A novel analytical ELISA-based methodology for pharmacologically active saikosaponins.

A competitive enzyme-linked immunosorbent assay (ELISA) for saikosaponins was established using monoclonal antibody (MAb) 3G10. Hybridoma 3G10 prepared by fusing splenocytes immunized with saikosaponin a-BSA (SSa-BSA) conjugate and a hypoxanthine-aminopterin-thymidine (HAT)-sensitive mouse myeloma cell line, P3-X63-Ag8-U1, secreted monoclonal antibodies with wide cross-reactivity to saikosaponins including saikosaponin b(2) (SSb(2)), c (SSc) and d (SSd), which are stereo and/or regio isomers of SSa. The method, at an effective measuring range of 0.6 mug /ml to 2.3 mug/ml of SSa, successfully detected total saikosaponins in Bupleuri radix and Kampo medicines prescribed with Bupleuri radix. Good correlation between ELISA and HPLC analyses of total saikosaponin in a crude extract of Bupleuri radix was obtained after hydrolysis of acyl saikosaponins by treatment with a mild alkaline solution.

Avaliaçäo de testes imunológicos em pacientes com aborto recorrente / Evaluation of immunologic tests in recurrent abortion

INTRODUÇÃO: O aborto recorrente é um grande enigma, pois apesar de várias causas que lhe säo atribuidas poucas tem um real valor. O papel do fator imunológico tem sido pesquisado amplamente. OBJETIVO: Avaliar alguns testes imunológicos em pacientes com aborto recorrente. TIPO DE ESTUDO: prospectivo LOCAL: Setor de Reproduçäo Humana do Departamento de Ginecologia e Obstetrícia da Faculdade de Medicina de Ribeiräo Preto. PARTICIPANTES: Num estudo piloto foram selecionados nove casais com duas perdas fetais ou mais sem causa aparente e nove casais voluntários com pelo menos dois filhos, sem história de aborto e com idade inferior a 40 anos VARIAVEIS ESTUDADAS: A freqüência de compartilhamento de antígenos HLA e de anticorpos linfocitotóxicos contra antígenos paternos foram avaliados por métodos sorológicos, a variaçäo de fenótipos celulares (CD4, CD8, CD19, CD16, CD56 e HLA-DR) por citometria de fluxo, a atividade "natural killer" (NK) pela liberaçäo de 51Cr e a dosagem de progesterona por radioimunoensaio. RESULTADOS: Näo houve diferença de compartilhamento entre casais com aborto recorrente tanto em relaçäo à classe I quanto II e näo se detectou o aparecimento de anticorpos citotóxicos no grupo investigado. Houve um número absoluto maior de células CD8+(587 vs 448 linfócitos/mmü, p=0,01) e das CD19+(215 vs 182 linfócitos/mmü, p=0,05) nas pacientes. A atividade NK näo foi estatisticamente diferente entre os dois grupos estudados, mas houve uma tendência à reduçäo da atividade NK entre pacientes com aborto recorrente. Näo houve correlaçäo da atividade NK com um número de células CD16+ e CD56+ nem com dosagem de progesterona nos dois grupos estudados. CONCLUSÃO: Estes dados sugerem que o compartilhamento de antígenos HLA, o aparecimento de anticorpos linfocitotóxicos e elevaçäo da atividade NK podem näo ser importantes para a ocorrência de abortos repetidos. o aumento de células CD8+ e CD19+ circulantes pode ocorrer independente de qualquer terapêutica e a citotoxicidade contra antígenos fetais pode ser mediada por células T e näo por células NK.

Humoral immune response to human aortic valve homografts.

The humoral response to homograft valves in humans is largely unknown. The anti-human lymphocyte antigen (HLA) antibody production, specificity, and immunoglobulin class were examined sequentially in 73 patients undergoing aortic valve replacement. In addition, the long-term production of antibodies was examined in a cross-sectional study of 160 patients at periods varying from 1 to 15 years postoperatively. Human lymphocyte antigen antibodies were produced in 17 of 30 antibiotic-sterilized homografts (56%) and in 15 of 15 "homovital" homograft recipients, compared with 6 of the 28 control xenograft recipients (21%) (p < 0.001). The HLA antibodies were immunoglobulin G in all 15 homovital homografts, in 11 of 17 antibiotic-sterilized homografts, and in four of the six xenograft cases. Human lymphocyte antigen specificities could be assigned to the antibodies in 21 cases. In 10 of 11 cases in which donor HLA typing data were available, the antibodies detected were directed against donor HLA class I antigens. Of six possible determinants of HLA antibody production, the type of homograft valve implanted (homovital or antibiotic sterilized) correlated with antibody formation. In the cross-sectional study, 66 of the 85 homovital homograft recipients tested for HLA antibodies after 1 year were found to have antibodies, compared with 29 of 75 antibiotic-sterilized homograft recipients (p = 0.00003). We conclude that homografts appear to stimulate a strong donor HLA-specific antibody response, particularly of the immunoglobulin G class. This is most common in homovital valve recipients. These antibodies can persist for 15 years after operation. The clinical significance of this response requires further investigation.

Niveles de anticuerpos anti-Gal en personas infectadas y no-infectadas por trypanosoma cruzi: probable inducción por bacterias y por el parásito / Anti-Gal antibodies levels in trypanosoma cruzi infected and non-infected persons: probable induction by bacteria and by the parasite

Se estudiaron los niveles de anticuerpos contra epítopes Gal Ó 1,3 Gal en 407 sueros humanos chagásicos (92) y no chagásicos (315), mediante la reacción de hemaglutinación con eritrocitos de conejo; con inmunoelectrotransferencia se investigó la reactividad de sueros con altos títulos de anticuerpos anti-Gal frente a antígenos de escherichia coli y serratia marcescens. Finalmente, utilizando un anticuerpo anti-Gal purificado se identificó epítopes Gal Ó 1,3 Gal en formas metacíclicas de 12 cepas altoandinas chilenas de trypanosoma cruzi. Entre los 92 sueros chagásicos, se demostró que en el 68,5 por ciento (63) de los menos chagásicos se detectó anticuerpos anti-Gal a títulos ò 1:1.600, mientras que entre los sueros no chagásicos, sólo el 15,6 por ciento (49) mostró respuesta anti-Gal a títulos similares. Estos datos sugieren que la determinación de estos anticuerpos podría contribuir a complementar el diagnóstico de la infección, especialmente cuando se establezcan títulos de corte ò 1:3.200. La inmunoelectrotransferencia mostró que sueros de personas infectadas con T. cruzi reconocen varios antígenos presentes en E. coli y S. marcescens, lo que refuerza la idea de que a lo menos en parte estas bacterias serían capaces de estimular estas respuestas. El análisis autorradiográfico utilizando anticuerpo anti-Gal purificado, mostró diferencias en la expresión de los epítopes Gal Ó 1,3 Gal en las diferentes cepas de T. cruzi. Estos resultados sugieren que los anticuerpos anti-Gal podrían tener real significado en los mecanismos de inmunidad natural y protección de la infección en chilenos infectados con T. cruzi

Immunoglobulin G lymphocytotoxic antibodies in clinical liver transplantation: studies toward further defining their significance.

Twenty-two consecutive liver allograft recipients, who tested positive for immunoglobulin G (IgG) lymphocytotoxicity were subjected to pretransplantation and posttransplantation immunologic monitoring of anti-donor IgG lymphocytotoxic antibody titers, total hemolytic complement activity (CH100), circulating immune complexes (CIC), and platelet counts in an effort to improve our understanding of the preformed antibody state in clinical hepatic transplantation. Ten contemporaneous liver transplant recipients whose crossmatch results were negative and who experienced severe hepatocellular damage early after transplantation were included as controls. Crossmatch test results were negative 1 day after transplantation and during the 1 month follow-up remained negative in 14 of 22 (64%) sensitized recipients, most of whom had relatively low (< or = 1:16) anti-donor IgG antibody titers before transplantation. After transplantation, this group and the control group experienced no thrombocytopenia, no increase of CIC, and a gradual increase in CH100 activity that reached normal levels within 1 week. A strong negative correlation between prothrombin time (PT) and CH100 activity in these groups of patients suggested that changes in CH100 activity (P < .0005) were tightly linked to liver synthetic function. In contrast, the crossmatch test results remained positive after transplantation in 8 of 22 (36%) sensitized recipients, all of whom had relatively high (> 1:32 to 1024) pretransplantation titers of anti-donor IgG antibodies. After transplantation these patients developed a syndrome that was characterized by decreased CH100 activity and increased CIC compared with pretransplantation levels and refractory thrombocytopenia that was associated with a 50% allograft failure rate because of biopsy-proven humoral and acute (cellular) rejection.(ABSTRACT TRUNCATED AT 250 WORDS)

Caracterizaçäo parcial de receptores solúveis E presentes em soros de pacientes com hanseníase / Partial characterization of E-soluble receptor (Rs) present in Hansen's disease (HD) patients sera

Os receptores solúveis para eritrócitos de carneiro (E) podem ser encontrados sob forma solúvel em soros humanos, e em níveis elevados em patologias associadas com a imunossupressäo. No presente trabalho, concordando com os dados da literatura observamos nível de receptores solúveis para E (Rs) em níveis elevados em soros de pacientes com hanseníase. A partir desses soros, isolamos Rs de peso moleculares distintos, Rs1 (= 58 KDa) e Rs2 (acima de 150 KDa), por cromatografia por gel filtraçäo (Sephadex G-200) e por troca iônica (DEAE celulose), concordando com os resultados obtidos anteriormente com soros de pacientes urêmicos ou neoplásicos. As fraçöes positivas detectadas, por ensaio imunoenzimático, quando analisadas por eletroforese em gel de poliacrilamida e por "western blotting" utilizando soro anti-Rs, demonstraram apenas uma banda de Rs1 e uma ou duas bandas para Rs2. Para verificar se os mesmos apresentavam alguma relaçäo com CD2, molécula de superfície de linfócito T que interage com E, e com CD58, ligante natural de CD2, foi realizado ensaio imunoenzimático utilizando anticorpos monoclonais respectivos. Os resultados obtidos sugerem a inexistência de relaçäo de Rs1 e Rs2 com a molécula CD2 ou CD58

Role of antibody synthesis and complement activation in concordant xenograft retransplantation.

A mouse-to-rat heart retransplantation model was used to study the effects of complement depletion and antibody production with regard to graft survival and anti-donor antibody specificity. Retransplantation was performed 3 weeks after the first transplantation in the presence of absence of 15-deoxyspergualin (DSG) immunosuppression. Untreated animals rejected their first graft after 3 days and retransplantation resulted in a hyperacute rejection within 2 min. A low titer of preformed anti-mouse lymphocytotoxic antibodies of the IgM subclass was found in serum collected from the unoperated rat. The rejection gave rise to a synthesis of IgG antidonor antibodies reacting with both graft endothelium and sarcolemma. Immunofluorescent staining of the rejected first heart graft showed moderate IgM and IgG antibody deposits on the graft vascular endothelium, while only IgG was found in the second graft. There was no C3 deposition found in the first mouse graft, as was the case in the second mouse graft. Anti-mouse antibodies cross-reacted with hamster antigens and a hyperacute rejection of a hamster heart graft occurred in a mouse-sensitized rat. Immunofluorescent staining revealed that the antibodies did not bind to hamster heart endothelium, as was expected, but, instead, to graft sarcolemma. DSG treatment prolonged the survival of the first graft by a median of 8 days. Continuous treatment until retransplantation resulted in a prolongation to 30 (20-127) min of the survival of the second graft and no increase in antibody titers against mouse antigens was observed. However, immunofluorescent staining revealed a weak binding of anti-mouse antibodies of the IgM subclass in the rejected mouse heart graft. Additional complement depletion with cobra venom factor in DSG-treated animals resulted in a prolongation of the median graft survival to 48 hr (6-96). No sign or minimal signs of antibody deposition were found in these grafts, but histology revealed massive mononuclear infiltration. In conclusion, xenograft transplantation in a concordant situation results in a shift of antidonor antibody Ig synthesis from IgM to IgG. If daily DSG treatment is administered from the day of transplantation, this reduces the synthesis of antidonor antibodies, and if complement is also depleted, the survival of the second graft is prolonged. The significance of the mononuclear infiltration remains to be established.

Predictors for live birth after unexplained spontaneous abortions: correlations between immunologic test results, obstetric histories, and outcome of next pregnancy without treatment.

Our objective was to determine whether results from tests for maternal serum antinuclear antibodies, cytotoxic antibodies to paternal lymphocytes, parental histocompatibility types, and blocking factors for maternal-paternal mixed lymphocyte reactions were predictive of pregnancy outcome without immunologic treatment. Pregnancy outcome data from 95 women with a history of unexplained recurrent spontaneous abortions who underwent immunologic tests at Jefferson Medical College were evaluated with multiple logistic regression analyses. The number of prior spontaneous abortions, history of another relevant diagnosis, parental sharing of one histocompatibility antigen, and maternal age were related to the outcome of the next pregnancy in women given no immunologic treatment (p = 0.05). No significant correlation was found between results from the immunologic tests or other history characteristics evaluated and outcome of the next pregnancy. The immunologic tests evaluated were not clinically useful predictors of pregnancy outcome.

Immunosuppressive treatment of venous allografts.

In order to evaluate whether temporary immunosuppressive therapy is able to improve the results obtained with viable venous allografts and achieve better results than with synthetic grafts, 142 arterial reconstructions were performed in mongrel dogs bypassing their ligated femoral arteries. Histological as well as immunological studies were performed and patency determined by weekly palpation and regular angiography. The 6-month cumulative patency rates were: Group I: synthetic grafts (a) Dacron: 48%, (b) plasma-TFE: 53%. Group II: fresh grafts (a) autografts: 100%, (b) allografts: 37%, (c) allografts treated with cyclosporin 4 mg kg-1 daily for 1 month: 74% (100% after 1 month). Group III: grafts preserved in Hanks' solution with 15% DMSO at -160 degrees C for 1 month (a) autografts: 77%, (b) allografts: 35%, (c) allografts treated with methylprednisolone 1 mg kg-1 daily: 38%, (e) allografts treated with cyclosporin and methylprednisolone: 83%. Group IV: human saphenous veins implanted as xenografts and treated with cyclosporin and methylprednisolone: 18%. Immunosuppressive therapy with cyclosporin seems to be able to prevent early thromboses due to rejection seen after implantation of viable fresh or cryopreserved venous allografts, and the results are significantly better than those obtained with synthetic grafts. Tissue matching might further improve these results. This study suggests that cryopreserved venous allografts could be used for the creation of a vein-bank and their use, in combination with tissue typing and temporary immunosuppressive therapy may be warranted for arterial reconstructions when autologous saphenous vein is not available.

Acquired immunodeficiency syndrome-associated lymphomas: clinical, pathologic, immunologic, and viral characteristics of 111 cases.

The incidence of lymphomas in individuals infected with the human immunodeficiency virus has increased progressively since the beginning of the acquired immunodeficiency syndrome (AIDS) epidemic. The present series includes 111 patients, all diagnosed and studied at one hospital in New York City. There were 108 men and three women; the average age was 39 years and male homosexuality was the predominant risk factor. The materials examined originated from 138 surgical specimens and 24 autopsies. There were 11 cases of Hodgkin's lymphoma and 100 cases of non-Hodgkin's lymphomas (NHL), a proportion strongly skewed in favor of the latter. Hodgkin's lymphoma in AIDS patients was characterized by advanced clinical stage, high histologic grade, and frequent bone marrow involvement. Non-Hodgkin's lymphoma in AIDS patients, in contrast to the general population, originated predominantly in extranodal locations (61 cases) versus locations in which the lymph nodes were the site of the primary tumors (39 cases). In the digestive tract, the unusual oral and anal primary locations were often noted and were possibly related to specific risk factors. There were 15 cases of NHL of the central nervous system, an incidence 14 times greater than that recorded in the general population. The majority of NHLs were of high histologic grade, Burkitt's and large cell immunoblastic, representing most of the cerebral and gastrointestinal tumors. All NHLs were of B-cell immunophenotype. Lymphadenopathies with the histologic features of human immunodeficiency virus infection, particularly of the late stage (type C), often preceded NHL. Probing for Epstein-Barr virus genome was more frequently positive in Hodgkin's lymphoma than in NHL. Immunologic evaluations showed severely depressed T cell counts and CD4 to CD8 cell ratios as well as markedly increased levels of antilymphocyte antibodies. Reflecting the background of profound immune deficiency, the AIDS-associated lymphomas were characterized by high aggressiveness, early tendency to generalization, frequent post-treatment relapse, and short periods of survival.

Antibodies to hepatocyte derived antigens and liver damage in patients after bone marrow transplantation.

The follow-up sera from 33 patients who received allogenic bone marrow transplantation (BMT) were tested by ELISA for antibodies to liver derived antigens present in a macromolecular, lipid associated, protein complex (LSP). Anti-LSP were found in 20% of patients with graft-vs-host disease (1 with acute GVHD, 3 with chronic GVHD), but in none of the 13 patients without GVHD. Lymphocytotoxic antibodies (LCTA) were frequently detected with similar prevalence in patients with and without GVHD. In the 4 anti-LSP +ve cases, LCTA serum levels did not follow the trend of anti-LSP antibody levels. Liver biopsy was performed in 10 patients with clinical and biochemical sign of GVHD and showed features of hepatic GVHD in six cases; although piecemeal necrosis was present in 3 cases, anti-LSP were detected only in one patient. An anti-LSP response can be elicited in patients after BMT only during GVHD, with no relationship to LCTA and without a close association with signs of periportal hepatocyte damage.

Immunological studies of renal allograft recipients treated with total lymphoid irradiation.

It is well known that highly sensitized patients and/or high responders, even under CsA therapy, constitute a risk category for transplantation. Based on this evidence, in 1982, our group initiates a pilot study using total lymphoid irradiation (TLI) as a pre-transplant modulator of patient's immuno-response. TLI has been employed in 30 uremic, non diabetic, patients. During this experience the first protocol, characterized by pre-transplant TLI greater than 2,000 rads (13 pts.) and post-transplant conventional therapy, was abandoned because of the severe TLI side effects. In the second protocol TLI dose never exceeded 2,000 rads and CsA was given, at initial dose of 7-12 mg/Kg/day according to CsA blood through levels. The immunological monitoring was performed during TLI treatment and in the postoperative clinical course by cell markers profile determination and functional assays. The data obtained have demonstrated that TLI treatment causes a prolonged depression in CD4 positive cells, a predominant recovery of T suppressor population, a pronounced impairment of T functions and a development of specific unresponsiveness to donor antigens. Furthermore the TLI plus CsA protocol, showing an additive effect which steadily decreases patient immunoreactivity, a lack of side effects and a stable long term graft function seems to be a more useful method for transplantation in high-risk or in strongly immunoreactive patients.

Removal of lymphocytotoxic antibodies by pretransplant immunoadsorption therapy in highly sensitized renal transplant recipients.

A high level of panel-reactive antibodies (PRA) in potential renal transplant recipients is associated with a long waiting time until transplantation and correlates inversely with graft outcome. We report our experience with the employment of immunoadsorption (IA) using a column composed to sepharose-bound staphylococcal protein A (which has a relatively selective affinity for binding IgG compared with other immunoglobulins) to decrease the PRA levels and expedite transplantation in 6 highly sensitized potential renal transplant recipients (1 primary and 5 awaiting second transplants). All patients had PRA levels of greater than or equal to 70% for a duration of 1 year prior to IA. Only patients with antibody specificity localized to 1 or 2 HLA A or B antigens were accepted for the study. IA procedures were performed on alternate days until a twofold decrease in antibody titer had occurred (maximum: 6 procedures). Repeat procedures were initiated if the HLA antibody titer returned to its baseline value. Intravenous cyclophosphamide (CY) (10 mg/kg/day every 3 weeks) and methylprednisolone (MP) (0.5 mg/kg/day) were provided as adjunctive immunosuppression until transplantation. A total of 44 immunoadsorption procedures were performed (27 primary and 17 repeat) with treatment of 2.49 +/- 0.02 plasma volumes per session. Serum IgG concentration decreased 95 +/- 3% and PRA activity decreased 75 +/- 16% after the primary treatment course. Four patients received cadaveric grafts within 3.7 +/- 1.2 months following the last IA procedure. Three grafts are functioning at 1 year, 8 months, and 8 weeks posttransplant. The remaining graft demonstrated primary nonfunction. All four patients had a past positive crossmatch using pre-IA sera with their respective donors. Patients not transplanted exhibited rapid resynthesis of IgG and a return of the PRA towards baseline levels within a few weeks after IA. We conclude that IA can effectively remove HLA antibodies and expedite graft availability in highly sensitized patients.

[Conflicting xenograft. Role of preoperative total lymphoid irradiation]. / Xénogreffes discordantes. Le rôle de l'irradiation lymphoïde totale pré-opératoire.

This study deals with an experimental model of discordant cardiac xenograft between 24 donor lambs of the Préalpes race and 24 recipient Camborough pigs divided up into 4 groups: I control (6) without immunosuppressive treatment; II (5) with pharmacological immunosuppression (IP); III (13) with PI and total lymphoid irradiation (TLI) and immediate graft, divided up into IIIa (5) with high-rate (HR) TLI and IIIb with low-rate (LR) TLI; IV (4) with a two-week lapse between TLI and grafting. The best graft survival rate (GSR) is obtained either after delayed LR-TLI or after LR-TLI without delay. This study seems to be the first one demonstrating that for discordant xenogenic grafts, TLI associated to PI with cyclosporin A (Cy A) significantly prolongs the survival of the graft (30 times).

Production of antiidiotypic antibodies in the rat: in vitro characterization of specificity and correlation with in vivo specific suppression of cardiac allograft immune reaction across major histocompatibility complex.

We studied the effect of antiantidonor major histocompatibility complex antibodies (antiidiotypic antibodies) in vivo on ACI cardiac allograft survival in Lewis rats and correlated the results with in vitro mixed lymphocyte culture. Lewis anti-ACI hyperimmune sera (Ab1) were obtained from animals that have rejected successive ACI skin grafts. Purified immunoglobulin (Ig) G and IgM fractions were obtained from the sera. These putative "idiotypic antibodies" (IgG fractions) were used to immunize groups of five naive Lewis rats. Purified Ig (0.5 mg) was mixed with 0.5 ml incomplete Freund's adjuvant and injected intraperitoneally -15, -7, and -3 days before and at the time of ACI cardiac allografting. The median allograft survival time was 11.2 +/- 0.7 days in animals treated with Ab1 compared with 6.4 +/- 0.5 days in untreated control rats (p less than 0.001). Use of IgM with adjuvant did not prolong graft survival. Purified IgG obtained from sera collected before transplantation was tested for antiidiotypic antibodies with the complement-mediated cytotoxicity assay. For this, serial dilutions of the hyperimmune serum were tested for cytotoxicity against ACI lymphocyte in the presence of Ig from sera collected after immunization with Ab1. Blocking was demonstrated by sera and IgG obtained from Lewis rats that received anti-ACI IgG (Ab1) with adjuvant. The blocking activity of purified IgG (Ab2) was strain specific because it did not block the reaction of Lewis hyperimmune sera against third-party Wistar-Furth rats. Thoracic duct lymphocytes from immunized recipients showed no blastogenic responses when tested in in mixed lymphocyte culture for reactivities against splenocytes from ACI rats. The finding that Lewis rats treated with Ig from sera containing anti-ACI antibodies exhibit impaired anti-ACI T- and B-cell reactivity and prolong allograft survival suggests that pretreatment of recipients with idiotypic antibodies leads to development of antiidiotypic antibodies that modulate alloreactivity suppressing allograft rejection.

Lymphocyte subpopulations and neutrophil function in chronic human Chagas' disease

Numeros absolutos de leucocitos e linfocitos, de celulas T totais, indutoras/auxiliares, supresorras/citotoxicas e de celulas B estavam diminuidos no sangue periferico de pacientes com doenca de Chagas cronica. Como anticorpos antilinfocitarios estavam presentes em apenas uma minoria de pacientes, eles provavelmente nao sao responsaveis pelas anormalidades das subpopulacoes de linfocitos. Neutrofilos de pacientes estimulados por plasma autologo tratado por endotoxina mostravam atiividade quimiotatica diminuida que deve ser devida a um defeito celular intrinseco e nao a inibicao plasmatica. A migracao aleatoria dos neutrofilos estava normal. A reducao do corante "nitroblue tetrazolium" (NBT) por neutrofilos estimulados por endotoxina tambem estava diminuioda nos pacientes. Estes achados estendem a documentacao da imunossupressao na doenca de Chagas humana. Eles podem ser relevantes para autoimunidade e para defesa contra microorganismos e celulas tumorais, pelo menos em um subgrupo de pacientes com anormalidades mais pronunciadas

Lymphocyte subpopulations and neutrophil function in chronic human Chagas' disease.

The absolute numbers of total leukocytes, lymphocytes. T cells, helper/inducer, suppressor/cytotoxic and B cells were decreased in the peripheral blood of patients with chronic Chagas' disease. Since antilymphocyte antibodies were present only in a minority of patients they probably cannot account for the abnormalities in lymphocyte subsets. Patient neutrophils stimulated with endotoxin-treated autologous plasma showed depressed chemotactic activity and this seems to be an intrinsic cellular defect rather than plasma inhibition. Random migration of neutrophils was normal. Reduction of nitroblue tetrazolium by endotoxin-stimulated neutrophils was also decreased. These findings further document the presence of immunosuppression in human Chagas' disease. They may be relevant to autoimmunity, defense against microorganisms and against tumor cells at least in a subset of patients with more severe abnormalities.

Avaliaçäo da especifidade dos anticorpos linfocitotóxicos em lúpus eritematoso sistêmico: correlaçäo com atividade clínica de doença / Evaluation of lymphocytoxic antibodies specificity in systemic lupus erythematosus: correlation with the clinical activity of the disease

Pacientes portadores de lúpus eritematoso sistêmico (LES), caracterizados em relaçäo ao estadiamento clínico, em atividade e remisäo da doença, foram estudados quanto a presença de anticorpos linfocitotóxicos ciruclantes no soro, através da citoxicidade mediada por complemento (CMC). Soros de 35 pacientes (42 soros) foram testados contra painel de linfócitos periféricos de 31 indivíduos normais com tipagem para antígenos HLA classe I conhecidos (HLA A, B e C), e os experimentos executados em diferentes diluiçöes e temperaturas. As análises demonstraram que 66,66% dos soros apresentaram anticorpos linfocitotóxicos dirigidos contra células de pelo menos um dos doadores normais. A freqüência destes anticorpos mostrou significância estatística nos pacientes em atividade (80,95%) quando comparados aos em remissäo (52,38%). Doentes lúpicos que recebiam diferentes doses de corticosteróides foram separados em grupos, e concluímos que a CMC independe da quantidade de prednisona recebida pelos pacientes. Na maioria dos casos os anticorpos linfocitotóxicos näo estavam dirigidos contra os determinantes anigénicos de histocompatibilidade classe I, pois apenas 3 dos 42 soros reconheceram de forma constante células de doadores, especialmente os de antígenos HLA A1, A2, A3, A11, B5 e B35, permitindo inferir que outros marcadores da superfície linfocitária sejam os maiores pela CMC encontrada nos pacientes com LES. Neste estudo näo observamos variaçöes na identificaçäo dos anticorpos linfocitotóxicos quando executamos as reaçöes nas diferentes temperaturas (4- e 22-C)