Clinical Applications of Point-of-Care Testing in Different Conditions.

BACKGROUND: The use of point-of-care testing (POCT) in different clinical applications is justified by the fact that the time to release the result is shortened, allowing the physician to define the diagnosis and most appropriate therapy in a shorter time. However, the negative aspects must also be highlighted and studied so that we can move forward with the use of these devices. These negative aspects include greater analytical imprecision compared to laboratory automation, the variability between different equipment from different manufacturers, the risk of inappropriate use, a low level of global regulation, higher costs compared with laboratory testing and cost ineffectiveness in terms of health care. Methods and. RESULTS: This review presents some clinical applications of POCT in different scenarios, such as for diabetes mellitus, infectious diseases, pediatrics, and chronic kidney disease, among others. CONCLUSIONS: We hope to see a global consensus on an acceptable quality standard for performing POCT that is adaptable, practical, and cost effective in primary care settings, ensuring patient safety, and minimizing the risk of harm.

Point-of-Care Testing: General Aspects.

Point-of-Care Testing (POCT) has been highlighted in the health care sector in recent decades. On the other hand, due to its low demand, POCT is at a disadvantage compared to conventional equipment, since its cost is inversely proportional to the volume of use. In addition, for the implementation of POCT to succeed, it is essential to rely on the work of a multidisciplinary team. The awareness of health professionals of the importance of each step is perhaps the critical success factor. The trend towards the continuous advancement of the use of POCT and the great potential of its contributions reinforce the need to implement quality management tools, including performance indicators, to ensure their results. This review presents some advantages and disadvantages concerning POCT and the real need to use it. A worldwide call for the availability of easy-to-use health technologies that are increasingly closer to the final user is one of the main reasons for this focus.

Healthy individuals carrying the PCSK9 p.R46L variant and familial hypercholesterolemia patients carrying PCSK9 p.D374Y exhibit lower plasma concentrations of PCSK9.

BACKGROUND: We measured plasma PCSK9 concentrations in healthy men with a PCSK9 (proprotein convertase subtilisin/kexin type 9) loss-of-function variant (p.R46L), in statin-treated patients with a clinical diagnosis of familial hypercholesterolemia (FH) and carrying a PCSK9 gain-of-function mutation (p.D374Y), and in statin-treated patients with FH due to different genetic causes. METHODS: PCSK9 was measured with a previously described ELISA. RESULTS: In 81 healthy middle-aged Caucasian men, the PCSK9 concentration was significantly associated with the concentrations of total cholesterol (r = 0.42; P < 0.0001), LDL cholesterol (r = 0.34; P = 0.01), and triglycerides (r = 0.25; P = 0.02). In p.R46L carriers, mean (SD) concentrations of PCSK9 were 15% lower than in RR individuals [65.5 microg/L (21.6 microg/L) vs 77.5 microg/L (18.2 microg/L); P = 0.03]. In patients with the p.D374Y variant (n = 7), the mean PCSK9 concentration was significantly lower than in the combined group of patients with an LDLR (low density lipoprotein receptor) mutation (n = 25), an APOB [apolipoprotein B (including Ag(x) antigen)] variant encoding p.R3527Q (n = 6), or no detectable mutation (n = 14) [96.4 microg/L (42.5 microg/L) vs 151.6 microg/L (69.6 microg/L); P = 0.02]. Two of the 14 patients with no mutation had PCSK9 concentrations below the mean for p.D374Y carriers; sequencing of the PCSK9 gene and promoter revealed no mutations. Among 409 FH patients, we identified 6 carriers of the promoter variant -287G>A (1.5%), a frequency similar to that (1.0%) previously reported for 2772 healthy men in the UK. In neither group was the -287G>A variant associated with differences in lipid traits. CONCLUSIONS: The loss-of-function p.R46L variant is associated with the expected lower concentrations of circulating PCSK9; the gain-of-function p.D374Y mutation is also associated with lower concentrations, presumably because of the higher affinity of this variant for the LDL receptor and its more rapid clearance. In treated FH patients, a low plasma PCSK9 concentration does not appear to be a useful screening tool for identifying novel PCSK9 mutations.

The PCSK9 gene R46L variant is associated with lower plasma lipid levels and cardiovascular risk in healthy U.K. men.

In the present study, we have determined the relative frequency of the R46L, I474V and E670G variants in the PCSK9 (protein convertase subtilisin/kexin type 9) gene and its association with plasma lipid levels and CHD (coronary heart disease) in healthy U.K. men and patients with clinically defined definite FH (familial hypercholesterolaemia). Genotypes were determined using PCR and restriction enzyme digestion in 2444 healthy middle-aged (50-61 years) men from the prospective NPHSII (Second Northwick Park Heart Study), with 275 CHD events (15 years of follow-up), and in 597 U.K. FH patients from the Simon Broome Register. In the NPHSII healthy men, the R46L genotype distribution was in Hardy-Weinberg equilibrium and the frequency of 46L was 0.010 [95% CI (confidence interval), 0.007-0.013], with one man homozygous for the 46L allele. There was significant association of the 46L allele with lower mean (S.D.) total cholesterol [5.74 (1.01) mmol/l for RR compared with 5.26+/-1.03 mmol/l for RL; P=0.001], apolipoprotein B [0.87 (0.24) g/l for RR compared with 0.75 (0.26) g/l for RL; P<0.0001] and low-density lipoprotein cholesterol [4.01 (0.95) mmol/l for RR compared with 3.62 (0.97) mmol/l for RL; P=0.02]) levels, after adjustment for age, general medical practice, smoking, body mass index and systolic blood pressure. As expected, 46L carriers had a low risk of definite or possible CHD [hazard ratio, 0.46 (95% CI, 0.11-1.84)], but this was not statistically significant (P=0.27). Two other common PCSK9 variants I474V [V allele frequency, 0.179 (95% CI, 0.17-0.19)] and E670G [G allele frequency, 0.034 (CI, 0.03-0.04)] were not associated with any significant effects on lipid levels or CHD risk. In FH patients, the frequency of 46L was 0.003 (95% CI, 0.00-0.01), which was significantly lower (P=0.037) than the healthy subjects. In the four FH patients carrying 46L, mean untreated total cholesterol levels were not different (P=0.91) in carriers and non-carriers (median, 10.3 mmol/l compared with 10.2 mmol/l respectively, after adjustment for age, gender and mutation type). In conclusion, the PCSK9 46L allele is more frequent in healthy U.K. men than in FH patients and is strongly associated with a protective plasma lipid profile risk for CHD. Its low frequency (approx. 2% carriers) means that it does not make a major contribution to determining population CHD risk in the U.K.

Clinical correlation between a point-of-care testing system and laboratory automation for lipid profile.

BACKGROUND: We evaluated the clinical correlation between the CardioChek PA analyzer and a clinical laboratory reference method to use for screening program purposes. METHODS: Fasting blood samples were collected on 516 patients (age 20-85 y). One venous sample was collected using a serum tube for the evaluation on a COBAS reference analyzer. A second venous sample was collected in a lithium heparin tube and was evaluated on the CardioChek PA analyzer (CCPA venous). A fingerstick sample (CCPA fingerstick) was evaluated only on the CardioChek PA analyzer. Linear regression analyses were performed for each measured analyte, total cholesterol, HDL-cholesterol and triglycerides. RESULTS: The correlation between the CCPA fingerstick and CCPA venous was extremely high for HDL-C and triglycerides, and good for total cholesterol. Our results demonstrated a good clinical agreement for total cholesterol, HDL-C and triglycerides between 97.7% and 94.6% in the comparison of the CCPA to the reference analyzer. CONCLUSIONS: We identified the pre-analytic phase as an important step to guarantee the quality of results and indicate that the CardioChek PA is a reliable lipid point-of-care testing system that can be used for the application of clinical screening anywhere.

Assessing the adherence to and the therapeutic effectiveness of hypolipidemic agents in a population of patients in Brazil: a retrospective cohort study.

OBJECTIVE: to evaluate the relation between patient adherence and therapeutic effectiveness of hypolipidemic agents in clinical practice. METHODS: A retrospective cohort study of 417 patients using hypolipidemic drugs (simvastatin, atorvastatin) between 2003 and 2010 was performed. The population studied consists of patients assisted by the Public Health Service in the far-west region of the State of Santa Catarina, Brazil. The Medication Possession Ratio obtained from pharmacy refill data was used to measure patient adherence. Therapeutic effectiveness was evaluated based on the difference obtained in the serum levels of total cholesterol, LDL-cholesterol, HDL-cholesterol and triglycerides, before and after taking the drug, in an average time of 8.3 months. RESULTS: Following the treatment with hypolipidemic agents, it has been observed a reduction of 14.3% for total cholesterol, 19.6% for LDL-cholesterol, and 14.4% for triglycerides. HDL-cholesterol increased by an 8.0% average. The major changes in lipid profile were promoted by atorvastatin 20 mg daily. The medication adherence rate decreased over the monitoring period. Adherence rates below 60% were associated with therapeutic failure, while rates equal to 80% or higher were associated with the best response to the lipid-lowering drugs. CONCLUSION: Adherence to hypolipidemic agents is higher at the beginning of the treatment, but it decreases over time, affecting the achievement of therapeutic goals.

New ways to deal with known preanalytical issues: use of transilluminator instead of tourniquet for easing vein access and eliminating stasis on clinical biochemistry.

INTRODUCTION: Tourniquet due venous stasis can alter both concentration and/or activity of several blood analytes, but is rarely regarded as an issue of laboratory variability. To overcome the problem transillumination devices (TD) have been proposed for a stasis-free phlebotomy. In this paper the use of a TD in place of tourniquet during blood collection has been evaluated. MATERIALS AND METHODS: Blood was collected from 250 volunteers divided in five homogenous groups of tourniquet times (G1: 30 sec, G2: 60 sec, G3: 90 sec, G4:120 sec, G5: 180 sec) and compared to blood obtained using TD. All samples were analyzed for glucose (GLU), total protein (TP), albumin (ALB), triglycerides (TRIG), potassium (K), sodium (NA), phosphate (PHOS), calcium (CA), alkaline phosphatase (ALKP) and magnesium (MG). RESULTS: In respect of TD, G1 did not show statistically significant increases in all clinical chemistry tests; G2 showed increases for GLU, TP, ALB, TRIG, K, CA, MG and ALKP. G3 and G4, showed no significant increase only for PHOS. G5 showed significant increases in all the tests evaluated. Moreover, clinically significant variations were observed for TP, ALB, K and CA in G2 to G5; for NA in G3 to G5; for MG in G4 and G5; for GLU, TRIG, ALKP only in G5. CONCLUSIONS: These results support the application of TD in blood collection for routine clinical chemistry laboratory tests, suggesting its use should be more diffused.

Clinical correlation between the Point-of-care testing method and the traditional clinical laboratory diagnosis in the measure of the lipid profile in patients seen in medical offices / Correlação clínica entre a metodologia Point-of-care testing e o diagnóstico laboratorial tradicional na dosagem do perfil lipídico de pacientes atendidos em consultórios médicos

ABSTRACT Introduction: Elevated plasma levels of lipids are considered the main modifiable risk factor for the cardiovascular disease. The Point-of-care testing (POCT) method provides quick results and allows anticipating diagnosis and treatment. Objective: To compare the lipid profile results obtained from both POCT and the traditional clinical laboratory. Methods: Fasting blood samples were collected from 111 patients who sought, for any reason, the private medical offices participating on this study. Capillary whole blood samples were analyzed in CardioChek® PA (CCPA) equipment, and the serum samples were analyzed in clinical laboratories (LAB) that have internal and external quality control, with certification. The mean values of each variable of the lipid profile obtained by CCPA and LAB were calculated. Linear regression was used to determine the existence of correlation between the two methods. Results: We observed a positive correlation between the values obtained by CCPA and LAB for all variables of the lipid profile. Our data, extracted from the routine use of CCPA in private medical offices, supports a substantial contribution of the POCT methodology in the detection of the main cardiovascular risk factors. Conclusion: The POCT CardioChek® PA Analyzer is an easy-to-operate tool, with adequate analytical performance and a good correlation with the results of the conventional laboratory method, therefore, considered a reliable method.

RESUMO Introdução: Níveis plasmáticos elevados de lipídios são considerados como principal fator de risco modificável para a doença cardiovascular. A metodologia Point-of-care testing (POCT) fornece resultados rápidos e permite antecipar o diagnóstico e o tratamento. Objetivo: Comparar os resultados do perfil lipídico obtidos pelo POCT e pelo laboratório convencional. Métodos: Foram coletadas amostras em jejum de 111 pacientes que procuraram, por qualquer motivo, os consultórios médicos privados participantes desta pesquisa. As amostras de sangue total da punção capilar foram analisadas no equipamento CardioChek® PA (CCPA) e as de sangue da punção venosa, coletadas e analisadas em laboratórios clínicos (LAB) que apresentam controle de qualidade interno e externo, com certificação. Os valores médios de cada variável do perfil lipídico obtidos pelo CCPA e pelo LAB foram calculados. Regressão linear foi utilizada para determinar a existência de correlação entre os dois métodos. Resultados: Observamos correlação positiva entre os valores obtidos pelo CCPA e pelo LAB para todas as variáveis do perfil lipídico. Nossos dados, extraídos do uso rotineiro do CCPA em consultórios médicos privados, suporta substancial contribuição da metodologia POCT na detecção dos principais fatores de risco cardiovascular. Conclusão: O analisador POCT CCPA configura-se como uma ferramenta de fácil operação, com performance analítica adequada e excelente correlação com os resultados do método laboratorial convencional, portanto confiáveis.

Suitability of a transport box for blood sample shipment over a long period.

BACKGROUND: Safety transport boxes are increasingly used to ship laboratory specimens but there is little information on their capacity to maintain suitable transportation temperatures. MATERIALS AND METHODS: Inner temperature was assessed using a commercially available transport box during an 8-h transportation period in the heat. RESULTS: Temperature stability was unsatisfactory during approximately 64% of the transportation time (i.e., from 125 to 450 min). CONCLUSIONS: Transport boxes might be unsuitable for shipping specimens over long periods.

Butyrylcholinesterase and diabetes mellitus in the CHE2 C5- and CHE2 C5+ phenotypes.

OBJECTIVE: To investigate the relationship between butyrylcholinesterase (BChE) activities (total and band specific) and diabetes mellitus. SUBJECTS AND METHODS: BChE activities (BChEA, AC(4/5), AC(OF) and RC(5)) were analyzed in 101 type 1 (DM1) and in 145 type 2 (DM2) diabetic patients, in relation to phenotype, weight and incidence of metabolic syndrome (MS) in these patients. The C(4/5) and C(5) complex were separated from other molecular forms (C(OF)) using an acid agar gel. RESULTS: The BChE activity (BChEA) and the absolute activities of C(4/5) (AC(4/5)) and C(OF) (AC(OF)) showed a high positive correlation coefficient to weight in the CHE2 C5- group, while the relative activity of C5 complex (RC5) showed a negative correlation to weight. CONCLUSIONS: The present study suggests that the positive correlation of the BChE activities to diabetes mellitus and to insulin resistance may depend on the CHE2 locus variability. High values of BChE activities were associated with insulin resistance only in CHE2 C5- diabetic patients, while in CHE2 C5+ diabetic patients, the presence of C(5) complex, especially in a relatively high proportion, leads to less fat storage and better protection against metabolic syndrome.

Prospective double-blind crossover study of Camellia sinensis (green tea) in dyslipidemias.

BACKGROUND: Epidemiological studies have established an association between dyslipidemias and atherosclerosis. Nutritional therapy is a key point in the prevention strategy for individuals who present with risk factors for atherosclerotic disease. OBJECTIVES: To investigate the effects of green tea (Camellia sinensis) in patients with dyslipidemias. METHODS: The study included 33 patients aged between 21 and 71 years who had a low-fat diet (25-35% of total calories and 200 mg of cholesterol per day). They were randomized for two sequential treatments: 250-mg capsules of green tea dry extract or placebo for a total period of 16 weeks; each patient received green tea (Camellia sinensis) for eight weeks and placebo for another eight weeks. RESULTS: Baseline lipid values (mg/dL) were: HDL-cholesterol 60.7 +/- 7.3; total cholesterol 255 +/- 30.9; LDL-cholesterol 158.8 +/- 29.0; triglycerides 169.0 +/- 61.3 and Apo-B 120.2 +/- 18.9. Mean lipid variations induced by the use of green tea (Camellia sinensis) showed a 3.9% reduction (p = 0.006) in total cholesterol concentrations and a 4.5% reduction (p = 0.026) in LDL-cholesterol. The intake of green tea did not significantly influence HDL-cholesterol, triglyceride, and Apo-B levels. Non-significant results were found in the assessment of blood lipids (total cholesterol and LDL-cholesterol) with the use of placebo. CONCLUSION: A beneficial effect of green tea (Camellia sinensis) was demonstrated, with a significant reduction of total cholesterol and LDL-cholesterol levels in eight weeks, in the patients studied.

Association of lipoprotein lipase D9N polymorphism with myocardial infarction in type 2 diabetes: the genetics, outcomes, and lipids in type 2 diabetes (GOLD) study.

The association of polymorphisms affecting lipid metabolism with the risk of myocardial infarction (MI) in type 2 diabetes mellitus was investigated. The Genetics, Outcomes and Lipids in type 2 Diabetes (GOLD) Study is a prospective, multicenter study, conducted on 990 patients presenting diabetes and MI (n=386), or diabetes without previous manifestation of stroke, peripheral or coronary arterial disease (n=604), recruited from 27 institutions in Brazil. APO A1 (A/G -75 and C/T +83) and APO C3 (C/G 3'UTR) non-coding sequences, CETP (Taq 1B), LPL (D9N), APO E (epsilon2, epsilon3, epsilon4,), PON-1 (Q192R), and two LCAT variants Arg(147)-->Trp and Tyr(171)-->Stop were tested by PCR-RFLP. There was a higher prevalence of LPL DN genotype (19% vs.12%, p=0.03) and a higher frequency of the N allele (11% vs. 7%) among subjects with MI when compared to controls, with an odds ratio of MI for carriers of 9N allele of 2.46 (95% CI=1.79-3.39, p<0.0001). This association was present in men and women, in non-smokers and in hypertensive patients. A logistic regression model including gender, duration of diabetes, systolic blood pressure, HDL-C, left ventricle hypertrophy and D9N polymorphism showed that the latter still remained significantly associated with MI (OR=1.50, 95% CI=1.02-2.25, p=0.049). These findings suggest that D9N polymorphism can be a useful risk marker for myocardial infarction and that further potential candidate genes should be screened for exploratory analysis and for future therapeutic intervention in diabetes.