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PURPOSE: To compare the treatment response and progression-free survival (PFS) in advanced hepatocellular carcinoma (HCC) patients who received sorafenib treatment either alone or combined with radioembolization (RE). METHODS: Follow-up images of the patients treated within a multicenter phase II trial (SORAMIC) were assessed by mRECIST. A total of 177 patients (73 combination arm [RE + sorafenib] and 104 sorafenib arm) were included in this post-hoc analysis. Response and progression characteristics were compared between treatment arms. Survival analyses were done to compare PFS and post-progression survival between treatment arms. Multivariate Cox regression analysis was used to compare survival with factors known to influence PFS in patients with HCC. RESULTS: The combination arm had significantly higher objective response rate (61.6% vs. 29.8%, p < 0.001), complete response rate (13.7% vs. 3.8%, p = 0.022), and a trend for higher disease control rate (79.2% vs. 72.1%, p = 0.075). Progression was encountered in 116 (65.5%) patients and was more common in the sorafenib arm (75% vs. 52.0%, p = 0.001). PFS (median 8.9 vs. 5.4 months, p = 0.022) and hepatic PFS were significantly better in the combination arm (9.0 vs. 5.7 months, p = 0.014). Multivariate analysis confirmed the treatment arm as an independent predictor of PFS. CONCLUSION: In advanced HCC patients receiving sorafenib, combination with RE has an additive anticancer effect on sorafenib treatment resulting in a higher and longer tumor response. However, the enhanced response did not translate into prolonged survival. Better patient selection and superselective treatment could improve outcomes after combination therapy.
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Carcinoma Hepatocelular , Neoplasias Hepáticas , Humanos , Carcinoma Hepatocelular/terapia , Sorafenibe/uso terapêutico , Sorafenibe/efeitos adversos , Radioisótopos de Ítrio/uso terapêutico , Neoplasias Hepáticas/tratamento farmacológico , Compostos de Fenilureia/uso terapêuticoRESUMO
Neutralizing antibodies can prevent hepatitis C virus (HCV) infection, one of the leading causes of cirrhosis and liver cancer. Here, we characterized the immunoglobulin repertoire of memory B-cell antibodies against a linear epitope in the central front layer of the HCV envelope (E2; amino acids 483-499) in patients who were infected in a single-source outbreak. A reverse transcription polymerase chain reaction-based immunoglobulin gene cloning and recombinant expression approach was used to express monoclonal antibodies from HCV E2 peptide-binding immunoglobulin G-positive memory B cells. We identified highly mutated antibodies with a neutralizing effect in vitro against different genotype isolates sharing similar gene features. Our data confirm the importance of VH1-69 use for neutralizing activity. The data offer a promising basis for vaccine research and the use of anti-E2 antibodies as a means of passive immunization.
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Anticorpos Amplamente Neutralizantes/imunologia , Epitopos de Linfócito B/imunologia , Hepacivirus/imunologia , Anticorpos Anti-Hepatite C/imunologia , Hepatite C Crônica/imunologia , Imunoglobulina G/imunologia , Proteínas do Envelope Viral/imunologia , Adulto , Idoso , Anticorpos Monoclonais/imunologia , Linfócitos B/imunologia , Estudos de Coortes , Feminino , Genótipo , Células HEK293 , Hepacivirus/genética , Hepatite C Crônica/prevenção & controle , Hepatite C Crônica/virologia , Humanos , Memória Imunológica , Masculino , Pessoa de Meia-Idade , Imunoglobulina rho(D)/imunologia , Anticorpos de Domínio Único/genética , Vacinas contra Hepatite Viral/imunologiaRESUMO
BACKGROUND: Liquid biopsy based on cell-free DNA circulating in plasma has shown solid results as a non-invasive biomarker. In the present study we evaluated the utility of circulating free DNA (cfDNA) and the sub-type tumor DNA (ctDNA) in hepatocellular cancer (HCC) patients to assess therapy response and clinical outcome. METHODS: A cohort of 13 patients recruited in the context of the SORAMIC trial with unresectable, advanced HCC and different etiological and clinicopathological characteristics was included in this exploratory study. Plasma samples were collected between liver micro-intervention and beginning of sorafenib-based systemic therapy and then in correspondence of three additional follow-ups. DNA was isolated from plasma and next generation sequencing (NGS) was performed on a panel of 597 selected cancer-relevant genes. RESULTS: cfDNA levels showed a significant correlation with the presence of metastases and survival. In addition cfDNA kinetic over time revealed a trend with the clinical history of the patients, supporting its use as a biomarker to monitor therapy. NGS-based analysis on ctDNA identified 28 variants, detectable in different combinations at the different time points. Among the variants, HNF1A, BAX and CYP2B6 genes showed the highest mutation frequency and a significant association with the patients' clinicopathological characteristics, suggesting a possible role as driver genes in this specific clinical setting. CONCLUSIONS: Taken together, the results support the prognostic value of cfDNA/ctDNA in advanced HCC patients with the potential to predict therapy response. These findings support the clinical utility of liquid biopsy in advanced HCC improving individualized therapy and possible earlier identification of treatment responders.
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Biomarcadores Tumorais/genética , Carcinoma Hepatocelular/sangue , Carcinoma Hepatocelular/genética , Ácidos Nucleicos Livres/sangue , Neoplasias Hepáticas/sangue , Neoplasias Hepáticas/genética , Pesquisa Translacional Biomédica , Idoso , Idoso de 80 Anos ou mais , Carcinoma Hepatocelular/patologia , Feminino , Humanos , Neoplasias Hepáticas/patologia , Masculino , Pessoa de Meia-Idade , Mutação/genética , Prognóstico , Análise de Sobrevida , Resultado do TratamentoRESUMO
BACKGROUND & AIMS: GALAD and BALAD-2 are statistical models for estimating the likelihood of the presence of hepatocellular carcinoma (HCC) in individual patients with chronic liver disease and the survival of patients with HCC, respectively. Both models use objective measures, particularly the serum markers α-fetoprotein (AFP), AFP-L3, and des-γ-carboxyprothrombin. We aimed to validate these models in an international cohort of patients with HCC and assess their clinical performance. METHODS: We collected data on cancer diagnosis and outcomes of 6834 patients (2430 with HCC and 4404 with chronic liver disease) recruited from Germany, Japan, and Hong Kong. We also collected data from 229 patients with other hepatobiliary tract cancers (cholangiocarcinoma or pancreatic adenocarcinoma) and 92 healthy individuals (controls). For reference, the original UK cohort (on which the GALAD model initially was built and BALAD-2 was validated) was included in the analysis. We assessed the effects of tumor size and etiology on GALAD model performance, and its ability to correctly discriminate HCC from other hepatobiliary cancers. We assessed the performance of BALAD-2 in patients with different stages of HCC. RESULTS: In all cohorts, the area under the receiver operating characteristic curve (AUROC), quantifying the ability of GALAD to discriminate patients with HCC from patients with chronic liver disease, was greater than 0.90-similar to the series on which the model originally was built (AUROC, 0.97). GALAD discriminated patients with HCC from those with other hepatobiliary cancers with an AUROC value of 0.95; values were slightly lower for patients with small unifocal HCCs, ranging from 0.85 to 0.95. Etiology and treatment of chronic viral hepatitis had no effect on the performance of this model. BALAD-2 analysis assigned patients with HCC to 4 distinct prognostic groups-overall and when patients were stratified according to disease stage. CONCLUSIONS: We validated the performance of the GALAD and BALAD-2 models for the diagnosis of HCC and predicting patient survival, respectively (based on levels of the serum markers AFP, AFP-L3, and des-γ-carboxyprothrombin), in an international cohort of almost 7000 patients. These systems might be used in HCC surveillance and determination of patient prognosis.
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Biomarcadores/sangue , Carcinoma Hepatocelular/diagnóstico , Técnicas de Apoio para a Decisão , Testes Diagnósticos de Rotina/métodos , Neoplasias Hepáticas/diagnóstico , Adulto , Idoso , Ásia , Estudos de Coortes , Europa (Continente) , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Análise de SobrevidaAssuntos
Antivirais/uso terapêutico , Vírus da Hepatite E/genética , Hepatite E/sangue , Hepatite E/tratamento farmacológico , Hepatite Crônica/sangue , Hepatite Crônica/tratamento farmacológico , RNA Viral/sangue , Sofosbuvir/uso terapêutico , Adulto , Feminino , Seguimentos , Alemanha/epidemiologia , Hepatite E/epidemiologia , Hepatite E/virologia , Vírus da Hepatite E/efeitos dos fármacos , Hepatite Crônica/epidemiologia , Hepatite Crônica/virologia , Humanos , Masculino , Pessoa de Meia-Idade , Projetos Piloto , Estudos Prospectivos , Falha de Tratamento , Adulto JovemRESUMO
BACKGROUND AND AIMS: Our purpose was to assess the impact of muscle quality on overall survival (OS) in patients with advanced HCC. METHODS: This is a subanalysis of the SORAMIC trial. Overall, 363 patients were included. The SIRT/Sorafenib treatment group comprised 182 patients and the sorafenib group 181 patients. Myosteatosis was defined as skeletal muscle density (SMD) < 41 HU for patients with a body mass index up to 24.9 kg/m2 and <33 HU for patients with a body mass index ≥25 kg/m2. Albumin-gauge score was calculated as follows: serum albumin (g/dL) × SMD (HU). To assess the impact of muscle quality on clinical variables and OS, a Cox regression model was used. Hazard ratios are presented together with 95 % confidence intervals (95 % CI). Kaplan-Meier curves were used for survival analysis. RESULTS: In the SIRT/sorafenib cohort, low albumin-gauge score was an independent predictor of worse OS, HR = 1.74, CI 95% (1.16-2.62), p = 0.01. In the sorafenib cohort, muscle quality parameters did not predict OS. In alcohol-induced HCC (n = 129), myosteatosis independently predicted OS, HR = 1.85, CI 95% (1.10; 3.12), p = 0.02. In viral-induced HCC (n = 99), parameters of muscle quality did not predict OS. In patients with NASH/Non-alcoholic fatty liver disease (NAFLD) induced HCC, albumin-gauge score was a strong independent predictor of worse OS in the subgroup undergoing combined treatment with SIRT and sorafenib, HR = 9.86, CI 95% (1.12; 86.5), p = 0.04. CONCLUSIONS: Myosteatosis predicts independently worse OS in patients with alcohol-induced HCC undergoing combined treatment with SIRT and sorafenib. In patients with NASH/NAFLD induced HCC undergoing treatment with SIRT and sorafenib, albumin-gauge score predicts independently worse OS. IMPACT AND IMPLICATIONS: Associations between parameters of muscle quality and OS are different in accordance to the treatment strategy and etiology of HCC. These findings highlight the prognostic potential of skeletal muscle quality in patients with advanced HCC.
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Carcinoma Hepatocelular , Neoplasias Hepáticas , Músculo Esquelético , Sorafenibe , Humanos , Sorafenibe/uso terapêutico , Masculino , Feminino , Carcinoma Hepatocelular/mortalidade , Carcinoma Hepatocelular/tratamento farmacológico , Neoplasias Hepáticas/mortalidade , Neoplasias Hepáticas/tratamento farmacológico , Músculo Esquelético/patologia , Pessoa de Meia-Idade , Idoso , Antineoplásicos/uso terapêutico , Antineoplásicos/efeitos adversos , Estimativa de Kaplan-Meier , Índice de Massa Corporal , Compostos de Fenilureia/uso terapêutico , Compostos de Fenilureia/efeitos adversos , Albumina Sérica/análise , Albumina Sérica/metabolismo , Niacinamida/análogos & derivados , Niacinamida/uso terapêutico , Niacinamida/efeitos adversosRESUMO
Hepatocellular carcinoma (HCC) is a leading cause of cancer death, and medical treatment options are limited. The multikinase inhibitor sorafenib was the first approved drug widely used for systemic therapy in advanced HCC. Sorafenib might affect polyunsaturated fatty acids (PUFA)-derived epoxygenated metabolite levels, as it is also a potent inhibitor of the soluble epoxide hydrolase (sEH), which catalyzes the conversion of cytochrome-P450 (CYP)-derived epoxide metabolites derived from PUFA, such as omega-6 arachidonic acid (AA) and omega-3 docosahexaenoic acid (DHA), into their corresponding dihydroxy metabolites. Experimental studies with AA-derived epoxyeicosatrienoic acids (EETs) have shown that they can promote tumor growth and metastasis, while DHA-derived 19,20-epoxydocosapentaenoic acid (19,20-EDP) was shown to have anti-tumor activity in mice. In this study, we found a significant increase in EET levels in 43 HCC patients treated with sorafenib and a trend towards increased levels of DHA-derived 19,20-EDP. We demonstrate that the effect of sorafenib on CYP- metabolites led to an increase of 19,20-EDP and its dihydroxy metabolite, whereas DHA plasma levels decreased under sorafenib treatment. These data indicate that specific supplementation with DHA could be used to increase levels of the epoxy compound 19,20-EDP with potential anti-tumor activity in HCC patients receiving sorafenib therapy.
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[This corrects the article DOI: 10.3389/fphar.2023.1124214.].
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BACKGROUND: Body composition parameters have been reported to be prognostic factors in patients with oncologic diseases. However, the available data on patients with HCC are conflicting. The aim of this study was to assess the impact of body composition on survival in patients with HCC treated with sorafenib or selective internal radioembolization (SIRT) and sorafenib. METHODS: This is an exploratory subanalysis of the prospective, randomized controlled SORAMIC trial. Within the palliative arm of the study, patients were selected if a baseline abdominal CT was available. A broad set of skeletal muscle and adipose tissue parameters were measured at the L3 level. Low skeletal muscle mass (LSMM) and density parameters were defined using published cutoffs. The parameters were correlated with overall survival. RESULTS: Of 424 patients in the palliative study arm, 369 patients were included in the analysis. There were 192 patients in the combined sorafenib/SIRT and 177 patients in the sorafenib group. Median overall survival was 9.9 months for the entire cohort and 10.8 and 9.2 months for the SIRT/sorafenib and sorafenib groups, respectively. There was no relevant association of either body composition parameter with overall survival in either the overall cohort or in the SIRT/sorafenib or sorafenib subgroups. CONCLUSIONS: This subanalysis of the prospective SORAMIC trial does not suggest a relevant influence of body composition parameters of survival in patients with advanced HCC. Body composition parameters therefore do not serve in patient allocation in this palliative treatment cohort.
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Carcinoma Hepatocelular , Neoplasias Hepáticas , Humanos , Sorafenibe , Estudos Prospectivos , Composição CorporalRESUMO
BACKGROUND: Parameters of body composition have prognostic potential in patients with oncologic diseases. The aim of the present study was to analyse the prognostic potential of radiomics-based parameters of the skeletal musculature and adipose tissues in patients with advanced hepatocellular carcinoma (HCC). METHODS: Radiomics features were extracted from a cohort of 297 HCC patients as post hoc sub-study of the SORAMIC randomized controlled trial. Patients were treated with selective internal radiation therapy (SIRT) in combination with sorafenib or with sorafenib alone yielding two groups: (1) sorafenib monotherapy (n = 147) and (2) sorafenib and SIRT (n = 150). The main outcome was 1-year survival. Segmentation of muscle tissue and adipose tissue was used to retrieve 881 features. Correlation analysis and feature cleansing yielded 292 features for each patient group and each tissue type. We combined 9 feature selection methods with 10 feature set compositions to build 90 feature sets. We used 11 classifiers to build 990 models. We subdivided the patient groups into a train and validation cohort and a test cohort, that is, one third of the patient groups. RESULTS: We used the train and validation set to identify the best feature selection and classification model and applied it to the test set for each patient group. Classification yields for patients who underwent sorafenib monotherapy an accuracy of 75.51% and area under the curve (AUC) of 0.7576 (95% confidence interval [CI]: 0.6376-0.8776). For patients who underwent treatment with SIRT and sorafenib, results are accuracy = 78.00% and AUC = 0.8032 (95% CI: 0.6930-0.9134). CONCLUSIONS: Parameters of radiomics-based analysis of the skeletal musculature and adipose tissue predict 1-year survival in patients with advanced HCC. The prognostic value of radiomics-based parameters was higher in patients who were treated with SIRT and sorafenib.
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Radioembolization (RE) is a viable therapy option in patients with intrahepatic cholangiocarcinoma (ICC). This study delineates a prognostic score regarding overall survival (OS) after RE using routine pre-therapeutic parameters. A retrospective analysis of 39 patients (median age, 61 [range, 32−82] years; 26 females, 13 males) with ICC and 42 RE procedures was conducted. Cox regression for OS included age, ECOG, hepatic and extrahepatic tumor burden, thrombosis of the portal vein, ascites, laboratory parameters and dose reduction due to hepatopulmonary shunt. Median OS after RE was 8.0 months. Using univariable Cox, ECOG ≥ 1 (hazard ratio [HR], 3.8), AST/ALT quotient (HR, 1.86), high GGT (HR, 1.002), high CA19-9 (HR, 1.00) and dose reduction of 40% (HR, 3.8) predicted shorter OS (each p < 0.05). High albumin predicted longer OS (HR, 0.927; p = 0.045). Multivariable Cox confirmed GGT ≥ 750 [U/L] (HR, 7.84; p < 0.001), ECOG > 1 (HR, 3.76; p = 0.021), albumin ≤ 41.1 [g/L] (HR, 3.02; p = 0.006) as a three-point pre-therapeutic prognostic score. More specifically, median OS decreased from 15.3 months (0 risk factors) to 7.6 months (1 factor) or 1.8 months (≥2 factors; p < 0.001). The proposed score may aid in improved pre-therapeutic patient identification with (un-)favorable OS after RE and facilitate the balance between potential life prolongation and overaggressive patient selection.
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PURPOSE: SORAMIC is a randomized controlled trial in patients with advanced hepatocellular carcinoma (HCC) undergoing sorafenib ± selective internal radiation therapy (SIRT). We investigated the value of extracellular vesicle (EV)-based proteomics for treatment response prediction. EXPERIMENTAL DESIGN: The analysis population comprised 25 patients receiving SIRT+sorafenib and 20 patients receiving sorafenib alone. Patients were classified as responders or nonresponders based on changes in AFP and imaging or overall survival. Proteomic analysis was performed on plasma EVs by LC/MS, followed by bioinformatics analysis. Clinical relevance of candidate EV proteins was validated by survival and receiver-operating characteristic analysis with bootstrap internal sampling validation. Origin of circulating EV was explored by IHC staining of liver and tumor tissues and transcriptomics of blood cells. RESULTS: Proteomic analysis identified 56 and 27 EV proteins that were differentially expressed in plasma EVs between responders and nonresponders receiving SIRT+sorafenib and sorafenib alone, respectively. High EV-GPX3/ACTR3 and low EV-ARHGAP1 were identified as candidate biomarkers at baseline from the 13 responders to SIRT+sorafenib with statistically significant AUC = 1 for all and bootstrap P values 2.23 × 10-5, 2.22 × 10-5, and 2.23 × 10-5, respectively. These patients showed reduced abundance of EV-VPS13A and EV-KALRN 6 to 9 weeks after combined treatment with significant AUC and bootstrap P values. In reverse, low GPX3 and high ARHGAP1 demonstrated better response to sorafenib monotherapy with AUC = 0.9697 and 0.9192 as well as bootstrap P values 8.34 × 10-5 and 7.98 × 10-4, respectively. HCC tumor was the likely origin of circulating EVs. CONCLUSIONS: In this exploratory study, EV-based proteomics predicted response to SIRT+sorafenib and sorafenib-only treatment in patients with advanced HCC of metabolic origin.
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Carcinoma Hepatocelular , Vesículas Extracelulares , Neoplasias Hepáticas , Sorafenibe , Carcinoma Hepatocelular/tratamento farmacológico , Carcinoma Hepatocelular/radioterapia , Vesículas Extracelulares/patologia , Humanos , Neoplasias Hepáticas/tratamento farmacológico , Neoplasias Hepáticas/radioterapia , Niacinamida/uso terapêutico , Compostos de Fenilureia/uso terapêutico , Proteômica , Sorafenibe/uso terapêuticoRESUMO
PURPOSE: To explore the potential correlation between baseline interleukin (IL) values and overall survival or objective response in patients with hepatocellular carcinoma (HCC) receiving sorafenib. METHODS: A subset of patients with HCC undergoing sorafenib monotherapy within a prospective multicenter phase II trial (SORAMIC, sorafenib treatment alone vs. combined with Y90 radioembolization) underwent baseline IL-6 and IL-8 assessment before treatment initiation. In this exploratory post hoc analysis, the best cut-off points for baseline IL-6 and IL-8 values predicting overall survival (OS) were evaluated, as well as correlation with the objective response. RESULTS: Forty-seven patients (43 male) with a median OS of 13.8 months were analyzed. Cut-off values of 8.58 and 57.9 pg/mL most effectively predicted overall survival for IL-6 and IL-8, respectively. Patients with high IL-6 (HR, 4.1 [1.9-8.9], p < 0.001) and IL-8 (HR, 2.4 [1.2-4.7], p = 0.009) had significantly shorter overall survival than patients with low IL values. Multivariate analysis confirmed IL-6 (HR, 2.99 [1.22-7.3], p = 0.017) and IL-8 (HR, 2.19 [1.02-4.7], p = 0.044) as independent predictors of OS. Baseline IL-6 and IL-8 with respective cut-off values predicted objective response rates according to mRECIST in a subset of 42 patients with follow-up imaging available (IL-6, 46.6% vs. 19.2%, p = 0.007; IL-8, 50.0% vs. 17.4%, p = 0.011). CONCLUSION: IL-6 and IL-8 baseline values predicted outcomes of sorafenib-treated patients in this well-characterized prospective cohort of the SORAMIC trial. We suggest that the respective cut-off values might serve for validation in larger cohorts, potentially offering guidance for improved patient selection.
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Carcinoma Hepatocelular/tratamento farmacológico , Interleucina-6/sangue , Interleucina-8/sangue , Neoplasias Hepáticas/tratamento farmacológico , Sorafenibe/uso terapêutico , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Carcinoma Hepatocelular/diagnóstico , Carcinoma Hepatocelular/mortalidade , Carcinoma Hepatocelular/patologia , Progressão da Doença , Europa (Continente)/epidemiologia , Feminino , Seguimentos , Humanos , Neoplasias Hepáticas/diagnóstico , Neoplasias Hepáticas/mortalidade , Neoplasias Hepáticas/patologia , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Prognóstico , Análise de Sobrevida , Turquia/epidemiologia , Adulto JovemRESUMO
BACKGROUND: To confirm the prognostic value of previously published baseline interleukin 6 (IL6) and IL8 cutoff values in survival and liver dysfunction in patients with advanced HCC undergoing 90Y radioembolization. METHODS: A total of 83 patients (77 male) represented a subset of HCC patients undergoing 90Y radioembolization combined with sorafenib as part of the prospective multicenter phase II trial SORAMIC. IL6 and IL8 levels were determined in serum samples collected at baseline. In this post hoc analysis, we sought to confirm the prognostic value of baseline cutoff values of 6.53 pg/mL and 60.8 pg/mL for IL6 and IL8, respectively, in overall survival (OS) or liver dysfunction (grade 2 bilirubin increase) after treatment. RESULTS: Median OS was 12.0 months. While low baseline albumin and high bilirubin values were associated with high IL6, liver cirrhosis, alcoholic liver disease, and portal vein infiltration were associated with high IL8. In univariate analysis, high baseline IL6 and IL8 were associated with significantly shorter overall survival (7.8 vs. 19.0 months for IL6 and 8.4 vs. 16.0 months for IL8). In addition to IL values, liver cirrhosis, Child-Pugh grade, baseline albumin (< 36 g/dL), and total bilirubin (≥ 17 µmol/L), and higher mALBI grade (2b &3) values were associated with OS. At multivariate analysis, high baseline IL6 was the only independent prognostic factor for OS (HR 2.35 [1.35-4.1], p = 0.002). Risk factors for liver dysfunction were high baseline IL6, albumin, and total bilirubin, and mALBI grade as found in univariate analysis. High baseline IL6 (HR 2.67 [1.21-5.94], p = 0.016) and total bilirubin ≥ 17 µmol/L (HR 3.73 [1.72-8.06], p < 0.001) were independently associated with liver dysfunction. CONCLUSION: In advanced HCC patients receiving 90Y radioembolization combined with sorafenib, baseline IL6 values proved to be prognostic, confirming previous findings in patients undergoing 90Yradioembolization. IL6 might be useful for patient selection or stratification in future trials.
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The gut is home to the body's largest population of plasma cells. In healthy individuals, IgA is the dominating isotype, whereas patients with inflammatory bowel disease also produce high concentrations of IgG. In the gut lumen, secretory IgA binds pathogens and toxins but also the microbiota. However, the antigen specificity of IgA and IgG for the microbiota and underlying mechanisms of antibody binding to bacteria are largely unknown. Here we show that microbiota binding is a defining property of human intestinal antibodies in both healthy and inflamed gut. Some bacterial taxa were commonly targeted by different monoclonal antibodies, whereas others selectively bound single antibodies. Interestingly, individual human monoclonal antibodies from both healthy and inflamed intestines bound phylogenetically unrelated bacterial species. This microbiota cross-species reactivity did not correlate with antibody polyreactivity but was crucially dependent on the accumulation of somatic mutations. Therefore, our data suggest that a system of affinity-matured, microbiota cross-species-reactive IgA is a common aspect of SIgA-microbiota interactions in the gut.
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Anticorpos Monoclonais/genética , Anticorpos Monoclonais/imunologia , Microbioma Gastrointestinal/imunologia , Imunoglobulina A Secretora/genética , Imunoglobulina A Secretora/imunologia , Mucosa Intestinal/imunologia , Mucosa Intestinal/microbiologia , Mutação , Adulto , Animais , Doença de Crohn/imunologia , Doença de Crohn/microbiologia , Doença de Crohn/patologia , Reações Cruzadas/genética , Proteínas de Ligação a DNA/deficiência , Proteínas de Ligação a DNA/genética , Fezes/microbiologia , Humanos , Imunoglobulina G/imunologia , Intestino Delgado/imunologia , Intestino Delgado/microbiologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Pessoa de Meia-Idade , Doadores de Tecidos , Adulto JovemAssuntos
Hepatite A/diagnóstico , Hepatite E/diagnóstico , Antivirais/uso terapêutico , Contaminação de Alimentos , Hepatite A/patologia , Hepatite A/prevenção & controle , Hepatite A/transmissão , Hepatite A/virologia , Vacinas contra Hepatite A/uso terapêutico , Vírus da Hepatite A/fisiologia , Vírus da Hepatite A/ultraestrutura , Hepatite E/epidemiologia , Hepatite E/patologia , Hepatite E/prevenção & controle , Hepatite E/transmissão , Hepatite E/virologia , Vírus da Hepatite E/fisiologia , Vírus da Hepatite E/ultraestrutura , Humanos , Higiene , Microbiologia da Água , Abastecimento de ÁguaRESUMO
Mucosal antibody responses play a major role in mediating homeostasis with the intestinal flora. It has been suggested that imbalance in the IgA+ and IgG+ intestinal B cell repertoire may be associated with the development of diseases such as inflammatory bowel disease. Despite this, little is known about the antibody specificity of human intestinal plasmablasts. Here, we have determined the reactivity profile of single isolated IgA+ and IgG+ plasmablasts from human terminal ileum using antibody cloning and in vitro expression. We found that approximately 25% of intestinal IgA and IgG plasmablast antibodies were polyreactive; the majority were antigen-specific. Antigen specificity was not only directed against enteropathogenic microbes but also against commensal microbes and self antigens. Regardless of their reactivity, all intestinal antibodies were somatically mutated and showed signs of antigen-mediated selection, suggesting that they developed from antigen-specific B cell responses. Together, our data indicate that antigen-specific immune responses to intestinal microbes are largely responsible for the maintenance of intestinal homeostasis and thus provide a basis for understanding the deregulated immune responses observed in patients with inflammatory bowel disease.