Introduction: Laboratory personnel (LP) represent a high-risk group of healthcare workers for whom the primary laboratory environment and specific work activities are a major source of potential exposure to health hazards. This study aimed to evaluate the developed matrix and assess risk based on self-assessment. Methods: This multicenter, qualitative, and cross-sectional study was conducted on LP employed in biomedical laboratories. The respondents were divided into groups according to their territorial affiliation. The data collection tool used was a six-area questionnaire distributed online through a network of professional associations. For the risk assessment, a matrix was developed with scores ranging from 0 to 650, dividing the risk level into four categories. Descriptive and inferential statistical methods were used for the statistical analysis. Results: The developed model combined the classification of risk and risk factors with a certainty of p < 0.001. The regression analysis showed that working conditions had the greatest influence on overall risk, followed by physical, biological, and physical hazards. Of the 640 respondents, the medium risk category was the highest in European Union (EU) countries (81.2%). Comparing the values in the high-risk category between the Bosnians and Herzegovinians (BiH) group and the Republic of Serbia, Republic of Northern Macedonia, and Montenegro (SCM) group with the EU group, a doubling (16.6%: 36.7%) and tripling (16.6%: 52.1%) of the proportion was found, respectively (p < 0.001). Overall, 1.7% of the LPs from BiH fell into the high-risk category. Conclusions: The designed matrix provides a reliable basis for identifying risk predictors in the study population and can serve as a useful tool for conducting risk assessments in biomedical laboratories. The results of the risk assessment indicate significant differences between the studied groups and highlight the need for increased control of BiH workplaces through new regulatory requirements.

BACKGROUND The pre-analytical phase, which includes all preparatory actions to the analytical procedure, is part of the process during which there is the greatest possibility of laboratory errors. This study was conducted to investigate the frequency and types of laboratory errors during work in the clinical laboratory as well as the frequency and types of laboratory errors in the pre-analytical phase of laboratory work. METHODS The retrospective, descriptive study covered the period from 01/01/2016 to 12/31/2016 within which the presence of 5 different indicators of quality of work, i.e., pre-analytical errors, was monitored: improperly drawn blood, coagulated blood sample, hemolyzed blood sample, improperly marked referral for analysis, and insufficient sample for analysis. RESULTS The most common error in the pre-analytical phase of our study was "coagulated sample", followed by: "improperly drawn blood", "improperly marked referral", "insufficient sample for analysis", and "hemolyzed sample". Using the chi-squared test, a statistically significant difference was found in the frequency of occurrence of certain types of indicators in different departments (p < 0.005). CONCLUSIONS Reduction of these errors can be achieved through analyzing and correcting the reasons for them, education, and by joint action of experts and international organizations, continual training of staff as well as to following the adopted guidelines and standards.

BACKGROUND Clinical Chemistry is the backbone of medical treatment, diagnostics, and prevention. The laborato-ries are trying to improve the quality and to reduce diagnostic errors and processing time and safeguard trace-ability of all laboratory procedures to ensure patient safety. Six sigma belongs to statistical quality control and provides a new methodology for measuring and improving process performance in laboratory. METHODS Activities of AST, ALT, CK, LDH, Amy, and γ-GT were determined by standard kinetic methods on a Vitros 5600 biochemistry analyzer. Two daily quality controls (Verifier I and Verifier II) were run over 60 days. Total percent CV was calculated from routine daily QC. Between-instrument bias was also calculated from daily QC. RESULTS The calculated sigma metrics for AST were 6.9 and 3.8; for ALT 9.3 and 5.6; for CK 6.6 and 5.3; LDH 5.2 and 5.2; for γ-GT 4.9 and 2.7; and for amylase 8.7 and 7.1. Analytical performance for AST, ALT, CK, LDH, and Amylase is world class. On the other hand, γ-GT analytical performance is poor. CONCLUSIONS Six Sigma benefits from earlier quality management approaches that creates new challenges for medical laboratories.

Introduction: Diabetes mellitus type 2 has become a global health-care problem of modern society due to a pronounced increase of prevalence to pandemic proportions and vascular complications. At present, glycated hemoglobin (HbA1c) is widely accepted as a measure of glycemic control in established diabetes. The aim of this study was to analyze the lipid profile in serum of patients with diabetes mellitus type 2, and its relationship with HbA1c levels. Methods: The observational cross-sectional study included 60 diabetic patients, 30 men, and 30 women, age 32–94 years. Patients were assigned into two groups based on HbA1c values; Group 1: HbA1c ≤ 7% (good glycemic control) and Group 2: HbA1c > 7% (poor glycemic control). We analyzed the concentration of glucose, HbA1c, and lipid profile including total cholesterol levels, triglycerides (TAG), low-density lipoproteins (LDL), and high-density lipoproteins (HDL). Results: Significantly lower values of glucose concentration, TAG and the ratio TAG/HDLc were obtained in the group of patients with good glycemic control. (p < 0.0005) Patients with good glycemic control had lower values of Castelli 1 and Castelli 2 index, and atherogenic index of plasma, compared to patients with poor glycemic control, but this difference was not significant. (p > 0.005) Our study revealed a significant positive correlation between HbA1c and triglyceride level (r = 0.375; p = 0.003) and HbA1c and ratio triglyceride/HDLc (r = 0.335; p = 0.009). Conclusion: HbA1c can also be used as a predictor of dyslipidemia in type 2 diabetics in addition to as a glycemic control parameter.

Summary Background: The production of erythrocytes is regulated by the hormone erythropoietin (EPO), which maintains the blood haemoglobin (Hb) levels constant under normal conditions. Human EPO is a glycoprotein hormone and its synthesis is controlled by the hypoxia-inducible transcription factor. The aim of this study was to establish EPO and Hb levels in patients with chronic kidney disease (CKD), as well as in control subjects, and to investigate the relationship between these parameters. Methods: This cross-sectional, observational study included 356 subjects with CKD divided into 4 subgroups according to their glomerular filtration rate (GFR). The control group consisted of 206 age and sex matched healthy subjects with GFR rate ≥90 mL/min/1.73 m2. EPO, Hb and serum creatinine levels were determined by using immunochemical and spectrophotometric methods. GFR was determined using the MDRD formula. Results: The CKD patients had significantly lower levels of haemoglobin (p<0.0005) and hematocrit (p<0.0005) compared to control group. Our results showed that Hb levels decreased, whereas serum creatinine increased with the increasing renal failure. The CKD patients in all four groups had significantly lower (p<0.0005) Hb levels, and significantly higher (p<0.0005) creatinine levels compared to the control group. The median EPO in group I and II were significantly higher (p=0.002; p=0.018), while median EPO in group III and IV were significantly lower (p=0.03; p=0.011) compared to the control group. Conclusions: In patients with CKD, GFR positively correlated with Hb and EPO, while the correlation between GFR and serum creatinine was negative.

Introduction: Anti GAD (antibodies on glutamic acid decarboxylase) and anti-IA2 antibodies (against tyrosine phosphatase), today, have their place and importance in diagnosis and prognosis of Type 1 diabetes. Huge number of patients with diabetes mellitus type 1 have these antibodies. Insulin antibodies are of critical importance in diagnosis of diabetes mellitus type 1 for pediatric population. Materials and methods: During 2014, the samples of 80 patients from Clinical Center University Sarajevo (CCUS) Pediatrics clinic’s, Endocrinology department were analyzed on anti-GAD and IA2 antibodies. The samples of serums of all patients were analyzed with ELISA tests using Anti GAD ELISA (IgG) kites from EUROIMMUN company. These are quantitative in vitro tests for human antibodies against decarboxylase of glutamine acid (GAD) and IA2, in serum or EDTA plasm. Results: During the period of one year, in CCUS’s Organizational unit, Institute for Clinical Immunology, 80 samples of patients with anti GAD and IA2 antibodies were analyzed. Out of total number of samples, 41 were male patients, or 51% and 39 female, or 49%. The youngest patient was born in 2012, and the oldest in 1993. Age average was represented by the patients born in 2001. Share of positive results for IA2 antibodies and GAD antibodies was 37% for IA2 antibodies, and 63% for GAD antibodies. Discussion: During an autoimmune – mediated Diabetes mellitus type 1 leads to T-cell mediated destruction of beta cells of pancreatic islets, reduced production of insulin and glucose metabolism. Studies have shown that these bodies are the most intense single marker for identifying persons with increased risk for diabetes development.

Introduction: Hypoxia is a basic stimulant in production of erythropoietin (EPO). The primary function of erythrocytes is the transport of oxygen to tissues. Erythropoietin stimulates erythropoiesis which leads to increased production of erythrocytes- their total mass. This increases the capacity of the blood to carry oxygen, reduces the hypoxic stimulus and provides a negative feedback of stopping EPO production. The aim of this study was to establish a quantitative relationship between the concentration of erythropoietin, hemoglobin and hematocrit in different values of renal insufficiency. Material and methods: The survey was conducted on 562 subjects divided into two groups: with and without renal insufficiency. EPO, hemoglobin, hematocrit, serum creatinine and additional parameters iron, vitamin B12, and folic acid were determined by using immunochemical and spectrophotometric methods and glomerular filtration rate (GFR) was calculated as well. Results: EPO values (median) grow to the first degree of renal insufficiency, as compared to EPO values of healthy subjects, this increase is statistically significant, p=0.002. With further deterioration of renal function the values of EPO between all pathological groups are decreasing, and this decrease is statistically significant between first and second degree of renal insufficiency (RI) p<0.001. In the group of healthy subjects EPO is correlated rho = -0.532, p <0.0005 with hematocrit. The correlations are negative and strong and can be predicted by regression line (EP0 = 41.375- Hct * .649; EPO = 61.41–Hb * 0.355). In the group of subjects with the first degree of renal insufficiency EPO is in correlation with hematocrit rho=-0.574, p<0, 0005. It is also correlated with hemoglobin rho=-0.580, p< 0.0005. The correlation is negative (EP0= 42.168- Hct * 0.678). In the group of subjects with the third degree of renal insufficiency EPO is in correlation with hemoglobin rho=0.257, p=0.028. The correlation is medium strong and positive. In the group of subjects with third and fourth degree of renal insufficiency EPO is not in correlation with hemoglobin and hematocrit p>0.05. Conclusion: Renal dysfunction, depending on the level of RI effects differently on the biosynthesis of EPO in a diseased kidney, and consequently it also has a different effect on biosynthesis of HB in bone marrow and its content in the blood.

Introduction: Glycated hemoglobin (HbA1c) is formed by non-enzymatic binding of glucose to the free amino group of the N-terminal end of the s-chain of hemoglobin A. HbA1c is representative of the mean blood glucose level over three months. The aim of the study was to evaluate the Hemoglobin A1c immunoturbidimetric assay performance on two different commercial systems.Methods: We evaluated the precision and trueness for determination of HbA1c in whole blood. Concentrations of total hemoglobin and HbA1c were evaluated on Dimension Xpand (Siemens) and Cobas 501 (Roche) analyzers. HbA1c was measured in a latex agglutination inhibition test. Commercial controls Liquichek Diabetes Control Level 1 and Liquichek Diabetes Control Level 2 (Bio Rad) at two levels were used for quality control. Analytical validation of HbA1c included: within-run imprecision, between-day imprecision, inaccuracy and comparison determination on the human samples on 2 systems: Dimension Xpand and Cobas 501 analyzers. Results: Within-run imprecision on the commercially controls for Level 1 is 4.5% and Level 2 is 3.2% between-day imprecision on commercially controls is 6.1% Level 1 and 5.1% Level 2 for respectively inac- curacy on commercially controls for Level 1 is 1.8% and Level 2 is 4.8%. Method comparison on human samples shows the correlation coefficient of 0.99.Conclusion: The presented results of the analytical evaluation methods for the determination of HbA1c showed an acceptable accuracy and precision.

ABSTRACT The study aim was to explore the pattern of the changes in haematological and iron status parameters of acute coronary syndrome patients through period 1-7 day of hospital admission in order to define the type of anaemia. Forty-one patients (15 female and 26 male patients, aged 36-81years) of the Clinic for Heart Disease and Rheumatism, University Clinical Center Sarajevo have been included in the cross-sectional study. Haematological and serum iron status parameters have measured on days 1 and 7 of hospital admission. A decrease in haemoglobin levels to <13g/dl in men and <12g/dl in women was notified as anaemia. A significant reduction in red blood cells count, haemoglobin, haematocrit (p<0.01), iron, total iron binding capacity (p<0.05) and significant ferritin elevation (p<0.05) within period the 1-7 day were noted. Percent of anemic patients on day 1 was 17.07 % with increase of number on day 7 (36.36%). Serum ferritin has been elevated with reduction of red blood cells count, mean cell volume, mean corpuscular haemoglobin (p<0.05); haemoglobin, haematocrit (p<0.01) at first 24 hours of admission in anemic versus non-anemic patients. Anemic patients had significantly lower values of percent transferrin saturation (p<0.05), red blood cells count, haemoglobin, haematocrit (p<0.01) compared to non anemic on day 7. A statistically significant negative correlations were obtained between serum iron and C-reactive protein; cardiac troponin I and total iron binding capacity (rho=-0.389, p<0.05; rho=-0.331; p<0.05, respectively). Observed changes in laboratory parameters through period 1-7 day indicate inflammatory type of anaemia in acute coronary syndrome. Key words: anaemia, acute coronary syndrome, haematological, iron status, parameters