Antiphospholipid antibodies in Brazilian hepatitis C virus carriers

Hepatitis C, a worldwide viral infection, is an important health problem in Brazil. The virus causes chronic infection, provoking B lymphocyte dysfunction, as represented by cryoglobulinemia, non-organ-specific autoantibody production, and non-Hodgkin's lymphoma. The aim of this research was to screen for the presence of antiphospholipid autoantibodies in 109 Brazilian hepatitis C virus carriers without clinical history of antiphospholipid syndrome. Forty healthy individuals were used as the control group. IgA, IgG, and IgM antibodies against cardiolipin and ß2-glycoprotein I were measured with an enzyme-linked immunosorbent assay, using a cut-off point of either 20 UPL or 20 SBU. While 24 (22.0 percent) hepatitis C carriers had moderate titers of IgM anticardiolipin antibodies (median, 22.5 MPL; 95 percentCI: 21.5-25.4 MPL), only three carriers (<3 percent) had IgG anticardiolipin antibodies (median, 23 GPL; 95 percentCI: 20.5-25.5 GPL). Furthermore, IgA anticardiolipin antibodies were not detected in these individuals. Male gender and IgM anticardiolipin seropositivity were associated in the hepatitis C group (P = 0.0004). IgA anti-ß2-glycoprotein-I antibodies were detected in 29 of 109 (27.0 percent) hepatitis C carriers (median, 41 SAU; 95 percentCI: 52.7-103.9 SAU). Twenty patients (18.0 percent) had IgM anti-ß2-glycoprotein I antibodies (median, 27.6 SMU; 95 percentCI: 23.3-70.3 SMU), while two patients had IgG antibodies against this protein (titers, 33 and 78 SGU). Antiphospholipid antibodies were detected in only one healthy individual, who was seropositive for IgM anticardiolipin. We concluded that Brazilian individuals chronically infected with hepatitis C virus present a significant production of antiphospholipid antibodies, mainly IgA anti-ß2-glycoprotein I antibodies, which are not associated with clinical manifestations of antiphospholipid syndrome.

Immunoglobulin E and systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is an autoimmune disease characterized by intense polyclonal production of autoantibodies and circulating immune complexes. Some reports have associated SLE with a Th2 immune response and allergy. In the present study 21 female patients with SLE were investigated for total IgE and IgE antibodies to dust house aeroallergens by an automated enzyme-linked fluorescent assay, and were also evaluated for antinuclear IgE autoantibodies by a modified indirect immunofluorescence test using HEp-2 cells as antigen substrate. Additionally, immunocapture ELISA was used to investigate serum anti-IgE IgG autoantibodies. Serum IgE above 150 IU/ml, ranging from 152 to 609 IU/ml (median = 394 IU IgE/ml), was observed in 7 of 21 SLE patients (33 percent), 5 of them presenting proteinuria, urinary cellular casts and augmented production of anti-dsDNA antibodies. While only 2 of 21 SLE patients (9.5 percent) were positive for IgE antibodies to aeroallergens, all 10 patients with respiratory allergy (100 percent) from the atopic control group (3 males and 7 females), had these immunoglobulins. SLE patients and healthy controls presented similar anti-IgE IgG autoantibody titers (X = 0.37 ± 0.20 and 0.34 ± 0.18, respectively), differing from atopic controls (0.94 ± 0.26). Antinuclear IgE autoantibodies were detected in 17 of 21 (81 percent) sera from SLE patients, predominating the fine speckled pattern of fluorescence, that was also observed in IgG-ANA. Concluding, SLE patients can present increased IgE levels and antinuclear IgE autoantibodies without specific clinical signs of allergy or production of antiallergen IgE antibodies, excluding a possible association between SLE and allergy.

Antileishmanial IgG and IgE antibodies recognize predominantly carbohydrate epitopes of glycosylated antigens in visceral leishmaniasis

The specificity of human antileishmanial IgG and IgE antibodies to glycosylated antigens of Leishmania chagasi was evaluated. An ELISA was performed with soluble leishmanial antigen (SLA) and a panel of 95 sera including samples from patients with subclinical infection (SC) and visceral leishmaniasis (VL), subjects cured of visceral leishmaniasis (CVL), and from healthy individuals from endemic areas (HIEA). Antileishmanial IgG were verified for 18 (40 percent) of 45 SC subjects (mean absorbance of 0.49 ± 0.17). All nine sera from VL patients had such antibody (0.99 ± 0.21), while 11 (65 percent) of 17 CVL individuals were seropositive (0.46 ± 0.05). Only three (12 percent) of 24 HIEA controls reacted in IgG-ELISA. Antileishmanial IgE was detected in 26 (58 percent) of 45 SC patients (0.35 ± 0.14), and in all VL patients (0.65 ± 0.29). These antibodies were also detected in 13(76 percent) of 17 CVL subjects (0.42 ± 0.14) while all HIEA controls were seronegative. There was no correlation between antileishmanial IgG and IgE antibody absorbances. Mild periodate oxidation at acid pH of SLA carbohydrates drastically diminished its antigenicity in both IgG and IgE-ELISA, affecting mainly the antigens of 125, 102, 94, and 63 kDa as demonstrated by western immunoblotting.

Autoantibody production in chronic idiopathic urticaria is not associated with Helicobacter pylori infection

Chronic idiopathic urticaria (CIU) is a dermatological syndrome, characterized by raised erythematous skin lesions, that affects 20 percent of the general population and has been associated with autoimmunity. However, some reports have also suggested a close relationship between CIU and Helicobacter pylori infection, which is endemic in developing countries and associated with chronic gastritis, peptic ulcer disease, and gastric carcinoma. In the present study, we investigated the occurrence of autoantibodies in sera from 23 CIU subjects infected with H. pylori and from 23 CIU subjects without this infection. The presence of anti-thyroid antibodies was determined by indirect hemagglutination assay and the presence of autoantibodies to IgE and C1INH was determined by ELISA. Antibodies to thyroid antigens were detected at low titers from 100 to 400 in three of 23 (13 percent) CIU-infected subjects and in four of 23 (17 percent) CIU-noninfected subjects. The titers of anti-IgE autoantibodies were similar in these CIU groups, presenting absorbances of 1.16 ± 0.09 and 1.07 ± 0.16, respectively, while a titer of 1.14 ± 0.15 was detected in the healthy control group. The concentration of anti-C1INH autoantibodies was the same in the CIU-infected and -noninfected subjects (7.28 ± 1.31 and 7.91 ± 2.45 ng/ml, respectively), and was 7.20 ± 2.25 ng/ml in the healthy control group. However, the serum levels of complexed anti-C1INH antibodies were increased in CIU-infected subjects compared to CIU-noninfected subjects and healthy controls with an absorbance of 1.51 ± 0.21 vs 1.36 ± 0.16 and 1.26 ± 0.23, respectively (P < 0.05), indicating an impaired clearance of immune complexes in CIU-infected patients. In conclusion, no correlation was observed between H. pylori infection and autoantibody production in CIU patients consistent with reports of clinical studies.

IgG anti-IgE autoantibodies in visceral leishmaniasis

Procedures for IgG depletion in visceral leishmaniasis (VL) and schistosomiasis sera using Sepharose-protein G beads also deplete IgE. In this study, the presence of IgG anti-IgE autoantibodies in sera from patients with VL (n = 10), and hepatic-intestinal schistosomiasis (n = 10) and from healthy individuals (n = 10) was investigated. A sandwich ELISA using goat IgG anti-human IgE to capture serum IgE and goat anti-human IgG peroxidase conjugate to demonstrate the binding of IgG to the IgE captured was performed. VL sera had higher titers (p < 0.05) of IgG anti-IgE autoantibodies (OD = 2.01 ± 0.43) than sera from healthy individuals (OD = 1.35 ± 0.16) or persons infected with Schistosoma mansoni (OD = 1.34 ± 0.18). The immunoblotting carried out with eluates from Sepharose-protein G beads used to deplete IgG from these sera and goat anti-human IgE peroxidase conjugate, showed a similar pattern of bands, predominating the 75 kDa epsilon-heavy chain and also polypeptides resulting from physiological enzymatic digestion of IgE. A frequent additional band immediately above 75 kDa was observed only in VL sera

Detection of specific IgE antibodies in parasite diseases

Activation of Th1 or Th2 cells is associated with production of specific immunoglobulin isotypes, offering the opportunity to use antibody measurement for evaluation of T cell function. Schistosomiasis and visceral leishmaniasis are diseases associated with Th2 activation. However, an IgE response is not always detected in these patients. In the present study we evaluated specific IgE antibodies to S. mansoni and L. chagasi antigens by ELISA after depletion of serum IgG with protein G immobilized on Sepharose beads or RF-absorbent (purified sheep IgG antibodies anti-human IgG). In schistosomiasis patients, specific IgE to SWAP antigen was demonstrable in only 10 of 21 patients (48 percent) (mean absorbance + or - SD = 0.102 + or - 0.195) when unabsorbed serum was used. Depletion of IgG with protein G increased the number of specific IgE-positive tests to 13 (62 percent) and the use of RF-absorbent increased the number of positive results to 20 (95 percent) (mean absorbances + or - SD = 0.303 + or - 0.455 and 0.374 + or - 0.477, respectively). Specific IgE anti-L. chagasi antibodies were not detected in unabsorbed serum from visceral leishmaniasis patients. When IgG was depleted with protein G, IgE antibodies were detected in only 3 (11 percent) of 27 patients, and the use of RF-absorbent permitted the detection of this isotype in all 27 visceral leishmaniasis sera tested (mean absorbance + or - SD = 0.104 + or - 0.03). These data show that the presence of IgG antibodies may prevent the detection of a specific IgE response in these parasite diseases. RF-absorbent, a reagent that blocks IgG-binding sites and also removes rheumatoid factor, was more efficient than protein G for the demonstration of specific IgE antibodies

Partial characterization of hemagglutinin activity of the marine sponge Anthosigmella varians

The marine sponge Anthosigmella varians contains proteins that agglutinate human erythrocytes irrespective of their ABO group antigens. The hemagglutination reaction depends on divalent cations andf is not inhibited by L-arabinose, D-xylose, L-rhamnose, D-galactose, D-glucose, L and D-fucose, N-acetyl-D-galactosamine, N-acetyl-D-glucosamine, methyl-alpha-Dmannopiranoside, D-cellobiose, lactose, maltose, melibiose nor raffinose (33 mM each). A partial purification of the hemagglutinins with 31-fold ioncrease in SA and 80% recovery of activity was obtained after gel filtration and ion-exchange gradient elution chromatography. Hemadsorption experiments carried our with out with the semipurified fraction using glutaraldehyde-fixed human erythrocytes suggest that protein with molecular weight of 90 and 34 kDa participate in this rection

Isolation of a lectin from the marine sponge Desmapsama anchorata by affinity chromatography on raffinose-sepharose 6B

A mitogenic lectin for human lymphocytes is present in the marine sponge Desmapsama anchorata. The protein hemagglutinates red blood cells irrespective of ABO group antigens. We now report the isolation of this lectin, by affinity chromatography on a column of raffinose conjugated to epoxy-activated Sepharose 6B, in 8.3% yield and with a purification index of 27 based on hemagglutinating activity. The isolated lectin is a glycoprotein with two subunits with molecular weights of about 18 and 36 kDa which display carbohydrate combining sites of similar specificities and can be associated in different forms

Isolation and funectional characterization of a mitogenic lection from the marine sponge Cinachyrella alloclada

1. A D-galactose-specific lectin was isolated from crude extracts of the marine sponge Cinachyrella alloclada by affinity chromatography on sepharose 4B. 2. The lectin agglutinated human erythrocytes irrespective of ther ABO group antigens. 3. Hemagglutination inhibition tests indicated that the lectin binds D-galactose or carbohydrates having a terminal nonreducing D-galactosyl group. 4. C. alloclada lectin was mitogenic for human periheral blood lymphocytes when AB serum was omitted during the first 24 h of culture. 5 Human serum apparently contains substances which bind or inactivate this lectin

Experimental Chagas' disease in mice infected with one LD50 of parasite

A evoluçäo da Doença de Chagas em camundongos infectados com dose letal 50% (LD50) de Trypanosoma cruzi cepa Y foi acompanhada determinando-se o nível de parasitemia, alteraçöes hematológicas e o nível de anticorpos anti T.cruzi. Os resultados obtidos demonstraram que os animais apresentam pico de parasitemia no 10 + ou - 2 dias que declina rapidamente. A maioria das mortes ocorreu durante a 3a. semana quando a parasitemia é raramente detectada em esfregaços sanguíneos. A comparaçäo dos dados hematológicos obtidos dos animais infectados com os dos controles correspondentes indicou a ocorrência de leve anemia (2a. a 6a. semanas), neutropenia (2a. semana) seguido por neutrofília (3a. semana) e eosinopenia (2a. a 5a. semana). Os soros dos animais infectados testados por imunofluorescência com as três formas do parasito mostraram títulos crescentes de anticorpos a partir da 3a. semana. Experiências de absorçäo cruzada mostraram que os tripomastigotas e amastigotas tem determinantes antigênicos próprios. Além disso essas formas possuem determinantes que säo comuns à forma epimastigota. O soro dos animais infectados apresentou reaçäo de precipitaçäo quando testado com a fraçäo (Fad) que contém glicopeptídeos do extrato de epimastigota ao passo que nenhuma reaçäo foi observada quando testado com a proteinase purificada a partir deste mesmo extrato

Utilizacao da fracao semipurificada da proteinase do Trypanosoma cruzi no imunodiagnostico da doenca de Chagas. / Use of the semipurifiec fraction of Trypanosoma cruzi proteinase in the immunodiagnosis of Chagas' disease

Foram sensibilizadas hemacias humanas 0 Rh negativo com a fracao semipurificada (Fp) da proteinase do Trypanosoma cruzi, e testadas quanto a antigenicidade com soros de pacientes portadores de tripanossomiase americana cronica e de outras doencas parasitarias nao relacionadas.Reacoes de hemaglutinacao positivas foram observadas com os soros de pacientes chagasicos e com alguns soros de individuos portadores de leishmaniose cutaneomucosa. Nao foram observadas reacoes cruzadas com os soros de pacientes portadores de leishmaniose visceral, malaria, toxoplasmose, sifilis, esquistossomose e mononucleose.Os resultados obtidos sao favoraveis ao emprego desta fracao antigenica em testes da imunodiagnostico da tripanossomiase americana

Esquistossomose mansonica: I Evolucao do quadro patologico: analise parasitologica, hematologica e histopatologica / Schistosomiasi mansoni: I. Evolution of the patologic picture; parasitologic, hematologic and hsitopatologic analysisisis

Com o objetivo de acompanhar a evolucao da infeccao bissexual primaria de camundongos por S. mansoni, foram infectados camundongos Swiss com 100 cercarias da linhagem mineira (BH) de Schistosoma mansoni. A evolucao da infeccao foi acompanhada por um periodo de 8 semanas. Foi verificada uma relacao entre o numero de granulomas hepaticos e o numero de vermes totais. O ganho de peso corporal, o peso do baco e a percentagem do peso do figado em relacao ao peso corporal foram diferentes quando comparados os animais infectados e controles. O quadro leucocitario dos camundongos infectados apresentou alteracoes no numero de leucocitos totais, neutrofilos e linfocitos. Os exames histologicos do baço e do fígado revelaram alteraçöes nestes órgäos de acordo com a fase de infecçäo

Esquistossomose mansonica. II - Evolucao dos niveis de proteinas sericas e do perfil eletroforetico por tecnicas de imunoeletroforese quantitativa. / Schistosomiasis mansoni. II. Evolution of the levels of serum proteins and of the electrophoretic profile by quantitative immunoelectrophoresis technics

Camundongos Swiss foram infectados com 100 cercarias da linhagem mineira (BH) do Schistosoma mansoni e sacrificados semanalmente no periodo de 8 semanas de infeccao. Os niveis de proteinas sericas totais destes animais nao diferiram dos apresentados pelos animais controles. Os niveis de albumina serica determinados por "Rocket immunoelectrophoresis" acharam-se diminuidos nas quinta, sexta e setima semanas de infeccao. O perfil obtido por imunoeletroforese cruzada revelou alteracoes em componentes sericos com mobilidade nas regioes de gama, beta e em menor grau de alfaglobulinas, apos a oviposicao do parasito