RESUMO
OBJECTIVE: To assess the efficacy of etanercept in reducing tenosynovitis evaluated by MRI of the hand (h-MRI) in patients with active rheumatoid arthritis (RA) refractory to disease-modifying antirheumatic drug (DMARD) after 6 weeks of treatment. METHODS: 31 patients with active RA defined by a disease activity score (DAS28) >3.2 and synovitis in the hands were randomised into two groups: 19 patients received 50 mg weekly subcutaneous etanercept added to previous DMARD treatment and 12 patients continued with previous DMARD therapy. Clinical evaluation, blood tests, functional capacity evaluation and h-MRI were performed at the start of the investigation and at week 6. Tenosynovitis was evaluated on T1-weighted sequences with fat suppression after gadolinium as the presence of a peritendinous signal enhancement on axial images using a new method including wrist and finger tendons. The reliability, sensitivity to change and responsiveness of this method were also evaluated. RESULTS: Scores for tenosynovitis showed a significant reduction in the etanercept group compared with placebo (p=0.01) after 6 weeks of treatment. Adding MRI joint synovitis to tenosynovitis scores gave an even higher significant reduction in the etanercept group (p=0.007). A positive and statistically significant correlation between tenosynovitis and DAS28, erythrocyte sedimentation rate and C-reactive protein was found, but not with functional capacity. Responsiveness for tenosynovitis was small but was higher when joint synovitis scores were added. CONCLUSION: Addition of etanercept significantly reduced MRI tenosynovitis of the wrist and fingers in patients with active RA refractory to DMARD treatment. The method of scoring tenosynovitis showed good reliability and moderate responsiveness.
Assuntos
Antirreumáticos/uso terapêutico , Artrite Reumatoide/tratamento farmacológico , Articulações dos Dedos , Imunoglobulina G/uso terapêutico , Receptores do Fator de Necrose Tumoral/uso terapêutico , Tenossinovite/tratamento farmacológico , Articulação do Punho , Adulto , Idoso , Artrite Reumatoide/complicações , Quimioterapia Combinada , Etanercepte , Feminino , Articulações dos Dedos/patologia , Humanos , Imageamento por Ressonância Magnética/métodos , Masculino , Pessoa de Meia-Idade , Índice de Gravidade de Doença , Tenossinovite/etiologia , Tenossinovite/patologia , Resultado do Tratamento , Fator de Necrose Tumoral alfa/antagonistas & inibidores , Articulação do Punho/patologiaRESUMO
UNLABELLED: With the aim of characterizing radioiodinated 4-amino-N-1-[3-(4-fluorophenoxy)propyl]-4-methyl-4-piperidinyl]5-iodo-2-methoxybenzamide ((123)I-R91150) as a SPECT ligand for subtype 2A of the 5-hydroxytryptamine receptor (5-HT(2A)), tracer kinetic compartmental analyses were compared with the tissue ratio method (TR). The pseudoequilibrium interval after a single bolus injection was identified, and a reference database of specific uptake ratio (SUR) values was obtained. Within-scan and between-subject variability was also assessed. METHODS: Nineteen healthy men (mean age +/- SD, 24.4 +/- 3.3 y) were included and separated into 2 groups. Dynamic scans with venous blood sampling from 0 to 470 min after a single bolus injection of (123)I-R91150 was completed for 7 of the 9 subjects included in group A, and in one of them compartmental modeling was performed with an arterial blood input function using 1-tissue-compartment (1TC) and 2-tissue-compartment (2TC) models. Binding potential (BP) using the simplified reference tissue model (SRTM) (BP(SRTM)) and SUR values using TR over time were also calculated. The 10 remaining subjects (group B) underwent a single scan at pseudoequilibrium with the aim of improving the precision of mean normal SUR estimates. Regions of interest in cortical regions and basal ganglia for specific uptake, and in cerebellum for nonspecific uptake, were manually drawn on each subject's MR images and translated to the corresponding SPECT slices after coregistration. RESULTS: The 1TC model correlated well with the 2TC model (BP(2TC) = 1.04.BP(1TC) - 0.01, R(2) = 0.98), and both methods correlated with BP(SRTM) and SUR with little bias (BP(1TC) = 1.10 BP(SRTM) + 0.03, R(2) = 0.98; BP(2TC) = 1.15 BP(SRTM) + 0.01, R(2) = 0.98; BP(SRTM) = 0.99 SUR(mean) + 0.01, R(2) = 0.98). SUR values stabilized from 180 min after injection in most cortical regions, ranging from 0.51 +/- 0.10 in the orbitofrontal region to 0.27 +/- 0.09 in the parietal region. Within-scan and between-subject variability among regions ranged from 10% to 14.8%, and from 18.3% to 35.4%, respectively. CONCLUSION: (123)I-R91150 distribution agrees with autoradiography results, showing highly specific binding in cortical regions. The correlations found among 1TC, 2TC, SRTM, and TR outcome measurements support the use of TR for quantification of 5-HT(2A) receptor binding with (123)I-R91150 SPECT and a simple protocol avoiding arterial blood sampling and serial scanning over time.
Assuntos
Encéfalo/diagnóstico por imagem , Encéfalo/metabolismo , Radioisótopos do Iodo/farmacocinética , Piperidinas/farmacocinética , Receptor 5-HT2A de Serotonina/metabolismo , Adulto , Humanos , Interpretação de Imagem Assistida por Computador/métodos , Ligantes , Masculino , Taxa de Depuração Metabólica , Compostos Radiofarmacêuticos/farmacocinética , Valores de Referência , Distribuição Tecidual , Tomografia Computadorizada de Emissão de Fóton Único/métodosRESUMO
RATIONALE: To assess the paroxetine-induced serotonin transporter (SERT) occupancy (SERTocc) using in vivo (123)I-ADAM SPECT. OBJECTIVES: (123)I-ADAM SPECT was used to investigate the SERTocc induced by paroxetine in major depression disorder (MDD) patients, to compare the SERT availability in drug-free MDD patients and healthy volunteers, and to study the relationship between paroxetine plasma concentrations (Cp) and SERTocc. MATERIALS AND METHODS: Measures of SERT availability by means of (123)I-ADAM SPECT were obtained in ten MDD patients before and after 4- to 6-week treatment with paroxetine 20 mg/day. (123)I-ADAM SPECT measures of SERT availability from a group of ten previously studied age-matched healthy volunteers were used for comparison. The relationship between percentages of SERTocc and paroxetine Cp was studied using an E (max) model. RESULTS: Mean SERTocc values were 66.4 +/- 9.5% in midbrain, 63.0 +/- 9.6% in thalamus, and 61.3 +/- 10.9% in striatum. No significant differences in SERTocc were found among these three regions. No significant differences in mean SERT availability were found in any region between drug-free MDD patients (midbrain = 1.14 +/- 0.15; thalamus = 0.85 +/- 0.13; striatum = 0.70 +/- 0.07) and healthy volunteers (midbrain = 1.19 +/- 0.22; thalamus = 0.96 +/- 0.14; striatum = 0.67 +/- 0.15). The E (max) model returned a SERTocc(max) = 70.5% and a Cp(50) = 2.7 ng/ml. CONCLUSIONS: Using (123)I-ADAM SPECT, treatment with paroxetine 20 mg/day leads to more than 60% SERTocc on average in cerebral regions with known high SERT density. Data from this study do not support the existence of SERT availability differences between drug-free MDD patients and healthy volunteers. Finally, the E (max) model is suitable for the study of paroxetine Cp relationship to (123)I-ADAM SPECT-measured SERTocc. This approach may be useful for pharmacokinetic-pharmacodynamic relationships in drug development.
Assuntos
Encéfalo/metabolismo , Transtorno Depressivo/metabolismo , Paroxetina/farmacologia , Proteínas da Membrana Plasmática de Transporte de Serotonina/metabolismo , Adulto , Encéfalo/efeitos dos fármacos , Cinanserina/análogos & derivados , Cinanserina/metabolismo , Corpo Estriado/efeitos dos fármacos , Corpo Estriado/metabolismo , Transtorno Depressivo/tratamento farmacológico , Transtorno Depressivo/patologia , Feminino , Humanos , Radioisótopos do Iodo , Masculino , Mesencéfalo/efeitos dos fármacos , Mesencéfalo/metabolismo , Pessoa de Meia-Idade , Paroxetina/sangue , Paroxetina/uso terapêutico , Ensaio Radioligante/métodos , Antagonistas da Serotonina/farmacologia , Inibidores Seletivos de Recaptação de Serotonina/sangue , Inibidores Seletivos de Recaptação de Serotonina/farmacologia , Inibidores Seletivos de Recaptação de Serotonina/uso terapêutico , Tálamo/efeitos dos fármacos , Tálamo/metabolismo , Tomografia Computadorizada de Emissão de Fóton Único , Resultado do TratamentoRESUMO
UNLABELLED: (123)I-ADAM (2-([2-([dimethylamino]methyl)phenyl]thio)-5-(123)I-iodophenylamine) has been recently proposed as a new serotonin transporter (SERT) ligand for SPECT. The objective of this study was to characterize (123)I-ADAM in healthy volunteers. (123)I-ADAM distribution in the normal brain, pseudoequilibrium interval after a single injection, normal specific uptake values, and long-term test-retest variability and reliability were investigated. METHODS: Ten healthy volunteers underwent 2 SPECT sessions under the same conditions 47.6 +/- 24.0 d apart. Scans were sequentially acquired from the time of (123)I-ADAM intravenous injection up to 12 h after injection. Regions of interest (ROIs) for cerebellum (C), midbrain, thalamus, striatum, mesial temporal region, and cortex were drawn on MR images and pasted to corresponding SPECT slices after coregistration. Specific uptake ratios (SURs) at pseudoequilibrium and the simplified reference tissue model (SRTM) methods were used for quantification. SURs were obtained as ([region - C]/C) at each time point. Test-retest variability and reliability (intraclass correlation coefficient [ICC]) were calculated. RESULTS: The highest (123)I-ADAM specific uptake was found in the midbrain and thalamus, followed by the striatum and mesial temporal region. Quantification results using SUR and SRTM were correlated with R = 0.93 (test) and R = 0.94 (retest). SURs remained stable in all regions from 4 to 6 h after injection. Using SUR, test-retest variability/ICC were 13% +/- 11%/0.74 in midbrain, 16% +/- 13%/0.63 in thalamus, 19% +/- 18%/0.62 in striatum, and 22% +/- 19%/0.05 in mesial temporal region. CONCLUSION: (123)I-ADAM accumulates in cerebral regions with high known SERT density. The optimal imaging time for (123)I-ADAM SPECT quantification is suggested to be from 4 to 6 h after a single injection. Long-term test-retest variability and reliability found in the midbrain are comparable to that reported with other (123)I-labeled SPECT ligands. These results support the use of (123)I-ADAM SPECT for SERT imaging after a single injection in humans.
Assuntos
Encéfalo/diagnóstico por imagem , Encéfalo/metabolismo , Cinanserina/análogos & derivados , Aumento da Imagem/métodos , Glicoproteínas de Membrana/metabolismo , Proteínas de Membrana Transportadoras/metabolismo , Proteínas do Tecido Nervoso/metabolismo , Tomografia Computadorizada de Emissão de Fóton Único/métodos , Adulto , Idoso , Cinanserina/administração & dosagem , Cinanserina/farmacocinética , Feminino , Seguimentos , Humanos , Injeções Intravenosas , Masculino , Taxa de Depuração Metabólica , Pessoa de Meia-Idade , Compostos Radiofarmacêuticos/administração & dosagem , Compostos Radiofarmacêuticos/farmacocinética , Valores de Referência , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Proteínas da Membrana Plasmática de Transporte de Serotonina , Fatores de Tempo , Distribuição TecidualRESUMO
OBJECTIVE: To demonstrate the efficacy of etanercept to reduce synovitis as measured by magnetic resonance imaging (MRI) as early as 6 weeks after starting treatment in patients with active rheumatoid arthritis (RA). METHODS: Twenty-two patients with active RA despite disease modifying antirheumatic drug (DMARD) treatment were included in this prospective, controlled study. Patients were randomized in 2 groups. In the treatment group, etanercept was added at usual doses during 6 weeks. In the control group, patients continued with prior DMARD therapy. MRI of the dominant wrist and 2nd-5th MCP joints were obtained at baseline and at 6 weeks and evaluated according to OMERACT recommendations. Results of changes in synovitis in the treatment group were compared with changes in the control group. RESULTS: Changes in synovitis measured by MRI of the hand (OMERACT evaluation) in the etanercept group showed a significant reduction after 6 weeks of treatment compared with no changes in the control group. Reduction of synovitis in the treatment group also showed good correlation with decrease of various clinical and laboratory measures. CONCLUSION: In patients with active RA despite DMARD therapy, etanercept, but not placebo, reduced synovitis as measured by MRI after 6 weeks.