External quality assessment practices in medical laboratories: an IFCC global survey of member societies

OBJECTIVES

Clinical laboratory results are required for critical medical decisions, underscoring the importance of quality results. As part of total quality management, external quality assessment (EQA) is a vital component to ensure laboratory accuracy. The goal of this survey was to evaluate the current status of global laboratory quality systems and assess the need for implementation, expansion, or harmonization of EQA programs (EQAP) for Clinical Chemistry and Laboratory Medicine.

METHODS

The International Federation of Clinical Chemistry and Laboratory Medicine (IFCC) Task Force on Global Laboratory Quality (TF-GLQ) conducted a survey of IFCC full and affiliate members (n=110) on laboratory quality practice. A total of 41 (37.3%) countries representing all IFCC regions except North America provided responses about EQA availability and practices.

RESULTS

All 41 countries perform EQA, 38 reported that their laboratories had EQA policies and procedures, and 39 further act/evaluate unacceptable EQA results. 39 countries indicated they have international and/or national EQAP and 30 use alternative performance assessments. EQA frequency varied among countries. Generally, an EQAP provided the EQA materials (40/41) with four countries indicating that they did not have an EQAP in their country.

CONCLUSIONS

Globally, most laboratories participate in an EQAP and have defined quality procedures for EQA. There remain gaps in EQA material availability and implementation of EQA as a part of a total laboratory quality system. This survey highlights the need for education, training, and harmonization and will guide efforts of the IFCC TF-GLQ in identifying areas for enhancing global laboratory quality practices.

Insights on antioxidant therapeutic strategies in type 2 diabetes mellitus: A narrative review of randomized control trials

BACKGROUND

Type 2 diabetes mellitus (T2DM) is a metabolic disease of impaired glucose utilization. Imbalance in generation and elimination of free radicals generate oxidative stress which modulates glucose metabolism and insulin regulation, resulting in the occurrence and progression of diabetes and associated complications. Antioxidant supplements in T2DM can be seen as a potential preventive and effective therapeutic strategy.

AIM

To compare randomized controlled trials (RCTs) in which antioxidants have been shown to have a therapeutic effect in T2DM patients.

METHODS

We systematically searched the electronic database PubMed by keywords. RCTs evaluating the effect of antioxidant therapy on glycaemic control as well as oxidant and antioxidant status as primary outcomes were included. The outcomes considered were: A reduction in blood glucose; changes in oxidative stress and antioxidant markers. Full-length papers of the shortlisted articles were assessed for the eligibility criteria and 17 RCTs were included.

RESULTS

The administration of fixed-dose antioxidants significantly reduces fasting blood sugar and glycated hemoglobin and is associated with decreased malondialdehyde, advanced oxidation protein products, and increased total antioxidant capacity.

CONCLUSION

Antioxidant supplements can be a beneficial approach for the treatment of T2DM.

Significant Association of Antiepileptic Drug Polytherapy with Decreased FT4 Levels in Epileptic Patients

Epileptic patients have to continue anti-epileptic drugs (AED) over a long period of time which can have deleterious effects on the endocrine system including the thyroid hormones with rare check. Risk factors for the development of thyroid dysfunction are still unclear. Therefore the aim of study was to evaluate thyroid functions in epileptic patients receiving anti-epileptic drugs (AED) as monotherapy and polytherapy and to determine potential risk of low thyroid function in epileptic patients receiving treatment. This cross-sectional study included 100 epilepsy patients more than 12 years of age. Serum levels of free thyroxin (FT4), free triiodothyronine (FT3), and thyroid stimulating hormone (TSH) were evaluated in all subjects in addition to serum AED levels. TSH levels were found to be significantly higher in the polytherapy subgroup (p < 0.05) in comparison to the monotherapy group. 44% of the patients in the VPA monotherapy group had raised TSH levels and 41.2% of the patients on CBZ had low FT4. A significant negative correlation was observed between CBZ and FT4 (p < 0.05). Female sex and old age were additional risk factors detected for deranged thyroid function. Female patients with epilepsy, an older age and AED polytherapy were found to be associated with a higher risk of thyroid dysfunction. Thus, Thyroid function in these patients should be monitored closely. In conclusion, we observed significant changes in thyroid hormone levels in patients receiving antiepileptic treatment in both monotherapy and polytherapy. Elevated CBZ levels were significantly associated with decreased FT4 levels.

Point of Care Testing of Serum Electrolytes and Lactate in Sick Children

OBJECTIVE

To evaluate the electrolyte and lactate abnormalities in hospitalized children using a point of care testing (POCT) device and assess the agreement on the electrolyte abnormalities between POCT and central laboratory analyzer with venous blood.

METHODS

This observational study recruited hospitalized children aged 1 month to 12 years within two hours of admission. A paired venous sample and heparinized blood sample were drawn and analyzed by the central laboratory and POCT device (Stat Profile Prime Plus-Nova Biomedical, Waltham, MA, USA) for sodium and potassium. Lactate was measured on the POCT device only. The clinical and outcome parameters of children with electrolyte abnormalities or elevated lactate (>2mmol/L), and the agreement between POCT values and central laboratory values were assessed.

RESULTS

A total of 158 children with median (IQR) age 11 (6-10) months and PRISM score 5 (2-9) were enrolled. The proportion of children with abnormal sodium and potassium levels, and acidosis on POCT were 87 (55.1%), 47 (29.7%) and 73 (46.2%), respectively. The interclass coefficient between POCT and laboratory values of sodium and potassium values was 0.74 and 0.71 respectively; P<0.001. Children with hyperlactatemia (81, 51.3%) had higher odds of shock (OR 4.58, 95% CI: 1.6-12.9), mechanical ventilation (OR 2.7, 95% CI 1.1-6.6, P=0.02) and death (OR 3.1, 95% CI 1.3-7.5 P=0.01) compared to those with normal lactate.

CONCLUSION

POCT can be used as an adjunct for rapid assessment of biochemical parameters in sick children. Lactate measured by POCT was a good prognostic indicator.

Evaluation of Thyroid Hormone Status in Children with Steroid Resistant Nephrotic Syndrome: A North India Study

BACKGROUND

Steroid resistant nephrotic syndrome (SRNS) has a chronic and progressive course. Limited data is available evaluating thyroid function parameters in SRNS patients. The aim of the present study was to evaluate the thyroid hormone status in Indian children with SRNS.

MATERIALS & METHODS

The present cross-sectional study included 50 patients aged 1-12 years with SRNS. As per Up:Uc ratio divided into three groups: Group A) 16 patients of SRNS in complete remission Group B) 14 patients of SRNS in partial remission Group C) 20 patients of SRNS in relapse. Serum levels of FT3, FT4 and TSH were measured in all.

RESULTS

20% of the children (n=10) with SRNS had hypothyroidism (7 subclinical hypothyroidism and 3 with overt hypothyroidism). One child was found to be in complete remission, 4 in partial remission and 5 in relapse phase. TSH levels were found to be significantly elevated in children with relapse (p = 0.042). Serum albumin showed a significant negative correlation with Up:Uc ratio ( p < 0.0001) whereas total cholesterol showed a significant positive correlation (p < 0.001). On correlating TSH level with Up:Uc ratio a significant positive correlation ( p = 0.0098) was observed.

CONCLUSION

Subclinical hypothyroidism in SRNS is temporary and may improve with remission. However prolonged proteinuria in SRNS patients may lead to progressive damage of the renal tubules and impaired absorption of Low Molecular Weight (LMW) proteins which may further exhaust the thyroid reserve and lead to overt hypothyroidism. Therefore thyroid examination should be routinely advocated in these children.

Oxidative stress and antioxidants in hypertension-a current review

Free radicals or reactive oxygen species (ROS) are generated by oxygen metabolism which is balanced by the rate of oxidant formation and the rate of oxidant elimination. Oxidative stress is a result of imbalance between the generation of reactive oxygen species (ROS) and the antioxidant defence systems. Hypertension is one of the major risk factors for cardiovascular diseases and is considered as a leading cause of mortality and morbidity. These diseases affect more than 600 million people and it has been estimated that 29% of the world population will be suffering from hypertension by 2025. It has been indicated by experimental evidence that reactive oxygen species (ROS) play an important role in the pathophysiology of hypertension. The vasculature is a rich source of NADPH oxidase which produces most of the reactive oxygen species and plays an important role in renal dysfunction and vascular damage. Recent studies indicate that increased oxidative stress is the important mediator of endothelial injury in the pathology of hypertension associated to increased production of pro oxidants such as superoxideanion hydrogen peroxide, reduced nitric oxide synthesis and decreased bioavailability of antioxidants. Oxidative stress is found to be associated with endothelial dysfunction, inflammation, hypertrophy, apoptosis, cell migration, fibrosis, and angiogenesis in relation to vascular remodelling of hypertension. Results in humans are still less conclusive inspite of data available that involve oxidative stress as a causative factor of essential hypertension. The aim of this review is to present a novel focus on the role of oxidative stress in the pathophysiology of hypertension and recent biomarkers which are found to be associated with reactive oxygen species and the role of antioxidants as therapy of hypertension.

Vitamin D deficiency among pediatric osteoarticular tuberculosis patients

OBJECTIVES

We prospectively investigated serum 25 hydroxy vitamin D concentrations in children suffering from osteoarticular tuberculosis. The age or sex correlation to vitamin D levels in affected subjects was also calculated.

METHODS

Twenty five untreated children with osteoarticular tuberculosis were taken as cases along with equal number of age and sex matched 'healthy' controls. The following laboratory references for defining the vitamin D status were used (<30 nmol/L = deficiency; 30-75 nmol/L = insufficiency; > 75 nmol/L = sufficiency). The cases were further grouped based on gender differences and age (<5 or >5 years).

RESULTS

Out of 25 cases, there were 14 (56%) with deficiency of vitamin D. In 'apparently' healthy subjects, all 25 controls (100%) had hypovitaminosis D. The osteoarticular tuberculosis patients had significant lower levels of vitamin D when compared with their healthy peers irrespective of gender or age differences.

CONCLUSIONS

The osteoarticular tuberculosis cases had low serum vitamin D levels compared to healthy controls. The low vitamin D levels were persistent irrespective of gender and age in osteoarticular tuberculosis children. There was widespread vitamin D insufficiency in apparently healthy controls.

Renal function in diabetic nephropathy

Diabetic nephropathy is the kidney disease that occurs as a result of diabetes. Cardiovascular and renal complications share common risk factors such as blood pressure, blood lipids, and glycemic control. Thus, chronic kidney disease may predict cardiovascular disease in the general population. The impact of diabetes on renal impairment changes with increasing age. Serum markers of glomerular filtration rate and microalbuminuria identify renal impairment in different segments of the diabetic population, indicating that serum markers as well as microalbuminuria tests should be used in screening for nephropathy in diabetic older people. The American Diabetes Association and the National Institutes of Health recommend Estimated glomerular filtration rate (eGFR) calculated from serum creatinine at least once a year in all people with diabetes for detection of kidney dysfunction. eGFR remains an independent and significant predictor after adjustment for conventional risk factors including age, sex, duration of diabetes, smoking, obesity, blood pressure, and glycemic and lipid control, as well as presence of diabetic retinopathy. Cystatin-C (Cys C) may in future be the preferred marker of diabetic nephropathy due differences in measurements of serum creatinine by various methods. The appropriate reference limit for Cys C in geriatric clinical practice must be defined by further research. Various studies have shown the importance of measurement of albuminuria, eGFR, serum creatinine and hemoglobin level to further enhance the prediction of end stage renal disease.