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.
Atrophy ; Complement Membrane Attack Complex ; Dermatitis* ; Dermatomyositis* ; Diagnosis ; Extremities ; Myositis* ; Phenotype* ; Skin Manifestations

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.
Atrophy ; Complement Membrane Attack Complex ; Dermatitis ; Dermatomyositis ; Diagnosis ; Extremities ; Myositis ; Phenotype ; Skin Manifestations

OBJECTIVETo 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.

METHODSThe 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.

RESULTSFocal 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.

CONCLUSIONC5b-9 contributes to the pathogenesis of necrotizing myopathy mediated by pathologies in the blood vessels.

Aged ; Complement Membrane Attack Complex ; metabolism ; Female ; Humans ; Male ; Middle Aged ; Muscle, Skeletal ; blood supply ; Muscular Diseases ; blood ; pathology ; Necrosis

OBJECTIVETo 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).

METHODSSerum 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.

RESULTS①In 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).

CONCLUSIONDeficiency 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.

Anemia, Aplastic ; Blood Platelets ; Clone Cells ; Complement Membrane Attack Complex ; Flow Cytometry ; Hemoglobinuria, Paroxysmal ; Humans ; P-Selectin ; Thrombosis

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.
Antigen-Antibody Complex ; Complement Factor H ; Complement Membrane Attack Complex ; Complement System Proteins* ; Dermatitis Herpetiformis ; Epidermolysis Bullosa Acquisita ; Fluorescent Antibody Technique, Direct ; Humans ; Lupus Erythematosus, Systemic ; Pemphigoid, Bullous ; Skin ; Skin Diseases*

Asthma ; blood ; Child ; Child, Preschool ; Complement Membrane Attack Complex ; analysis ; Enzyme-Linked Immunosorbent Assay ; Female ; Humans ; Intercellular Adhesion Molecule-1 ; blood ; Male ; Vascular Cell Adhesion Molecule-1 ; blood

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.
Adolescent ; Adult ; Child ; Child, Preschool ; Complement Membrane Attack Complex ; analysis ; Female ; Humans ; Interleukin-18 ; blood ; Male ; Middle Aged ; Purpura, Thrombocytopenic, Idiopathic ; immunology ; Tumor Necrosis Factor-alpha ; analysis

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.
Anaphylaxis/diagnosis* ; Basophils/cytology* ; Carboxypeptidases A/metabolism* ; Complement Membrane Attack Complex/metabolism* ; Contrast Media ; Flow Cytometry ; Granulocytes/cytology* ; Humans ; Mast Cells/cytology* ; Tetraspanin 30/metabolism*

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.
Antibodies ; Autoantibodies ; Basement Membrane ; Blister ; Complement Membrane Attack Complex ; Complement System Proteins ; Epidermis ; Epidermolysis Bullosa Acquisita* ; Epidermolysis Bullosa* ; Fluorescent Antibody Technique ; Fluorescent Antibody Technique, Indirect ; Immunoglobulin G ; Pemphigoid, Bullous* ; Pemphigus* ; Skin Diseases, Vesiculobullous

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.
Animals ; Antigens, CD45/analysis ; Antigens, CD46/analysis ; Antigens, CD55/analysis ; Complement C3/analysis ; Complement C4b/analysis ; Complement Membrane Attack Complex/analysis ; Complement System Proteins/*analysis ; Cyclosporine/*toxicity ; Disease Models, Animal ; Immunity, Innate/drug effects ; Immunoblotting ; Immunohistochemistry ; Immunosuppressive Agents/toxicity ; Kidney/*drug effects/immunology/pathology ; Kidney Diseases/*chemically induced/immunology ; Mice ; Microscopy, Confocal ; Peptide Fragments/analysis