RESUMO
BACKGROUND AND AIMS: This study evaluated the minimal clinically important short-term improvement in the Modified Multiplier Simple Endoscopic Score for crohn's Disease [MM-SES-CD], a novel modified scoring system of the SES-CD, which reliably predicted 1-year endoscopic remission [ER]. METHODS: This post-hoc analysis of two CD clinical trial programmes pooled data of 198 participants with baseline ulcers and SES-CD ≥3, who had baseline, post-induction [8-12 weeks], and 1-year endoscopic assessments. Different cut-off values for endoscopic response were evaluated using receiver operating characteristic [ROC] curves, positive likelihood ratios [PLR], and negative likelihood ratios [NLR]. ER [SES-CD <3] was the binary classifier in all cases. A distribution of cut-offs minimising NLR and maximising PLR was created with 10 000 bootstrapped resamples. An optimal cut-point for low and high probability of 1-year ER was determined based on the maximum Youden Index. RESULTS: MM-SES-CD ≥40% reduction from baseline was selected as the cut-off maximising PLR and minimising NLR. Among 7.6% [15/198] participants achieving this cut-off post-induction, 1-year ER was 46.7%. One-year ER was 16.9% among those not achieving this cut-off. This threshold predicted 1-year ER with 95.0% (95% confidence interval [CI] 90.4%-97.8%) specificity and a PLR of 3.7 [95% CI 1.4-9.5], which was higher than traditional endoscopic response criteria of SES-CD ≥50% reduction [specificity 62.5%, 95% CI 54.5%-70.0%; PLR 1.9, 95% CI 1.4-2.5]. Lower thresholds of MM-SES-CD reduction also were highly specific for 1-year ER [e.g., MM-SES-CD ≥20% reduction was achieved in 19.7% of patients with 83.1% specificity]. CONCLUSIONS: In CD patients, post-induction endoscopic response defined by MM-SES-CD ≥40% reduction from baseline identified patients most likely to achieve 1-year ER.
Assuntos
Doença de Crohn , Terapia Biológica , Doença de Crohn/tratamento farmacológico , Endoscopia , Humanos , Indução de Remissão , Índice de Gravidade de Doença , ÚlceraRESUMO
BACKGROUND & AIMS: There is no consensus on the best way to integrate biomarkers into inflammatory bowel disease (IBD) research and clinical practice. The International Organization for the Study of Inflammatory Bowel Disease aimed to outline biomarker definitions, categories, and operating properties required for their use in registration trials and clinical practice. Using fecal calprotectin as an example, we provide a framework for biomarker development and validation in patients with IBD. METHODS: We reviewed international society guidelines, regulatory agency guidance documents, and standardized reporting guidelines for biomarkers, in combination with publications on fecal calprotectin levels in patients with IBD. We assessed the validity of fecal calprotectin to serve as a surrogate biomarker of IBD activity and outlined a framework for further validation and development of biomarkers. RESULTS: No endpoints have been fully validated as surrogates of risk of disease complications; mucosal healing is the most valid endpoint used to determine risk of disease complications. Fecal level of calprotectin has not been validated as a biomarker for IBD activity because of lack of technical and clinical reliability, assessment of performance when used as a replacement for endoscopy, and assessment of responsiveness to changes in disease states. The level of fecal calprotectin can be used only as a prognostic factor for disease recurrence in patients in remission after medical or surgical treatment. CONCLUSIONS: We reviewed guidelines, regulatory documents, and publications to identify properties required for the development of biomarkers of IBD activity and areas in need of clarification from regulatory agencies and societies. We propose a path forward for research of biomarkers for IBD.
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Ensaios Clínicos como Assunto/métodos , Procedimentos Clínicos , Fezes/química , Doenças Inflamatórias Intestinais/terapia , Complexo Antígeno L1 Leucocitário/metabolismo , Biomarcadores/metabolismo , Consenso , Humanos , Doenças Inflamatórias Intestinais/diagnóstico , Doenças Inflamatórias Intestinais/metabolismo , Valor Preditivo dos Testes , Recidiva , Indução de Remissão , Reprodutibilidade dos Testes , Projetos de Pesquisa , Fatores de Risco , Fatores de Tempo , Resultado do TratamentoRESUMO
Specific blockade of the endothelial ligands intercellular adhesion molecule-1 [ICAM-1] and mucosal addressin cell adhesion molecule [MAdCAM] involved in leukocyte recruitment to the site of inflammation as therapeutic targets in inflammatory bowel disease [IBD] has been recognized from their overexpression in the inflamed mucosa and successful intervention based on these ligands in preclinical animal models. Interventions to target ICAM-1 in human IBD are confined to the ICAM-1 anti-sense oligonucleotide alicaforsen. While results with parenteral formulations of alicaforsen in Crohn's disease have largely been negative, efficacy signals derived from studies with an enema formulation in ulcerative colitis and pouchitis are promising and have led to a Food and Drug Administration Fast-Track designation for the latter. A large phase III programme in pouchitis is underway. Phase II studies with the anti-MAdCAM-1 antibody [SHP647] delivered positive results in ulcerative colitis and anti-inflammatory signals in Crohn's disease. Furthermore, it was shown that SHP647 does not affect the number and composition of cells in cerebrospinal fluid, suggesting that the compound is not affecting immune surveillance in the central nervous system. In addition, both alicaforsen and SHP647 are promising compounds based on the clear safety profile observed so far.
Assuntos
Fármacos Gastrointestinais/uso terapêutico , Imunoglobulinas/metabolismo , Doenças Inflamatórias Intestinais/tratamento farmacológico , Molécula 1 de Adesão Intercelular/metabolismo , Mucoproteínas/metabolismo , Oligonucleotídeos Fosforotioatos/uso terapêutico , Animais , Anticorpos Monoclonais Humanizados/uso terapêutico , Moléculas de Adesão Celular , Movimento Celular , Humanos , Imunoglobulinas/imunologia , Molécula 1 de Adesão Intercelular/imunologia , Leucócitos/imunologia , Terapia de Alvo Molecular , Mucoproteínas/antagonistas & inibidores , Mucoproteínas/imunologia , Pouchite/tratamento farmacológicoRESUMO
Inflammatory bowel disease is believed to be caused by a combination of genetic and environmental stimuli such as our diet. Diets high in meat and fats and low in fruits and vegetables have been associated with new-onset inflammatory bowel disease. This has triggered interest in using dietary modification as a treatment. The 3 principle models of dietary intervention are supplementation with selected dietary components, exclusion of selected dietary components, or use of dietary formulas in place of a normal diet. Despite the high level of interest in dietary interventions as a treatment for inflammatory bowel disease, few well-designed clinical trials have been conducted to firmly establish the optimal diet to induce or maintain remission. This may be in part related to the challenges of conducting dietary intervention trials. This review examines these challenges and potential approaches to be used in dietary intervention trials.
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Ensaios Clínicos como Assunto , Dieta/métodos , Doenças Inflamatórias Intestinais/dietoterapia , Suplementos Nutricionais , Alimentos Formulados , Humanos , Projetos de PesquisaRESUMO
OBJECTIVE: Iron isomaltoside 1000 (Monofer®) is a high-dose intravenous (IV) iron, which in a recent 8 weeks trial in inflammatory bowel disease (IBD) subjects with iron deficiency anemia (IDA) demonstrated good tolerability and efficacy. The present trial is an extension to this trial, which evaluates the need for additional high IV iron doses to maintain a stable hemoglobin (Hb) ≥12.0 g/dl. MATERIAL AND METHODS: This was a prospective, open-label, 12 months trial of European IBD subjects willing to participate after completing the lead-in trial. Subjects were allowed re-dosing with 500-2000 mg single doses of iron isomaltoside 1000 infused over â¼15 min at 3 months intervals depending on a predefined algorithm. Outcome measures included Hb, safety parameters and need for additional iron dosing. RESULTS: A total of 39 subjects were enrolled of which 34 subjects required re-dosing with a median cumulative 1-year dose of 1.8 g (mean cumulative dose 2.2 g). The mean (SD) Hb was 12.3 (1.5) g/dl at baseline, 12.8 (1.6) g/dl at 3 months, 12.8 (1.6) g/dl at 6 months, 12.9 (1.4) g/dl at 9 months and 12.9 (1.6) g/dl at 12 months. Seventy-four percent of subjects who had an Hb ≥12.0 g/dl at baseline were able to maintain Hb ≥12.0 g/dl till the end of the trial at 12 months. Nonserious probably related hypersensitivity reactions without significant hypotension were reported at the beginning of the infusion in two subjects, who recovered without sequelae. CONCLUSION: Repeated treatment of iron deficiency with iron isomaltoside 1000 could avoid episodes of IDA without major safety issues.
Assuntos
Anemia Ferropriva/tratamento farmacológico , Anemia Ferropriva/etiologia , Dissacarídeos/administração & dosagem , Compostos Férricos/administração & dosagem , Doenças Inflamatórias Intestinais/complicações , Doenças Inflamatórias Intestinais/tratamento farmacológico , Administração Intravenosa , Adulto , Áustria , Relação Dose-Resposta a Droga , Esquema de Medicação , Feminino , Seguimentos , Humanos , Hungria , Doenças Inflamatórias Intestinais/diagnóstico , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Medição de Risco , Fatores de Tempo , Resultado do TratamentoRESUMO
BACKGROUND & AIMS: Ulcerative colitis (UC) is difficult to treat, and standard therapy does not always induce remission. Fecal microbiota transplantation (FMT) is an alternative approach that induced remission in small series of patients with active UC. We investigated its safety and efficacy in a placebo-controlled randomized trial. METHODS: We performed a parallel study of patients with active UC without infectious diarrhea. Participants were examined by flexible sigmoidoscopy when the study began and then were randomly assigned to groups that received FMT (50 mL, via enema, from healthy anonymous donors; n = 38) or placebo (50 mL water enema; n = 37) once weekly for 6 weeks. Patients, clinicians, and investigators were blinded to the groups. The primary outcome was remission of UC, defined as a Mayo score ≤2 with an endoscopic Mayo score of 0, at week 7. Patients provided stool samples when the study began and during each week of FMT for microbiome analysis. The trial was stopped early for futility by the Data Monitoring and Safety Committee, but all patients already enrolled in the trial were allowed to complete the study. RESULTS: Seventy patients completed the trial (3 dropped out from the placebo group and 2 from the FMT group). Nine patients who received FMT (24%) and 2 who received placebo (5%) were in remission at 7 weeks (a statistically significant difference in risk of 17%; 95% confidence interval, 2%-33%). There was no significant difference in adverse events between groups. Seven of the 9 patients in remission after FMT received fecal material from a single donor. Three of the 4 patients with UC ≤1 year entered remission, compared with 6 of 34 of those with UC >1 year (P = .04, Fisher's exact test). Stool from patients receiving FMT had greater microbial diversity, compared with baseline, than that of patients given the placebo (P = .02, Mann-Whitney U test). CONCLUSIONS: FMT induces remission in a significantly greater percentage of patients with active UC than placebo, with no difference in adverse events. Fecal donor and time of UC appear to affect outcomes. ClinicalTrials.gov Number: NCT01545908.
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Terapia Biológica/métodos , Colite Ulcerativa/terapia , Fezes/microbiologia , Microbiota , Adulto , Idoso , Colite Ulcerativa/fisiopatologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Indução de RemissãoRESUMO
OBJECTIVES: In the largest head-to-head comparison between an oral and an intravenous (IV) iron compound in patients with inflammatory bowel disease (IBD) so far, we strived to determine whether IV iron isomaltoside 1,000 is non-inferior to oral iron sulfate in the treatment of iron deficiency anemia (IDA). METHODS: This prospective, randomized, comparative, open-label, non-inferiority study was conducted at 36 sites in Europe and India. Patients with known intolerance to oral iron were excluded. A total of 338 IBD patients in clinical remission or with mild disease, a hemoglobin (Hb) <12 g/dl, and a transferrin saturation (TSAT) <20% were randomized 2:1 to receive either IV iron isomaltoside 1,000 according to the Ganzoni formula (225 patients) or oral iron sulfate 200 mg daily (equivalent to 200 mg elemental iron; 113 patients). An interactive web response system method was used to randomize the eligible patient to the treatment groups. The primary end point was change in Hb from baseline to week 8. Iron isomaltoside 1,000 and iron sulfate was compared by a non-inferiority assessment with a margin of -0.5 g/dl. The secondary end points, which tested for superiority, included change in Hb from baseline to weeks 2 and 4, change in s-ferritin, and TSAT to week 8, number of patients who discontinued study because of lack of response or intolerance of investigational drugs, change in total quality of life (QoL) score to weeks 4 and 8, and safety. Exploratory analyses included a responder analysis (proportion of patients with an increase in Hb ≥2 g/dl after 8 weeks), the effect of regional differences and total iron dose level, and other potential predictors of the treatment response. RESULTS: Non-inferiority in change of Hb to week 8 could not be demonstrated. There was a trend for oral iron sulfate being more effective in increasing Hb than iron isomaltoside 1,000. The estimated treatment effect was -0.37 (95% confidence interval (CI): -0.80, 0.06) with P=0.09 in the full analysis set (N=327) and -0.45 (95% CI: -0.88, -0.03) with P=0.04 in the per protocol analysis set (N=299). In patients treated with IV iron isomaltoside 1,000, the mean change in s-ferritin concentration was higher with an estimated treatment effect of 48.7 (95% CI: 18.6, 78.8) with P=0.002, whereas the mean change in TSAT was lower with an estimated treatment effect of -4.4 (95% CI: -7.4, -1.4) with P=0.005, compared with patients treated with oral iron. No differences in changes of QoL were observed. The safety profile was similar between the groups. The proportion of responders with Hb ≥2 g/dl (IV group: 67%; oral group: 61%) were comparable between the groups (P=0.32). Iron isomaltoside 1,000 was more efficacious with higher cumulative doses of >1,000 mg IV. Significant predictors of Hb response to IV iron treatment were baseline Hb and C-reactive protein (CRP). CONCLUSIONS: We could not demonstrate non-inferiority of IV iron isomaltoside 1,000 compared with oral iron in this study. Based on the dose-response relationship observed with the IV iron compound, we suggest that the true iron demand of IV iron was underestimated by the Ganzoni formula in our study. Alternative calculations including Hb and CRP should be explored to gauge iron stores in patients with IBD.
Assuntos
Anemia Ferropriva/tratamento farmacológico , Anemia Ferropriva/etiologia , Dissacarídeos/uso terapêutico , Compostos Férricos/uso terapêutico , Doenças Inflamatórias Intestinais/complicações , Ferro/uso terapêutico , Administração Oral , Adulto , Dissacarídeos/administração & dosagem , Feminino , Compostos Férricos/administração & dosagem , Humanos , Injeções Intravenosas , Ferro/administração & dosagem , Masculino , Estudos Prospectivos , Qualidade de Vida , Resultado do TratamentoRESUMO
OBJECTIVES: Fecal microbiota transplantation (FMT) from healthy donors, which is an effective alternative for treatment of Clostridium difficile-associated disease, is being considered for several disorders such as inflammatory bowel disease, irritable bowel syndrome, and metabolic syndrome. Disease remission upon FMT is thought to be facilitated by an efficient colonization of healthy donor microbiota, but knowledge of the composition and temporal stability of patient microbiota after FMT is lacking. METHODS: Five patients with moderately to severely active ulcerative colitis (Mayo score ≥6) and refractory to standard therapy received FMT via nasojejunal tube and enema. In addition to clinical activity and adverse events, the patients' fecal bacterial communities were monitored at multiple time points for up to 12 weeks using 16S rRNA gene-targeted pyrosequencing. RESULTS: FMT elicited fever and a temporary increase of C-reactive protein. Abundant bacteria from donors established in recipients, but the efficiency and stability of donor microbiota colonization varied greatly. A positive clinical response was observed after 12 weeks in one patient whose microbiota had been effectively augmented by FMT. This augmentation was marked by successive colonization of donor-derived phylotypes including the anti-inflammatory and/or short-chain fatty acid-producing Faecalibacterium prausnitzii, Rosebura faecis, and Bacteroides ovatus. Disease severity (as measured by the Mayo score) was associated with an overrepresentation of Enterobacteriaceae and an underrepresentation of Lachnospiraceae. CONCLUSIONS: This study highlights the value of characterizing temporally resolved microbiota dynamics for a better understanding of FMT efficacy and provides potentially useful diagnostic indicators for monitoring FMT success in the treatment of ulcerative colitis.
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Colite Ulcerativa/terapia , Fezes/microbiologia , Metagenoma/genética , RNA Ribossômico 16S/análise , Transplante , Adulto , Bacteroides/genética , Proteína C-Reativa , Clostridium/genética , Colite Ulcerativa/microbiologia , Enema , Enterobacteriaceae/genética , Feminino , Humanos , Intubação Gastrointestinal , Masculino , Pessoa de Meia-Idade , Fatores de Tempo , Adulto JovemAssuntos
Doença de Crohn/diagnóstico , Doença de Crohn/terapia , Adolescente , Corticosteroides/uso terapêutico , Ácidos Aminossalicílicos/uso terapêutico , Antibacterianos/uso terapêutico , Anti-Inflamatórios/uso terapêutico , Anticorpos Monoclonais/uso terapêutico , Artrite/diagnóstico , Artrite/tratamento farmacológico , Artrite/etiologia , Criança , Terapias Complementares , Doença de Crohn/complicações , Doença de Crohn/psicologia , Feminino , Humanos , Imunossupressores/uso terapêutico , Infliximab , Fístula Intestinal/diagnóstico , Fístula Intestinal/etiologia , Fístula Intestinal/terapia , Masculino , Gravidez , Complicações na Gravidez/terapia , Psicoterapia , Purinas/uso terapêutico , Recidiva , Dermatopatias/diagnóstico , Dermatopatias/tratamento farmacológico , Dermatopatias/etiologia , Fator de Necrose Tumoral alfa/antagonistas & inibidoresRESUMO
OBJECTIVES: The Crohn's disease (CD) susceptibility gene, nucleotide-binding oligomerizetion domain 2 (NOD2)/caspase recruitment domain 15 (CARD15), is linked to the innate immune response associated with altered epithelial bacterial defense. Its relevance in antibiotic therapy of perianal fistulating CD remains elusive. The aim of the study was to explore systematically the association between NOD2/CARD15 variants and clinical response of perianal fistulas in patients using antibiotic therapy. METHODS: Fifty-two patients (median age 36 yr) with draining perianal fistulas were treated with ciprofloxacin (N = 49) or metronidazole (N = 3) for a median duration of 7 wk. Complete response was defined as the absence of any draining fistula despite gentle finger compression. Genotyping for NOD2/CARD15 variants and human beta (beta)-defensin 2 (HBD-2) copies was performed by 5' nuclease assays (Applied Biosystems, Foster City, CA). The examiners and laboratory investigators were blinded. The Fisher exact test and Wilcoxon signed rank test were used for statistical analysis. RESULTS: Ciprofloxacin was discontinued in one patient due to diarrhea after 2 wk. Complete fistula response was observed in 13 of 39 patients with NOD2/CARD15 wild-type (33.3%) compared with none in patients carrying NOD2/CARD15 variants (0%, P= 0.02). The median number of HBD-2 gene copies between responders and partial/nonresponders was similar. CONCLUSIONS: The study result suggests a substantial contribution of NOD2/CARD15 to the antibiotic treatment outcome of perianal fistulating CD. NOD2/CARD15 variants may predispose to an altered intestinal microflora in perianal fistulas that is less responsive to antibiotic treatment.
Assuntos
Anti-Infecciosos/uso terapêutico , Ciprofloxacina/uso terapêutico , Doença de Crohn/tratamento farmacológico , Doença de Crohn/genética , Predisposição Genética para Doença/genética , Genótipo , Metronidazol/uso terapêutico , Proteína Adaptadora de Sinalização NOD2/genética , Polimorfismo de Nucleotídeo Único/genética , Fístula Retal/tratamento farmacológico , Fístula Retal/genética , Adulto , Alelos , Anti-Infecciosos/efeitos adversos , Ciprofloxacina/efeitos adversos , Doença de Crohn/diagnóstico , Feminino , Triagem de Portadores Genéticos , Humanos , Masculino , Metronidazol/efeitos adversos , Pessoa de Meia-Idade , Prognóstico , Estudos Prospectivos , Falha de Tratamento , beta-Defensinas/genéticaRESUMO
OBJECTIVE: 6-thioguanine (6-TG) has emerged as a promising therapeutic alternative in patients with Crohn's disease intolerant or resistant to azathioprine (AZA) and/or 6-mercaptopurine (6-MP). The aim of the present study was to evaluate the safety and efficacy of 6-TG in patients with ulcerative colitis (UC) or indeterminate colitis (IC) intolerant or resistant to AZA/6-MP. MATERIAL AND METHODS: Twenty patients with an acute flare, steroid-dependent or steroid-refractory disease attending our outpatient department were included in the study. Measurement of 6-TG nucleotide levels was done to check compliance. Complete, partial and non-response were defined by means of the clinical activity index and the daily steroid demand. Secondary outcome parameters included changes in cumulative steroid doses, C-reactive protein (CRP) levels, and an endoscopic score. RESULTS: Out of 20 patients 4 were excluded owing to noncompliance; 2/16 compliant patients (13%) had to be prematurely withdrawn because of adverse events, which ceased upon drug discontinuation. By per-protocol analysis, 5/14 patients (36%) were complete, 6/14 (43%) partial and 3/14 (21%) non-responders. In addition to the reduction of the cumulative steroid dose over 3 months, CRP decreased in the study population and the endoscopic score decreased in treatment responders. CONCLUSIONS: Treatment with 6-TG was effective in patients with UC or IC previously intolerant or resistant to AZA/6-MP. Future work is needed to define a subpopulation of patients at low risk for its potential hepatotoxicity, which we assume will benefit from 6-TG.
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Anti-Inflamatórios/uso terapêutico , Colite Ulcerativa/tratamento farmacológico , Tioguanina/uso terapêutico , Adulto , Idoso , Anti-Inflamatórios/administração & dosagem , Anti-Inflamatórios/efeitos adversos , Azatioprina/efeitos adversos , Azatioprina/metabolismo , Biomarcadores/sangue , Proteína C-Reativa/metabolismo , Colite Ulcerativa/sangue , Colite Ulcerativa/metabolismo , Relação Dose-Resposta a Droga , Endoscopia Gastrointestinal , Feminino , Genótipo , Nucleotídeos de Guanina/sangue , Humanos , Masculino , Mercaptopurina/efeitos adversos , Mercaptopurina/metabolismo , Metiltioinosina/sangue , Metiltransferases/genética , Metiltransferases/metabolismo , Pessoa de Meia-Idade , Orosomucoide/metabolismo , Cooperação do Paciente , Estudos Prospectivos , Qualidade de Vida , Tioguanina/administração & dosagem , Tioguanina/efeitos adversos , Tionucleotídeos/sangue , Resultado do TratamentoRESUMO
IL-10-deficient mice exhibit spontaneous enterocolitis and other symptoms akin to Crohn's disease, indicating that IL-10 might regulate normal physiology in the gut. However, clinical trials with IL-10 in Crohn's disease were disappointing, although some patients showed healing of intestinal mucosa. This study searched for genetic polymorphisms within the IL-10 pathway. We decided to screen for mutations of the IL-10R1 cDNA in healthy volunteers and Crohn's disease patients and identified two novel variants: a serine 138-to-glycine (S138G) and a glycine 330-to-arginine (G330R) substitution. The allelic frequency in a European cohort was relatively high (16% for the S138G and 33% for the G330R), and S138G was in strong linkage disequilibrium with G330R. A similar allele frequency was found in a group of Crohn's patients. In IL-10R1 G330R-expressing monocytes, the inhibitory effect of IL-10 on TNF-alpha production was diminished, indicating that this variant may be a loss-of-function allele. No such difference was observed between haplotypes 4 (G330R only) and 7 (S138G and G330R). In addition, these IL-10R1 variants had no influence on the IL-10R1 expression density. Structural analysis of the S138G variant revealed that the substitution of S138G may interfere with binding of IL-10 to IL-10R1.
Assuntos
Variação Genética/imunologia , Interleucina-10/metabolismo , Monócitos/imunologia , Monócitos/metabolismo , Receptores de Interleucina/química , Receptores de Interleucina/genética , Fator de Necrose Tumoral alfa/antagonistas & inibidores , Fator de Necrose Tumoral alfa/biossíntese , Substituição de Aminoácidos/genética , Substituição de Aminoácidos/imunologia , Arginina/genética , Doença de Crohn/genética , Doença de Crohn/imunologia , DNA Complementar/análise , Frequência do Gene/imunologia , Genótipo , Glicina/genética , Haplótipos/imunologia , Humanos , Substâncias Macromoleculares , Modelos Moleculares , Polimorfismo de Nucleotídeo Único/imunologia , Receptores de Interleucina/biossíntese , Receptores de Interleucina/fisiologia , Receptores de Interleucina-10 , Serina/genéticaRESUMO
The bacterial tripeptide formyl-Met-Leu-Phe (fMLP) induces the secretion of enzyme(s) with phospholipase A(2) (PLA(2)) activity from human neutrophils. We show that circulating human neutrophils express groups V and X sPLA(2) (GV and GX sPLA(2)) mRNA and contain GV and GX sPLA(2) proteins, whereas GIB, GIIA, GIID, GIIE, GIIF, GIII, and GXII sPLA(2)s are undetectable. GV sPLA(2) is a component of both azurophilic and specific granules, whereas GX sPLA(2) is confined to azurophilic granules. Exposure to fMLP or opsonized zymosan results in the release of GV but not GX sPLA(2) and most, if not all, of the PLA(2) activity in the extracellular fluid of fMLP-stimulated neutrophils is due to GV sPLA(2). GV sPLA(2) does not contribute to fMLP-stimulated leukotriene B(4) production but may support the anti-bacterial properties of the neutrophil, because 10-100 ng per ml concentrations of this enzyme lead to Gram-negative bacterial membrane phospholipid hydrolysis in the presence of human serum. By use of a recently described and specific inhibitor of cytosolic PLA(2)-alpha (group IV PLA(2)alpha), we show that this enzyme produces virtually all of the arachidonic acid used for the biosynthesis of leukotriene B(4) in fMLP- and opsonized zymosan-stimulated neutrophils, the major eicosanoid produced by these pro-inflammatory cells.