Current trends in the analytical determination of vitamin D.

INTRODUCTION: Vitamin D is a micronutrient that plays a large role in bone disease, and researchers are now discovering that it also does so in non-skeletal disease, thus making high-quality analytical determination necessary. To make this determination, a series of immunochemical and physical methods are used. These methods present a series of different ways of handling samples as well as different methodologies that bring a series of advantages and limitations based on the scope of work in which the vitamin D analysis methodology is applied. Although the Liquid Chromatography-tandem Mass Spectrometry (LC-MS/MS) is the gold standard method of analytical vitamin D determination, and is the only one to offer a more complete and accurate view of all metabolites of this vitamin, it is necessary to standardize all the analysis methodologies that allow accurate, reliable and quality analytical determination, since it is essential to obtain results that can reliably be extrapolated to the population, and that can be decisive in assessing a large number of pathologies.

INTRODUCCIÓN: La vitamina D es un micronutriente que ejerce un gran papel en enfermedades óseas y actualmente se está descubriendo que también lo hace en enfermedades no óseas, por lo que una determinación analítica de calidad es necesaria. Para realizar esta determinación se emplean una serie de métodos inmunoquímicos y físicos, los cuales van a presentar una serie de tratamientos diferentes de las muestras, así como diferentes metodologías que van a traer una serie de ventajas y limitaciones conforme al ámbito de trabajo en que se aplique la metodología de análisis de la vitamina D. A pesar de que la cromatografía líquida-espectrometría de masas en tándem (LC-MS/MS) es el método gold standard de determinación analítica de la vitamina D, y de que es el que ofrece una visión más completa y precisa de todos los metabolitos de esta vitamina, es necesaria una estandarización de todas las metodologías de análisis que permitan una determinación analítica precisa, fiable y de calidad, ya que es imprescindible obtener unos resultados que sean extrapolables con fiabilidad a la población y que puedan ser determinantes para valorar un gran número de patologías.

Lipoprotein(a) in Patients Undergoing Transcatheter Aortic Valve Replacement.

Lipoprotein(a) [Lp(a)] is a genetically determined risk factor for calcific aortic valve stenosis (CAVS) for which transcatheter aortic valve replacement (TAVR) is increasingly utilized as treatment. We evaluated the effect of a program to increase testing of and define the prevalence of elevated Lp(a) among patients undergoing TAVR. Educational efforts and incorporation of a "check-box" Lp(a) order to the preoperative TAVR order set were instituted. Retrospective chart review was performed in 229 patients requiring TAVR between May 2013 and September 2018. Of these patients, 57% had an Lp(a) level measured; testing rates increased from 0% in 2013 to 96% in 2018. Lipoprotein(a) testing occurred in 11% of patients before and in 80% of patients after the "check-box" order set ( P < .001). The prevalence of elevated Lp(a) (≥30 mg/dL) was 35%; these patients had a higher incidence of coronary artery disease requiring revascularization compared with patients with normal Lp(a) (65% vs 47%; P = .047). Patients with Lp(a) ≥30 mg/dL also had higher incidence of paravalvular leak compared with those with normal Lp(a) (13% vs 4%; P = .04). This study defines the prevalence of elevated Lp(a) in advanced stages of CAVS and provides a practice pathway to assess procedural complications and long-term outcomes of TAVR in patients with elevated Lp(a) levels.

The effects of an educational meeting and subsequent computer reminders on the ordering of laboratory tests by rheumatologists: an interrupted time series analysis.

OBJECTIVES: To examine the effects of an educational meeting and subsequent computer reminders on the number of ordered laboratory tests. METHODS: Using interrupted time series analysis we assessed whether trends in the number of laboratory tests ordered by rheumatologists between September 2012 and September 2015 at the Sint Maartenskliniek (the Netherlands) changed following an educational meeting (September 2013) and the introduction of computer reminders into the Computerised Physician Order Entry System (July 2014). The analyses were done for the set of tests on which both interventions had focussed (intervention tests; complement, cryoglobulins, immunoglobins, myeloma protein) and a set of control tests unrelated to the interventions (alanine transferase, anti-cyclic citrullinated peptide, C-reactive protein, creatine, haemoglobin, leukocytes, mean corpuscular volume, rheumatoid factor and thrombocytes). RESULTS: At the start of the study, 101 intervention tests and 7660 control tests were ordered per month by the rheumatologists. After the educational meeting, both the level and trend of ordered intervention and control tests did not change significantly. After implementation of the reminders, the level of ordered intervention tests decreased by 85.0 tests (95%-CI -133.3 to -36.8, p<0.01), the level of control tests did not change following the introduction of reminders. CONCLUSIONS: In summary, an educational meeting alone was not effective in decreasing the number of ordered intervention tests, but the combination with computer reminders did result in a large decrease of those tests. Therefore, we recommend using computer reminders in addition to education if reduction of inappropriate test use is aimed for.

Primary care requests for anaemia chemistry tests in Spain: potential iron, transferrin and folate over-requesting.

AIM: To study the regional variability of requests for anaemia chemistry tests in primary care in Spain and the associated economic costs of potential over-requesting. METHODS: Requests for anaemia tests were examined in a cross-sectional study. Clinical laboratories from different autonomous communities (AACCs) were invited to report on primary care anaemia chemistry tests requested during 2014. Demand for iron, ferritin, vitamin B12 and folate tests per 1000 inhabitants and the ratios of the folate/vitamin B12 and transferrin/ferritin requests were compared between AACCs. We also calculated reagent costs and the number of iron, transferrin and folate tests and the economic saving if every AACC had obtained the results achieved by the AACC with best practice. RESULTS: 110 laboratories participated (59.8% of the Spanish population). More than 12 million tests were requested, resulting in reagent costs exceeding €16.5 million. The serum iron test was the most often requested, and the ferritin test was the most costly (over €7 million). Close to €4.5 million could potentially have been saved if iron, transferrin and folate had been appropriately requested (€6 million when extrapolated to the whole Spanish population). CONCLUSIONS: The demand for and expenditure on anaemia chemistry tests in primary care in Spain is high, with significant regional differences between different AACCs.

Trends and variability in blood lead concentrations among US children and adolescents.

Using data from the National Health and Nutrition Examination Survey for the period 2003-2012, the objective of this study was to evaluate trends in blood lead levels (BLL) among children aged 1-5 and 6-11 years and smoker and nonsmoker adolescents aged 12-19 years. Regression models with log10 transformed values of BLLs as dependent variable were fitted to evaluate how gender, race/ethnicity, smoking, and exposure to secondhand smoke at home affect BLLs. Irrespective of age, gender, and race/ethnicity, BLLs declined over the study period (p ≤ 0.01). Overall, adjusted BLLs declined by 0.00114 µg/dL for every 2 years. Children aged 1-5 years had about 50 % higher BLLs than smoker adolescents, about 75 % higher BLLs than nonsmoker adolescents, and about 45 % higher BLLs than children aged 6-11 years. While overall, children aged 1-5 years with BLL ≥ 5 µg/dL made up 3.24 %, 7.8 % non-Hispanic Black children aged 1-5 years had BLL ≥ 5 µg/dL. Males were found to have higher adjusted BLLs than females, and non-Hispanic Blacks were found to have higher adjusted BLLs than non-Hispanic Whites. Higher poverty income ratio was associated with lower adjusted BLLs (ß = -0.02916, p < 0.01). Children living in owner-occupied homes had lower adjusted BLLs than children living in renter-occupied homes. BLLs increased with increase in number of smokers smoking inside the home (ß = 0.02496, p = 0.02). In conclusion, while BLLs have declined for all age groups, genders, and races/ethnicities, certain races/ethnicities like non-Hispanic Blacks continue to have substantially higher BLLs than non-Hispanic Whites.

Diagnosis of Disorders of Iron Metabolism in Dogs and Cats.

Iron is an essential element and is used by every cell in the body. This article summarizes iron metabolism and disorders associated with iron metabolism in dogs and cats. The diagnostic tests currently in use for assessing iron status are discussed.

[Research progress on the effects of acupuncture-moxibustion serum].

The acupuncture-moxibustion serum has received wide attention as a new idea and method. Its application on researches in vivo and the treatment of disease not only has an important theory value, but also provides new ideas for overcoming the limitations of researches in vivo and some disease's treatment. Literature regarding the basic research of acupuncture-moxibustion serum for last more than 10 years is reviewed, and the effects of acupuncture-moxibustion serum on respiratory system, digestive system, cardiovascular system, nervous system, immune system, anti-aging, bone metabolism and anti-cancer are summarized, hoping to provide references for clinical treatment and evidence-based medicine.

Temporal trends of hemoglobin A1c testing.

OBJECTIVE: The study of utilization patterns can quantify potential overuse of laboratory tests and find new ways to reduce healthcare costs. We demonstrate the use of distributional analytics for comparing electronic health record (EHR) laboratory test orders across time to diagnose and quantify overutilization. MATERIALS AND METHODS: We looked at hemoglobin A1c (HbA1c) testing across 119,000 patients and 15 years of hospital records. We examined the patterns of HbA1c ordering before and after the publication of the 2002 American Diabetes Association guidelines for HbA1c testing. We conducted analyses to answer three questions. What are the patterns of HbA1c ordering? Do HbA1c orders follow the guidelines with respect to frequency of measurement? If not, how and why do they depart from the guidelines? RESULTS: The raw number of HbA1c orderings has steadily increased over time, with a specific increase in low-measurement orderings (<6.5%). There is a change in ordering pattern following the 2002 guideline (p<0.001). However, by comparing ordering distributions, we found that the changes do not reflect the guidelines and rather exhibit a new practice of rapid-repeat testing. The rapid-retesting phenomenon does not follow the 2009 guidelines for diabetes diagnosis either, illustrated by a stratified HbA1c value analysis. DISCUSSION: Results suggest HbA1c test overutilization, and contributing factors include lack of care coordination, unexpected values prompting retesting, and point-of-care tests followed by confirmatory laboratory tests. CONCLUSIONS: We present a method of comparing ordering distributions in an EHR across time as a useful diagnostic approach for identifying and assessing the trend of inappropriate use over time.

Point-of-care technologies for molecular diagnostics using a drop of blood.

Molecular diagnostics is crucial for prevention, identification, and treatment of disease. Traditional technologies for molecular diagnostics using blood are limited to laboratory use because they rely on sample purification and sophisticated instruments, are labor and time intensive, expensive, and require highly trained operators. This review discusses the frontiers of point-of-care (POC) diagnostic technologies using a drop of blood obtained from a finger prick. These technologies, including emerging biotechnologies, nanotechnologies, and microfluidics, hold the potential for rapid, accurate, and inexpensive disease diagnostics.

Patterns of preoperative laboratory testing in patients undergoing outpatient plastic surgery procedures.

BACKGROUND: Preoperative laboratory testing is commonplace in the clinical setting and is often utilized at surgeon discretion. We searched the American College of Surgeons-National Surgical Quality Improvement Program (ACS-NSQIP) data set to determine the impact of preoperative laboratory testing in ambulatory plastic surgery patients. OBJECTIVE: The authors assess the utilization and predictive value of preoperative laboratory testing in outpatient plastic surgery procedures. METHODS: Patients undergoing ambulatory plastic surgery were identified from the 2005 to 2010 NSQIP databases. Laboratory tests were categorized by group: hematologic, chemistry, coagulation, and liver function tests (LFT). We defined complications in 2 groups: major postoperative and wound complications. Multivariate analyses were used to identify patient characteristics associated with testing and to assess the ability of laboratory testing to predict postoperative complications. RESULTS: A total of 5359 (62.0%) patients underwent testing; 881 (16.4%) tests were performed on the day of surgery. In patients with no defined NSQIP comorbidities, 59.4% underwent preoperative testing and had a significantly lower rate of abnormal findings (33.4% vs 25.3%, P < .0001). In multivariate analyses, testing was associated with older age, American Society of Anesthesiologists class >2, Hispanic or African American race, body contouring procedures, epidural or spinal procedures, and with diabetes, hypertension, and cancer. Major complications occurred in 0.34% of patients. Our analysis demonstrated that neither testing nor abnormal results were associated with postoperative complications, either major (P = .178) or wound (P = .150). CONCLUSIONS: We found no association between abnormal laboratory testing and postoperative morbidity. Preoperative testing in low-risk ambulatory plastic surgery patients may be costly and has limited direct clinical benefit.

Vitamin D assays: past and present debates, difficulties, and developments.

Clinical interest in Vitamin D and its purported roles not only in calcium and bone metabolism but in several other medical conditions (diabetes, cardiovascular disease, multiple sclerosis, cancer, psychiatric disorders, neuro-muscular disease) has led to a surge in laboratory requests for 25 hydroxy vitamin D and 1,25 dihydroxy vitamin D measurement. Circulating 25 hydroxy vitamin D concentration is routinely used as the best indicator of vitamin D status, but measurement of other metabolites, especially the physiologically active 1,25 dihyroxy vitamin D, are of clinical value. Over the last 40 years the development of assays for vitamin D and its metabolites from early competitive binding assays through to immunoassay and liquid chromatography aligned to mass spectrometry have demonstrated various analytical challenges, the advantages and disadvantages of each method are constantly changing with new technological developments. Immunoassay remains the predominant mode of measurement for 25-hydroxy vitamin D although problems with equimolar recovery of the D2 and D3 metabolites remain an issue. Standardisation of all assays has been improved but not resolved with the currently available reference materials as evidenced by the international vitamin D external quality assurance scheme, DEQAS. The choice of method for each laboratory remains a balance mainly between turn around time, convenience, cost and the specificity and accuracy of the information obtained. With increasing discussion and clinical interest surrounding other vitamin D metabolites the vitamin D assay debate is set to continue.

Variation in prostate specific antigen (PSA) test ordering in primary care centers: tendencies 2002-2009.

BACKGROUND: We aimed to compare the variation in PSA test ordering behavior between ten different health centers according to patients' age and the tendencies in PSA testing during the period of study (2002 - 2009). METHODS: The study subjects attended 10 primary care centers in Alicante, Spain (2002 - 2009). Variables included: patient age, primary center, and year. We calculated percentages of PSA testing for each age group over the total PSA testing in each center and year. RESULTS: A great variability has been shown between the different centers, mainly in patients where the controversy in PSA testing is higher: in the group including patients younger than 50 and those older than 85 years old. PSA testing percentages increased along the period of study for all the groups of age, except for the group of patients aged between 50 and 75 years old, where accordingly, PSA testing percentages decreased along the time. CONCLUSIONS: These results may contribute to the discussion about the use of PSA testing and show the importance of a consensus among healthcare providers to facilitate adoption of an approach while international recommendations come to an agreement.

UK Renal Registry 13th Annual Report (December 2010): Chapter 3: demographic and biochemistry profile of kidney transplant recipients in the UK in 2009: national and centre-specific analyses.

INTRODUCTION: National transplant registries routinely focus on centre-specific patient and graft survival rates following renal transplantation. However other outcomes such as graft function (as measured by eGFR), haemoglobin, biochemical variables and blood pressure are also important quality of care indicators. METHODS: Renal transplant activity, incident graft survival data and donor information were obtained from NHS Blood and Transplant. Laboratory and clinical variables and prevalent survival data were obtained from the UK Renal Registry. Data were analysed separately for prevalent and one year post-transplant patients. RESULTS: Increasing live and donor after cardiac death donors were responsible for the increasing transplant activity within the UK. During 2009, 2.9% of prevalent transplant patients experienced graft failure and transplant patient death rates remained stable at 2.5 per 100 patient years. There was centre variation in outcomes including eGFR, haemoglobin and biochemical variables in prevalent and 1 year posttransplant patients. Analysis of prevalent transplants by chronic kidney disease stage showed 14.3% with an eGFR <30 ml/min/1.73 m(2) and 1.9% with an eGFR <15 ml/min/1.73 m(2). Of those with CKD stage 5T, 33.3% had haemoglobin concentrations <10.5 g/dl, 22.4% phosphate concentrations ≥ 1.8 mmol/L and 7.7% adjusted calcium concentrations ≥ 2.6 mmol/L. CONCLUSION: Significant variations in clinical outcomes (unadjusted for patient-specific variables) amongst kidney transplant recipients continued to exist in the UK, and may reflect differences in healthcare delivery between renal centres.

Umbilical cord blood stem cells: towards a proteomic approach.

The first umbilical cord blood (UCB) transplant to a sibling with Fanconi's anaemia in 1988 represented a breakthrough in the field of transplantation. Thereon, several transplants have been performed with UCB-derived hematopoietic stem cells (HSCs) and a plethora of studies have investigated the plasticity of UCB-derived stem and progenitor cells. However, these studies have not been hitherto translated into clinical trials and, although UCB is routinely used as an alternative source of HSCs, no substantial advances have been made in the field of clinical regenerative medicine. The real deal is the lack of knowledge about the molecular processes governing the events of differentiation which transform immature UCB stem cells into terminally-committed hematopoietic, muscle, bone and nervous cells. In order to fill this void, several studies have been recently focused on the identification of the peculiar proteomic profile of UCB-derived stem cells. Hereby, we concisely review recent proteomic surveys addressing UCB-derived stem and progenitor cells. Notably, comparative studies detected a wider spectrum of proteins in immature cells rather than in more differentiated populations, as if maturation events could represent a bottleneck to protein expression. Future research projects should try to shed light on these processes and their completion could pave the way for unprecedented treatments.

[The medical laboratory in preventive care]. / Laboruntersuchungen in der Gesundheitsvorsorge.

Preventive care has the aim to prevent the occurrence of disease and to detect disease at an early stage, in order to allow for timely interventions. Before tests can be implemented into routine prevention care, several criteria have to be satisfied. Laboratory tests such as fasting glucose, lipids, fecal occult blood testing are widely used within preventive programs. The use of other parameters, such as PSA, TSH, creatinine, urine albumin (albumin/creatinine ration, ACR) similarly might get an important role. This article focuses on the role of laboratory tests in preventive care with a special emphasis on recommendations on their use in Central Europe.

Type and screen completion for scheduled surgical procedures. A College of American Pathologists Q-Probes study of 8941 type and screen tests in 108 institutions.

CONTEXT: Market-driven changes in the timing of elective surgeries and admissions have introduced barriers to completing pretransfusion testing in a timely manner. Consequently, blood bank personnel may not have adequate time to identify appropriate blood products for scheduled surgeries. Incomplete pretransfusion testing can delay surgery and significantly compromise patient safety. OBJECTIVES: To identify the incidence of avoidable problems associated with obtaining timely samples for adequate pretransfusion type and screen (T&S) testing, to identify the practices and characteristics associated with improved rates of pretransfusion testing completed prior to surgery, and to determine the likelihood of antibody identification problems that affect the availability of blood. DESIGN: Participants in the College of American Pathologists (CAP) Q-Probes laboratory quality improvement program were asked to collect data on when a T&S was collected in anticipation of elective scheduled surgery, when the T&S was completed, when the surgery started, and the results of those T&S tests. Participants also completed questionnaires describing their facilities, procedures, and practices. SETTING AND PARTICIPANTS: One hundred eight public and private institutions participated in this Q-Probes Study, 97% of which were located in the United States. MAIN OUTCOMES MEASURES: Type and screen collection and completion relative to the start of surgery, and the results of those tests. RESULTS: Of the 8941 T&Ss, 64.6% were collected prior to the day of surgery. The median laboratory completed approximately 69% of their T&S testing for scheduled surgeries at least 1 day prior to the surgery. Of those T&S tests that were collected on the day of surgery, the median laboratory completed almost 23% after the start of surgery. For 10% of participants, more than 75% of all T&Ss collected on the same day as surgery were not complete until after the start of surgery. When red blood cell-directed antibodies were identified, 78.7% were considered clinically significant, and 95.2% were alloantibodies. Positive antibody screens were significantly associated with delayed surgery and special efforts needed to obtain blood. Of those institutions with a specific protocol in place to collect T&S samples prior to hospital admission, the median laboratory completed the T&S at least 1 day prior to surgery 74% of the time. When the institution coupled the T&S collection protocol with T&S collection earlier than 3 days prior to surgery, the median laboratory completed the T&S at least 1 day prior to surgery almost 87% of the time. Type and screen collection less than 3 days prior to surgery resulted in special efforts needed to obtain blood more than 1% of the time. Type and screen collected on the same day as surgery directly resulted in a surgery delay 0.8% of the time. CONCLUSIONS: Patients are unnecessarily being placed at risk by inadequate mechanisms to ensure available blood for surgery. All T&Ss were collected for scheduled surgeries with adequate opportunity for a T&S to be completed in advance of the surgery. Specific protocols helped improve the performance in terms of completing the T&S prior to surgery, as did mechanisms that permitted T&S collections in advance of the admission. Type and screen collection time relative to surgery was significantly associated with the incidence of surgery delay due to unavailable blood; the less time between collection and surgery, the less likely blood was available.

Glicemia capilar medida por dois aparelhos de automonitorizaçäo: quanto eles podem estimar a glicemia plasmática na rotina médica? / Capillary blood glucose measurement by tho self-monitoring equipment: how can they to estimate a plasma blood grucose in medical routine?

O desenvolvimento de monitores portáteis para automonitorização da glicose sangüínea tem fácil aceitação pelos pacientes e médicos, sendo amplamente utilizado atualmente, o que torna essencial avaliar o quanto esses resultados correspondem à glicemia plasmática. Assim, avaliamos a acurácia e precisão de dois monitores digitais à disposição no mercado: um utiliza a glicose desidrogenase (Ap1) e o outro a glicose oxigenase (Ap2) na mensuração da glicemia capilar