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2.
Clin Chem Lab Med ; 59(9): 1516-1526, 2021 08 26.
Artigo em Inglês | MEDLINE | ID: mdl-33915609

RESUMO

OBJECTIVES: Fabry disease (FD) is an X-linked lysosomal storage disorder, resulting from a deficiency of the enzyme α-galactosidase A, responsible for breaking down glycolipids such as globotriaosylceramide and its deacylated derivative, globotriaosylsphingosine (LysoGb3). Here, we compare the levels of LysoGb3 in dried blood spots (DBS) and plasma in patients with classic and late-onset phenotypes. METHODS: LysoGb3 measurements were performed in 104 FD patients, 39 males and 65 females. Venous blood was collected. A portion was spotted onto filter paper and another portion separated to obtain plasma. The LysoGb3 concentrations in DBS and plasma were determined by highly sensitive electrospray ionization liquid chromatography tandem mass spectrometry. Agreement between different matrices was assessed using linear regression and Bland Altman analysis. RESULTS: The method on DBS was validated by evaluating its precision, accuracy, matrix effect, recovery, and stability. The analytical performances were verified by comparison of a total of 104 paired DBS and plasma samples from as many FD patients (representing 46 GLA variants). There was a strong correlation between plasma and the corresponding DBS LysoGb3 concentrations, with few exceptions. Discrepancies were observed in anemic patients with typically low hematocrit levels compared to the normal range. CONCLUSIONS: The method proved to be efficient for the rapid analysis of LysoGb3. DBS provides a convenient, sensitive, and reproducible method for measuring LysoGb3 levels for diagnosis, initial phenotypic assignment, and therapeutic monitoring in patients with FD.


Assuntos
Doença de Fabry , Esfingolipídeos , Biomarcadores , Teste em Amostras de Sangue Seco , Doença de Fabry/diagnóstico , Feminino , Glicolipídeos , Humanos , Masculino , alfa-Galactosidase/genética
3.
Anal Chem ; 92(9): 6341-6348, 2020 05 05.
Artigo em Inglês | MEDLINE | ID: mdl-31922725

RESUMO

Liquid chromatography-tandem mass spectrometry (LC-MS/MS) assays were developed to measure arylsulfatase A (ARSA) activity in leukocytes and dried blood spots (DBS) using deuterated natural sulfatide substrate. These new assays were highly specific and sensitive. Patients with metachromatic leukodystrophy (MLD) and multiple sulfatase deficiency (MSD) displayed a clear deficit in the enzymatic activity and could be completely distinguished from normal controls. The leukocyte assay reported here will be important for diagnosing MLD and MSD patients and for monitoring the efficacy of therapeutic treatments. ARSA activity was measured in DBS for the first time without an antibody. This new ARSA DBS assay can serve as a second-tier test following the sulfatide measurement in DBS for newborn screening of MLD. This leads to an elimination of most of the false positives identified by the sulfatide assay.


Assuntos
Cerebrosídeo Sulfatase/análise , Teste em Amostras de Sangue Seco , Leucócitos/enzimologia , Leucodistrofia Metacromática/sangue , Doença da Deficiência de Múltiplas Sulfatases/sangue , Cerebrosídeo Sulfatase/metabolismo , Cromatografia Líquida , Humanos , Leucodistrofia Metacromática/diagnóstico , Leucodistrofia Metacromática/enzimologia , Estrutura Molecular , Doença da Deficiência de Múltiplas Sulfatases/diagnóstico , Doença da Deficiência de Múltiplas Sulfatases/enzimologia , Sulfoglicoesfingolipídeos/química , Espectrometria de Massas em Tandem
5.
Clin Chim Acta ; 488: 98-103, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30395869

RESUMO

Mucopolysaccharidoses are a group of lysosomal storage disorders (LSDs) characterized by the accumulation of glycosaminoglycans (GAGs). Recently, LC-MS/MS has been widely applied in GAGs analysis combined with different sample preparations for cleaving GAGs to disaccharide units. The aim of the present is paper is to present a new method for the simultaneous quantification of urinary dermatan sulfate (DS) and heparan sulfate (HS) by LC-MS/MS, after butanolysis reaction. Chromatographic separation was achieved with a gradient of acetonitrile and water in 0.1% formic acid on a Kinetex Biphenyl analytical column in 21 min. Calibration curves ranging from 0.78 to 50 µg/mL for HS and from 1.56 to 100 µg/mL for DS were prepared and the coefficient of determination (r2) was higher than 0.99 for both analytes. Intra-day and inter-day imprecisions and the bias for both compounds were <10.0%. Up to now, most analytical procedures for quantifying GAGs have not had a high level of reproducibility among laboratories, despite the availability of various techniques. The adoption of a new protocol incorporating the methods outlined in this paper could significantly improve the quality and reproducibility of MS results. A procedure using simple steps for preparing samples and reagents that are easily available on the market could promote the standardization of analytical procedures and increase the use of these measurements in clinical practice.


Assuntos
Butanóis/química , Dermatan Sulfato/urina , Heparitina Sulfato/urina , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Pré-Escolar , Cromatografia Líquida , Humanos , Lactente , Recém-Nascido , Pessoa de Meia-Idade , Espectrometria de Massas em Tandem , Adulto Jovem
6.
J Matern Fetal Neonatal Med ; 31(8): 973-980, 2018 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-28274169

RESUMO

PURPOSE: To investigate the feasibility of a study based on treatment with topiramate (TPM) added to moderate hypothermia in newborns with hypoxic ischemic encephalopathy (HIE). MATERIALS AND METHODS: Multicenter randomized controlled trial. Term newborns with precocious metabolic, clinical and electroencephalographic (EEG) signs of HIE were selected according to their amplified integrated EEG pattern and randomized to receive either TPM (10 mg/kg once a day for the first three days of life) plus moderate hypothermia or hypothermia alone. Safety was assessed by monitoring cardiorespiratory parameters and blood samples collected to check renal, liver, metabolic balance and TPM pharmacokinetics. Efficacy was evaluated by the combined frequency of mortality and severe neurological disability as primary outcome. Incidence of magnetic resonance injury, epilepsy, blindness, hearing loss, neurodevelopment at 18-24 months of life was assessed as secondary outcomes. RESULTS: Forty-four asphyxiated newborns were enrolled in the study. Twenty one newborns (10 with moderate and 11 with severe HIE) were allocated to hypothermia plus TPM and 23 (12 moderate and 11 severe HIE) to hypothermia. No statistically or clinically significant differences were observed for safety, primary or secondary outcomes. However, a reduction in the prevalence of epilepsy was observed in newborns co-treated with TPM. CONCLUSIONS: Results of this pilot trial suggest that administration of TPM in newborns with HIE is safe but does not reduce the combined frequency of mortality and severe neurological disability. The role of TPM co-treatment in preventing subsequent epilepsy deserves further studies.


Assuntos
Frutose/análogos & derivados , Hipotermia Induzida , Hipóxia-Isquemia Encefálica/tratamento farmacológico , Fármacos Neuroprotetores/uso terapêutico , Estudos de Viabilidade , Feminino , Frutose/farmacocinética , Frutose/uso terapêutico , Humanos , Hipóxia-Isquemia Encefálica/diagnóstico por imagem , Recém-Nascido , Imageamento por Ressonância Magnética , Masculino , Neuroimagem , Fármacos Neuroprotetores/farmacocinética , Topiramato , Resultado do Tratamento
7.
Pediatr Res ; 81(2): 307-314, 2017 02.
Artigo em Inglês | MEDLINE | ID: mdl-27814346

RESUMO

BACKGROUND: Oral propranolol reduces retinopathy of prematurity (ROP) progression, although not safely. This study evaluated safety and efficacy of propranolol eye micro-drops in preterm newborns with ROP. METHODS: A multicenter open-label trial, planned according to the Simon optimal two-stage design, was performed to analyze safety and efficacy of propranolol micro-drops in newborns with stage 2 ROP. To this end, hemodynamic and respiratory parameters were monitored, and blood samples were collected weekly, for 3 wk. Propranolol plasma levels were also monitored. The progression of the disease was evaluated with serial ophthalmologic examinations. RESULTS: Twenty-three newborns were enrolled. Since the fourth of the first 19 newborns enrolled in the first stage of the study showed a progression to stage 2 or 3 with plus, the second stage was prematurely discontinued. Even though the objective to complete the second stage was not achieved, the percentage of ROP progression (26%) was similar to that obtained previously with oral propranolol administration. However, no adverse effects were observed and propranolol plasma levels were significantly lower than those measured after oral administration. CONCLUSION: Propranolol 0.1% eye micro-drops are well tolerated, but not sufficiently effective. Further studies are required to identify the optimal dose and administration schedule.


Assuntos
Propranolol/administração & dosagem , Retinopatia da Prematuridade/tratamento farmacológico , Administração Oftálmica , Administração Oral , Administração Tópica , Progressão da Doença , Feminino , Hemodinâmica , Humanos , Recém-Nascido , Masculino , Neovascularização Fisiológica/efeitos dos fármacos , Segurança do Paciente , Projetos Piloto , Propranolol/sangue , Respiração
8.
Pediatr Blood Cancer ; 63(7): 1290-2, 2016 07.
Artigo em Inglês | MEDLINE | ID: mdl-27100060

RESUMO

A newborn with unresectable kaposiform hemangioendothelioma associated with Kasabach Merritt phenomenon, unresponsive to vincristine and prednisone, received second-line treatment with propranolol at a dose of 2 mg/kg/day, starting at 2 months of life and continued for 13 months. There was only slight reduction in tumor mass, but measurement of propranolol levels showed extremely low plasma concentrations. The propranolol dose was progressively increased to 3.5 mg/kg/day, leading to a substantial increase in plasma levels associated with clinically relevant tumor reduction. This case highlights the importance of relating propranolol dose to its plasma concentration before considering the treatment ineffective for this vascular tumor.


Assuntos
Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Hemangioendotelioma/tratamento farmacológico , Doenças do Recém-Nascido/tratamento farmacológico , Síndrome de Kasabach-Merritt/tratamento farmacológico , Propranolol/administração & dosagem , Sarcoma de Kaposi/tratamento farmacológico , Humanos , Recém-Nascido , Masculino
9.
Clin Chem Lab Med ; 54(4): 627-32, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-26466166

RESUMO

BACKGROUND: Purine nucleoside phosphorylase (PNP) deficiency has been recently introduced in the newborn screening program in Tuscany. In order to improve the PNP screening efficiency, we developed a 2nd tier test to quantify PNP primary markers deoxyguanosine (dGuo) and deoxyinosine (dIno). METHODS: Dried blood spots (DBS) samples were extracted with 200 µL of methanol and 100 µL of water (by two steps). Internal standards were added at a final concentration of 10 µmol/L. After extraction, samples were analysed by LC-MS/MS. The chromatographic run was performed in gradient mode by using a Synergi Fusion column. RESULTS: The assay was linear over a concentration range of 0.05-50 µmol/L (R2>0.999) for dGuo and 0.5-50 µmol/L (R2>0.998) for dIno. Intra- and interassay imprecision (mean CVs) for dIno and dGuo ranged from 2.9% to 12%. Limit of quantitaion (LOQ) were found to be 0.05 µmol/L and 0.5 µmol/L for dGuo and dIno, respectively. The reference ranges, obtained by measuring dGuo and dIno concentrations on DBS, were close to zero for both biomarkers. Moreover, DBS samples from seven patients with confirmed PNP were retrospectively evaluated and correctly identified. CONCLUSIONS: The LC-MS/MS method can reliably measure dIno and dGuo in DBS for the diagnosis of PNP. Validation data confirm the present method is characterised by good reproducibility, accuracy and imprecision for the quantitation of dIno and dGuo. The assay also appears suitable for use in monitoring treatment of PNP patients.


Assuntos
Teste em Amostras de Sangue Seco , Triagem Neonatal , Purina-Núcleosídeo Fosforilase/deficiência , Erros Inatos do Metabolismo da Purina-Pirimidina/sangue , Adulto , Cromatografia Líquida , Humanos , Recém-Nascido , Doenças da Imunodeficiência Primária , Purina-Núcleosídeo Fosforilase/sangue , Purina-Núcleosídeo Fosforilase/metabolismo , Erros Inatos do Metabolismo da Purina-Pirimidina/diagnóstico , Erros Inatos do Metabolismo da Purina-Pirimidina/metabolismo , Espectrometria de Massas em Tandem
10.
J Pharm Biomed Anal ; 109: 164-70, 2015 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-25770414

RESUMO

Carbamazepine (CBZ) is a first-line drug for the treatment of different forms of epilepsy and the first choice drug for trigeminal neuralgia. CBZ is metabolized in the liver by oxidation into carbamazepine-10,11-epoxide (CBZE), its major metabolite which is equipotent and known to contribute to the pharmacological activity of CBZ. The aim of the present study was to develop and validate a reliable, selective and sensitive liquid chromatography-tandem mass spectrometry method for the simultaneous quantification of CBZ and its active metabolite in dried blood spots (DBS). The extraction process was carried out from DBS using methanol-water-formic acid (80:20:0.1, v/v/v). Chromatographic elution was achieved by using a linear gradient with a mobile phase consisting of acetonitrile-water-0.1% formic acid at a flow rate of 0.50mL/min. The method was linear over the range 1-40mg/L and 0.25-20mg/L for CBZ and CBZE, respectively. The limit of quantification was 0.75mg/L and 0.25mg/L for CBZ and CBZE. Intra-day and inter-day assay precisions were found to be lower than 5.13%, 6.46% and 11.76%, 4.72% with mean percentage accuracies of 102.1%, 97.5% and 99.2%, 97.8% for CBZ and CBZE. We successfully applied the method for determining DBS finger-prick samples in paediatric patients and confirmed the results with concentrations measured in matched plasma samples. This novel approach allows quantification of CBZ and its metabolite from only one 3.2mm DBS disc by LC-MS/MS thus combining advantages of DBS technique and LC-MS/MS in clinical practice.


Assuntos
Anticonvulsivantes/sangue , Carbamazepina/sangue , Monitoramento de Medicamentos/métodos , Adolescente , Biotransformação , Calibragem , Criança , Pré-Escolar , Cromatografia Líquida de Alta Pressão , Feminino , Hematócrito , Humanos , Lactente , Limite de Detecção , Masculino , Padrões de Referência , Reprodutibilidade dos Testes , Manejo de Espécimes , Espectrometria de Massas em Tandem
11.
Clin Chim Acta ; 440: 31-5, 2015 Feb 02.
Artigo em Inglês | MEDLINE | ID: mdl-25447695

RESUMO

Phenytoin (PHT) is one of the most commonly used anticonvulsant drugs for the treatment of epilepsy and bipolar disorders. The large amount of plasma required by conventional methods for drug quantification makes mass spectrometry combined with dried blood spot (DBS) sampling crucial for pediatric patients where therapeutic drug monitoring or pharmacokinetic studies may be difficult to realize. DBS represents a new convenient sampling support requiring minimally invasive blood drawing and providing long-term stability of samples and less expensive shipment and storage. The aim of this study was to develop a LC-MS/MS method for the quantification of PHT on DBS. This analytical method was validated and gave good linearity (r(2)=0.999) in the range of 0-100mg/l. LOQ and LOD were 1.0mg/l and 0.3mg/l, respectively. The drug extraction from paper was performed in a few minutes using a mixture composed of organic solvent for 80%. The recovery ranged from 85 to 90%; PHT in DBS showed to be stable at different storage temperatures for one month. A good correlation was also obtained between PHT plasma and DBS concentrations. This method is both precise and accurate and appears to be particularly suitable to monitor treatment with a simple and convenient sample collection procedure.


Assuntos
Cromatografia Líquida/métodos , Teste em Amostras de Sangue Seco/métodos , Monitoramento de Medicamentos/métodos , Fenitoína/sangue , Espectrometria de Massas em Tandem/métodos , Calibragem , Estabilidade de Medicamentos , Humanos , Limite de Detecção , Modelos Lineares , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Razão Sinal-Ruído
12.
Pediatr Res ; 76(4): 378-85, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-25029260

RESUMO

BACKGROUND: Oral propranolol, a nonselective ß-blocker, is able to reduce the progression of retinopathy of prematurity in newborns, but it appeared unsafe. This study aimed to find, in rabbits, a propranolol eye drop concentration able to induce lower plasma but higher retinal concentrations than those obtained after oral administration. METHODS: Male New Zealand white rabbits were treated with oral propranolol (0.25 mg/kg/6 h) for 5 d, and propranolol concentrations were measured after 1, 2, 3, and 6 h in plasma, aqueous humor, vitreous humor, and retina. These concentrations were compared with those obtained after the administration of one drop of 25 µl of propranolol 0.1% prepared in saline, applied every 6 h to both eyes for 5 d. A Draize eye test and histological analyses were performed to assess eye drop tolerability. RESULTS: The administration of eye drops produced retinal concentrations similar to, but plasma concentrations significantly lower than, those measured after oral administration. The local tolerability profile was excellent. CONCLUSION: Propranolol eye drops are able to ensure high retinal and low plasma concentrations of propranolol, and this finding opens the perspective of possible topical treatment with propranolol in newborns with retinopathy of prematurity.


Assuntos
Antagonistas Adrenérgicos beta/administração & dosagem , Propranolol/administração & dosagem , Administração Oftálmica , Antagonistas Adrenérgicos beta/metabolismo , Antagonistas Adrenérgicos beta/farmacocinética , Animais , Contagem de Colônia Microbiana , Masculino , Propranolol/efeitos adversos , Propranolol/farmacocinética , Coelhos
13.
J Allergy Clin Immunol ; 134(1): 155-9, 2014 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-24767876

RESUMO

BACKGROUND: Purine nucleoside phosphorylase (PNP) deficiency is a rare form of autosomal recessive combined primary immunodeficiency caused by a enzyme defect leading to the accumulation of inosine, 2'-deoxy-inosine (dIno), guanosine, and 2'-deoxy-guanosine (dGuo) in all cells, especially lymphocytes. Treatments are available and curative for PNP deficiency, but their efficacy depends on the early approach. PNP-combined immunodeficiency complies with the criteria for inclusion in a newborn screening program. OBJECTIVE: This study evaluate whether mass spectrometry can identify metabolite abnormalities in dried blood spots (DBSs) from affected patients, with the final goal of individuating the disease at birth during routine newborn screening. METHODS: DBS samples from 9 patients with genetically confirmed PNP-combined immunodeficiency, 10,000 DBS samples from healthy newborns, and 240 DBSs from healthy donors of different age ranges were examined. Inosine, dIno, guanosine, and dGuo were tested by using tandem mass spectrometry (TMS). T-cell receptor excision circle (TREC) and kappa-deleting recombination excision circle (KREC) levels were evaluated by using quantitative RT-PCR only for the 2 patients (patients 8 and 9) whose neonatal DBSs were available. RESULTS: Mean levels of guanosine, inosine, dGuo, and dIno were 4.4, 133.3, 3.6, and 3.8 µmol/L, respectively, in affected patients. No indeterminate or false-positive results were found. In patient 8 TREC levels were borderline and KREC levels were abnormal; in patient 9 TRECs were undetectable, whereas KREC levels were normal. CONCLUSION: TMS is a valid method for diagnosis of PNP deficiency on DBSs of affected patients at a negligible cost. TMS identifies newborns with PNP deficiency, whereas TREC or KREC measurement alone can fail.


Assuntos
Síndromes de Imunodeficiência/diagnóstico , Mutação , Purina-Núcleosídeo Fosforilase/deficiência , Purina-Núcleosídeo Fosforilase/genética , Erros Inatos do Metabolismo da Purina-Pirimidina/diagnóstico , Adolescente , Pré-Escolar , Reparo do DNA , Desoxiguanosina/análise , Desoxiguanosina/metabolismo , Teste em Amostras de Sangue Seco , Feminino , Guanosina/análise , Guanosina/metabolismo , Humanos , Síndromes de Imunodeficiência/genética , Síndromes de Imunodeficiência/patologia , Lactente , Recém-Nascido , Inosina/análogos & derivados , Inosina/análise , Inosina/metabolismo , Linfócitos/patologia , Masculino , Triagem Neonatal , Doenças da Imunodeficiência Primária , Erros Inatos do Metabolismo da Purina-Pirimidina/genética , Erros Inatos do Metabolismo da Purina-Pirimidina/patologia , Espectrometria de Massas em Tandem
14.
J Pharm Biomed Anal ; 88: 201-6, 2014 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-24076575

RESUMO

Severe combined immunodeficiency due to adenosine-deaminase defect (ADA-SCID) is usually deadly in childhood because of severe recurrent infections. When clinical diagnosis is done, permanent damages due to infections or metabolite accumulation are often present. Gene therapy, bone marrow transplantation or enzyme replacement therapy may be effective if started early. The aim of this study was to set-up a robust method suitable for screening with a minimized preparation process and with inexpensive running costs, for diagnosing ADA-SCID by tandem mass spectrometry. ADA-SCID satisfies all the criteria for inclusion in a newborn screening program. We describe a protocol revised to incorporate adenosine and 2-deoxyadenosine testing into an expanded newborn screening program. We assessed the effectiveness of this approach testing dried blood spots from 4 genetically confirmed early-onset and 5 delayed-onset ADA-SCID patients. Reference values were established on 50,000 healthy newborns (deoxyadenosine <0.09µmol/L, adenosine <1.61µmol/L). We also developed a second tier test to distinguish true positives from false positives and improve the positive predictive value of an initial abnormal result. In the first 18 months, the pilot project has identified a newborn with a genetically confirmed defect in adenosine deaminase (ADA) gene. The results show that the method having great simplicity, low cost and low process preparations can be fully applicable to a mass screening program.


Assuntos
Adenosina Desaminase/sangue , Teste em Amostras de Sangue Seco , Triagem Neonatal/métodos , Imunodeficiência Combinada Severa/sangue , Espectrometria de Massas em Tandem , Calibragem , Humanos , Recém-Nascido , Projetos Piloto , Valor Preditivo dos Testes , Valores de Referência , Reprodutibilidade dos Testes , Estudos Retrospectivos , Imunodeficiência Combinada Severa/diagnóstico
15.
J Pediatr ; 163(6): 1570-1577.e6, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-24054431

RESUMO

OBJECTIVE: To evaluate safety and efficacy of oral propranolol administration in preterm newborns affected by an early phase of retinopathy of prematurity (ROP). STUDY DESIGN: Fifty-two preterm newborns with Stage 2 ROP were randomized to receive oral propranolol (0.25 or 0.5 mg/kg/6 hours) added to standard treatment or standard treatment alone. To evaluate safety of the treatment, hemodynamic and respiratory variables were continuously monitored, and blood samples were collected weekly to check for renal, liver, and metabolic balance. To evaluate efficacy of the treatment, the progression of the disease (number of laser treatments, number of bevacizumab treatments, and incidence of retinal detachment) was evaluated by serial ophthalmologic examinations, and plasma soluble E-selectin levels were measured weekly. RESULTS: Newborns treated with propranolol showed less progression to Stage 3 (risk ratio 0.52; 95% CI 0.47-0.58, relative reduction of risk 48%) or Stage 3 plus (relative risk 0.42 95% CI 0.31-0.58, relative reduction of risk 58%). The infants required fewer laser treatments and less need for rescue treatment with intravitreal bevacizumab (relative risk 0.48; 95% CI 0.29-0.79, relative reduction of risk 52 %), a 100% relative reduction of risk for progression to Stage 4. They also had significantly lower plasma soluble E-selectin levels. However, 5 of the 26 newborns treated with propranolol had serious adverse effects (hypotension, bradycardia), in conjunction with episodes of sepsis, anesthesia induction, or tracheal stimulation. CONCLUSION: This pilot study suggests that the administration of oral propranolol is effective in counteracting the progression of ROP but that safety is a concern.


Assuntos
Antagonistas Adrenérgicos beta/uso terapêutico , Propranolol/uso terapêutico , Retinopatia da Prematuridade/tratamento farmacológico , Antagonistas Adrenérgicos beta/efeitos adversos , Feminino , Humanos , Recém-Nascido Prematuro , Masculino , Projetos Piloto , Propranolol/efeitos adversos , Fatores de Risco , Método Simples-Cego
16.
Pharmacology ; 91(5-6): 275-80, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23711937

RESUMO

AIM: To evaluate the relationship between the pharmacokinetic (PK) parameters and therapeutic and adverse effects of rufinamide (RUF) in children with epileptic encephalopathies (EE) aged <4 years. METHODS: PK analysis was conducted at the steady state using a previously validated liquid chromatography tandem-mass spectrometric method in 15 children aged 6-42 months treated with RUF in add-on. Responders were defined as patients who achieved >50% decrease of seizures. Tolerability was evaluated by analysis of a parental report of adverse effects, a clinical examination and laboratory tests. RESULTS: Maximum plasma concentration (47.40 ± 35.36 mg/l), average plasma concentration (39.94 ± 24.53 mg/l) and half-life (13.66 ± 4.43 h) were extremely variable and considerably higher than those reported in older children treated with the same dose regimen. At the last evaluation, 9 patients (60%) were responders. CONCLUSION: RUF is efficacious and is well tolerated in children with EE. Nonetheless, a correlation between dose, serum concentration and efficacy could not be demonstrated. The variability in measured concentrations may be related to polytherapy that is necessary for controlling seizures in this very severe form of epilepsy, in which the off-label use of RUF is justified.


Assuntos
Anticonvulsivantes/farmacocinética , Deficiência Intelectual/sangue , Espasmos Infantis/sangue , Triazóis/farmacocinética , Anticonvulsivantes/sangue , Anticonvulsivantes/uso terapêutico , Pré-Escolar , Feminino , Humanos , Lactente , Recém-Nascido , Deficiência Intelectual/tratamento farmacológico , Síndrome de Lennox-Gastaut , Masculino , Espasmos Infantis/tratamento farmacológico , Triazóis/sangue , Triazóis/uso terapêutico
17.
J Pharm Biomed Anal ; 78-79: 34-8, 2013 May 05.
Artigo em Inglês | MEDLINE | ID: mdl-23434527

RESUMO

Propranolol, a non-selective beta blocker drug, is used in young infants and newborns for treating several heart diseases; its pharmacokinetics has been extensively evaluated in adult patients using extrapolation to treat pediatric population. The purpose of the present study was to develop and validate a method to measure propranolol levels in dried blood spots. The analysis was performed by using liquid chromatography/tandem mass spectrometry operating in multiple reaction monitoring mode. The calibration curve in matrix was linear in the concentration range of 2.5-200 µg/L with correlation coefficient r=0.9996. Intra-day and inter-day precisions and biases were less than 8.0% (n=10) and 11.5% (n=10) respectively. The recoveries ranged from 94 to 100% and the matrix effect did not result in a severe signal suppression. Propranolol on dried blood spot showed a good stability at three different temperatures for one month. This paper describes a micromethod for measuring propranolol levels on dried blood spot, which determines a great advantage in neonates or young infants during pharmacokinetic studies because of less invasive sampling and small blood volume required.


Assuntos
Antagonistas Adrenérgicos beta/sangue , Cromatografia Líquida/métodos , Propranolol/sangue , Espectrometria de Massas em Tandem/métodos , Calibragem , Humanos , Reprodutibilidade dos Testes
18.
J Allergy Clin Immunol ; 131(6): 1604-10, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23280131

RESUMO

BACKGROUND: Adenosine deaminase (ADA)-severe combined immunodeficiency (SCID) is caused by genetic variants that disrupt the function of ADA. In its early-onset form, it is rapidly fatal to infants. Delayed or late-onset ADA-SCID is characterized by insidious progressive immunodeficiency that leads to permanent organ damage or death. Quantification of T-cell receptor excision circles (TRECs) or tandem mass spectrometry (tandem-MS) analysis of dried blood spots (DBSs) collected at birth can identify newborns with early-onset ADA-SCID and are used in screening programs. However, it is not clear whether these analyses can identify newborns who will have delayed or late-onset ADA-SCID before symptoms appear. OBJECTIVE: We performed a retrospective study to evaluate whether tandem-MS and quantitative TREC analyses of DBSs could identify newborns who had delayed-onset ADA-SCID later in life. METHODS: We tested stored DBSs collected at birth from 3 patients with delayed-onset ADA-SCID using tandem-MS (PCT EP2010/070517) to evaluate levels of adenosine and 2'-deoxyadenosine and real-time PCR to quantify TREC levels. We also analyzed DBSs from 3 newborns with early-onset ADA-SCID and 2 healthy newborn carriers of ADA deficiency. RESULTS: The DBSs taken at birth from the 3 patients with delayed-onset ADA-SCID had adenosine levels of 10, 25, and 19 µmol/L (normal value, <1.5 µmol/L) and 2'-deoxyadenosine levels of 0.7, 2.7, and 2.4 µmol/L (normal value, <0.07 µmol/L); the mean levels of adenosine and 2'-deoxyadenosine were respectively 12.0- and 27.6-fold higher than normal values. DBSs taken at birth from all 3 patients with delayed-onset ADA deficiency had normal TREC levels, but TRECs were undetectable in blood samples taken from the same patients at the time of diagnosis. CONCLUSION: Tandem-MS but not TREC quantification identifies newborns with delayed- or late-onset ADA deficiency.


Assuntos
Adenosina Desaminase/sangue , Agamaglobulinemia/diagnóstico , Receptores de Antígenos de Linfócitos T/sangue , Imunodeficiência Combinada Severa/diagnóstico , Espectrometria de Massas em Tandem , Adenosina Desaminase/deficiência , Adenosina Desaminase/genética , Desoxiadenosinas/metabolismo , Ativação Enzimática , Eritrócitos/metabolismo , Humanos , Imunoglobulinas/sangue , Imunofenotipagem , Recém-Nascido , Subpopulações de Linfócitos/metabolismo , Receptores de Antígenos de Linfócitos T/genética , Estudos Retrospectivos
19.
Eur J Mass Spectrom (Chichester) ; 19(6): 497-503, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-24378468

RESUMO

In recent years, new treatments have become available to treat some lysosomal storage disorders (LSDs) and many studies suggest that there is a benefit with starting therapy early. Newborn screening should detect diseases early enough for prompt treatment. Some countries include additional conditions, such as some LSDs, into their newborn screening panels. Mucopolysaccharidosis Type I (MPS I) is an autosomal recessive disorder caused by the deficiency of α-L-iduronidase (IDUA) activity. Currently, enzyme replacement therapy (ERT) or bone marrow transplantation is available and this has raised a growing interest for the development of a newborn screening test. In 2009, we reported a new fast and simplified tandem mass spectrometry-based method for quantifying five enzyme activities on dried blood spots. Here, we describe the inclusion of IDUA activity determination for the simultaneous detection of six lysosomal storage diseases. We have defined reference normal ranges by testing 680 healthy newborns and 240 adults. The assay was checked through three confirmed MPS I patients whose IDUA activity was below the normal range. Reproducibility of the assays has been established by assessing the intra-day and inter-day assay imprecisions. This quick assay has been devised to be implemented in newborn screening by liquid chromatography tandem mass spectrometry.


Assuntos
Cromatografia Líquida/métodos , Teste em Amostras de Sangue Seco/métodos , Espectrometria de Massas/métodos , Mucopolissacaridose I/diagnóstico , Triagem Neonatal/métodos , Cromatografia Líquida/normas , Teste em Amostras de Sangue Seco/normas , Humanos , Iduronidase/análise , Iduronidase/sangue , Iduronidase/química , Recém-Nascido , Espectrometria de Massas/normas , Reprodutibilidade dos Testes
20.
BMC Pediatr ; 12: 144, 2012 Sep 05.
Artigo em Inglês | MEDLINE | ID: mdl-22950861

RESUMO

BACKGROUND: Despite progresses in neonatal care, the mortality and the incidence of neuro-motor disability after perinatal asphyxia have failed to show substantial improvements. In countries with a high level of perinatal care, the incidence of asphyxia responsible for moderate or severe encephalopathy is still 2-3 per 1000 term newborns. Recent trials have demonstrated that moderate hypothermia, started within 6 hours after birth and protracted for 72 hours, can significantly improve survival and reduce neurologic impairment in neonates with hypoxic-ischemic encephalopathy. It is not currently known whether neuroprotective drugs can further improve the beneficial effects of hypothermia. Topiramate has been proven to reduce brain injury in animal models of neonatal hypoxic ischemic encephalopathy. However, the association of mild hypothermia and topiramate treatment has never been studied in human newborns. The objective of this research project is to evaluate, through a multicenter randomized controlled trial, whether the efficacy of moderate hypothermia can be increased by concomitant topiramate treatment. METHODS/DESIGN: Term newborns (gestational age ≥ 36 weeks and birth weight ≥ 1800 g) with precocious metabolic, clinical and electroencephalographic (EEG) signs of hypoxic-ischemic encephalopathy will be randomized, according to their EEG pattern, to receive topiramate added to standard treatment with moderate hypothermia or standard treatment alone. Topiramate will be administered at 10 mg/kg once a day for the first 3 days of life. Topiramate concentrations will be measured on serial dried blood spots. 64 participants will be recruited in the study. To evaluate the safety of topiramate administration, cardiac and respiratory parameters will be continuously monitored. Blood samplings will be performed to check renal, liver and metabolic balance. To evaluate the efficacy of topiramate, the neurologic outcome of enrolled newborns will be evaluated by serial neurologic and neuroradiologic examinations. Visual function will be evaluated by means of behavioural standardized tests. DISCUSSION: This pilot study will explore the possible therapeutic role of topiramate in combination with moderate hypothermia. Any favourable results of this research might open new perspectives about the reduction of cerebral damage in asphyxiated newborns.


Assuntos
Frutose/análogos & derivados , Hipotermia Induzida , Hipóxia-Isquemia Encefálica/terapia , Fármacos Neuroprotetores/uso terapêutico , Terapia Combinada , Frutose/efeitos adversos , Frutose/uso terapêutico , Humanos , Recém-Nascido , Fármacos Neuroprotetores/efeitos adversos , Topiramato
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