Bhawna Singh

Evaluation of errors in a clinical laboratory: a one-year experience

Abstract Background: Efficient laboratory service is the cornerstone of modern health care systems. Scientific innovations have contributed to substantial improvements in the field of laboratory science, but errors still prevail. These errors are classified as preanalytical, analytical and postanalytical, depending upon the time of presentation. Methods: The data for 67,438 routine venous blood specimens were scrutinized, and errors were documented over the period of 1 year in the clinical biochemistry laboratory of Govind Ballabh Pant Hospital in Delhi, India. Results: Preanalytical errors were most common, with a frequency of 77.1% followed by postanalytical 15% and analytical 7.9%, respectively. Conclusions: Our study illustrates the importance of proper venipuncture procedures, analytical expertise and correct transcription of numerical data for precise and accurate reporting of results to clinicians. There is an urgent need for close inter-departmental cooperation to meet the goal of ensuring patient well being. Clin Chem Lab Med 2010;48:63–6.

Hepcidin: A novel peptide hormone regulating iron metabolism

BACKGROUND Hepcidin is a low-molecular weight hepatic peptide regulating iron homeostasis. Hepcidin inhibits the cellular efflux of iron by binding to, and inducing the internalization and degradation of, ferroportin, the exclusive iron exporter in iron-transporting cells. It has been recently recognized as a main hormone behind anemia of chronic disease. METHOD A comprehensive literature search was conducted from the websites of Pubmed Central, the US National Library of Medicines digital archive of life sciences literature (http://www.pubmedcentral.nih.gov/) and the National Library of Medicine (http://www.ncbl.nlm.nih.gov). The data was also assessed from journals and books that published relevant articles in this field. RESULT Hepcidin regulates iron uptake constantly on a daily basis, to maintain sufficient iron stores for erythropoiesis. Hepcidin, by its iron regulatory action on iron metabolism may be expected to have an important role in immune regulation, inflammatory diseases and malignancies. Hepcidin is the underlying cause of anemia in these clinical settings. CONCLUSION Hepcidin analysis may prove to be a novel tool for differential diagnosis and monitoring of disorders of iron metabolism, and establishment of therapeutic measures in various disease conditions like hereditary hemochromatosis, anemia associated with chronic kidney disease, rheumatoid arthritis and cancers.

NAD(P)H oxidases in coronary artery disease.

Reactive oxygen species (ROS), especially superoxide anion and hydrogen peroxide, are important signaling molecules in cardiovascular cells. ROS participate in growth, apoptosis, and migration of vascular smooth muscle cells, in the modulation of endothelial function, including endothelium-dependent relaxation and expression of proinflammatory phenotype, and in the modification of the extracellular matrix. They have also been linked to hypertension and to pathological states associated with uncontrolled growth and inflammation leading to coronary artery disease (CAD). The NAD(P)H oxidase is a multisubunit enzyme that catalyzes the reduction of molecular oxygen to form superoxide (O2*-). Although first described in phagocytes, NAD(P)H oxidases have also been demonstrated as major sources of superoxide in vascular cells and myocytes. Enhanced superoxide production increases nitric oxide inactivation and leads to an accumulation of peroxynitrites and hydrogen peroxide. An entire new family of NAD(P) H oxidase (Nox) homologs has emerged, which vary widely in cell and tissue distribution as well as in function and regulation. Recent and ongoing research tends to highlight the biochemical characters, activation paradigms, structure, and function of this enzyme. In this review, we provide a brief overview of structural features of NAD(P)H oxidases and then discuss their role in pathophysiology of CAD.

Association between insulin resistance and hypothyroidism in females attending a tertiary care hospital

The effect of thyroid status on insulin sensitivity is of great interest but despite various studies there is conflicting data on this subject. The study group comprised of 25 female subjects each with subclinical hypothyroidism, overt hypothyroidism and euthyroid controls. Serum samples of all the patients were assayed for thyroid profile, Insulin and lipid profile. Homeostasis model of assessment (HOMA-IR) was employed to assess the level of insulin resistance. Patients with hypothyroidism demonstrated insulin resistance and dyslipidemia as observed by the higher HOMA-IR and cholesterol and triglyceride levels respectively as compared to the controls. A significantly positive correlation between TSH and HOMA-IR level was also observed in the hypothyroidism group. Thyroid dysfunction leads to alterations in glucose and lipid metabolism which is an important risk factor for cardiovascular diseases. The dyslipidemia and insulin resistance should be managed aggressively to reduce the impending risk.

Association of macrovascular complications of type 2 diabetes mellitus with serum magnesium levels.

BACKGROUND Diabetes mellitus and its complications are a significant cause of morbidity and mortality worldwide. Micronutrients have been evaluated as potential preventive and therapeutic measures in diabetes. The present study evaluated serum magnesium levels in diabetic patients-uncomplicated and those with macrovascular complications. METHOD This study was done on 150 subjects (60 normal, healthy controls and 90 diabetics). The 90 diabetic patients were selected in the following categories-30 patients without complications (Study Group I), 30 diabetic patients with coronary artery disease (Study Group II) and 30 diabetic patients with peripheral vascular disease (Study Group III). Plasma glucose, glycated hemoglobin and serum magnesium levels were estimated in all the patients. RESULTS Fasting plasma glucose and glycated hemoglobin levels were significantly higher in all the 3 study groups as compared to the controls, however, serum magnesium levels were significantly lower (p<0.05). In diabetic patients with coronary atherosclerosis or peripheral vascular disease, a significant negative correlation was observed between serum magnesium and fasting plasma glucose and glycated hemoglobin indicating the role of hypomagnesemia in diabetic complications. CONCLUSION Dietary supplementation with magnesium in addition to classical therapies for diabetes may help in prevention of diabetic complications.

Evaluating Laboratory Performance With Quality Indicators

Objective: Quality indicators in the clinical laboratory provide a useful tool for continuous improvement of laboratory services. The goal of this study was to design and review quality indicators from time to time in an effort to improve the performance of the laboratory. Methods: The study included an evaluation of different quality indicators collected from the biochemistry laboratory of a tertiary care hospital in New Delhi over a period of 1 year. A total of 84250 samples were processed, and the quality indicators monitored were classified into the following 3 categories: preanalytical, analytical, and post-analytical. Results: Hemolysis (0.7%) was the most common anomaly observed during the assessment of pre-analytical indicators followed by improper samples for coagulation profile (0.34%). In the analytical phase, the frequency for fibrin clots was 1.2%. Conclusion: Working constantly to improve the outcome of these indicators by taking corrective measures over a period of time will definitely help to improve the quality of laboratory services and patient health care. * IOM : Institute of Medicine GBPH : Govind Ballabh Pant Hospital OPD : Out Patient Department QC : Quality Control TAT : turnaround time LIS : laboratory information system

Modification of Jaffe’s kinetic method decreases bilirubin interference: A preliminary report

The negative interference of bilirubin on serum creatinine determined by the kinetic alkaline picrate (Jaffe) reaction is the unresolved problem. Though high performance liquid chromatography and gas chromatography with mass spectroscopy have been proposed to be gold standards for creatinine estimation but they are not readily available in most of the clinical chemistry laboratories due to economic and technical constraints. Most of the present day analyzers use Jaffe’s kinetic method without deproteinization. Though enzymatic methods are now routinely used as most accurate method but they are not acceptable due to cost constraints. Hence this study was planned to find out a possible solution to the problem of bilirubin interference by a minor modification in the commonly used Jaffe method so that it is amenable for use on the currently used analyzers.

Potential Biochemical Markers for Preterm Labor: A Pilot Study in North India

Preterm delivery is a major contributor for neonatal mortality. Intensive research is underway to establish a reliable biomarker that can ascertain the risk of preterm delivery in pregnant women. The aim of our study was to evaluate the role of various biochemical parameters as potential biomarker for risk assessment for preterm labor. Forty women presenting with preterm labor and 40 women who delivered at term were included in the study. Parameters that were evaluated include corticotrophin (ACTH), prolactin, thyroid stimulating hormone (TSH), ferritin and Alkaline Phosphatase (ALP). Serum ACTH, ferritin, ALP and Ferritin/Iron ratio were significantly higher in the subjects who delivered prematurely as compared to the controls. Comparison of sensitivity, specificity, likelihood ratio, positive and negative predictive values for different cut offs for ACTH, ferritin, ALP and ferritin/iron ratio was carried out. Ferritin emerged as the best marker with area under curve of 0.96 as compared to 0.88 for ACTH, 0.825 for ALP and 0.735 for ferritin/iron ratio. Our study establishes the superiority of ferritin as a predictive biomarker for preterm labor as compared to the rest of the parameters evaluated.

Acute presentation of dizziness in vitamin B12 deficient old patient of cardiac disease: A case report

BACKGROUND Neuropsychiatric and hematological manifestations of vitamin B12 deficiency are well known. The present report highlights the biochemical basis for the impaired synthesis of DNA and neurological disorders associated with vitamin B12 deficiency. METHODS We present a case of an old patient who developed acute ataxia, dizziness and imbalance 2 days after pacemaker implantation in a cardiac care unit. RESULTS On evaluation, the patient was found to have low vitamin B12 levels (121 pmol/l) with raised plasma homocysteine levels (28 μmol/l) and methylmalonic acid levels (17 μmol/l). Neurological examination revealed signs and symptoms of peripheral neuropathy. CT scan of the brain was found to be normal. The usual hematological presentation was absent in this case. The patient responded dramatically to parenteral vitamin B12 supplementation. CONCLUSION Though frequent, the vitamin B12 deficiency often goes unnoticed in elderly population. So, with this report we emphasize that deficiency of serum vitamin B12 levels should be suspected and evaluated in elderly patients presenting with neuropsychiatric symptoms.

Role of surrogate markers in assessment of insulin resistance in females with thyroid disorders

INTRODUCTION Thyroid status is known to affect insulin sensitivity although conflicting data have been reported regarding hypothyroid and hyperthyroid states. Assessment of insulin resistance is difficult, therefore we compared homeostasis model assessment (HOMA), glucose to insulin (G:I) ratio, glucose to C-peptide (G:C) ratio and ferritin of hypothyroid and hyperthyroid subjects with euthyroid, euglycemic subjects. METHODS The study group comprised of 40 hypothyroid, 25 hyperthyroid female subjects and 40 euthyroid controls. Serum samples of all the patients were assayed for thyroid profile, glucose, Insulin, C-peptide and ferritin. Homeostasis model of assessment (HOMA-IR), (G:I), (G:C) and ferritin were employed as surrogate measures to assess the level of insulin resistance. The area under the curves for the surrogate markers was determined from the receiver operating characteristics (ROC) curves for the hypothyroid and hyperthyroid patients. RESULTS Patients with hypothyroidism demonstrated insulin resistance as observed by the higher HOMA-IR and G:I ratio as compared to the controls whereas insulin resistance was not detected in the hyperthyroid patients in our study. CONCLUSION Thyroid dysfunction attributes to deranged glucose metabolism. Assessment of the surrogate markers might prove to be beneficial in detecting insulin resistance at the incipient stages and subsequent management.