Newborn blood spot screening for sickle cell disease by using tandem mass spectrometry: implementation of a protocol to identify only the disease states of sickle cell disease.

BACKGROUND: The currently recommended technologies of HPLC and isoelectric focusing for newborn blood spot screening for sickle cell disease (SCD) identify both the disease and carrier states, resulting in large numbers of infants being followed up unnecessarily. Analysis of blood spot tryptic peptides performed by using tandem mass spectrometry (MS/MS) is an alternative technology to detect hemoglobin (Hb) variant disorders. METHODS: We analyzed 2154 residual newborn blood spots and 675 newborn blood spots from infants with Hb variants by using MS/MS after trypsin digestion. Screening cutoffs were developed by using the ratio between the variant peptide-to-wild-type peptide abundance for HbS, C, D(Punjab), O(Arab), Lepore, and E peptides. A postanalytical data analysis protocol was developed using these cutoffs to detect only the disease states of SCD and not to identify carrier states. A parallel study of 13 249 newborn blood spots from a high-prevalence SCD area were analyzed by both MS/MS and HPLC. RESULTS: Screening cutoffs developed distinguished the infants with the disease states of SCD, infants who were carriers of SCD, and infants with normal Hb. In the parallel study no false-negative results were identified, and all clinically relevant cases were correctly identified using the MS/MS protocol. Unblinding the data revealed a total of 328 carrier infants that were successfully excluded by the protocol. CONCLUSIONS: The screening protocol developed correctly identified infants with the disease states of SCD. Furthermore, large numbers of sickle cell carrier infants were successfully not identified, thereby avoiding unnecessary follow-up testing and referral for genetic counseling.

Measurement of urinary free cortisol by tandem mass spectrometry and comparison with results obtained by gas chromatography-mass spectrometry and two commercial immunoassays.

BACKGROUND: Determination of urinary free cortisol (UFC) is an important adjunct for the assessment of adrenal function. In this study, we have analysed cortisol concentrations in urine samples by gas chromatography-mass spectrometry (GC-MS), liquid chromatography-tandem mass spectrometry (LC-MS/MS) and two immunoassays. The results were compared with GC-MS. The interference of cortisol ring-A metabolites in immunoassays was also assessed. METHODS: The GC-MS technique involved solvent extraction, LH-20 clean-up and derivatization. Only solid-phase extraction procedure was used for LC-MS/MS. The samples were analysed in positive electro-spray ionization mode, monitoring the transitions for cortisol and deuterated-cortisol at m/z 363.3 > 121.2 and m/z 365.3 > 122.2, respectively. Immunoassays were performed according to the manufacturer's instructions. RESULTS: When compared with GC-MS results both immunoassays (Coat-A-Count; approximately 1.9-fold, Centaur; approximately 1.6-fold) overestimated UFC concentrations. Cortisol ring-A dihydro- and tetrahydrometabolites contribute significantly to this overestimation. There was no interference by these metabolites in either GC-MS or LC-MS/MS methods. The sensitivity of the LC-MS/MS procedure was 2 nmol/L and the intra- and inter-assay variations were <5% in each quality-control sample. The comparison of the UFC results achieved by assaying the study samples with GC-MS and LC-MS/MS indicated that the agreement between the two methods was excellent (LC-MS/MS = 1.0036GC-MS - 0.0841; r2 = 0.9937). CONCLUSIONS: The interference of cortisol ring-A metabolites in immunoassays contribute to overestimation of UFC concentrations. The LC-MS/MS procedure had the sensitivity, specificity, linearity, precision and accuracy for the determination of UFC concentrations. The method is suitable for routine use provided that method-dependant reference values are established.

Newborn screening for sickle cell disorders using tandem mass spectrometry: three years' experience of using a protocol to detect only the disease states.

Background Tandem mass spectrometry (MS/MS) has recently become an alternative method for the newborn screening of sickle cell disorders (SCD), as it is able to detect haemoglobin (Hb) peptides following digestion of bloodspots with trypsin. Using the SpOtOn Diagnostics Reagent Kit, we previously developed a screening protocol to detect only the disease states of SCD, using action values based on the ratio between the variant Hb peptide to wild-type peptide abundances for the HbS, C, DPunjab, OArab, E and Lepore peptides. Methods Action values using the ratios between the wild type HbA (ßT1-3) peptides and the foetal Hb (γT2) peptide were developed to identify bloodspot samples from premature and transfused infants. An evaluation was undertaken to assess the transferability of the action values onto an additional MS/MS instrument. We report here our experience using this MS/MS protocol. Results During a three-year period, we screened 100,456 babies and identified 10 SCD cases (1 HbS/HPFH, 5 HbS/S and 4 HbS/C) and a case of HbE/ß-thalassaemia that was identified as a by-product. The Hb variant to wild-type peptide ratio action values were transferable to a second MS/MS instrument. Our protocol prevented the identification of an estimated 810 carrier infants. Gestational age-related action values for HbA to HbF peptide ratios were required to minimize the number of samples referred for second-line testing to exclude ß-thalassaemia. Conclusion MS/MS is a robust alternative screening technology for SCD; in addition, it also optimizes the use of equipment and expertise that currently exist in newborn screening laboratories.

A pilot study of complementary and alternative medicine use in patients with fibromyalgia syndrome.

UNLABELLED: Fibromyalgia syndrome (FMS) is a complex disorder, with primary symptoms of sleep disturbances, pain, and fatigue. FMS is one of the most common reasons for patient visits to a rheumatologist. Previous studies have suggested that complementary and alternative medicine (CAM) use in patients with rheumatic diseases is common, but such data specific to FMS patients is limited. OBJECTIVE: The following study sought to describe the prevalence of CAM use in a primary care practice of patients with FMS and assess whether these patients discuss CAM use with their physician, physician-extender, and/or pharmacist. METHODS: A one-group cross-sectional survey design was implemented in a large, community-based, private physician practice of patients diagnosed with FMS. A self-administered questionnaire was distributed during clinic visits. It solicited information related to demographic characteristics; FMS-specific health background; whether CAM use had been discussed with a health care provider; and the "ever-use" of common types of CAM. Respondents returned the questionnaire via US mail in a postage-paid, self-addressed envelope. RESULTS: A total of 115 surveys were distributed with 54 returned for analysis (47% completion rate). The sample was predominantly female, well educated and had a mean age of 55.6 years. All respondents were White. Most respondents (92.6%) reported using some type of CAM. Exercise (92.2%), chiropractic treatment (48.1%), lifestyle and diet (45.8%), relaxation therapy (44.9%), and dietary and herbal supplements (36.5%) were most commonly reported CAM therapies "ever-used" by respondents. Dietary and herbal supplements with the highest prevalence of "ever-use" were magnesium (19.2%), guaifenesin (11.5%), and methylsulfonylmethane (MSM) (9.6%). Respondents most commonly discussed CAM with the clinic rheumatologist and the primary care physician (53.7% and 38.9%, respectively). Only 14.8% of respondents discussed CAM with a pharmacist. However, a significantly higher proportion of respondents who "ever-used" dietary and herbal supplements discussed CAM with a pharmacist compared to those who never used dietary and herbal supplements [chi square=6.03, p=0.014]. CONCLUSION: This pilot study suggests that CAM use is common in patients diagnosed with FMS. Compared to other healthcare providers, respondents were least likely to discuss CAM with a pharmacist. However, respondents who used dietary and herbal supplements were more likely to discuss CAM with a pharmacist compared to those who did not, suggesting the potential influence of pharmacist intervention.

A pilot study of complementary and alternative medicine use in patients with fibromyalgia syndrome

Fibromyalgia syndrome (FMS) is a complex disorder, with primary symptoms of sleep disturbances, pain, and fatigue. FMS is one of the most common reasons for patient visits to a rheumatologist. Previous studies have suggested that complementary and alternative medicine (CAM) use in patients with rheumatic diseases is common, but such data specific to FMS patients is limited. Objective: The following study sought to describe the prevalence of CAM use in a primary care practice of patients with FMS and assess whether these patients discuss CAM use with their physician, physician-extender, and/or pharmacist. Methods: A one-group cross-sectional survey design was implemented in a large, community-based, private physician practice of patients diagnosed with FMS. A self-administered questionnaire was distributed during clinic visits. It solicited information related to demographic characteristics; FMS-specific health background; whether CAM use had been discussed with a health care provider; and the «ever-use» of common types of CAM. Respondents returned the questionnaire via US mail in a postage-paid, self-addressed envelope. Results: A total of 115 surveys were distributed with 54 returned for analysis (47% completion rate). The sample was predominantly female, well educated and had a mean age of 55.6 years. All respondents were White. Most respondents (92.6%) reported using some type of CAM. Exercise (92.2%), chiropractic treatment (48.1%), lifestyle and diet (45.8%), relaxation therapy (44.9%), and dietary and herbal supplements (36.5%) were most commonly reported CAM therapies «ever-used» by respondents. Dietary and herbal supplements with the highest prevalence of «ever-use» were magnesium (19.2%), guaifenesin (11.5%), and methylsulfonylmethane (MSM) (9.6%). Respondents most commonly discussed CAM with the clinic rheumatologist and the primary care physician (53.7% and 38.9%, respectively). Only 14.8% of respondents discussed CAM with a pharmacist. However, a significantly higher proportion of respondents who «ever-used» dietary and herbal supplements discussed CAM with a pharmacist compared to those who never used dietary and herbal supplements (chi square=6.03, p=0.014). Conclusion: This pilot study suggests that CAM use is common in patients diagnosed with FMS. Compared to other healthcare providers, respondents were least likely to discuss CAM with a pharmacist. However, respondents who used dietary and herbal supplements were more likely to discuss CAM with a pharmacist compared to those who did not, suggesting the potential influence of pharmacist intervention (AU)

El síndrome de fibromialgia (SFM) es un desorden complejo, con síntomas primarios de alteraciones del sueño, dolor y fatiga. SFM es una de las razones más frecuentes por las que los pacientes visitan al reumatólogo. Estudios previos han sugerido que es frecuente el uso de la medicina complementaria y alternativa (MCA) en pacientes con enfermedades reumáticas, pero tales datos relativos a SFM son escasos. Objetivo: El siguiente estudio trató de describir la prevalencia de uso de MCA en atención primaria en pacientes con SFM y evaluar si estos pacientes comentan la MCA con sus médicos, o con sus auxiliares médicos y/o con el farmacéutico. Métodos: Se empleó un diseño de investigación transversal de un grupo de pacientes diagnosticados de SFM de un gran consultorio privado de un médico. Durante las horas de visita, se distribuyó un cuestionario auto-administrado. Solicitaba información relacionada con las características demográficas; antecedentes sanitarios específicos del SFM; si se había discutido la posibilidad de usar MCA con el profesional de la salud; y el uso «alguna vez» de los tipos frecuentes de MCA. Los respondentes retornaban el cuestionario por correo en un sobre pre-pagado. Resultados: Se distribuyeron un total de 115 encuestas con 54 devueltas para análisis (47% cumplimentación). La muestra era predominantemente mujeres, bien educadas y con una media de edad de 55,6 años. Todos los respondentes eran blancos. La mayoría (92,6%) comunicaban usar algunos tipos de MCA. Los más frecuentemente comunicados como los que habían usado «alguna vez» eran ejercicio (92,2%), tratamiento quiropráctico (48,1%), estilos de vida y dieta (45,8%), terapia de relajación (44,9%), suplementos dietéticos y herbales (36,5%). Los suplementos dietéticos y plantas medicinales con una prevalencia más alta fueron magnesio (19,2%), guaifenesina (11,5%) y metilsulfonilmetano (9,6%). Los respondentes discutieron normalmente el uso de MCA con el reumatólogo y el médico de atención primaria (53,7% y 38,9%, respectivamente). Sólo el 14,8% de los respondentes lo había discutido con un farmacéutico. Sin embargo, una proporción mayor de respondentes que habían usado «alguna vez» suplementos dietéticos y plantas medicinales discutieron el uso de MCA con el farmacéutico que aquellos que nunca los habían usado (chi cuadrado=6.03, p=0.014). Conclusión: Este estudio piloto sugiere que la medicina complementaria y alternativa se usa frecuentemente en pacientes diagnosticados de SFM. Comparados con otros profesionales de la salud, los respondentes discutían menos su MCA con el farmacéutico. Sin embargo, los que habían usado suplementos dietéticos y plantas medicinales discutían más fácilmente sobre su MCA con el farmacéutico que los que no los habían usado nunca, lo que apunta al posible papel del farmacéutico en este campo (AU)