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1.
Clin Exp Rheumatol ; 42(1): 24-29, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38079340

RESUMO

OBJECTIVES: Early confirmation of the diagnosis of connective tissue diseases (CTD) is important, as prolonged disease activity can result in irreversible organ damage. Although antinuclear antibodies (ANAs) have been shown to precede the diagnosis of SLE, this has not been investigated in large cohorts for other CTDs. In this study, we investigated whether the presence of antinuclear autoantibodies in undiagnosed patients suspected of having CTDs is predictive of development of a future CTD. METHODS: We screened the Electronic Health Records of a cohort of 1030 patients, who were tested for ANAs and their specificity in 2013/2014, to evaluate whether new CTD diagnoses had been recorded by a clinician between the original blood draw date and 2020. We compared the prevalence of ANAs in patients who developed a new CTD diagnosis during follow-up with patients with similar symptoms at baseline who did not receive a subsequent CTD diagnosis and with patients with an established CTD at baseline. RESULTS: Sixteen out of 1030 patients had developed a new CTD in the studied time period. The mean time period between baseline blood draw and subsequent CTD diagnosis of these patients was approximately 2.3 years. Eleven out of 16 (69%) newly diagnosed patients had positive ANA screening tests, compared to 54% of patients with a CTD diagnosis at baseline (p=ns) and 30% of symptomatic undiagnosed patients (p<0.001). This resulted in a positive predictive value (PPV) of 7% and a negative predictive value (NPV) of 98% for the development of a new CTD in undiagnosed symptomatic patients. For specific ANAs associated with the suspected CTD, the PPV was 12%, with a NPV of 98%. CONCLUSIONS: Progression to a CTD diagnosis is rare in undiagnosed patients. Undiagnosed patients with symptoms associated with a CTD who progress to a CTD more often have ANAs than patients with similar symptoms who do not progress to a CTD. ANA testing can be used to more stringently select patients who should remain in follow-up.


Assuntos
Anticorpos Antinucleares , Doenças do Tecido Conjuntivo , Humanos , Doenças do Tecido Conjuntivo/diagnóstico , Doenças do Tecido Conjuntivo/complicações , Valor Preditivo dos Testes
2.
J Peripher Nerv Syst ; 29(2): 193-201, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38528725

RESUMO

BACKGROUND AND AIMS: To further substantiate the role of antibody-mediated complement activation in multifocal motor neuropathy (MMN) immunopathology, we investigated the distribution of promotor polymorphisms of genes encoding the membrane-bound complement regulators CD46, CD55, and CD59 in patients with MMN and controls, and evaluated their association with disease course. METHODS: We used Sanger sequencing to genotype five common polymorphisms in the promotor regions of CD46, CD55, and CD59 in 133 patients with MMN and 380 controls. We correlated each polymorphism to clinical parameters. RESULTS: The genotype frequencies of rs28371582, a 21-bp deletion in the CD55 promotor region, were altered in patients with MMN as compared to controls (p .009; Del/Del genotype 16.8% vs. 7.7%, p .005, odds ratio: 2.43 [1.27-4.58]), and patients carrying this deletion had a more favorable disease course (mean difference 0.26 Medical Research Council [MRC] points/year; 95% confidence interval [CI]: 0.040-0.490, p .019). The presence of CD59 rs141385724 was associated with less severe pre-diagnostic disease course (mean difference 0.940 MRC point/year; 95% CI: 0.083-1.80, p .032). INTERPRETATION: MMN susceptibility is associated with a 21-bp deletion in the CD55 promotor region (rs2871582), which is associated with lower CD55 expression. Patients carrying this deletion may have a more favorable long-term disease outcome. Taken together, these results point out the relevance of the pre-C5 level of the complement cascade in the inflammatory processes underlying MMN.


Assuntos
Antígenos CD55 , Regiões Promotoras Genéticas , Humanos , Antígenos CD55/genética , Masculino , Feminino , Pessoa de Meia-Idade , Idoso , Adulto , Proteína Cofatora de Membrana/genética , Antígenos CD59/genética , Deleção de Sequência , Polineuropatias/genética , Polineuropatias/fisiopatologia , Polineuropatias/imunologia , Progressão da Doença , Genótipo
3.
Proc Natl Acad Sci U S A ; 118(51)2021 12 21.
Artigo em Inglês | MEDLINE | ID: mdl-34916298

RESUMO

The thyroid maintains systemic homeostasis by regulating serum thyroid hormone concentrations. Here we report the establishment of three-dimensional (3D) organoids from adult thyroid tissue representing murine and human thyroid follicular cells (TFCs). The TFC organoids (TFCOs) harbor the complete machinery of hormone production as visualized by the presence of colloid in the lumen and by the presence of essential transporters and enzymes in the polarized epithelial cells that surround a central lumen. Both the established murine as human thyroid organoids express canonical thyroid markers PAX8 and NKX2.1, while the thyroid hormone precursor thyroglobulin is expressed at comparable levels to tissue. Single-cell RNA sequencing and transmission electron microscopy confirm that TFCOs phenocopy primary thyroid tissue. Thyroid hormones are readily detectable in conditioned medium of human TFCOs. We show clinically relevant responses (increased proliferation and hormone secretion) of human TFCOs toward a panel of Graves' disease patient sera, demonstrating that organoids can model human autoimmune disease.


Assuntos
Regulação da Expressão Gênica/fisiologia , Doença de Graves/metabolismo , Organoides/metabolismo , Células Epiteliais da Tireoide/fisiologia , Animais , Meios de Cultura , Humanos , Camundongos , Fator de Transcrição PAX8/genética , Fator de Transcrição PAX8/metabolismo , Tireoglobulina/genética , Tireoglobulina/metabolismo , Fator Nuclear 1 de Tireoide/genética , Fator Nuclear 1 de Tireoide/metabolismo
4.
Allergy ; 77(5): 1559-1569, 2022 05.
Artigo em Inglês | MEDLINE | ID: mdl-34731517

RESUMO

BACKGROUND: Component-resolved diagnostics (CRD) help predict hazelnut allergy (HA) in children, but are of unknown diagnostic value in adults. This study aimed to evaluate the diagnostic accuracy of IgE to hazelnut extract and components in adults. METHODS: A Dutch population of consecutively presenting adults suspected of HA, who underwent a double-blind placebo-controlled food challenge, were included. Serum IgE to hazelnut extract and Cor a 1, 8, 9, and 14 was measured on ImmunoCAP. Diagnostic accuracy was assessed by area under the curve (AUC) analysis. RESULTS: Of 89 patients undergoing challenge, 46 had challenge-confirmed HA: 17 based on objective and 29 based on subjective symptoms. At commonly applied cutoffs 0.1 and 0.35 kUA /L, high sensitivity was observed for IgE to hazelnut extract and Cor a 1 (range 85-91%), and high specificity for IgE to Cor a 8, 9 and 14 (range 77-95%). However, the AUCs for hazelnut extract and components were too low for accurate prediction of HA (range 0.50-0.56). Combining hazelnut extract and component IgE measurements did not significantly improve accuracy. Higher IgE levels to Cor a 9 and 14 were tentatively associated with HA with objective symptoms, but the corresponding AUCs still only reached 0.68 and 0.63, respectively. CONCLUSIONS: Although hazelnut allergic adults are generally sensitized to hazelnut extract and Cor a 1, and hazelnut tolerant adults are usually not sensitized to Cor a 8, 9, or 14, challenge testing is still needed to accurately discriminate between presence and absence of HA in adults from a birch-endemic country.


Assuntos
Corylus , Hipersensibilidade a Noz , Alérgenos , Antígenos de Plantas , Corylus/efeitos adversos , Humanos , Imunoglobulina E , Hipersensibilidade a Noz/diagnóstico , Extratos Vegetais
5.
J Allergy Clin Immunol ; 147(4): 1420-1429.e7, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-32926878

RESUMO

BACKGROUND: Activation of the classical and lectin pathway of complement may contribute to tissue damage and organ dysfunction of antibody-mediated diseases and ischemia-reperfusion conditions. Complement factors are being considered as targets for therapeutic intervention. OBJECTIVE: We sought to characterize ARGX-117, a humanized inhibitory monoclonal antibody against complement C2. METHODS: The mode-of-action and binding characteristics of ARGX-117 were investigated in detail. Furthermore, its efficacy was analyzed in in vitro complement cytotoxicity assays. Finally, a pharmacokinetic/pharmacodynamic study was conducted in cynomolgus monkeys. RESULTS: Through binding to the Sushi-2 domain of C2, ARGX-117 prevents the formation of the C3 proconvertase and inhibits classical and lectin pathway activation upstream of C3 activation. As ARGX-117 does not inhibit the alternative pathway, it is expected not to affect the antimicrobial activity of this complement pathway. ARGX-117 prevents complement-mediated cytotoxicity in in vitro models for autoimmune hemolytic anemia and antibody-mediated rejection of organ transplants. ARGX-117 exhibits pH- and calcium-dependent target binding and is Fc-engineered to increase affinity at acidic pH to the neonatal Fc receptor, and to reduce effector functions. In cynomolgus monkeys, ARGX-117 dose-dependently reduces free C2 levels and classical pathway activity. A 2-dose regimen of 80 and 20 mg/kg separated by a week, resulted in profound reduction of classical pathway activity lasting for at least 7 weeks. CONCLUSIONS: ARGX-117 is a promising new complement inhibitor that is uniquely positioned to target both the classical and lectin pathways while leaving the alternative pathway intact.


Assuntos
Anticorpos Monoclonais/farmacologia , Complemento C2/antagonistas & inibidores , Inativadores do Complemento/farmacologia , Animais , Anticorpos Monoclonais/sangue , Anticorpos Monoclonais/farmacocinética , Cálcio , Ativação do Complemento/efeitos dos fármacos , Complemento C2/análise , Complemento C2/metabolismo , Inativadores do Complemento/sangue , Inativadores do Complemento/farmacocinética , Mapeamento de Epitopos , Feminino , Humanos , Concentração de Íons de Hidrogênio , Macaca fascicularis , Masculino
6.
Rheumatology (Oxford) ; 60(2): 785-801, 2021 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-32810267

RESUMO

OBJECTIVES: Vasculopathy is an important hallmark of systemic chronic inflammatory connective tissue diseases (CICTD) and is associated with increased cardiovascular risk. We investigated disease-specific biomarker profiles associated with endothelial dysfunction, angiogenic homeostasis and (tissue) inflammation, and their relation to disease activity in rare CICTD. METHODS: A total of 38 serum proteins associated with endothelial (dys)function and inflammation were measured by multiplex-immunoassay in treatment-naive patients with localized scleroderma (LoS, 30), eosinophilic fasciitis (EF, 8) or (juvenile) dermatomyositis (34), 119 (follow-up) samples during treatment, and 65 controls. Data were analysed by unsupervised clustering, Spearman correlations, non-parametric t test and ANOVA. RESULTS: The systemic CICTD, EF and dermatomyositis, had distinct biomarker profiles, with 'signature' markers galectin-9 (dermatomyositis) and CCL4, CCL18, CXCL9, fetuin, fibronectin, galectin-1 and TSP-1 (EF). In LoS, CCL18, CXCL9 and CXCL10 were subtly increased. Furthermore, dermatomyositis and EF shared upregulation of markers related to interferon (CCL2, CXCL10), endothelial activation (VCAM-1), inhibition of angiogenesis (angiopoietin-2, sVEGFR-1) and inflammation/leucocyte chemo-attraction (CCL19, CXCL13, IL-18, YKL-40), as well as disturbance of the Angiopoietin-Tie receptor system and VEGF-VEGFR system. These profiles were related to disease activity, and largely normalized during treatment. However, a subgroup of CICTD patients showed continued elevation of CXCL10, CXCL13, galectin-9, IL-18, TNFR2, VCAM-1, and/or YKL-40 during clinically inactive disease, possibly indicating subclinical interferon-driven inflammation and/or endothelial dysfunction. CONCLUSION: CICTD-specific biomarker profiles revealed an anti-angiogenic, interferon-driven environment during active disease, with incomplete normalization under treatment. This warrants further investigation into monitoring of vascular biomarkers during clinical follow-up, or targeted interventions to minimize cardiovascular risk in the long term.


Assuntos
Biomarcadores/sangue , Dermatomiosite , Endotélio Vascular/imunologia , Eosinofilia , Fasciite , Esclerodermia Localizada , Autoimunidade , Quimiocina CXCL10/sangue , Quimiocina CXCL13/sangue , Dermatomiosite/sangue , Dermatomiosite/diagnóstico , Eosinofilia/sangue , Eosinofilia/diagnóstico , Fasciite/sangue , Fasciite/diagnóstico , Feminino , Galectinas/sangue , Fatores de Risco de Doenças Cardíacas , Humanos , Masculino , Pessoa de Meia-Idade , Monitorização Imunológica/métodos , Países Baixos , Gravidade do Paciente , Receptores Tipo II do Fator de Necrose Tumoral/sangue , Esclerodermia Localizada/sangue , Esclerodermia Localizada/diagnóstico , Molécula 1 de Adesão de Célula Vascular/sangue
7.
Allergy ; 76(9): 2753-2764, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-33969502

RESUMO

BACKGROUND: Specific IgE against a peanut 2S albumin (Ara h 2 or 6) is the best predictor of clinically relevant peanut sensitization. However, sIgE levels of peanut allergic and those of peanut sensitized but tolerant patients partly overlap, highlighting the need for improved diagnostics to prevent incorrect diagnosis and consequently unnecessary food restrictions. Thus, we sought to explore differences in V(D)J gene transcripts coding for peanut 2S albumin-specific monoclonal antibodies (mAbs) from allergic and sensitized but tolerant donors. METHODS: 2S albumin-binding B-cells were single-cell sorted from peripheral blood of peanut allergic (n=6) and tolerant (n=6) donors sensitized to Ara h2 and/or 6 (≥ 0.1 kU/l) and non-atopic controls (n=5). h 2 and/or 6 (≥ 0.1 kU/l). Corresponding h heavy and light chain gene transcripts were heterologously expressed as mAbs and tested for specificity to native Ara h2 and 6. HCDR3 sequence motifs were identified by Levenshtein distances and hierarchically clustering. RESULTS: The frequency of 2S albumin-binding B cells was increased in allergic (median: 0.01%) compared to tolerant (median: 0.006%) and non-atopic donors (median: 0.0015%, p = 0.008). The majority of mAbs (74%, 29/39) bound specifically to Ara h 2 and/or 6. Non-specific mAbs (9/10) were mainly derived from non-atopic controls. In allergic donors, 89% of heavy chain gene transcripts consisted of VH3 family genes, compared with only 54% in sensitized but tolerant and 63% of non-atopic donors. Additionally, certain HCDR3 sequence motifs were associated with allergy (n = 4) or tolerance (n = 3) upon hierarchical clustering of their Levenshtein distances. CONCLUSIONS: Peanut allergy is associated with dominant VH3 family gene usage and certain public antibody sequences (HCDR3 motifs).


Assuntos
Hipersensibilidade a Amendoim , Albuminas 2S de Plantas/genética , Alérgenos , Antígenos de Plantas , Arachis , Humanos , Imunoglobulina E , Hipersensibilidade a Amendoim/diagnóstico , Receptores de Antígenos de Linfócitos B
8.
Clin Exp Allergy ; 50(12): 1415-1423, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-32909666

RESUMO

BACKGROUND: Although hen's egg allergy is more prevalent in children, up to 0.6% of adults from different European countries suffer from a persistent or newly onset hen's egg allergy, making accurate diagnosis in adults necessary. However, sensitization to hen's egg extracts, components and linear epitopes is solely studied in children. METHODS: Hen's egg allergic (n = 16) and tolerant (n = 19) adults were selected by sensitization towards recombinant components rGal d 1 and/or 3. Sensitization profiles towards egg white and yolk extract and the native components Gal d 1, 2, 3 and 4 were respectively evaluated with the ImmunoCAP or the EUROLINE system. Characterization of linear epitopes was performed with a peptide microarray containing 15mer peptides representing the entire sequence of mature Gal d 1 and 3. RESULTS: Overall, sIgE titres against hen's egg extracts and single components overlapped largely between allergic and tolerant adults. Although the median sIgE/sIgG4 ratio to Gal d 1 was increased in allergic adults, the range was comparable between both groups. Clinically relevant sensitization to Gal d 1 was confirmed by sIgE-binding to the linear epitopes aa30-41, aa39-50 or aa84-95 in 6/13 allergic adults, mainly suffering from objective symptoms. In comparison, these epitopes were recognized by 1/15 tolerant patient. Only a few linear epitopes were detected for Gal d 3, suggesting a greater importance of conformational epitopes for the recognition of Gal d 3. CONCLUSION AND CLINICAL RELEVANCE: Specific IgE-binding to linear epitopes of Gal d 1 is highly specific in identifying hen's egg allergic adults with objective symptoms.


Assuntos
Hipersensibilidade a Ovo/diagnóstico , Proteínas do Ovo/administração & dosagem , Epitopos Imunodominantes , Imunoglobulina E/sangue , Testes Imunológicos , Ovomucina/administração & dosagem , Adulto , Idoso , Biomarcadores/sangue , Hipersensibilidade a Ovo/sangue , Hipersensibilidade a Ovo/imunologia , Proteínas do Ovo/imunologia , Feminino , Humanos , Masculino , Análise em Microsséries , Pessoa de Meia-Idade , Ovomucina/imunologia , Valor Preditivo dos Testes , Proteínas Recombinantes/administração & dosagem , Proteínas Recombinantes/imunologia , Estudos Retrospectivos , Adulto Jovem
9.
Clin Exp Allergy ; 50(3): 364-371, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-31925825

RESUMO

BACKGROUND: The pathogenesis of chronic spontaneous urticaria (CSU) and the mechanism of action of omalizumab in CSU remain unclear. OBJECTIVE: In this study, we assessed the responsiveness and FcεRI expression of various subsets of leucocytes in patients with CSU treated with omalizumab. METHODS: In this prospective cohort study, 30 patients were treated with 6 administrations of 300 mg omalizumab every 4 weeks, followed by a follow-up period of 12 weeks. FcεRI expression and the percentage of basophils, monocytes, and dendritic cell subsets were analysed before and during treatment, and after follow-up. In addition, anti-IgE- and C5a-induced basophil degranulation was measured. The results were correlated with disease activity and response to omalizumab. RESULTS: In addition to a rapid and significant reduction in FcεRI on basophils, we demonstrated a reduction in FcεRI on plasmacytoid dendritic cells during omalizumab treatment, which persisted until 3 months after discontinuation. FcεRI expression on basophils and its reduction did not correlate with the treatment response. Omalizumab led to an increased percentage of basophils in blood but not of the other FcεRI-bearing leucocytes. Basophil responsiveness was differentially affected; anti-IgE-, but not C5a-induced basophil degranulation increased during the treatment. Apart from clinical non-responders showing a stronger increase in anti-IgE-induced basophil degranulation over a period time, no differences were found in omalizumab responders vs non-responders. CONCLUSIONS/CLINICAL RELEVANCE: FcεRI expression on basophils decreased rapidly, while anti-IgE-induced degranulation significantly increased due to omalizumab treatment in patients with CSU, persisting at least for 3 months after stopping the treatment. None of the markers were able to predict the effectiveness of treatment. Whether basophils play a role in omalizumab responsiveness in CSU remains unclear.


Assuntos
Urticária Crônica/tratamento farmacológico , Urticária Crônica/imunologia , Leucócitos/imunologia , Omalizumab/administração & dosagem , Receptores de IgE/imunologia , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos
10.
Am J Transplant ; 19(10): 2926-2933, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31155833

RESUMO

Whereas regular allocation avoids unacceptable mismatches on the donor organ, allocation to highly sensitized patients within the Eurotransplant Acceptable Mismatch (AM) program is based on the patient's HLA phenotype plus acceptable antigens. These are HLA antigens to which the patient never made antibodies, as determined by extensive laboratory testing. AM patients have superior long-term graft survival compared with highly sensitized patients in regular allocation. Here, we questioned whether the AM program also results in lower rejection rates. From the PROCARE cohort, consisting of all Dutch kidney transplants in 1995-2005, we selected deceased donor single transplants with a minimum of 1 HLA mismatch and determined the cumulative 6-month rejection incidence for patients in AM or regular allocation. Additionally, we determined the effect of minimal matching criteria of 1 HLA-B plus 1 HLA-DR, or 2 HLA-DR antigens on rejection incidence. AM patients showed significantly lower rejection rates than highly immunized patients in regular allocation, comparable to nonsensitized patients, independent of other risk factors for rejection. In contrast to highly sensitized patients in regular allocation, minimal matching criteria did not affect rejection rates in AM patients. Allocation based on acceptable antigens leads to relatively low-risk transplants for highly sensitized patients with rejection rates similar to those of nonimmunized individuals.


Assuntos
Rejeição de Enxerto/diagnóstico , Antígenos HLA/imunologia , Histocompatibilidade/imunologia , Imunização/métodos , Falência Renal Crônica/imunologia , Transplante de Rim/efeitos adversos , Seleção de Pacientes , Doadores de Tecidos/provisão & distribuição , Feminino , Seguimentos , Rejeição de Enxerto/etiologia , Rejeição de Enxerto/patologia , Sobrevivência de Enxerto/imunologia , Antígenos HLA/química , Teste de Histocompatibilidade , Humanos , Isoanticorpos/efeitos adversos , Falência Renal Crônica/cirurgia , Transplante de Rim/estatística & dados numéricos , Masculino , Pessoa de Meia-Idade , Prognóstico , Fatores de Risco , Obtenção de Tecidos e Órgãos/métodos , Imunologia de Transplantes
11.
Am J Transplant ; 19(12): 3335-3344, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31194283

RESUMO

The clinical significance of non-HLA antibodies on renal allograft survival is a matter of debate, due to differences in reported results and lack of large-scale studies incorporating analysis of multiple non-HLA antibodies simultaneously. We developed a multiplex non-HLA antibody assay against 14 proteins highly expressed in the kidney. In this study, the presence of pretransplant non-HLA antibodies was correlated to renal allograft survival in a nationwide cohort of 4770 recipients transplanted between 1995 and 2006. Autoantibodies against Rho GDP-dissociation inhibitor 2 (ARHGDIB) were significantly associated with graft loss in recipients transplanted with a deceased-donor kidney (N = 3276) but not in recipients of a living-donor kidney (N = 1496). At 10 years after deceased-donor transplantation, recipients with anti-ARHGDIB antibodies (94/3276 = 2.9%) had a 13% lower death-censored covariate-adjusted graft survival compared to the anti-ARHGDIB-negative (3182/3276 = 97.1%) population (hazard ratio 1.82; 95% confidence interval, 1.32-2.53; P = .0003). These antibodies occur independently from donor-specific anti-HLA antibodies (DSA) or other non-HLA antibodies investigated. No significant relations with graft loss were found for the other 13 non-HLA antibodies. We suggest that pretransplant risk assessment can be improved by measuring anti-ARHGDIB antibodies in all patients awaiting deceased-donor transplantation.


Assuntos
Autoanticorpos/imunologia , Rejeição de Enxerto/mortalidade , Sobrevivência de Enxerto/imunologia , Antígenos HLA/imunologia , Transplante de Rim/efeitos adversos , Complicações Pós-Operatórias/mortalidade , Inibidor beta de Dissociação do Nucleotídeo Guanina rho/imunologia , Adulto , Feminino , Seguimentos , Rejeição de Enxerto/diagnóstico , Rejeição de Enxerto/etiologia , Humanos , Isoanticorpos/imunologia , Falência Renal Crônica/imunologia , Falência Renal Crônica/mortalidade , Falência Renal Crônica/cirurgia , Doadores Vivos/estatística & dados numéricos , Masculino , Pessoa de Meia-Idade , Complicações Pós-Operatórias/diagnóstico , Complicações Pós-Operatórias/etiologia , Prognóstico , Estudos Retrospectivos , Fatores de Risco
12.
Clin Exp Allergy ; 49(1): 17-26, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-30294841

RESUMO

In vitro allergy diagnostics are currently based on the detection of specific IgE binding on intact allergens or a mixture thereof. This approach has drawbacks as it may yield false-negative and/or false-positive results. Thus, we reviewed the impact of known B-cell epitopes of food allergens to predict transience or persistence, tolerance or allergy and the severity of an allergic reaction and to examine new epitope mapping strategies meant to improve serum-based allergy diagnostics. Recent epitope mapping approaches have been worthwhile in epitope identification and may increase the specificity of allergy diagnostics by using epitopes predominately recognized by allergic patients in some cases. However, these approaches did not lead to discrimination between clinically relevant and irrelevant epitopes so far, since the polyclonal serum IgE-binding epitope spectrum seems to be too individual, independent of the disease status of the patients. New epitope mapping strategies are necessary to overcome these obstacles. The use of patient-derived monoclonal antibodies instead of patient sera for functional characterization of clinically relevant and irrelevant epitope combinations, distinguished by their ability to induce degranulation, might be a promising approach to gain more insight into the allergic reaction and to improve serum-based allergy diagnostics.


Assuntos
Alérgenos/imunologia , Linfócitos B/imunologia , Mapeamento de Epitopos , Epitopos de Linfócito B/imunologia , Hipersensibilidade Alimentar , Imunoglobulina E/imunologia , Animais , Linfócitos B/patologia , Hipersensibilidade Alimentar/diagnóstico , Hipersensibilidade Alimentar/imunologia , Hipersensibilidade Alimentar/patologia , Humanos
13.
Clin Exp Allergy ; 49(11): 1512-1519, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31520442

RESUMO

BACKGROUND: The peanut allergens Ara h 2, h 6, and h 7 are potent allergens and can trigger severe reactions. Ara h 7 consists of three isoforms differing in their ability to induce basophil degranulation, whereas the ability of Ara h 7.0201 is comparable to Ara h 2 and 6 as shown in previous literature. OBJECTIVE: To identify linear epitopes of Ara h 7.0101, Ara h 7.0201 and Ara h 7.0301 recognized by IgE and IgG4 from patients sensitized to Ara h 7 and to investigate their potential to elucidate divergent abilities of the Ara h 7 isoforms in inducing basophil activation. METHODS: Linear epitopes recognized by IgE and IgG4 were mapped by peptide microarray analysis containing 15-mer peptides of Ara h 2.0201, 6, 7.0101, 7.0201 and 7.0301 and 39 peanut allergic patients sensitized to Ara h 7 (discovery). For validation, 20-mer peptides containing the minimal epitope and surrounding amino acids were incubated with 25 sensitized patients and 10 controls (validation). RESULTS: Three out of 14 linear epitopes were unique for each isoform (Ara h 7.0101: aa 97-109; Ara h 7.0201: aa 122-133; Ara h 7.0301: aa 65-74) but scarcely recognized by IgE. The main linear IgE epitope (aa 51-57) located in the long flexible loop of all Ara h 7 isoforms was bound by antibodies from 31% of the patients (discovery and validation cohort). Regarding IgG4, 55% of the patients recognized an epitope present on all isoforms (aa 55-65), whereas epitope aa 129-137, only present on Ara h 7.0101/0.0301, was recognized by 38% of the patients. Recognition was highly individual, although 20% of the patients recognized any linear epitope neither by IgE nor by IgG4 despite a low mean z-score of ≥ 1.7. Remarkably, only 50% of the patients recognized one or more epitopes by IgE. CONCLUSION & CLINICAL RELEVANCE: Ara h 7 isoforms share many linear epitopes being easily accessible for antibody binding. Unique epitopes, essential to elucidate divergent potencies, were scarcely recognized, suggesting a crucial involvement of conformational epitopes.


Assuntos
Antígenos de Plantas/imunologia , Arachis/imunologia , Mapeamento de Epitopos , Epitopos/imunologia , Imunoglobulina E/imunologia , Imunoglobulina G/imunologia , Adolescente , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
14.
J Am Soc Nephrol ; 29(9): 2279-2285, 2018 09.
Artigo em Inglês | MEDLINE | ID: mdl-30049681

RESUMO

Background Complement-fixing antibodies against donor HLA are considered a contraindication for kidney transplant. A modification of the IgG single-antigen bead (SAB) assay allows detection of anti-HLA antibodies that bind C3d. Because early humoral graft rejection is considered to be complement mediated, this SAB-based technique may provide a valuable tool in the pretransplant risk stratification of kidney transplant recipients.Methods Previously, we established that pretransplant donor-specific anti-HLA antibodies (DSAs) are associated with increased risk for long-term graft failure in complement-dependent cytotoxicity crossmatch-negative transplants. In this study, we further characterized the DSA-positive serum samples using the C3d SAB assay.Results Among 567 pretransplant DSA-positive serum samples, 97 (17%) contained at least one C3d-fixing DSA, whereas 470 (83%) had non-C3d-fixing DSA. At 10 years after transplant, patients with C3d-fixing antibodies had a death-censored, covariate-adjusted graft survival of 60%, whereas patients with non-C3d-fixing DSA had a graft survival of 64% (hazard ratio, 1.02; 95% confidence interval, 0.70 to 1.48 for C3d-fixing DSA compared with non-C3d-fixing DSA; P=0.93). Patients without DSA had a 10-year graft survival of 78%.Conclusions The C3d-fixing ability of pretransplant DSA is not associated with increased risk for graft failure.


Assuntos
Anticorpos Anti-Idiotípicos/imunologia , Complemento C3d/imunologia , Rejeição de Enxerto/imunologia , Antígenos HLA/imunologia , Transplante de Rim/efeitos adversos , Sistema de Registros , Adulto , Distribuição por Idade , Soro Antilinfocitário/imunologia , Estudos de Coortes , Feminino , Seguimentos , Rejeição de Enxerto/epidemiologia , Humanos , Incidência , Transplante de Rim/métodos , Masculino , Pessoa de Meia-Idade , Cuidados Pré-Operatórios/métodos , Estudos Retrospectivos , Medição de Risco , Distribuição por Sexo , Doadores de Tecidos , Transplantados/estatística & dados numéricos , Imunologia de Transplantes
15.
Eur J Immunol ; 47(11): 1970-1981, 2017 11.
Artigo em Inglês | MEDLINE | ID: mdl-28691750

RESUMO

An association between T-cell lymphopenia and autoimmunity has long been proposed, but it remains to be elucidated whether T-cell lymphopenia affects B-cell responses to autoantigens. Human neonatal thymectomy (Tx) results in a decrease in T-cell numbers and we used this model to study the development of autoreactivity. Two cohorts of neonatally thymectomized individuals were examined, a cohort of young (1-5 years post-Tx, n = 10-27) and older children (>10 years, n = 26), and compared to healthy age-matched controls. T-cell and B-cell subsets were assessed and autoantibody profiling performed. Early post-Tx, a decrease in T-cell numbers (2.75 × 109 /L vs. 0.71 × 109 /L) and an increased proportion of memory T cells (19.72 vs. 57.43%) were observed. The presence of autoantibodies was correlated with an increased proportion of memory T cells in thymectomized children. No differences were seen in percentages of different B-cell subsets between the groups. The autoantigen microarray showed a skewed autoantibody response after Tx. In the cohort of older individuals, autoantibodies were present in 62% of the thymectomized children, while they were found in only 33% of the healthy controls. Overall, our data suggest that neonatal Tx skews the autoantibody profile. Preferential expansion and preservation of Treg (regulatory T) cell stability and function, may contribute to preventing autoimmune disease development after Tx.


Assuntos
Autoanticorpos/imunologia , Autoimunidade/imunologia , Linfócitos B/imunologia , Linfócitos T/imunologia , Timectomia/efeitos adversos , Autoantígenos/imunologia , Criança , Pré-Escolar , Feminino , Humanos , Memória Imunológica/imunologia , Lactente , Recém-Nascido , Masculino
17.
Optom Vis Sci ; 95(6): 515-522, 2018 06.
Artigo em Inglês | MEDLINE | ID: mdl-29787490

RESUMO

SIGNIFICANCE: New bitangential mini-scleral lens designs provide a highly precise fit, follow the scleral shape, are comfortable to wear, and can correct residual astigmatism. This new scleral lens design complements the arsenal of medical contact lenses available to eye care practitioners. PURPOSE: The aim of this study was to evaluate the subjective and objective performance of a new mini-scleral lens design with a bitangential periphery. METHODS: In this observational study, data were collected for up to 15 months (median, 84 days; interquartile range, 76 days) from the left eyes of 133 patients fitted with this newly designed lens. Data were recorded during regular visits at Visser Contact Lens Practice's scleral lens clinics: diagnosis, clinical indication for scleral lenses, previous contact lens type, subjective performance, horizontal visible iris diameter, corrected distance visual acuity, and scleral lens fitting characteristics. RESULTS: The most common indication was keratoconus (45%), followed by irregular astigmatism (22%), keratoplasty (16.5%), ocular surface disease (13.5%), and other forms of irregular astigmatism (3%). The majority of patients (79%) scored comfort as either a 4 or 5 (out of 5), and 82% wore their lenses 12 hours or longer a day. Most lenses (81%) had a diameter of 16 mm (median, 16 mm; range, 15.5 to 17 mm) and were composed of Boston XO2 (46%), Menicon Z (44%), Boston XO (9%), or Boston Equalens II (1%). The median corrected distance visual acuity was 0.022 logarithm of the minimal angle of resolution (interquartile range, 0.155). The fitting characteristics revealed optimal values for centration and movement in 91% and 83%, respectively. Finally, the median stabilization axis was 50 degrees. CONCLUSIONS: New mini-scleral lenses with bitangential peripheral geometry yield satisfactory clinical results and good subjective performance and are therefore an effective option for managing patients who have irregular astigmatism or other corneal pathology.


Assuntos
Lentes de Contato , Ceratocone/terapia , Erros de Refração/terapia , Esclera , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Ceratocone/fisiopatologia , Ceratoplastia Penetrante , Masculino , Pessoa de Meia-Idade , Desenho de Prótese , Ajuste de Prótese , Erros de Refração/fisiopatologia , Acuidade Visual/fisiologia
18.
Clin Exp Rheumatol ; 35(3): 462-470, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28240588

RESUMO

OBJECTIVES: The current strategy for antinuclear antibody (ANA) analysis involves screening for presence with a subsequent detailed analysis of their specificity. The aim of this study is to compare the clinical and financial efficacy of this strategy between different commercial tests in a large cohort of unselected patients. METHODS: In all consecutive 1030 patients associations were defined between results from different ANA test systems and the pre-test probability for connective tissue disease (CTDs). Test systems were used for screening (ANA-IIF vs. CTD screen) and definition of their fine specificity (profile 3 line blot vs. CTD single analytes). RESULTS: Positive ANA-IIF and/or CTD screen results were found in 304 sera. Further analysis for ANA-specificity by profile 3 line blot and CTD single analytes showed 86 discrepant results of which more than a third are clinically relevant, with the CTD single analyte assay performing better than the line blot in supporting or confirming the presence of a CTD. Autoantigens present in one test but absent in the other were of minor practical use. The ANA screening and identification strategies currently employed are not cost-effective as 83% of tests were performed in order to find specific autoantibodies in patients without the fitting clinical signs or symptoms. This causes many unexpected positive results and subsequent confusion with regard to interpretation. CONCLUSIONS: We advocate that some autoantigens should be excluded from the line blot and CTD assays and propose the use of a cost-effective and selective ANA specificity testing purely based on clinical guidance.


Assuntos
Anticorpos Antinucleares/sangue , Doenças Autoimunes/diagnóstico , Doenças do Tecido Conjuntivo/diagnóstico , Kit de Reagentes para Diagnóstico , Testes Sorológicos , Especificidade de Anticorpos , Doenças Autoimunes/sangue , Doenças Autoimunes/imunologia , Biomarcadores/sangue , Doenças do Tecido Conjuntivo/sangue , Doenças do Tecido Conjuntivo/imunologia , Análise Custo-Benefício , Custos de Cuidados de Saúde , Humanos , Valor Preditivo dos Testes , Kit de Reagentes para Diagnóstico/economia , Reprodutibilidade dos Testes , Testes Sorológicos/economia
19.
J Transl Med ; 14(1): 230, 2016 08 02.
Artigo em Inglês | MEDLINE | ID: mdl-27484705

RESUMO

BACKGROUND: Epstein-Barr virus and Cytomegalovirus reactivations frequently occur after allogeneic stem cell transplantation (SCT). METHODS: Here we investigated the role of immune cell reconstitution in the onset and subsequent severity of EBV- and CMV-reactivation. To this end, 116 patients were prospectively sampled for absolute T cell (CD4 and CD8), B-cell (CD19) and NK-cell (CD16 and CD56) numbers weekly post-SCT during the first 3 months and thereafter monthly until 6 months post-SCT. Viral load was monitored in parallel. RESULTS: In contrast to the general belief, we found that early T-cell reconstitution does not play a role in the onset of viral reactivation. CMV reactivation in the first 7 weeks after SCT however resulted in higher absolute CD8(+) T-cell numbers 6 months post-SCT in patients with high-level reactivation, many of which were CMV-specific. Interestingly, rapid reconstitution of CD4(+) T-cells, as well as NK cells and the presence of donor KIR3DL1, are associated with the absence of CMV-reactivation after SCT, suggestive of a protective role of these cells. In contrast, EBV-reactivations were not affected in any way by the level of immune reconstitution after SCT. CONCLUSION: In conclusion, these data suggest that CD4(+) T-cells and NK cells, rather than CD8(+) T-cells, are associated with protection against CMV-reactivation.


Assuntos
Linfócitos T CD4-Positivos/imunologia , Citomegalovirus/imunologia , Citoproteção , Células Matadoras Naturais/imunologia , Transplante de Células-Tronco , Adolescente , Adulto , Idoso , Linfócitos T CD8-Positivos/imunologia , Feminino , Humanos , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Prognóstico , Modelos de Riscos Proporcionais , Receptores KIR3DL1/metabolismo , Fatores de Risco , Transplante Homólogo , Adulto Jovem
20.
Clin Chem Lab Med ; 54(6): 1105-9, 2016 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-26812873

RESUMO

Daratumumab is a fully human anti-CD38 IgG1-κ monoclonal antibody (mAb) currently being evaluated in several Phase 2 and 3 clinical studies for the treatment of multiple myeloma (MM). In this clinical case study we demonstrate that daratumumab can be detected as an individual monoclonal band in serum immunofixation electrophoresis (IFE). M-protein follow-up by IFE is part of the International Myeloma Working Group (IMWG) criteria to assess treatment response. Therefore, it is crucial that the daratumumab band is not confused with the endogenous M-protein of the patient during IFE interpretation. Moreover, a significant number of IgG-κ M-proteins co-migrate with daratumumab. Co-migration introduces a bias in the M-protein quantification since pharmacokinetic studies show that daratumumab peak plasma concentrations reach up to 1 g/L. More importantly, co-migration can mask clearance of the M-protein by IFE which is necessary for classification of complete response by IMWG criteria (negative serum IFE). For optimal M-protein monitoring the laboratory specialist needs to be informed when patients receive daratumumab, and it is essential that the laboratory specialist is aware that a slow migrating band in the γ-region in those patients may be derived from the daratumumab. A daratumumab specific IFE reflex assay (DIRA) has been developed and can be utilized to abrogate interference. The here described mAb interference is not limited to daratumumab, and as therapeutic antibodies gain approval and enter into common clinical practice, laboratory specialists will need additional processes to characterize IFE interference and distinguish endogenous M-protein from therapeutic antibodies.


Assuntos
Anticorpos Monoclonais/uso terapêutico , Imunoensaio/métodos , Mieloma Múltiplo/diagnóstico , Mieloma Múltiplo/tratamento farmacológico , Idoso , Eletroforese das Proteínas Sanguíneas , Reações Cruzadas , Humanos , Imunoeletroforese , Imunoglobulina G/sangue , Cadeias kappa de Imunoglobulina/sangue , Cadeias lambda de Imunoglobulina/sangue , Masculino , Pessoa de Meia-Idade , Mieloma Múltiplo/imunologia , Proteínas do Mieloma/análise
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