deficiency results in spontaneous genomic DNA damage and robust interferon (IFN) expression via the cGAS-STING cytosolic DNA-sensing pathway. The resultant activation of JAK-STAT signaling and IFN-stimulated gene (ISG) expression broadly protects against virus infections, including RVs. Our work highlights a previously undocumented role of the cohesin complex in regulating IFN homeostasis and identifies new therapeutic avenues for manipulating the innate immunity.

Anti-nuclear antibodies in patients with breast cancer.

To study the prevalence of anti-nuclear antibodies (ANA) in breast cancer patients and its association with tumour characteristics. Ninety-one patients with breast mass detected by image studies and assigned to conduct diagnostic biopsy and eventual surgical treatment were studied for demographical, tumour data and presence of ANA. Serum of positive ANA patients was screened for the extractable nuclear antigen (ENA) profile. As comparison, 91 healthy individuals matched for age and from the same geographical area were included. In this sample 72 of 91 (79·1%) had malignant lesions (83% ductal infiltrative carcinoma). ANA was positive in 44·4% of patients with malignant tumour and in 15·7% of those with benign lesions (malignant versus benign with P = 0·03). Controls had ANA positivity in 5·4%, and when compared with tumour samples showed P < 0·0001. The most common immunofluorescence pattern was a fine dense speckled pattern. In the ANA-positive patients with malignant lesions, seven had positivity for ENA profile (three for anti-RNP and anti-Sm, one for just anti-RNP, two for anti-Ro and anti-La e two for just anti-La). It was not possible to associate ANA positivity with tumour histological characteristics or staging or with patient's age. A negative association of ANA with hormonal (oestrogen or oestrogen plus progesterone) receptor status was found (P = 0·01). In this sample, there was a high prevalence of ANA positivity in breast cancer patients with a negative association with the presence of hormonal receptors. More studies are needed to understand the real value of this finding.

No detectable human herpesvirus-8 oral shedding in seronegative-healthy, immunocompetent individuals from non-endemic regions for Kaposi's sarcoma: A pilot study.

AIM: Saliva can play an important role in human herpesvirus-8 (HHV-8) transmission in endemic regions for Kaposi's sarcoma (KS). Little is known about HHV-8 oral shedding in immunocompetent individuals from non-endemic regions for KS. METHODS: We conducted a prospective study of HHV-8 salivary excretion among 59 healthy, immunocompetent individuals from São Paulo, Brazil, followed up weekly for 4 months, resulting in 16 saliva samples from each participant. Antibodies to HHV-8 latency-associated nuclear antigen (LANA) and lytic-phase antigens were investigated with immunofluorescence assays (IFA). HHV-8 DNA detection was performed using real-time polymerase chain reaction (PCR). RESULTS: All 59 individuals were seronegative to LANA and lytic antibodies. HHV-8 DNA was undetectable in saliva samples in 100% of the participants, totaling 944 samples and being consistently negative during the different periods of sampling, which lasted approximately 120 days. No sequences of HHV-8 DNA were detected in the saliva samples of healthy, immunocompetent adults by using real-time PCR, with the resulting data being consistent with IFA-based serological tests. CONCLUSIONS: Unlike other herpesviruses, HHV-8 is not excreted in the saliva of healthy individuals from non-endemic regions for KS.

Detection of brain-directed autoantibodies in the serum of non-small cell lung cancer patients.

Antibodies against brain proteins were identified in the plasma of cancer patients and are defined to cause paraneoplastic neurological syndromes. The profiles of brain-directed antibodies in non-small cell lung cancer (NSCLC) are largely unknown. Here, for the first time, we compared autoantibodies against brain proteins in NSCLC (n = 18) against those present in age-matched non-cancer control subjects (n = 18) with a similar life-style, habit, and medical history. Self-recognizing immunoglobulin (IgG) are primarily directed against cells in the cortex (P = 0.008), hippocampus (P = 0.003-0.05), and cerebellum (P = 0.02). More specifically, IgG targets were prominent in the pyramidal, Purkinje, and granule cell layers. Furthermore, autoimmune IgG signals were localized to neurons (81%), astrocytes (48%), and endothelial (29%) cells. While cancer sera yielded overall higher intensity signals, autoantigens of 100, 65, 45, 37, and 30 kDa molecular weights were the most represented. Additionally, a group of 100 kDa proteins seem more prevalent in female adenocarcinoma patients (4/5, 80%). In conclusion, our results revealed autoantigen specificity in NSCLC, which implicitly depends on patient's demographics and disease history. Patients at risk for lung cancer but with no active disease revealed that the immune profile in NSCLC is disease-dependent.

Nuclear domain 10 components upregulated via interferon during human cytomegalovirus infection potently regulate viral infection.

Human cytomegalovirus (HCMV) is a ubiquitous betaherpesvirus that causes life-threatening disease in immunocompromised and immunonaïve individuals. Type I interferons (IFNs) are crucial molecules in the innate immune response to HCMV and are also known to upregulate several components of the interchromosomal multiprotein aggregates collectively referred to as nuclear domain 10 (ND10). In the context of herpesvirus infection, ND10 components are known to restrict gene expression. This raises the question as to whether key ND10 components (PML, Sp100 and hDaxx) act as anti-viral IFN-stimulated genes (ISGs) during HCMV infection. In this study, analysis of ND10 component transcription during HCMV infection demonstrated that PML and Sp100 were significantly upregulated whilst hDaxx expression remained unchanged. In cells engineered to block the production of, or response to, type I IFNs, upregulation of PML and Sp100 was not detected during HCMV infection. Furthermore, pre-treatment with an IFN-ß neutralizing antibody inhibited upregulation of PML and Sp100 during both infection and treatment with HCMV-infected cell supernatant. The significance of ND10 components functioning as anti-viral ISGs during HCMV infection was determined through knockdown of PML, Sp100 and hDaxx. ND10 knockdown cells were significantly more permissive to HCMV infection, as previously described but, in contrast to control cells, could support HCMV plaque formation following IFN-ß pre-treatment. This ability of HCMV to overcome the potently anti-viral effects of IFN-ß in ND10 expression deficient cells provides evidence that ND10 component upregulation is a key mediator of the anti-viral activity of IFN-ß.

Induction of Autoantibodies and Autoimmune Diseases in Patients with Psoriasis Receiving Tumor Necrosis Factor Inhibitors. / Inducción de anticuerpos y enfermedades autoinmunes en pacientes con psoriasis tratados con fármacos anti-TNFα.

BACKGROUND: The induction of antinuclear antibodies (ANA) and the onset of autoimmune diseases have been reported after treatment with tumor necrosis factor (TNF) inhibitors, though controversy persists. OBJECTIVES: To determine the frequency of onset of autoimmune diseases and of the appearance of autoantibodies in psoriasis patients administered TNF inhibitors (adalimumab and etanercept) subcutaneously and to correlate this with the effectiveness of treatment, adverse effects, and the order of use of TNF inhibitors. We also tried to identify any factors that might predict the appearance of ANA and autimmune diseases. METHODS: We performed a retrospective study of a cohort of 121 patients monitored over an 11-year period. ANA were measured at baseline and at 3, 6, and 12 months; positive results were followed up by study of antibodies to double-stranded DNA. Extractable nuclear antigen (ENA) antibodies were also studied at baseline and at 3, 6, and 12 months. Patients with a baseline assay of ANA and ENA at least one more assay during the first year were included in the study, and these antibodies were measured annually thereafter. Psoriasis area severity index was calculated and adverse effects were recorded at each visit. RESULTS: A significant increase in ANA positivity was observed during treatment of moderate-to-severe psoriasis with adalimumab and etanercept, but this was not associated with the onset of autoimmune diseases. No correlation was observed with treatment efficacy, the order of use of TNF inhibitors, or the appearance of adverse effects. No predictive factors for the appearance of ANA were identified, except for the body mass index. CONCLUSIONS: We recommend ANA measurement and screening for autoimmune diseases prior to treatment with TNF inhibitors, but not routine serial measurements of ANA during follow-up except in patients with signs or symptoms suggestive of autoimmune disease.

SP110b Controls Host Immunity and Susceptibility to Tuberculosis.

RATIONALE: How host genetic factors affect Mycobacterium tuberculosis (Mtb) infection outcomes remains largely unknown. SP110b, an IFN-induced nuclear protein, is the nearest human homologue to the mouse Ipr1 protein that has been shown to control host innate immunity to Mtb infection. However, the function(s) of SP110b remains unclear. OBJECTIVES: To elucidate the role of SP110b in controlling host immunity and susceptibility to tuberculosis (TB), as well as to identify the fundamental immunological and molecular mechanisms affected by SP110b. METHODS: Using cell-based approaches and mouse models of Mtb infection, we characterized the function(s) of SP110b/Ipr1. We also performed genetic characterization of patients with TB to investigate the role of SP110 in controlling host susceptibility to TB. MEASUREMENTS AND MAIN RESULTS: SP110b modulates nuclear factor-κB (NF-κB) activity, resulting in downregulation of tumor necrosis factor-α (TNF-α) production and concomitant upregulation of NF-κB-induced antiapoptotic gene expression, thereby suppressing IFN-γ-mediated monocyte and/or macrophage cell death. After Mtb infection, TNF-α is also downregulated in Ipr1-expressing mice that have alleviated cell death, less severe necrotic lung lesions, more efficient Mtb growth control in the lungs, and longer survival. Moreover, genetic studies in patients suggest that SP110 plays a key role in modulating TB susceptibility in concert with NFκB1 and TNFα genes. CONCLUSIONS: These results indicate that SP110b plays a crucial role in shaping the inflammatory milieu that supports host protection during infection by fine-tuning NF-κB activity, suggesting that SP110b may serve as a potential target for host-directed therapy aimed at manipulating host immunity against TB.

Brush Cytology and AgNOR in the Diagnosis of Oral Squamous Cell Carcinoma.

OBJECTIVE: We aimed to evaluate the role of brush cytology in the screening of oral lesions with malignant suspicion and compare it with histopathology in north-eastern India. STUDY DESIGN: Brush cytology samples taken from 48 patients were processed for conventional cytology (CC) and liquid-based cytology (LBC), and biopsy samples were also obtained. LBC samples were also stained to assess the argyrophilic nucleolar organizer region (AgNOR). The cytology was compared with histopathology, both individually and in combination with AgNOR. The smear quality was compared with histopathology for evaluating their diagnostic accuracy. RESULTS: The sensitivity of diagnosing oral cavity squamous cell carcinoma by LBC and CC alone was 75 and 85%, respectively, which improved on combining with the AgNOR count, with a cutoff of 6.5. The presence of round cells on cytology was significantly associated with high-grade lesions. LBC provided clearer cytomorphology but compromised the background information in high-grade lesions. CONCLUSION: Brush cytology is a minimally invasive tool for screening oral lesions with malignant suspicion. LBC and CC are complementary techniques for cytological screening and combining them with AgNOR can increase the diagnostic yield. With objective criteria for assessment, cytology can be an indispensable tool for screening oral lesions in a resource-limited set-up, especially in high-incidence regions.

Interferon Regulatory Factor 1 and Type I Interferon Cooperate To Control Acute Gammaherpesvirus Infection.

Gammaherpesviruses are ubiquitous pathogens that establish lifelong infection in >95% of adults worldwide and are associated with a variety of malignancies. Coevolution of gammaherpesviruses with their hosts has resulted in an intricate relationship between the virus and the host immune system, and perturbation of the virus-host balance results in pathology. Interferon regulatory factor 1 (IRF-1) is a tumor suppressor that is also involved in the regulation of innate and adaptive immune responses. Here, we show that type I interferon (IFN) and IRF-1 cooperate to control acute gammaherpesvirus infection. Specifically, we demonstrate that a combination of IRF-1 and type I IFN signaling ensures host survival during acute gammaherpesvirus infection and supports IFN gamma-mediated suppression of viral replication. Thus, our studies reveal an intriguing cross talk between IRF-1 and type I and II IFNs in the induction of the antiviral state during acute gammaherpesvirus infection. IMPORTANCE: Gammaherpesviruses establish chronic infection in a majority of adults, and this long-term infection is associated with virus-driven development of a range of malignancies. In contrast, a brief period of active gammaherpesvirus replication during acute infection of a naive host is subclinical in most individuals. Here, we discovered that a combination of type I interferon (IFN) signaling and interferon regulatory factor 1 (IRF-1) expression is required to ensure survival of a gammaherpesvirus-infected host past the first 8 days of infection. Specifically, both type I IFN receptor and IRF-1 expression potentiated antiviral effects of type II IFN to restrict gammaherpesvirus replication in vivo, in the lungs, and in vitro, in primary macrophage cultures.

Assessment transcallosal Diaschisis in a model of focal cerebral ischemia in rats / Evaluación de la diásquisis transcallosa en un modelo de isquemia cerebral focal en ratas

Objective: To evaluate transcallosal changes after a local ischemic injury in rats by using the monoclonal marker anti-NeuN (Mouse anti-neuronal nuclei). Methods: Twenty eight adult, male, Wistar rats were subjected to focal injury in the right hemisphere. The technique used was the experimental model of focal ischemic injury through intraluminal suture of the middle cerebral artery. Analyses were made for the five groups: and after the lesion (control), at 24 h, 96 h, 10 days and 20 days. Exofocal neuronal damage was inferred from neuronal immunoreactivity changes to NeuN. Results: In the cortex contralateral to the lesion, immunoreactivity was diminished. This was most notable in the supragranular layers 24 h post ischemia. After 96 h, there was a generalized diminishment of the inmmunoreactivity in supra and infragranular layers. At 10 and 20 days, the tissue recovered some NeuN immunoreactivity, but there were set changes in the VI layer. Conclusion: The immunoreactive changes to NeuN support the process of interhemispheric diaschisis. Changes in immunoreactivity could indicate metabolic stress secondary to the disruption in connectivity to the site of lesion.

Objetivo: Evaluar los cambios exofocales transcallosos después de lesión isquémica focal en ratas, mediante marcación inmunohistoquímica con el anticuerpo monoclonal anti-NeuN (Mouse Anti-Neuronal Nuclei). Métodos: Se intervinieron 28 ratas machos Wistar adultas. Mediante el modelo experimental de isquemia cerebral focal del territorio de la arteria cerebral media por filamento intraluminal, se les ocasionó una lesión focal en el hemisferio derecho. Posteriormente se evaluó el hemisferio contralateral, marcando la población neuronal con el anticuerpo monoclonal anti-NeuN. Se definieron cinco grupos de evaluación: uno de control, 24 h, 96 h, 10 días y 20 días. Se evaluaron los cambios neuronales exofocales después de la lesión con base en la observación de los cambios en la inmunoreactividad de las neuronas al NeuN. Resultados: Se redujo la inmunoreactividad en la corteza contralateral a la lesión. Este fenómeno fue más notable en las capas supragranulares después de 24 h post isquemia. Después de 96 h hubo una disminución generalizada de la inmmunoreactivity en las capas supra e infragranulares. A los 10 y 20 días, el tejido recobró alguna inmunoreactividad NeuN, estos cambios se dieron en la capa VI. Conclusiones: Los cambios inmunorreactivos a NeuN apoyan el proceso de diasquisis interhemisférica. Los cambios en la inmunorreactividad podrían indicar estrés metabólico secundario a la interrupción en la conectividad con el sitio de la lesión.

Humoral markers of active Epstein-Barr virus infection associate with anti-extractable nuclear antigen autoantibodies and plasma galectin-3 binding protein in systemic lupus erythematosus.

We investigated if signs of active Epstein-Barr virus and cytomegalovirus infections associate with certain autoantibodies and a marker of type I interferon activity in patients with systemic lupus erythematosus. IgM and IgG plasma levels against Epstein-Barr virus early antigen diffuse and cytomegalovirus pp52 were applied as humoral markers of ongoing/recently active Epstein-Barr virus and cytomegalovirus infections, respectively. Plasma galectin-3 binding protein served as a surrogate marker of type I interferon activity. The measurements were conducted in 57 systemic lupus erythematosus patients and 29 healthy controls using ELISAs. Regression analyses and univariate comparisons were performed for associative evaluation between virus serology, plasma galectin-3 binding protein and autoantibodies, along with other clinical and demographic parameters. Plasma galectin-3 binding protein concentrations were significantly higher in systemic lupus erythematosus patients (P = 0.009) and associated positively with Epstein-Barr virus early antigen diffuse-directed antibodies and the presence of autoantibodies against extractable nuclear antigens in adjusted linear regressions (B = 2.02 and 2.02, P = 0.02 and P = 0.002, respectively). Furthermore, systemic lupus erythematosus patients with anti-extractable nuclear antigens had significantly higher antibody levels against Epstein-Barr virus early antigen diffuse (P = 0.02). Our study supports a link between active Epstein-Barr virus infections, positivity for anti-extractable nuclear antigens and increased plasma galectin-3 binding protein concentrations/type I interferon activity in systemic lupus erythematosus patients.