Dermatomyositis sine dermatitis, a rare phenotype of idiopathic inflammatory myopathy / 영남의대학술지

Dermatomyositis (DM) is characterized by progressive proximal limb weakness and typical skin manifestations. The histological findings that show perifascicular atrophy and deposition of membrane attack complex are pathognomic features of DM. Dermatomyositis is categorized into classical DM and non-classical DM, which includes amyopathic DM and DM sine dermatitis. DM sine dermatitis is seldom described because of its rarity, making the diagnosis more challenging. We report a case of DM sine dermatitis, a rare phenotype of DM.

Dermatomyositis sine dermatitis, a rare phenotype of idiopathic inflammatory myopathy / 영남의대학술지

Dermatomyositis (DM) is characterized by progressive proximal limb weakness and typical skin manifestations. The histological findings that show perifascicular atrophy and deposition of membrane attack complex are pathognomic features of DM. Dermatomyositis is categorized into classical DM and non-classical DM, which includes amyopathic DM and DM sine dermatitis. DM sine dermatitis is seldom described because of its rarity, making the diagnosis more challenging. We report a case of DM sine dermatitis, a rare phenotype of DM.

Diagnostic Significance of BAT in Anaphylaxis to Non-ionic Contrast Media / 法医学杂志

OBJECTIVE@#To investigate the diagnostic significance of basophil activation test (BAT) in anaphylaxis to non-ionic contrast media through testing the content of CD63, mast cell-carboxypeptidase A3 (MC-CPA3), and terminal complement complex SC5b-9 of the individuals by testing their levels in the normal immune group and the anaphylaxis groups to β-lactam drugs and non -ionic contrast media.@*METHODS@#The CD63 expression of basophilic granulocyte in blood was detected by flow cytometry. The levels of MC-CPA3 in blood serum and SC5b-9 in blood plasma were detected by ELISA.@*RESULTS@#The CD63 expression of basophilic granulocyte in blood, the levels of MC-CPA3 and SC5b-9 of anaphylaxis to non-ionic contrast media and β-lactam drugs were significantly higher than that in normal immune group (P < 0.05).@*CONCLUSION@#There is activation of basophilic granulocytes, mast cells and complement system in anaphylaxis to non-ionic contrast media. BAT can be used to diagnose the anaphylaxis to non-ionic contrast media.

Study on C5b-9 deposited on the membrane of platelets and its dysfunction in patients with paroxysmal nocturnal hemoglobinuria / 中华血液学杂志

<p><b>OBJECTIVE</b>To explore the expression levels of terminal complement complex (C5b-9) and CD62p on platelets and the soluble C5b-9 (sC5b-9) level in serum in patients with PNH or PNH-aplastic anemia (AA).</p><p><b>METHODS</b>Serum levels of sC5b-9, complement C3 and C4 were detected by using ELISA in 25 patients with PNH/PNH-AA. The quantities of C5b-9 and CD62p on the membrane of platelets were detected by flow cytometry.</p><p><b>RESULTS</b>①In PNH/PNH-AA group, the serum sC5b-9 level [390.27(265.73-676.87) μg/L] was lower than that in control group [540.39(344.20-1 576.78) μg/L] (P<0.01). ②The platelet PNH clone (CD59⁻CD61⁺/CD61⁺) size [50.58(23.29-81.60)%] was bigger in the PNH/PNH-AA group than that [23.57(15.58-29.02)%] in control group (P<0.01). The percentages of C5b-9 deposition (C5b-9⁺CD61⁺/CD61⁺) were higher on the PNH clone platelets (CD59⁻CD61⁺) in the PNH/PNH-AA group [(17.53 ± 6.27)%] than those on the normal platelets (CD59⁺CD61⁺) in PNH patients 11.33±5.03）%］ and control [(10.88±3.58)%] group (P<0.01). ③ The expression of CD62p (CD62p⁺CD61⁺/CD61⁺) on PNH clone platelets in PNH patients [(61.98 ± 11.71)%] was higher than that on the normal platelets in PNH patients [(43.76±11.30)%] and control group [(38.23±18.07)%] (P<0.01). In addition, the expression of CD62p on normal platelets was higher in PNH patients than control (P<0.05). ④The deposition of C5b-9 positively correlated with the expression of CD62p on the platelets (r=0.559, P=0.002).</p><p><b>CONCLUSION</b>Deficiency of CD59 antigen on platelets in PNH patients may lead to the deposition of C5b-9 on its membrane and its dysfunction, which may contribute to thrombosis events in PNH.</p>

Role of C5b-9 expression in skeletal muscle blood vessels in necrotizing myopathy / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the expression of C5b-9 in the skeletal muscle blood vessels in patients with necrotizing myopathy and explore its role in the pathogenesis of this disease.</p><p><b>METHODS</b>The expression of C5b-9 and MHC-I in the skeletal muscular fibers and blood vessels in 4 patients with necrotizing myopathy was detected using enzymohistochemistry and immunohistochemistry.</p><p><b>RESULTS</b>Focal or dispersive necrotic muscle fibers with obvious phagocytosis were observed in all the 4 patients. No inflammatory cell infiltration was found in the perimysium or perivascular regions. HE staining showed a decreased number of local small blood vessels, and the some small blood vessels showed thickened vascular walls. Immunohistochemistry detected prominent C5b-9 expression in the necrotic muscle fibers and the blood vessels, and diffuse strong C5b-9 expression was found in the vascular walls, vascular endothelial cells and the smooth muscle layer. No MHC-I deposition was detected in the muscular fibers and blood vessels.</p><p><b>CONCLUSION</b>C5b-9 contributes to the pathogenesis of necrotizing myopathy mediated by pathologies in the blood vessels.</p>

Influência do sistema complemento na imunopatogênese da infecção pelo vírus dengue / Influence of complement system in the immunopathogenesis of dengue virus infection

O Sistema Complemento (SC) consiste numa rede de proteínas altamente regulada, podendo ser ativado pelas vias alternativa, clássica e da lectina e que convergem na clivagem de C3 e formação do complexo de ataque à membrana (C5b-9). Receptores do complemento (RC), envolvidos na regulação do SC, induzem mecanismos para eliminação de patógenos e a interação das imunidades inata e adaptativa. Estudos vem indicando que uma ativação desregulada do SC contribuiria à gravidade da dengue. A infecção humana pelo vírus Dengue (DENV) é caracterizada por um amplo espectro de sintomas clínicos, variando desde uma febre branda até distúrbios hemodinâmicos, podendo evoluir para choque hipovolêmico e morte. O objetivo principal do trabalho foi investigar o envolvimento do SC na infecção natural pelo DENV, através: (i) da avaliação quanto a expressão dos RC CR1/CD35, CR2/CD21, CR4/CD11c e CD59 nos monócitos CD14+ e linfócitos T CD4+ e TCD8+ por citometria de fluxo, (ii) dosagem de quantidades plasmáticas de SC5b-9 e das citocinas/quimiocinas TNF-alfa, IFN-gamma, CCL5, CCL2 por ELISA e por fim, (iii) avaliação da influência dos componentes do SC na alteração da permeabilidade de células endoteliais (CEs) pelo ensaio de citotoxidade pela enzima LDH. Neste estudo foram incluídos 66 pacientes com infecção pelo DENV-1 ou -2 e 12 indivíduos saudáveis. Os pacientes-DENV foram agrupados segundo a nova classificação da OMS: febre do dengue sem sinais de alarme (FD Sem SA), FD com sinais de alarme (FD Com SA) e dengue grave (G). Nossos resultados demonstraram diminuição significativa na frequência de monócitos CD14+ expressando CR1/CD35, CR4/CD11c e CD59 nos pacientes-DENV comparado aos controles. Além disso, diminuição na frequência de células T CD4+ e CD8+ expressando CR1/CD35 e CR2/CD21 nos pacientes-DENV comparado aos controles. Não observamos diferenças quanto a frequência de nonócitos CD14+ expressando CR2/CD21 ou de linfócitos T CD4+ e CD8+ expressando CR4/CD11c ou CD59 entre os grupos. A quantificação plasmática das citocinas/quimiocinas revelou: (i) maiores quantidades de TNF-alfa nos pacientes FD Sem SA e FD Com SA, (ii) quantidades aumentadas de CCL2 e (iii) diminuídas de CCL5 comparados aos controles saudáveis. Por fim, (iv) a quantidade de IFN-gamma não foi diferente entre grupos de pacientes e controles. Análises de correlação entre as quantidades de citocinas e expressão dos RC revelaram que TNF-alfa foi diretamente correlacionada com a frequência de monócitos CD14+ expressando de CD59 e CR4/CD11c, enquanto que CCL2 foi inversamente correlacionada com a frequência de linfócitos TCD8+ expressando CD59Quanto a dosagem do SC5b-9, quantidades plasmáticas desta molécula foram mais elevadas nos pacientes graves e que apresentaram manifestações hemorrágicas e extravasamento plasmático comparado aqueles sem estes sintomas. A adição de plasma de pacientes com quantidades elevadas de SC5b-9 promoveu maior lise de CEs in vitro, comparado aos plasmas de pacientes com quantidades menores de SC5b-9. Desta forma, nós concluímos que na infecção pelo DENV ocorre uma modulação dos RC nos monócitos e linfócitos T de pacientes, o que poderia levar a uma alteração funcional destas células. Além disso, TNF-alfa e CCL2 poderiam estar modulando a expressão de alguns dos RC nas células. Por fim, quantidades elevadas de SC5b-9, associada a ativação do SC, estaria associada as manifestações clínicas graves e na citotoxidade de CEs. Como perspectivas, serão avaliadas as alterações funcionais das células imunes e o grau de contribuição dos componentes do SC na patogênese da dengue. Desta forma, nossos dados levam a concluir que componentes do SC contribuem à patogênese da doença.

Do Archaea and bacteria co-infection have a role in the pathogenesis of chronic chagasic cardiopathy?

Chronic cardiopathy (CC) in Chagas disease is a fibrotic myocarditis with C5b-9 complement deposition. Mycoplasma and Chlamydia may interfere with the complement response. Proteolytic enzymes and archaeal genes that have been described in Trypanosoma cruzi may increase its virulence. Here we tested the hypothesis that different ratios of Mycoplasma, Chlamydia and archaeal organisms, which are frequent symbionts, may be associated with chagasic clinical forms. MATERIALS AND METHODS: eight indeterminate form (IF) and 20 CC chagasic endomyocardial biopsies were submitted to in situ hybridization, electron and immunoelectron microscopy and PCR techniques for detection of Mycoplasma pneumoniae (MP), Chlamydia pneumoniae(CP), C5b-9 and archaeal-like bodies. RESULTS: MP and CP-DNA were always present at lower levels in CC than in IF (p < 0.001) and were correlated with each other only in CC. Electron microscopy revealed Mycoplasma, Chlamydia and two types of archaeal-like bodies. One had electron dense lipid content (EDL) and was mainly present in IF. The other had electron lucent content (ELC) and was mainly present in CC. In this group, ELC correlated negatively with the other microbes and EDL and positively with C5b-9. The CC group was positive for Archaea and T. cruzi DNA. In conclusion, different amounts of Mycoplasma, Chlamydia and archaeal organisms may be implicated in complement activation and may have a role in Chagas disease outcome.

O envolvimento do sistema complemento nos processos de aterogênese / The involvement of the complement system in the processes in atherogenesis

A aterosclerose é considerada como uma doença inflamatória crônica desencadeada pela ativação de macrófagos, linfócitos T e sistema complemento (SC). O SC corresponde a um grupo de proteínas plasmáticas e de membrana, as quais são ativadas por uma cascata de interações que resultam na produção de várias moléculas pro-inflamatórias. Embora seja um dos mecanismos efetores do sistema imune inato, em certas circunstâncias, o SC pode por si contribuir para o desencadeamento de doenças cardiovasculares. Esta revisão contêm uma descrição sumarizada da cascata do SC e dos processos de aterogênese bem como o envolvimentode fatores imunológicos, em especial o SC, na patogênese da aterosclerose.

Atherosclerosis has been considered a chronic inflammatory illness induced by macrophage activation, T lymphocyte and complement system . This system corresponds to agroup of plasma and membrane proteins, which are activated by a cascade of interactions that result in the production of some pro-inflammatory molecules. Although it is one of the effector mechanisms of the innate immune system, in certain circumstances, the system complementcan itself contribute for “triggering” cardiovascular diseases. This review contains a brief description of the complement cascade and the processes of aterogenesis as well as the involvement of immunological factors, mainly the complement system activation on patogenesis of aterosclerosis.

Mechanism of Humoral and Cellular Immune Modulation Provided by Porcine Sertoli Cells

The understanding of main mechanisms that determine the ability of immune privilege related to Sertoli cells (SCs) will provide clues for promoting a local tolerogenic environment. In this study, we evaluated the property of humoral and cellular immune response modulation provided by porcine SCs. Porcine SCs were resistant to human antibody and complement-mediated formation of the membrane attack complex (38.41+/-2.77% vs. 55.02+/-5.44%, p=0.027) and cell lysis (42.95+/-1.75% vs. 87.99 +/-2.25%, p<0.001) compared to immortalized aortic endothelial cells, suggesting that porcine SCs are able to escape cellular lysis associated with complement activation by producing one or more immunoprotective factors that may be capable of inhibiting membrane attack complex formation. On the other hand, porcine SCs and their culture supernatant suppressed the up-regulation of CD40 expression (p<0.05) on DCs in the presence of LPS stimulation. These novel findings, as we know, suggest that immune modulatory effects of porcine SCs in the presence of other antigen can be obtained from the first step of antigen presentation. These might open optimistic perspectives for the use of porcine SCs in tolerance induction eliminating the need for chronic immunosuppressive drugs.

Activation of Intrarenal Complement System in Mouse Model for Chronic Cyclosporine Nephrotoxicity

PURPOSE: Local activation of the complement system plays a role in target organ damage. The aim of our study was to investigate the influence of cyclosporine (CsA)- induced renal injury on the complement system in the kidney. MATERIALS AND METHODS: Mice fed a low salt (0.01%) diet were treated with vehicle (VH, olive oil, 1mL/kg/day) or CsA (30mg/kg/day) for one or four weeks. Induction of chronic CsA nephrotoxicity was evaluated with renal function and histomorphology. Activation of the complement system was assessed through analysis of the expression of C3, C4d, and membrane attack complex (MAC), and the regulatory proteins, CD46 and CD55. CsA treatment induced renal dysfunction and typical morphology (tubulointerstitial inflammation and fibrosis) at four weeks. RESULTS: CsA-induced renal injury was associated with increased the expression of C3, C4d, and MAC (C9 and upregulation of complement regulatory proteins (CD 46 and CD55). Immunohistochemistry revealed that the activated complement components were mainly confined to the injured tubulointerstitium. CONCLUSION: CsA-induced renal injury is associated with activation of the intrarenal complement system.

Patogénesis de la endocarditis infecciosa / Pathogenesis of infectious endocarditis

Se discuten los mecanismos moleculares que llevan a la formación de las lesiones más características de la Endocarditis Infecciosa, en especial, la formación de vegetaciones y los diferentes mediadores involucrados provenientes de los gérmenes causales.

The expression of Smac and XIAP in rat hippocampus following limbic seizure induced by kainic acid injection into amygdaloid nucleus / 生理学报

To determine whether Smac/DIABLO (second mitochondrial activator of caspases/direct inhibitor of apoptosis protein-binding protein of low isoelectric point [PI]) and XIAP (X-chromosome-linked inhibitor of apoptosis protein) serve to regulate neuronal apoptosis following seizures, we investigated seizure-induced changes in caspase-9, Smac/DIABLO and XIAP protein expression and the in vivo effect of caspase-9 inhibition. Animals received unilateral intra-amygdaloid injection of kainic acid (0.5 microg) to induce seizures for 1 h. The seizures were then terminated by diazepam (30 mg/kg). Animals were killed 0, 2, 4, 8, 24 or 72 h following diazepam administration. The apoptotic and surviving neurons in hippocampus were observed by terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) and cresyl violet staining, the expression of Smac/DIABLO, XIAP and caspase-9 was detected with immunofluorescence and western blot. The results showed that the levels of XIAP and the 46-kDa proenzyme form of caspase-9 were unaffected by the seizures. The expression of Smac increased at 2 h and the 37-kD cleaved fragment of caspase-9 was detected at 4 h, TUNEL-positive neurons appeared at 8 h and reached maximal at 24 h following seizure cessation within the ipsilateral (the same side as the intra-amygdaloid injection of kainic acid) CA3 subfield of the hippocampus. Intracerebroventricular infusion of caspase-9 inhibitor z-LEHD-fluoromethyl ketone (z-LEHD-fmk) significantly decreased TUNEL-positive neurons and increased the number of surviving cells. Caspase-9 immunoreactivity increased and Smac/DIABLO, XIAP immunoreactivity became extensive within the ipsilateral CA3 neurons. TUNEL-positive neurons and the alterations of the expression of Smac/DIABLO and XIAP within the ipsilateral CA3 were not detected within the contralateral hippocampus. These results suggest that seizures lead the translocation of Smac/DIABLO into the cytosol, the activation of caspase-9 and the change of subcellular locoalization of XIAP. These changes may play a role in the brain damage induced by seizures. Caspase-9 is possibly a potential therapeutic target in the treatment of brain injury associated with seizures.

Interleukin-18 and its related cytokines in plasma of patients with idiopathic thrombocytopenic purpura / 中国实验血液学杂志

To explore the role of immune regulating cytokines in pathogenesis of the idiopathic thrombocytopenic purpura (ITP) and its clinical significance, the levels of IL-18, TNF-alpha and Sc5b-9 in plasma of 32 ITP patients and 18 normal individuals were detected using ELISA methods. The results showed that IL-18, TNF-alpha and sC5b-9 levels in plasma of ITP patients were higher than that in normal individuals. The level of IL-18 was positively correlated with the levels of TNF-alpha and sC5b-9. In conclusion, The rising levels of the IL-18, TNF-alpha and sC5b-9 were correlated with disorder of Th1/Th2 subsets, and may contribute to the immune dysfunction in ITP patients. The dynamic observation of these cytokines may be useful in directing the clinical treatment for ITP patients.

El sistema del complemento sérico: parte 1, mecanismos de reacción y efectos biológicos / The serum complement system: part1, activation mechanisms and biological effects

A un siglo de su descubrimiento por Bordet, se trata de poner un poco de orden en los mecanismos de activación del complemento a través de su hasta ahora conocidas rutas de activación clásica o de C1 y la vía alterna o de la properdina. Se hace además referencia a otras vías de activación descritas más recientemente como la activación iniciada por la lectina de unión a la manosa (MBL). Se destaca también la actividad de los componentes inhibidores o controladores, que frenan la actividad del sistema, evitando la producción de daños por la formación y liberación de péptidos con potente acción biológica derivados del mismo, tal el caso de las anafilatoxinas. Se hace además referencia a la presencia de receptores para el complemento, ubicados en la membrana de diversas células del sistema inmunológico, responsables de muchas de las principales actividades del sistema, como la fagocitosis de microorganismos a través de la unión de receptores para C3b (principal opsonina) sobre la membrana de las células fagocitarias

Novel mechanisms of immune evasion by Schistosoma mansoni

The interaction of Schistosoma mansoni with its host's immune system is largely affected by multiple specific and non-specific evasion mechanisms employed by the parasite to reduce the host's immune reactivity. Only little is known about these mechanisms on the molecular level. The four molecules described below are intrinsic parasitic proteins recently identified and studied in our laboratory. 1. m28--A 28kDa membrane serine protease. m28 cleaves iC3b and can thus restrict attack by effector cells utilizing complement receptors (especially CR3). Treatment with protease inhibitors potentiates killing of schistosomula by complement plus neutrophils. 2. Smpi56--A 56kDa serine protease inhibitor. Smpi56 binds covalently to m28 and to neutrophil's elastase and blocks their proteolytic activity. 3. P70--A 70kDa C3b binding protein. The postulated activity of P70 includes binding to C3b and blocking of complement activation of the C3 step. 4. SCIP-1--A 94kDa schistosome complement inhibitor. SCIP-1 shows antigenic and functional similarities to the human 18kDa complement inhibitor CD59. Like CD59, SCIP-1 binds to C8 and C9 and blocks formation of the complement membrane attack complex. Antibodies directed to human CD59 bind to schistosomula and potentiate their killing by complement. The structure and function of these four proteins as well as their capacity to induce protection from infection with S. mansoni are under investigation.

How Schistosoma mansoni evades complement-mediated immune attack

Schistosoma mansoni is a trematode that parasitizes man and other mammals, surviving in the vertebrate host for decades, despite eliciting a strong cellular and humoral immune response. The mechanism by which S. mansoni evades immune attack, even in the presence of specific antischistosome antibodies and complement has been the object of perplexity. It was originally proposed that schistosomes avoid antibody recognition by masking themselves with host antigens, and erythrocyte-derived molecules have been appointed as playing this role. We have discovered that schistosomula become complement-resistant by incorporating into their surface a complement inhibitory molecule released from human erythrocytes (HuE). This molecule was shown to be the decay-accelerating factor (DAF), a 70 kDa protein tethered to the surface of HuE by a glycosylphosphatidylinositol (GPI) anchor. The mechanism by which schistosomula acquire DAF from the surface of HuE and its importance to the survival of S.mansoni in the host are discussed.

Immunopathological studies in pemphigus vulgaris, bullous pemphigoid and epidermolysis bullosa acquisita / 대한피부과학회지

Pemphgus vulgaris (PV), Bullus pemphigoid (BP), and Epidermolysis bullous acqusita (EBA) are autoimmune bullous dermatoses, characterized by circulating IgG autoantibodies. These antibodies react with antigens located at the intercellular substance (ICS) of epidermis, basement membrane zone (BMZ), and subepidermal anchoring fibril zone (AFZ), respectively. The subclass distribution of IgG autoantibodies, and the properties and degrees of complement fixing activities of these autoantibodies in each of the above diseases have not been well understood. Indirect immunofluorescence and in vitro complement stainings were performed for the titration of subclasses of IgG antibodies and for the immunofluorescence staining reactivities of complement components C3, C4, C5b-9, H, C4bp, and S. Each serum specimen from five cases of PV, five cases of BP. and three cases of EBA was tested. The findings of multistep technique with monoclonal and polyclonal antibodies are as follows : All four subclasses of IgG antibodies were identified at the antigenic sites in these group, however there were some differences in the antibodies titers. In PV and BP the dominant subclass of highest antibody titer was IgG1 and/or IgG4. In EBA only IgG4 was dominant in all three cases. The results of complement component stainings, in most of the cases of PV, showed positive for C3 and C4 but were negative for the other components or inhibitor proteins at the ICS of epidermis. In BP most of the cases revealed positive staining reactivities at the BMZ for C3, C4, C5b-9, H, and C4bp-9 with no staining reactivities for the inhibitor proteins No significant relevancy was found between the titers of complement fixing IgG subclasses and the numbers of positive complement staining reactivities for complement components. The results suggest that the complement system may contribute more strongly to the formation of bullous lesions in BP and EBA than in PV.

Depositions of Complement Components and Their Inhibitors in Atuto - immune Dermatoses / 대한피부과학회지

The complement system is known to be involved in the pathogenesis of the skin lesions in pernphigus vulgaris, bullous pemphigoid, dermatitis herpetiformis, epidermolysis bullosa acquisita, and systemic lupus erythematosus. Authors examined the skin specimens of each disease cases, who did not show any evidence of complement deficiency, to determine the deposition of complement components(C4, C3, Chb-9) and their inhibitors(C4bp, Factor H, S-protein) by modified direct immunofluorescence. We also looked at the staining pattern and localization, for further insights of their pathobiologic contributions in each disease. The findings of deposits of complement components up to C9, as well as inhibitor proteins at the primary histopathologic sites, in the majority of those cases, may indicate that the complement system, to certain extent, involves the inflamrnatory reactions in these diseases. The co-localization of C5b-9 and S-protein could be regarded as the consequence of in situ formation of SC5b-9 complexs or as the result of non-lytic adsorbed complexes of fluid phase SC5b-9. The pathologic role of the complement seems to depend mostly on the complement-fixing biologic property and the amount of the tissue bound immune complexes, which are often heterogeneous to different diseases and among different patients.