INTRODUCTION Most COVID-19 cases are mild, but some require hospitalization due to pneumonia, with symptoms like hypoxia and dyspnea. This has led to speculation about erythrocyte involvement in the infection. This study aimed to examine the differences in the presence of dysmorphic erythrocytes in COVID-19 patients upon admission compared to healthy subjects, as well as to assess these differences in relation to the severity of the clinical presentation of COVID-19. METHODOLOGY This study included 150 participants: 100 COVID-19 patients and 50 healthy subjects who formed the control group. The COVID-19 positive participants were divided into two groups based on the deterioration or improvement of their health conditions during hospitalization. Hematological parameters were analyzed, and peripheral blood smears were prepared to observe morphological changes in erythrocytes. RESULTS The morphological changes observed in hospitalized COVID-19 patients included spiculated red blood cells (RBCs), spherocytes, stomatocytes, schistocytes, knizocytes, keratocytes, as well as mushroom- and cup-shaped RBCs. At admission, spiculated RBCs and spherocytes were more prevalent in patients showing improvement. Conversely, stomatocytes, knizocytes, keratocytes, and mushroom-shaped RBCs were more frequent in patients experiencing deterioration. Additionally, spiculated RBCs were more common in patients with improvement, while stomatocytes, schistocytes, knizocytes, keratocytes, mushroom-, and cup-shaped RBCs were more prevalent in deteriorating patients. CONCLUSIONS The complete blood count and the examination of peripheral blood smears in hospitalized patients may serve as fundamental tools to assist clinicians in differentiating disease severity and improving treatment decision-making.

Background: Thyroid hormones are essential regulators of energy expenditure, thermogenesis, and body composition. Although overt thyroid dysfunction is well known to alter basal metabolic rate (BMR) and body mass, emerging evidence suggests that even hormonal variations within the reference range may exert measurable effects on metabolic and body composition profiles. Women of reproductive age represent a population particularly sensitive to hormonal oscillations due to the interplay between endocrine, reproductive, and cardiometabolic health. Objective: The study aimed to a) analyze thyroid hormone levels (TSH, FT3, FT4) alongside anthropometric and body composition parameters in women of reproductive age; b) examine thyroid hormone levels, BMR, and body composition parameters across age groups; and c) investigate associations of thyroid hormones with BMR, body composition components, and unfavorable body composition patterns (visceral adiposity, elevated metabolic age, obesity) as well as metabolic indicators.. Methods: A total of 117 women aged 18–45 years were included in this cross-sectional, observational study conducted in Bosnia and Herzegovina between September 2023 and November 2024. Thyroid hormone levels were measured using electrochemiluminescence assays, while body composition was assessed by bioelectrical impedance analysis. Statistical analyses included descriptive methods, Pearson’s correlation, and Chi-square testing, with significance set at p<0.05. Results: TSH showed significant positive associations with fat-free mass, muscle mass, and BMR (p<0.05). FT3 was inversely correlated with metabolic age and visceral fat, while FT4 demonstrated weak negative associations with fat-free mass and metabolic age (p<0.05). Significant age-related differences were observed in fat percentage, fat mass, BMI, visceral fat, and metabolic age, with the most unfavorable profiles in women aged 31–40 years. Conclusion: Thyroid hormones, even within the reference range, are associated with body composition and metabolic parameters in women of reproductive age. Their role as early indicators of unfavorable metabolic patterns highlights potential implications for reproductive and cardiovascular risk assessment.

Background: Cardiometabolic risk (CMR), encompassing metabolic syndrome, type 2 diabetes mellitus, hypertension, and dyslipidemia, represents a major public health challenge in Bosnia and Herzegovina, where overweight and obesity prevalence is high. Objective: The study aimed to: a) examine the prevalence of three or more metabolic risk factors in relation to age; b) analyze biochemical parameters, lipid indices, and body composition indices in association with cardiometabolic risk (QRISK3); and c) identify age-specific thresholds for elevated risk.Methods: A cross-sectional, observational, descriptive–analytical study included 203 working-age participants (≤49, 50–54, 55–59, ≥60 years). The research instruments included: laboratory analysis, anthropometric and body composition parameters, and the Q3 risk calculator. Results: The prevalence of three or more metabolic risk factors increased with age, from <49 years to ≥60 years. Younger participants exhibited lower HDL and higher visceral fat, whereas older groups showed elevated glucose, ALT, and AST (p<0.05). The Q3 risk score increased significantly across age groups (median 8.15 to 24.80; p<0.001). Visceral fat, BMI, and body fat percentage emerged as strong predictors of risk in younger and middle-aged adults. Conclusion: Cardiometabolic risk develops already in early adulthood. Age-specific thresholds for visceral fat and biochemical markers may improve risk stratification, highlighting the importance of early screening and preventive interventions.

Introduction: The coronavirus disease 2019 (COVID-19) pandemic has caused a worldwide emergency. The disease is characterized primarily by symptoms of the respiratory system, but also by systemic inflammation. Since the onset of the disease, there has been a need for biomarkers to predict the severity of the clinical picture and the outcome of the disease. The aim of this study is to evaluate systemic inflammatory markers for predicting severity of COVID-19. Methods: The study was conducted at the Sarajevo Canton Health Center on a total of 170 adults suffering from COVID-19. 70 subjects had mild clinical picture, while the control group consisted of 100 subjects with moderate clinical picture. The results of complete and differential blood counts, C-reactive protein (CRP), and systemic inflammatory indexes (SII) (neutrophil/lymphocyte ratio [NLR], derived NLR [dNLR], platelet/lymphocyte ratio [PLR], and SII) were used to compare the groups. IBM SPSS Ver. 23 was used for statistical analysis and data processing. Results: The proportion of male patients in the group with a milder clinical picture was higher than the proportion of male patients with a moderate clinical picture, p = 0.016. The values of leukocytes and neutrophils were higher in patients with a moderate clinical picture (p = 0.006 and p < 0.001, respectively). The values of all inflammatory indexes (NLR, dNLR, PLR and SII) were higher in patients with a moderate clinical picture of COVID-19 than in patients with a mild clinical picture (p < 0.001 for NLR, dNLR, and SII; p = 0.023 for PLR). In the research, patient age showed no correlation and CRP showed no correlation with SII. Conclusion: SII show higher values in patients with a moderate compared with a mild clinical picture of COVID-19. These parameters can be cost-effective and useful indicators in patient classification, diagnosis, and probably in monitoring patients with COVID-19.

Background: A laboratory professional concerned with the quality of work in medical-biochemical laboratories ensures the accuracy and precision of laboratory analyses through the implementation of international and European guidelines for working with hazardous substances, through the availability and implementation of Standard Operating Procedures (SOPs). Laboratory hazards that affect the concentration and safety of workers arise from laboratory deficiencies such as: lack of preventive measures, knowledge and skills implemented through SOPs and good laboratory practice. Biophysical hazards in medical laboratories are manifested by needles and sharp objects, infectious materials, noise, vibration, radiation, poor air quality, temperature inversions. Objective: The aim of the research was to raise awareness of the quality of work in medical-biochemical laboratories in order to ensure the safety of workers. Methods: A cross-sectional questionnaire-based study was conducted among 100 laboratory professionals from Bosnia and Herzegovina (BiH) and Croatia. The research was conducted over a period of three months. Results: A higher percentage of exposure to infectious agents and needles and sharp objects was found among respondents from BiH compared to CRO (p=0.018 and p=0.001, respectively). We found that respondents employed in accredited laboratories are aware of exposure to hazards in a high percentage related to infectious agents, toxins (p=0.0012 and p=0.0046, respectively). A significant statistical difference was found between respondents with BiH and respondents with CRO in terms of knowledge of accreditation standards of medical-biochemical laboratories (p=0.0155). Respondents who have standard operating procedures available are aware of the hazards of infectious agents (p=0.0001), toxins (p=0.0466), needles and sharp objects (p=0.0052), noise (p=0.0030), vibration (p=0.0007) and extreme temperatures (p=0.0014). Conclusion: Efficient implementation and continuous compliance with the ISO 15189: 2018 standard requires constant commitment and active participation of laboratory staff. Laboratories must have standard operating procedures in place and actively monitor their use.

Introduction: COVID-19 is an infectious disease caused by the severe acute respiratory syndrom coronavirus 2 and causes a series of respiratory symptoms. Considering the appearance and development of symptoms, the course of COVID-19 can go from mild to severe. Depending on the course of COVID-19, the laboratory parameters change a lot, trying to defend the organism against the foreign pathogen and all the changes it causes. Therefore, the aim of this study is to observe the differences between biochemical, hematological and coagulation parameters depending on the disease stage of COVID-19 patients. Material and methods: We conducted cross-sectional study which included 160 COVID-19 patients from Sarajevo, Bosnia and Herzegovina. Biochemical, hematological and coagulation analyzes were performed. Results: COVID-19 patients with a severe clinical course have higher average values of fibrinogen (6.53±4.47,p<0.001), D-dimer (6.89±7.81, p<0.001), APTT (32.05±5.96, p=0.002), eosinophil (0.66±0.09, p=0.002) and CRP (93.42±75.86, p= 0.023), and lower values of lymphocytes (1.04±0.98, p<0.001), monocytes (0.45±0.3, p<0.001), compared to COVID-19 patients with a mild clinical course. COVID-19 patients with a severe clinical course had higher average values of neutrophils (10.12±5.80, p=0.002) and lower values of reactive lymphocytes (0.02±0.03, p<0.001) compared to COVID-19 patients with a mild clinical course. Conclusion: Biochemical, hematological and coagulation parameters can be a sensitive and specific biomarker for distinction of mild and severe COVID-19.

Background: A laboratory professional concerned with the quality of work in medical-biochemical laboratories ensures the accuracy and precision of laboratory analyses through the implementation of international and European guidelines for working with hazardous substances, through the availability and implementation of Standard Operating Procedures (SOPs). Laboratory hazards that affect the concentration and safety of workers arise from laboratory deficiencies such as: lack of preventive measures, knowledge and skills implemented through SOPs and good laboratory practice. Biophysical hazards in medical laboratories are manifested by needles and sharp objects, infectious materials, noise, vibration, radiation, poor air quality, temperature inversions. Objective: The aim of the research was to raise awareness of the quality of work in medical-biochemical laboratories in order to ensure the safety of workers. Methods: A cross-sectional questionnaire-based study was conducted among 100 laboratory professionals from Bosnia and Herzegovina (BiH) and Croatia. The research was conducted over a period of three months. Results: A higher percentage of exposure to infectious agents and needles and sharp objects was found among respondents from BiH compared to CRO (p=0.018 and p=0.001, respectively). We found that respondents employed in accredited laboratories are aware of exposure to hazards in a high percentage related to infectious agents, toxins (p=0.0012 and p=0.0046, respectively). A significant statistical difference was found between respondents with BiH and respondents with CRO in terms of knowledge of accreditation standards of medical-biochemical laboratories (p=0.0155). Respondents who have standard operating procedures available are aware of the hazards of infectious agents (p=0.0001), toxins (p=0.0466), needles and sharp objects (p=0.0052), noise (p=0.0030), vibration (p=0.0007) and extreme temperatures (p=0.0014). Conclusion: Efficient implementation and continuous compliance with the ISO 15189: 2018 standard requires constant commitment and active participation of laboratory staff. Laboratories must have standard operating procedures in place and actively monitor their use.

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.