RESUMEN
Visceral leishmaniasis (VL) is an infectious disease caused by Leishmania infantum. Clinically, VL evolves with systemic impairment, immunosuppression and hyperactivation with hypergammaglobulinemia. Although renal involvement has been recognized, a dearth of understanding about the underlying mechanisms driving acute kidney injury (AKI) in VL remains. We aimed to evaluate the involvement of immunoglobulins (Igs) and immune complexes (CIC) in the occurrence of AKI in VL patients. Fourteen VL patients were evaluated between early treatment and 12 months post-treatment (mpt). Anti-Leishmania Igs, CIC, cystatin C, C3a and C5a were assessed and correlated with AKI markers. Interestingly, high levels of CIC were observed in VL patients up to 6 mpt. Concomitantly, twelve patients met the criteria for AKI, while high levels of cystatin C were observed up to 6 mpt. Plasmatic cystatin C was positively correlated with CIC and Igs. Moreover, C5a was correlated with cystatin C, CIC and Igs. We did not identify any correlation between amphotericin B use and kidney function markers in VL patients, although this association needs to be further explored in subsequent studies. Our data reinforce the presence of an important renal function impairment during VL, suggesting the involvement of Igs, CIC, and C5a in this clinical condition.
Asunto(s)
Lesión Renal Aguda , Complejo Antígeno-Anticuerpo , Leishmaniasis Visceral , Humanos , Leishmaniasis Visceral/inmunología , Leishmaniasis Visceral/sangre , Lesión Renal Aguda/sangre , Lesión Renal Aguda/inmunología , Lesión Renal Aguda/parasitología , Masculino , Femenino , Complejo Antígeno-Anticuerpo/sangre , Adulto , Biomarcadores/sangre , Persona de Mediana Edad , Cistatina C/sangre , Adolescente , Adulto Joven , Anfotericina B/uso terapéutico , Leishmania infantum/inmunologíaRESUMEN
Severe coronavirus disease 2019 (COVID-19) is associated with an overactive inflammatory response mediated by macrophages. Here, we analyzed the phenotype and function of neutrophils in patients with COVID-19. We found that neutrophils from patients with severe COVID-19 express high levels of CD11b and CD66b, spontaneously produce CXCL8 and CCL2, and show a strong association with platelets. Production of CXCL8 correlated with plasma concentrations of lactate dehydrogenase and D-dimer. Whole blood assays revealed that neutrophils from patients with severe COVID-19 show a clear association with immunoglobulin G (IgG) immune complexes. Moreover, we found that sera from patients with severe disease contain high levels of immune complexes and activate neutrophils through a mechanism partially dependent on FcγRII (CD32). Interestingly, when integrated in immune complexes, anti-severe acute respiratory syndrome coronavirus 2 IgG antibodies from patients with severe COVID-19 displayed a higher proinflammatory profile compared with antibodies from patients with mild disease. Our study suggests that IgG immune complexes might promote the acquisition of an inflammatory signature by neutrophils, worsening the course of COVID-19.
Asunto(s)
Anticuerpos Antivirales/inmunología , Complejo Antígeno-Anticuerpo/inmunología , COVID-19/inmunología , Inmunoglobulina G/inmunología , Activación Neutrófila/inmunología , Adulto , Anciano , Anticuerpos Antivirales/sangre , Complejo Antígeno-Anticuerpo/sangre , Antígenos CD/inmunología , Antígeno CD11b/inmunología , Moléculas de Adhesión Celular/inmunología , Femenino , Proteínas Ligadas a GPI/inmunología , Humanos , Inmunoglobulina G/sangre , Interleucina-8/inmunología , Masculino , Persona de Mediana Edad , Neutrófilos/inmunología , Receptores de IgG/inmunología , SARS-CoV-2/inmunología , Adulto JovenRESUMEN
OBJECTIVES: Accurate serological assays are urgently needed to support public health responses to Zika virus (ZIKV) infection with its potential to cause foetal damage during pregnancy. Current flavivirus serology for ZIKV infections lacks specificity due to cross-reacting antibodies from closely related other flaviviruses. In this study, we evaluated novel serological tests for accurate ZIKV IgG detection. METHODS: Our ELISAs are based on immune complex binding. The high specificity is achieved by the simultaneous incubation of labelled ZIKV antigen and unlabelled flavivirus homolog protein competitors. Two assays were validated with a panel of 406 human samples from PCR-confirmed ZIKV patients collected in Brazil (n = 154), healthy blood donors and other infections from Brazil, Europe, Canada and Colombia (n = 252). RESULTS: The highest specificity (100% [252/252, 95% confidence interval (CI) 98.5-100.0]) was shown by the ZIKV ED3 ICB ELISA using the ED3 antigen of the ZIKV envelope. A similar test using the NS1 antigen (ZIKV NS1 ICB ELISA) was slightly less specific (92.1% [232/252, 95% CI 88.0-95.1]). The commercial Euroimmun ZIKV ELISA had a specificity of only 82.1% (207/252, 95% CI 76.8-86.7). Sensitivity was high (93-100%) from day 12 after onset of symptoms in all three tests. Seroprevalence of ZIKV IgG was analysed in 87 samples from Laos (Asia) confirming that the ED3 ELISA showed specific reactions in other populations. CONCLUSIONS: The novel ED3 ICB ELISA will be useful for ZIKV-specific IgG detection for seroepidemiological studies and serological diagnosis for case management in travellers and in countries where other flavivirus infections are co-circulating.
Asunto(s)
Complejo Antígeno-Anticuerpo/sangre , Inmunoglobulina G/sangre , Infección por el Virus Zika/sangre , Infección por el Virus Zika/diagnóstico , Virus Zika/aislamiento & purificación , Adolescente , Adulto , Anciano , Complejo Antígeno-Anticuerpo/inmunología , Brasil , Niño , Ensayo de Inmunoadsorción Enzimática/métodos , Femenino , Humanos , Inmunoglobulina G/inmunología , Laos , Masculino , Persona de Mediana Edad , Embarazo , Sensibilidad y Especificidad , Estudios Seroepidemiológicos , Pruebas Serológicas , Adulto Joven , Virus Zika/inmunología , Infección por el Virus Zika/inmunologíaRESUMEN
AIMS: To describe an anti-Strongyloides IgA, IgG and IgG immune complex antibody response profile in patients with pulmonary tuberculosis. METHODS AND RESULTS: Saliva and serum samples were collected from 100 individuals: group I, 50 apparently healthy individuals; and group II, 50 pulmonary tuberculosis patients. The IgA, IgG and IgG immune complex detection were carried out via an ELISA immunoenzymatic test. Optical density medians in saliva samples of IgA antibody (median of 7.21) and IgG-IC (median of 4.95) were significantly higher in tuberculosis group compared to control individuals (median IgA of 3.93 and IgG-IC of 2.38). CONCLUSION: This study presents antibody data to the field of pulmonary tuberculosis and strongyloidiasis coinfection, including saliva samples, and especially IgG immune complex detection.
Asunto(s)
Anticuerpos Antiprotozoarios/sangre , Complejo Antígeno-Anticuerpo/sangre , Inmunoglobulina A/sangre , Inmunoglobulina G/sangre , Strongyloides/inmunología , Adulto , Animales , Ensayo de Inmunoadsorción Enzimática , Femenino , Humanos , Larva/inmunología , Masculino , Persona de Mediana Edad , Saliva/inmunología , Estrongiloidiasis/inmunología , Estrongiloidiasis/patología , Tuberculosis Pulmonar/patologíaRESUMEN
The present study is aimed at evaluating serological method using scFv anti-Strongyloides sp. and reporting the frequencies of the results with conventional parasitological technique (faeces) in elderly individuals. Among 112 elderly individuals (≥60 years of age), 14.28% were positive for at least one enteroparasite, with one individual positive for S. stercoralis. Sera were evaluated for the presence of anti-Strongyloides sp. antibodies using total or detergent fraction extracts of Strongyloides venezuelensis, which presented positivity rates of 19.64% and 10.71%, respectively. An anti-HSP60 single-chain variable fragment from Strongyloides sp. was used to detect parasite antigens, with 5.36% (6 individuals) of ELISA-positive individuals returning a positive result. While the serological test indicates previous or recent infection and may be limited by antigen purification, the anti-HSP60 method reflects the presence of Strongyloides sp. immune complexes and exhibits greater sensitivity and specificity. Our results demonstrate the variable occurrence of enteroparasites in elderly individuals residing in long-term nursing homes and validate a novel epidemiological tool to describe infection cases by Strongyloides sp.
Asunto(s)
Anticuerpos Antihelmínticos/sangre , Complejo Antígeno-Anticuerpo/sangre , Antígenos Helmínticos/sangre , Chaperonina 60/sangre , Anticuerpos de Cadena Única/sangre , Estrongiloidiasis/diagnóstico , Anciano , Anciano de 80 o más Años , Animales , Anticuerpos Antihelmínticos/inmunología , Antígenos Helmínticos/inmunología , Brasil , Chaperonina 60/inmunología , Heces/parasitología , Femenino , Hogares para Ancianos , Humanos , Masculino , Persona de Mediana Edad , Casas de Salud , Sensibilidad y Especificidad , Anticuerpos de Cadena Única/inmunología , Strongyloides/crecimiento & desarrollo , Strongyloides/inmunología , Strongyloides/patogenicidad , Estrongiloidiasis/sangre , Estrongiloidiasis/inmunología , Estrongiloidiasis/parasitologíaRESUMEN
Visceral leishmaniasis (VL) is epidemic in Brazil with an increasing incidence of human cases and canine reservoirs, with host hypergammaglobulinemia. Conventional enzyme-linked immunosorbent assay (cELISA) based on several parasitic antigens is the main method for diagnosis and indication of treatment. Dissociative ELISA (dELISA) uses acidic treatment to free immunoglobulin G (IgG) from immune complexes, and its use revealed a significant positive fraction of suspected cases with negative serology. Looking for small molecules or haptens that block IgG antibodies, we purified by molecular exclusion chromatography, 1000-3000 MW molecules from promastigote soluble extract, mostly oligosaccharides comprising 6-13 sugar residues using MALDI-TOF analysis. Glycan-BSA complex (GBC) was constructed by conjugating promastigote glycans to BSA molecules, allowing their use in the solid support in cELISA or dELISA. Sera from experimentally infected hamsters showed higher levels of blocked monomeric IgG during infection, mostly against GBC, which was also present in lower concentrations in the promastigote soluble extract dELISA. Those data show that most of the specific monomeric IgG in serum are blocked by haptens composed by glycans produced by the parasite, better detected in the high dilution of sera in the dELISA assays. dELISA is a useful technique for detecting blocked monomeric antibodies that could have difficult clearance from blood, which could result in hypergammaglobulinemia.
Asunto(s)
Complejo Antígeno-Anticuerpo/sangre , Ensayo de Inmunoadsorción Enzimática/métodos , Inmunoglobulina G/sangre , Leishmaniasis Visceral/inmunología , Polisacáridos/sangre , Animales , Brasil/epidemiología , Cricetinae , Modelos Animales de Enfermedad , Epidemias , Humanos , Concentración de Iones de Hidrógeno , Hipergammaglobulinemia , Leishmaniasis Visceral/epidemiología , Polisacáridos/metabolismo , Albúmina Sérica Bovina/metabolismo , Espectrometría de Masa por Láser de Matriz Asistida de Ionización DesorciónRESUMEN
Strongyloidiasis is a human parasitosis that is considered a public health problem. Early diagnosis of this infection is extremely important in immunocompromised patients (i.e. subjects with alcoholism). This study aimed to evaluate anti-Strongyloides immunoglobulin G (IgG) and immunoglobulin A (IgA), assess levels of circulating immune complexes (IC) and determine IgG avidity in serum samples from alcoholic and nonalcoholic individuals. A total of 140 blood samples were collected from male individuals (70 alcoholic and 70 nonalcoholic subjects). Serum was obtained and analysed by enzyme-linked immunosorbent assay for IgG, IgA, IC detection and avidity determination. Anti-Strongyloides IgG was detected in 55.7% of alcoholic subjects and 32.8% nonalcoholics, while IC levels showed frequencies of 38.6% and 17.1% in these groups, respectively. Anti-Strongyloides IgA was lower among alcoholics (4.3%) than nonalcoholics (34.3%). Spearman's correlation coefficient reported a positive correlation between IgG, IC and IgA in alcoholic individuals and no correlation in nonalcoholics. The median avidity index was higher in alcoholics (83.8%) than nonalcoholic subjects (73.2%). In conclusion, this study shows that alcoholic subjects produced specific antibodies against S. stercoralis regardless of the possible immunosuppression caused by chronic alcoholism. Considering that alcoholics are more susceptible to the severe forms of strongyloidiasis, the implementation of immunological methods as a complementary approach to parasitological diagnostics (i.e. detection of IgG, IC and antibody avidity) appears to be an alternative method for early diagnosis in these individuals.
Asunto(s)
Alcohólicos , Anticuerpos Antihelmínticos/sangre , Complejo Antígeno-Anticuerpo/sangre , Estrongiloidiasis/diagnóstico , Estrongiloidiasis/inmunología , Adulto , Animales , Afinidad de Anticuerpos , Estudios Transversales , Ensayo de Inmunoadsorción Enzimática , Heces/parasitología , Humanos , Huésped Inmunocomprometido , Inmunoglobulina A/sangre , Inmunoglobulina G/sangre , Masculino , Persona de Mediana Edad , Strongyloides stercoralis , Estrongiloidiasis/sangreRESUMEN
Human strongyloidiasis is caused by helminth Strongyloides stercoralis. It has a worldwide distribution, often neglected and cause of severe morbidity. The parasitological diagnosis is hindered by the low and irregular amount of larvae in feces. The goal of the present study was to detect IgG and IgG immune complex using conventional serum samples and saliva as alternative samples. We collected samples from 60 individuals, namely: group I composed of 30 healthy individuals; and group II composed of 30 individuals eliminating S. stercoralis larvae in feces. We calculated the area under the curve, general index of diagnostic accuracy, Kappa index and determined the correlations between different diagnostic tests. The detection of IgG levels was performed by an immunoenzymatic assay with alkaline extract of S. venezuelensis larvae as antigen. Positivity of anti-S. stercoralis IgG in serum samples from group I was 3·3%, and from group II 93·3%. The detection of immune complex indicated that group I exhibited 3·3% and group II 56·7%. In the saliva samples, IgG detection was 26·7% for group I and 43·3% for group II. Immune complex was detected in 20% of group I, and 30% of group II. IgG immune complex in conventional serum samples and saliva as alternative samples can be considered biomarkers for the diagnosis of active strongyloidiasis.
Asunto(s)
Complejo Antígeno-Anticuerpo/análisis , Antígenos Helmínticos/inmunología , Inmunoglobulina G/análisis , Pruebas Inmunológicas/métodos , Saliva/química , Estrongiloidiasis/diagnóstico , Animales , Anticuerpos Antihelmínticos/sangre , Complejo Antígeno-Anticuerpo/sangre , Biomarcadores/análisis , Ensayo de Inmunoadsorción Enzimática , Heces/parasitología , Humanos , Inmunoglobulina G/sangre , Larva , Strongyloides stercoralis/inmunología , Estrongiloidiasis/inmunologíaRESUMEN
Potentially malignant disorders (PMDs) of oral cavity and oral cancer remain a cause of serious concern despite intensive research and development. Diet and immunity have been identified to play a crucial role as modifying factors in these diseases. Our study intended to explore this relationship by estimating and comparing the serum levels of copper, iron and circulating immune complexes (CICs) in patients diagnosed with PMDs and oral cancer and normal healthy individuals. In this study, 40 histopathologically diagnosed cases of PMDs and oral cancer were included along with 30 healthy controls and 5 ml of venous blood was drawn using venipuncture. Serum estimation of copper, iron and CIC then followed using the colorimetric and spectrophotometric methods. The data obtained was subjected to statistical analysis using one way ANOVA and Pearson's Product-Moment Correlation Test. The mean serum copper level was measured as 138.98 ± 10.13µg/100ml in the PMD group and 141.99 ± 21.44 µg/100ml in the oral cancer as compared to 105.5 + 18.81µ/100ml in the controls. The mean serum CIC levels was highest in the oral cancer (9.65 ± 0.16OD470) followed by the PMD group (0.18 + 0.21 OD470) and least in the control group (0.048 ± 0.02OD470). Whereas, the serum levels of iron showed a significant decrease in the PMD group (110.9 ± 10.54 µg/100ml) and the oral cancer group (114.29 ± 25.83 µg/100ml) as compared with the control group (136.85 ± 14.48 µg/100ml). There was no positive correlation obtained between the three groups with respect to the chosen parameters indicating that the variables were independent of each other. It can be thus be ascertained that trace elements like copper and iron as well as humoral responses (CICs) have a close relationship with PMDs and oral cancers.
Asunto(s)
Complejo Antígeno-Anticuerpo/sangre , Carcinoma de Células Escamosas/sangre , Cobre/sangre , Hierro/sangre , Liquen Plano Oral/sangre , Neoplasias de la Boca/sangre , Fibrosis de la Submucosa Bucal/sangre , Adulto , Distribución por Edad , Anciano , Análisis de Varianza , Biomarcadores/sangre , Estudios de Casos y Controles , Diagnóstico Precoz , Femenino , Humanos , Masculino , Persona de Mediana Edad , Lesiones Precancerosas/sangre , Valores de Referencia , Factores de Riesgo , Distribución por SexoRESUMEN
BACKGROUND: The immunogenic potential of dentin has been reported through dentin-reactive autoantibodies detection in human and animal model. This study aimed to investigate the formation and diagnostic value of immune complexes formation after autoantibodies production, and soluble dentin antigens levels associated to root resorption, in the course of orthodontic tooth movement, in rat experimental model. METHODS: Forty Wistar rats (n = 8 for each group) were submitted to orthodontic tooth movement, in which the maxillary right first molar was mesially moved by applying of 55 g of force for 3, 7, 14, or 21 days. Untreated group was used as control. Circulating autoantibodies to rat dentinal extract, immune complexes, and soluble dentinal antigen levels were determined by immunoenzyme assays. Additionally, dentinal antigens were analyzed by immunoblot. RESULTS: Higher serum dentin-reactive IgG and immune complex levels were detected in the 14- and 21-day groups (p < 0.05 and p < 0.001 respectively) but not in circulating dentinal antigen levels (p > 0.05), as compared to the control group. Reactivity was found to dentinal components with molecular mass (MM) ~120 and ~150 kDa, by immunoblot. CONCLUSION: This work represents the first evidence of immune complexes formation and circulating soluble dentin antigens associated to root resorption in orthodontic tooth movement. Immune complexes formation could be used to early diagnosis of external root resorption.
Asunto(s)
Complejo Antígeno-Anticuerpo/sangre , Dentina/inmunología , Técnicas de Movimiento Dental/métodos , Animales , Complejo Antígeno-Anticuerpo/inmunología , Autoanticuerpos/biosíntesis , Inmunoglobulina G/sangre , Incisivo/patología , Masculino , Maxilar/patología , Modelos Animales , Diente Molar/patología , Conejos , Ratas , Ratas Wistar , Resorción Radicular/patología , Estrés MecánicoRESUMEN
In the present study, antigens from parthenogenetic females and eggs of Strongyloides venezuelensis, or anti-parthenogenetic-female and anti-egg antigens were used to detect specific IgG and immune complex responses, respectively. Serum samples from experimentally infected immunocompetent and immunosuppressed rats were analysed on days 5, 8, 13 and 21 post-infection (dpi). An enzyme-linked immunosorbent assay (ELISA) was performed using alkaline parasite extract for specific IgG detection, and anti-parthenogenetic-female or anti-egg antigens for immune complex detection. The data were analysed using analysis of variance (ANOVA), followed by a Bonferroni test. When parthenogenetic female or egg extracts were used as antigens, specific IgGs were not detected in either immunocompetent or immunosuppressed rats. When anti-parthenogenetic-female or anti-S. venezuelensis-eggs were used, immune complexes were detected for the duration of the infection in immunosuppressed animals and were only detected between 5 and 13 dpi in immunocompetent animals. The duration of infection was not significantly different between the immunocompetent and immunosuppressed groups when anti-parthenogenetic-female or anti-S. venezuelensis-eggs were used. Parthenogenetic female extracts yielded significant differences between antibody and immune complex responses in immunocompetent rats from 5 to 13 dpi, but only on day 5 dpi in immunosuppressed rats. Exposure to S. venezuelensis egg extract yielded significant differences in both antibody and immune complex detection between immunocompetent and immunosuppressed rats for the duration of the infection. In conclusion, ELISA using alternative antigens may be a successful strategy for identifying immune complexes in serum samples and diagnosing active strongyloidiasis, particularly under conditions of immunosuppression.
Asunto(s)
Anticuerpos Antihelmínticos/sangre , Complejo Antígeno-Anticuerpo/sangre , Inmunoglobulina G/sangre , Terapia de Inmunosupresión , Strongyloides/inmunología , Estrongiloidiasis/diagnóstico , Cigoto/inmunología , Animales , Modelos Animales de Enfermedad , Ensayo de Inmunoadsorción Enzimática , Femenino , Masculino , Ratas , Estrongiloidiasis/inmunología , Estrongiloidiasis/parasitologíaRESUMEN
Abstract Potentially malignant disorders (PMDs) of oral cavity and oral cancer remain a cause of serious concern despite intensive research and development. Diet and immunity have been identified to play a crucial role as modifying factors in these diseases. Our study intended to explore this relationship by estimating and comparing the serum levels of copper, iron and circulating immune complexes (CICs) in patients diagnosed with PMDs and oral cancer and normal healthy individuals. In this study, 40 histopathologically diagnosed cases of PMDs and oral cancer were included along with 30 healthy controls and 5 ml of venous blood was drawn using venipuncture. Serum estimation of copper, iron and CIC then followed using the colorimetric and spectrophotometric methods. The data obtained was subjected to statistical analysis using one way ANOVA and Pearson's Product-Moment Correlation Test. The mean serum copper level was measured as 138.98 ± 10.13µg/100ml in the PMD group and 141.99 ± 21.44 µg/100ml in the oral cancer as compared to 105.5 + 18.81µ/100ml in the controls. The mean serum CIC levels was highest in the oral cancer (9.65 ± 0.16OD470) followed by the PMD group (0.18 + 0.21 OD470) and least in the control group (0.048 ± 0.02OD470). Whereas, the serum levels of iron showed a significant decrease in the PMD group (110.9 ± 10.54 µg/100ml) and the oral cancer group (114.29 ± 25.83 µg/100ml) as compared with the control group (136.85 ± 14.48 µg/100ml). There was no positive correlation obtained between the three groups with respect to the chosen parameters indicating that the variables were independent of each other. It can be thus be ascertained that trace elements like copper and iron as well as humoral responses (CICs) have a close relationship with PMDs and oral cancers.
Asunto(s)
Humanos , Masculino , Femenino , Adulto , Persona de Mediana Edad , Anciano , Fibrosis de la Submucosa Bucal/sangre , Neoplasias de la Boca/sangre , Carcinoma de Células Escamosas/sangre , Liquen Plano Oral/sangre , Cobre/sangre , Hierro/sangre , Complejo Antígeno-Anticuerpo/sangre , Lesiones Precancerosas/sangre , Valores de Referencia , Biomarcadores/sangre , Estudios de Casos y Controles , Factores de Riesgo , Análisis de Varianza , Distribución por Sexo , Distribución por Edad , Diagnóstico Precoz , Persona de Mediana EdadRESUMEN
UNLABELLED: High levels of circulating immunocomplexes (ICs) are found in patients with either infectious or sterile inflammation. We report that patients with either Plasmodium falciparum or Plasmodium vivax malaria have increased levels of circulating anti-DNA antibodies and ICs containing parasite DNA. Upon stimulation with malaria-induced ICs, monocytes express an NF-κB transcriptional signature. The main source of IC-induced proinflammatory cytokines (i.e., tumor necrosis factor alpha [TNF-α] and interleukin-1ß [IL-1ß])in peripheral blood mononuclear cells from acute malaria patients was found to be a CD14(+) CD16 (FcγRIIIA)(+) CD64 (FcγRI)(high) CD32 (FcγRIIB)(low) monocyte subset. Monocytes from convalescent patients were predominantly of the classical phenotype (CD14(+) CD16(-)) that produces high levels of IL-10 and lower levels of TNF-α and IL-1ß in response to ICs. Finally, we report a novel role for the proinflammatory activity of ICs by demonstrating their ability to induce inflammasome assembly and caspase-1 activation in human monocytes. These findings illuminate our understanding of the pathogenic role of ICs and monocyte subsets and may be relevant for future development of immunity-based interventions with broad applications to systemic inflammatory diseases. IMPORTANCE: Every year, there are approximately 200 million cases of Plasmodium falciparum and P. vivax malaria, resulting in nearly 1 million deaths, most of which are children. Decades of research on malaria pathogenesis have established that the clinical manifestations are often a consequence of the systemic inflammation elicited by the parasite. Recent studies indicate that parasite DNA is a main proinflammatory component during infection with different Plasmodium species. This finding resembles the mechanism of disease in systemic lupus erythematosus, where host DNA plays a central role in stimulating an inflammatory process and self-damaging reactions. In this study, we disclose the mechanism by which ICs containing Plasmodium DNA activate innate immune cells and consequently stimulate systemic inflammation during acute episodes of malaria. Our results further suggest that Toll-like receptors and inflammasomes have a central role in malaria pathogenesis and provide new insights toward developing novel therapeutic interventions for this devastating disease.
Asunto(s)
Complejo Antígeno-Anticuerpo/metabolismo , Citocinas/metabolismo , ADN Protozoario/inmunología , Inflamasomas/metabolismo , Malaria Falciparum/patología , Malaria Vivax/patología , Monocitos/metabolismo , Complejo Antígeno-Anticuerpo/sangre , Antígenos CD/análisis , Humanos , Inmunofenotipificación , Malaria Falciparum/inmunología , Malaria Vivax/inmunología , Monocitos/química , Multimerización de ProteínaRESUMEN
Visceral leishmaniasis, caused by Leishmania (Leishmania) chagasi, is a chronic parasitic disease of humans and dogs. Confirmation of the protozoal agent in bone marrow, lymph node or spleen aspirate is diagnostic, while specific-IgG serology is used mainly for epidemiology despite the general presence of high levels of serum immunoglobulin. Anecdotal reports of false-negative serology in active disease cases are known and are ascribed to the formation of immune complexes. Because dissociation of immune complexes can be accomplished by acid treatment, we devised a simple, routine enzyme immunoassay (ELISA) for the dissociation of immune complexes in serum samples using acid treatment in wells adsorbed with Leishmania antigen (dELISA). Confirmatory acid dot-blot was also developed for antigen detection by anti-Leishmania rabbit antiserum. In experimental L. chagasi hamster models, immune complexes interfered with ELISA mostly in the 30 and 60 days postinfection, according to both dELISA and antigen dot-blot results. In larger samples from endemic areas, dELISA was positive in 10% of seronegative dog samples (7/70) and 3.5% in negative human samples (3/88), showing that dELISA could be used in the serodiagnosis of visceral leishmaniasis. Moreover, dELISA could be used as an alternative approach to screening asymptomatic visceral leishmaniasis patients, instead of invasive confirmatory testing.
Asunto(s)
Complejo Antígeno-Anticuerpo/sangre , Antígenos de Protozoos/sangre , Perros/parasitología , Ensayo de Inmunoadsorción Enzimática/normas , Leishmania donovani/patogenicidad , Leishmaniasis Visceral/veterinaria , Animales , Antígenos de Protozoos/inmunología , Cricetinae , Modelos Animales de Enfermedad , Progresión de la Enfermedad , Enfermedades de los Perros/diagnóstico , Enfermedades de los Perros/inmunología , Enfermedades de los Perros/parasitología , Perros/inmunología , Ensayo de Inmunoadsorción Enzimática/métodos , Humanos , Concentración de Iones de Hidrógeno , Leishmania donovani/inmunología , Leishmaniasis Visceral/diagnóstico , Masculino , Mesocricetus , Carga de Parásitos , Conejos , Bazo/parasitología , Factores de TiempoRESUMEN
In order to establish an antigen, antibody and immune complex detection by enzyme-linked immunosorbent assay (ELISA) in serum samples, normal or immunocompromised Wistar rats experimentally infected with Strongyloides venezuelensis were used. The microtitre plates were coated with IgG anti-S. venezuelensis for antigen and immune complex detection and with alkaline parasite extract for antibody detection. Analysis revealed at least 12.5 µg/mL of S. venezuelensis specific antigens in serum samples. Assay for antigen detection was not a good approach for evaluating infection in normal or immunocompromised rats. In normal rats IgG specific for S. venezuelensis was preferentially detected during the first 13 days post-infection (p.i.) and immune complex detection was significantly reduced in 21 p.i. day. On the other hand, in immunocompromised rats, IgG and immune complex were detected during the entire kinetic (5, 8, 13 and 21 p.i). These results suggest that immune complex screening seems to be an alternative for early strongyloidiasis diagnosis in immunocompromised individuals.
Asunto(s)
Anticuerpos Antihelmínticos/sangre , Complejo Antígeno-Anticuerpo/sangre , Antígenos Helmínticos/sangre , Strongyloides/inmunología , Estrongiloidiasis/inmunología , Animales , Heces/parasitología , Huésped Inmunocomprometido , Inmunoglobulina G/sangre , Masculino , Recuento de Huevos de Parásitos , Ratas , Ratas Wistar , Estrongiloidiasis/sangre , Estrongiloidiasis/diagnósticoRESUMEN
The aim of this study was to use larval, parasitic female and egg antigens from Strongyloides venezuelensis to detect parasite-specific IgG and immune complexes in human serum samples by enzyme-linked immunosorbent assay (ELISA). In total, 95 serum samples were analysed, consisting of 30 patients harbouring S. stercoralis larvae, 30 healthy subjects and 35 patients with other parasites. Sensitivity, specificity and diagnostic efficiency were calculated. A significant statistical difference was found in the detection of immune complexes and antibodies in patients harbouring S. stercoralis larvae from larval and eggs antigens, with higher positivity using larval antigen. The larval antigen showed the highest values for sensitivity, specificity and diagnostic efficiency in ELISA from detection of immune complexes. For the first time we used IgG anti-larvae, IgG anti-parasitic females or IgG anti-eggs for immune complex detection. We concluded that the association of antibody and immune complex detection could be used in the diagnosis of human strongyloidiasis.
Asunto(s)
Complejo Antígeno-Anticuerpo/sangre , Antígenos Helmínticos , Inmunoglobulina G/sangre , Strongyloides/inmunología , Estrongiloidiasis/diagnóstico , Animales , Especificidad de Anticuerpos , Antígenos Helmínticos/inmunología , Femenino , Humanos , Pruebas Inmunológicas , Larva/inmunología , Óvulo/inmunología , Ratas , Ratas Wistar , Sensibilidad y Especificidad , Strongyloides/clasificación , Estrongiloidiasis/inmunología , Estrongiloidiasis/parasitologíaRESUMEN
OBJETIVO: Este estudo avaliou a presença de anticorpos antipeptídeos citrulinados cíclicos (anti-CCP), fator reumatoide (FR) e imunocomplexos circulantes (ICC) em pacientes sudaneses infectados por Leishmania donovani. PACIENTES E MÉTODOS: Os soros foram coletados de pacientes infectados por Leishmania (n = 116) e de sudaneses saudáveis (n = 93). Dezenove pacientes sudaneses com artrite reumatoide (AR) e anti-CCP+ foram incluídos como controles positivos. Os níveis de ICC e anti-CCP foram medidos por ELISA. Para avaliar a reatividade citrulina-específica foi usada a placa-controle com peptídeos-controle cíclicos contendo arginina em vez de citrulina. RESULTADOS: Entre os pacientes infectados por Leishmania e os pacientes com AR e anti-CCP+, a maioria (86%) era positiva para FR, enquanto a frequência de positividade para ICC foi maior entre pacientes com leishmaniose visceral (LV) (LV 38%; AR e anti-CCP+ 24%). Quando foi analisada a reatividade anti-CCP, 12% dos pacientes com LV foram positivos. Os níveis de anti-CCP entre os pacientes com LV correlacionaram-se bem com os níveis de ICC encontrados (r = 0,65; P < 0,0001). No grupo de AR não foi encontrada associação entre ICC e anti-CCP. A possibilidade de que a positividade para anti-CCP se deva a reações cruzadas com ICC foi descartada experimentalmente. Ao contrário do que foi visto no soro dos sudaneses com AR, a reatividade anti-CCP não se restringiu à citrulina, mas houve reação igual com os peptídeos-controle com arginina. CONCLUSÃO: O fato de a reatividade CCP não se ter restringido à citrulina comprova tratar-se mais de um efeito de inflamação extensa e ativação imune do que de um sinal de características patogênicas compartilhadas com artrite anti-CCP. Nossos achados ressaltam a importância de se interpretar um teste CCP positivo com cuidado ao se avaliar condições não reumáticas ou em áreas onde tais infecções predominam.
OBJECTIVE: The present study evaluated the presence of anti-cyclic citrullinated peptides antibodies (anti-CCP), rheumatoid factor (RF), and circulating immune complexes (CIC) in Sudanese patients infected with the Leishmania donovani parasite. PATIENTS AND METHODS: Sera were collected from Leishmania infected patients (n = 116) and healthy Sudanese (n = 93). Nineteen Sudanese anti-CCP+ RA patients were included as positive controls. Levels of CIC and anti-CCP were measured by ELISA. Control plate with cyclic control peptides containing arginine instead of citrulline was used to evaluate citrulline specifi c reactivity. RESULTS: Among Leishmania-infected patients and anti-CCP+ RA patients, most were RF positive (86%), while the frequency of CIC positivity was higher among visceral leishmaniasis (VL) patients (VL 38%; anti-CCP+ RA 24%). When anti-CCP reactivity was analysed, 12% of VL patients were found to be positive. The levels of anti-CCP among VL patients correlated well with the CIC levels found (r = 0.65, P < 0.0001). In RA group, no association was found between CIC and anti-CCP. The possibility that anti-CCP positivity was due to cross reactions with CIC was experimentally ruled out. Contrary to what was seen in Sudanese RA sera, the CCP reactivity was not restricted to citrulline but reacted equally well with the arginine control peptide. CONCLUSION: The finding that CCP reactivity was not restricted to citrulline argues that this is more an effect of extensive inflammation and immune activation than a sign of shared pathogenic characteristics with anti-CCP arthritis. Our fi ndings stress the importance to interpret a positive CCP test carefully when evaluated in non-rheumatic conditions or in areas where such infections predominate.
Asunto(s)
Adolescente , Adulto , Niño , Femenino , Humanos , Masculino , Adulto Joven , Complejo Antígeno-Anticuerpo/sangre , Autoanticuerpos/sangre , Leishmania donovani , Leishmaniasis Visceral/sangre , Leishmaniasis Visceral/inmunología , Péptidos Cíclicos/inmunología , Factor Reumatoide/inmunología , SudánRESUMEN
OBJECTIVE: The present study evaluated the presence of anti-cyclic citrullinated peptides antibodies (anti-CCP), rheumatoid factor (RF), and circulating immune complexes (CIC) in Sudanese patients infected with the Leishmania donovani parasite. PATIENTS AND METHODS: Sera were collected from Leishmania infected patients (n = 116) and healthy Sudanese (n = 93). Nineteen Sudanese anti-CCP+ RA patients were included as positive controls. Levels of CIC and anti-CCP were measured by ELISA. Control plate with cyclic control peptides containing arginine instead of citrulline was used to evaluate citrulline specifi c reactivity. RESULTS: Among Leishmania-infected patients and anti-CCP+ RA patients, most were RF positive (86%), while the frequency of CIC positivity was higher among visceral leishmaniasis (VL) patients (VL 38%; anti-CCP+ RA 24%). When anti-CCP reactivity was analysed, 12% of VL patients were found to be positive. The levels of anti-CCP among VL patients correlated well with the CIC levels found (r = 0.65, P < 0.0001). In RA group, no association was found between CIC and anti-CCP. The possibility that anti-CCP positivity was due to cross reactions with CIC was experimentally ruled out. Contrary to what was seen in Sudanese RA sera, the CCP reactivity was not restricted to citrulline but reacted equally well with the arginine control peptide. CONCLUSION: The finding that CCP reactivity was not restricted to citrulline argues that this is more an effect of extensive inflammation and immune activation than a sign of shared pathogenic characteristics with anti-CCP arthritis. Our fi ndings stress the importance to interpret a positive CCP test carefully when evaluated in non-rheumatic conditions or in areas where such infections predominate.
Asunto(s)
Complejo Antígeno-Anticuerpo/sangre , Autoanticuerpos/sangre , Leishmania donovani , Leishmaniasis Visceral/sangre , Leishmaniasis Visceral/inmunología , Péptidos Cíclicos/inmunología , Factor Reumatoide/inmunología , Adolescente , Adulto , Niño , Femenino , Humanos , Masculino , Sudán , Adulto JovenRESUMEN
BACKGROUND: In cancer patients, MUC1 glycoprotein may carry Lewis y which could be involved in immune response. PURPOSES: 1- to evaluate the presence of Lewis y and MUC1 in circulating immune complexes (Lewis y/CIC and MUC1/CIC, respectively) and their correlation; 2- to analyze the possible presence of Lewis y in carbohydrate chains of tumoral MUC1 glycoprotein and 3- to correlate serum and tissue parameters considered. METHODS: Pretreatment serum and tissue breast samples from 76 adenocarcinoma, 34 benign and 36 normal specimens were analyzed. Anti-MUC1 and anti-Lewis y MAbs were employed. To detect Lewis y/CIC and MUC1/CIC, ELISA tests were developed; serum samples containing MUC1 were previously selected by Cancer Associated Serum Antigen (CASA). Immunoprecipitation (IP) was performed in 9 malignant, benign and normal samples and analyzed by SDS-PAGE and Western blot. Lewis y and MUC1 expression was studied by immunohistochemistry (IHC). Statistical analysis was performed employing principal component analysis (PCA), ANOVA, Tukey HSD, Chi square test and classical correlation (p < 0.05). RESULTS: By ELISA, Lewis y/IgM/CIC levels showed statistically significant differences between breast cancer versus benign and normal samples; mean +/- SD values expressed in OD units were: 0.525 +/- 0.304; 0.968 +/- 0.482 and 0.928 +/- 0.447, for breast cancer, benign disease and normal samples, respectively, p < 0.05. Lewis y/IgG/CIC did not show any statistically significant difference. MUC1/IgM/CIC correlated with Lewis y/IgM/CIC. By CASA, 9 samples with MUC1 values above the cut off were selected and IP was performed, followed by SDS-PAGE and Western blot; bands at 200 kDa were obtained with each MAb in all the samples. By IHC, with C14 MAb, 47.5%, 31% and 35% of malignant, benign and normal samples, respectively, showed positive reaction while all the samples were positive with anti-MUC1 MAb; in both cases, with a different pattern of expression between malignant and non malignant samples. CONCLUSION: Our findings support that in breast cancer there was a limited humoral immune response through Lewis y/IgM/CIC levels detection which correlated with MUC1/IgM/CIC. We also found that Lewis y might be part of circulating MUC1 glycoform structure and also that Lewis y/CIC did not correlate with Lewis y expression.
Asunto(s)
Complejo Antígeno-Anticuerpo/sangre , Neoplasias de la Mama/sangre , Neoplasias de la Mama/inmunología , Inmunidad Humoral , Antígenos del Grupo Sanguíneo de Lewis/sangre , Mucina-1/sangre , Adulto , Anciano , Anciano de 80 o más Años , Complejo Antígeno-Anticuerpo/inmunología , Biomarcadores de Tumor/sangre , Biomarcadores de Tumor/inmunología , Western Blotting , Neoplasias de la Mama/patología , Electroforesis en Gel de Poliacrilamida , Ensayo de Inmunoadsorción Enzimática , Femenino , Humanos , Inmunohistoquímica , Inmunoprecipitación , Antígenos del Grupo Sanguíneo de Lewis/inmunología , Persona de Mediana Edad , Mucina-1/inmunología , Estadificación de NeoplasiasRESUMEN
The diagnostic test characteristics of detecting free and complex-dissociated IgG to three recombinant antigens of Mycobacterium tuberculosis (38-kDa, Ag16 and Ag85B), singly and in combination, were evaluated in sera from 161 tuberculous patients [smear-positive pulmonary TB (50), smear-negative pulmonary TB (pTBsm-) (60) and extrapulmonary TB (51)) and 214 control patients (mycobacteriosis (14), mycoses(14), leprosy(4), other underlying diseases (82) and healthy people (100)]. The individual antigens ranged from 25% to 42% in sensitivity and from 93% to 96% in specificity, while considering free IgG response. Addition of complex-dissociated antibodies against each individual antigen improved the sensitivity up to 55%. The number and levels of specific antibodies varied greatly from individual to individual. Combination of individual results for free and complex-dissociated IgG to 38-kDa, Ag16 and Ag85B offered 76% sensitivity and 83% specificity. When the three antigens were placed in the same well, the sensitivity was lower than that expected on the basis of single antigen (63%) but with a good specificity (95%), even in the group of mycobacteriosis or mycoses. The highest contribution of complex-dissociated IgG results to free IgG results was seen for the diagnosis of pTBsm- patients. In conclusion, although neither single recombinant antigen was reactive with most sera from TB patients even after the measurement of both free and complex-dissociated antibodies, the use of multi-antigen cocktails improved the diagnostic utility of the ELISA assay, allowing the identification of almost 70% of pTBsm-, with a high level of specificity; the use of additional, well selected antigens should lead to the detection of almost all patients with TB.