Determination of Reference Intervals of Some Biochemistry Tests by the Bhattacharya and Hoffmann Methods.

BACKGROUND: Clinical laboratory tests are being evaluated with reference intervals (RI). Therefore, it is important that each laboratory determines and classifies its own reliable RI for each test to ensure an accurate and effective interpretation. The proposed method for determining RI is the "direct" approach, but it is a difficult, troublesome, time-consuming, and expensive method. An alternative approach is the "indirect" approach. In this study, we aimed to compare the RI values determined by the indirect method from the Calcium (Ca), Magnesium (Mg), Phosphate (P), 25-Hydroxy Vitamin D (25(OH)D), and Parathyroid hormone (PTH) test results with the RI provided by the manufacturer. METHODS: A total of 1,520,314 Ca, Mg, P, 25(OH)D, and PTH test results, which were studied in our laboratory between January and November 2022, were included in the study. Data cleaning was done for individuals between the ages of 18 - 89, and only one record was allowed. The Tukey method was used to determine and exclude extreme values. Ca and Mg tests were divided into age groups (18 - 59 and 60 - 89 years), P, 25(OH)D, and PTH tests were divided into female - male groups. RI was calculated by using the Bhattacharya and Hoffmann methods. CLIA 19 acceptable limits were used to evaluate the compliance with the manufacturer's RI. RESULTS: The RI results obtained by applying the Bhattacharya and Hoffmann methods were found to be significantly consistent and compatible with each other. According to the manufacturer's RI, Ca and Mg were compatible with RI in both methods, P was considered compatible with PTH and 25(OH)D upper reference limit in the Bhattacharya method, P was considered compatible with 25(OH)D lower reference limit and PTH upper reference limit in the Hoffmann method, while 25(OH)D lower reference limit was found to be different in the Bhattacharya method, and 25(OH)D upper reference limit and PTH lower reference limit were found to be different in the P male group in the Hoffmann method. CONCLUSIONS: We believe that it is of great importance for each laboratory to determine the RI specific for the population they serve and to choose the analytical method they use according to age and gender while periodically updating them to interpret the test results correctly.

Tocilizumab Reduces Lung Injury in a Rat Lung Ischemia and Reperfusion Model.

OBJECTIVE: In this study, the effect of tocilizumab (TCZ) on lung tissue in lung ischemia-reperfusion (I/R) injury in rats was investigated. MATERIAL AND METHODS: A total of 24 Wistar rats were divided into 4 equal groups, with 6 rats in each group: Left lung I/R was applied to I/R groups. In the I/R groups, the left lung hilum was clamped for 45 minutes, and then the clamp was removed and reperfused for 120 minutes. In the TCZ groups, 4 mg/kg and 8 mg/kg of TCZ were administered intraperitoneally to the rats 30 minutes before surgery. RESULTS: The tumor necrosis factor-alpha mean value was not statistically significant between the groups (P = .091). Statistically significant results were observed between group I/R-TCZ (8 mg/kg) and group I/R for catalase. (P = .005). Statistically significant results were observed between group I/R-TCZ (8 mg/kg) and group I/R for malondialdehyde. (P = .009). The difference in total ischemia score between group I/R-TCZ (4 mg/kg) and group I/R-TCZ (8 mg/kg) and group I/R was statistically significant (P < .001). In terms of alveolar hemorrhage, there was a statistically significant difference between group I/R-TCZ (4 mg/kg) and group I/R-TCZ (8 mg/kg) and group I/R (P = .01 and P = .002, respectively). There was a statistically significant difference between group I/R-TCZ (8 mg/kg) and group I/R in terms of neutrophil accumulation (P = .01). In terms of interstitial edema, there was a statistically significant difference between group I/R-TCZ (4 mg/kg) and group I/R-TCZ (8 mg/kg) and group I/R (P = .006 and P = .001, respectively). In terms of pulmonary edema, there was a statistically significant difference between group I/R-TCZ (4 mg/kg) and group I/R-TCZ (8 mg/kg) and group I/R (P = .01 and P = .009, respectively). CONCLUSION: Lung tissue may be affected by I/R injury and this damage can be reversed with the use of TCZ.

Tissue Expressions of Regulatory Enzymes of the Krebs Cycle in Low- and High-grade Gliomas.

AIM: To compare tissue levels of the regulatory enzymes related to the Krebs cycle between low, and high-grade supratentorial gliomas. MATERIAL AND METHODS: Forty patients who underwent surgery for supratentorial gliomas (19 with low-grade and 21 with high-grade gliomas) were evaluated. The regulatory enzymes directly involved in the Krebs cycle, namely pyruvate dehydrogenase, citrate synthase, ?-ketoglutarate dehydrogenase, and isocitrate dehydrogenase, and two enzymes that indirectly regulate the Krebs cycle, namely glutamate dehydrogenase and glutaminase, were quantitatively studied in tumor tissues using ELISA. The results were compared between the two groups. RESULTS: The levels of all enzymes were higher in the high-grade glioma group but only pyruvate dehydrogenase, citrate synthase, and isocitrate dehydrogenase levels showed statistical significance. Moreover, all enzymes showed higher tissue levels in grade- II compared to grade-I gliomas, but only two enzymes, glutamate dehydrogenase and glutaminase, reached significantly higher levels. In the high-grade glioma group, all enzymes again showed higher tissue levels in grade-IV gliomas than in grade-III gliomas, but none showed statistical significance. CONCLUSION: Regulatory enzymes of the Krebs cycle are increased in high-grade gliomas compared to low-grade gliomas. Glutaminolysis enzymes, namely glutamate dehydrogenase and glutaminase, which are required for resupplying the Krebs cycle, are also increased in order to meet the high energy demand in high-grade gliomas.

Estimation of Reference Change Value and Biological Variation of Creatinine Measurements in Healthy Individuals.

INTRODUCTION: The aim of the this study was to assess the biological variation and reference change value (RCV) for creatinine in healthy individuals aged 18 - 45 years using both Jaffe and enzymatic methods. METHODS: Blood samples were collected from ten females and ten males, for four consecutive weeks in our labora-tory between November and December 2018. Samples were stored at -80°C before analysis and dissolved in one run and analyzed in duplicate in a single study with the Beckman Coulter AU2700 biochemistry analyzer. Data was evaluated using CV-ANOVA, and analytical (CVA), intra-individual (CVI), and inter-individual (CVG) variations were calculated. The RCV was calculated using the formula. RESULTS: The average CVA calculated at 95% confidence interval for creatinine using Jaffe's method was 2.51%, CVI was 4.51%, and CVG was 14.17%. The same measures for creatinine were 2.43%, 4.21% and 13.69%, respectively, using the enzymatic method. The individuality index (II) was 0.32 for the Jaffe's method and 0.31 for the enzymatic method. The average RCV calculated bilaterally in the 95% confidence interval for the Jaffe's and enzymatic methods were 14.26 and 13.43, respectively. CONCLUSIONS: This manuscript has underlined the fact that the II of creatinine is less than 0.6 indicating that the use of population-based reference intervals is limited, and interpretation of the RCV and analysis might be a more objective approach. Taken together, these results suggest that it could be valuable to calculate biological variation correctly and increase clinical awareness.

Immunophenotyping of lymphocytes and monocytes and the status of cytokines in the clinical course of Covid-19 patients.

Lymphopenia, T cell subgroup changes, and cytokine level differences are important in the early diagnosis and treatment of Covid-19 cases and similar pandemics. We aimed to investigate the T cell, monocyte subgroups, and cytokine differences according to disease severity. A total of 46 volunteers were included in the study. According to disease status, there were three groups (control, mild, and severe). The age, gender, smoking status, temperature, heart rate and oxygen saturation, complete blood count, C-reactive protein (CRP) was noted, and flow cytometric analyses were performed for T cell and monocyte subgroups, and cytokine levels. Temperature, heart rate, SPO2 , white blood cell (WBC), lympocyte count, trombocyte count, neutrophil/lymphocyte ratio, D-dimer and CRP levels, lymphocyte %, lymphocyte/monocyte rate, monocyte subtypes (%), CD3+ , CD4+ , CD8+ cell counts, interleukin (IL)-1ß, TNF-alpha, monocyte chemoattractant protein (MCP)-1, IL-6, IL-8, IL-10, IL-18, IL-23 were significantly different between groups. CRP, IL-8, neutrophil/lymphocyte ratio, NK cells (%) have positive correlation and negative correlation was observed at lymphocyte (count), lymphocyte (%), lymphocyte/monocyte, classical monocyte (%), lymphocyte (count), CD3+ (count), CD4+ (count). As conclusion, lymphocyte (%), Lymphocyte (count), CRP levels, CD3+ and CD4+ cell counts strongly correlate with disease severity are valuable parameters for determining the prognoses of Covid-19.

A new approach in acute myeloid leukemia (AML): Samatya-predicting score.

We aimed to examine the efficiency for prediction of prognosis and response in non-APL AML cases of the "Samatya-predicting score". A total of 213 patients diagnosed between January 2010-December 2020 were examined. Of the 158 patients included in the study, the median value of risk score was determined as 2,5. The sensitivity for mortality was 88% and the specificity was 42%. In terms of being non-responder to induction therapy, the sensitivity was 90,1%, the specificity was 25,3%. OS was shorter in those with high risk scores. This study makes an important contribution to the literature in terms of creating a different perspective to predict prognosis in AML.

Hemogram index parameters in the evaluation of male breast cancer and inflammatory response: a case-control study.

OBJECTIVE: Our aim was to investigate the hemogram index parameters and their clinical significance in the evaluation of the inflammatory response of patients with male breast cancer, who are rarely observed in the literature. METHODS: In total, 22 (n=22) healthy male and 28 (n=28) male breast cancer patients without synchronous/metachronous tumors were included in this study. They were grouped as the healthy male control group (Group 1) and the male breast cancer patient group (Group 2). The male breast cancer was divided into two subgroups, namely, early stage [(stage: 0/I/II) (Group 2A)] and late stage [(stage: III/IV) (Group 2B)], and their hemogram index parameters were compared. RESULTS: A significant (p>0.05) increase was observed in neutrophil/lymphocyte ratio (NLR) and·platelet/lymphocyte ratio (PLR) values in the late stage (Group 2B: stage III/IV) compared to the early stage (Group 2A: stage 0/I/II) and healthy control (Group 1) groups. CONCLUSIONS: In male breast cancer patients, neutrophil/lymphocyte ratio and platelet/lymphocyte ratio values were significantly higher as the stage of cancer increased. These readily available simple tests can be used to evaluate the host's inflammatory response in male breast cancer.

Circulating Levels of Thrombospondin-1 and Thrombospondin-2 in Patients with Common Brain Tumors.

AIM: To measure serum levels of thrombospondin-1 (TSP-1) and thrombospondin-2 (TSP-2) in patients with common brain tumors, namely high-grade glioma (HGG), low-grade glioma (LGG), and meningioma. MATERIAL AND METHODS: For this prospective study, a total of 56 patients were operated on for supratentorial gliomas and meningiomas, and 18 healthy subjects were evaluated. Serum levels of angiostatic molecules were measured with enzyme-linked immunosorbent assay. The results of patients were compared with those of healthy subjects. RESULTS: High serum levels of TSP-1 were seen in HGG, followed by LGG, meningioma groups, and controls. The only significant difference was found between HGGs and controls (p=0.004). There was a trend to decrease from HGG to controls. High serum levels of TSP-2 were seen in controls, followed by meningioma, LGG, and HGG. None of the patient groups showed significant differences compared with controls. Among the patient groups, TSP-2 was significantly higher in the meningioma group than the HGG group (p=0.01). No correlation was found with any of the molecules and the clinical parameters, including the presence of peritumoral edema or seizure, the anterior-posterior diameter of the tumor, and, more importantly, the grade of glioma. CONCLUSION: Our results indicate that TSP-2 might be more important than TSP-1 in preventing angiogenesis and a major angiostatic factor in glioma cells.

Circulating Levels of Thrombospondin-1 and Thrombospondin-2 in Patients with Temporal Lobe Epilepsy Before and After Surgery.

AIM: To measure the serum levels of strong angiostatic and synaptogenetic molecules thrombospondin-1 (TSP-1) and thrombospondin-2 (TSP-2) in patients with temporal lobe epilepsy (TLE) before and after surgery. MATERIAL AND METHODS: In this prospective study, 20 patients operated for TLE and 20 healthy subjects were included. Serum levels of TSP-1 and TSP-2 were measured using enzyme-linked immunosorbent assay (ELISA). RESULTS: Our findings showed that both groups had higher serum levels of both molecules "before" surgery than 10 days ?after? SURGERY: However, a significant difference was noted between ?before? and "after" surgery regarding TSP-1 (p=0.00001). Although a marked decrease was found "after" surgery with respect to TSP-2, the difference did not reach statistical significance (p=0.22). In patients with TLE, serum levels of both molecules ?before? surgery were found to be significantly higher than in healthy controls (TSP-1, p=0.00001; TSP-2, p=0.007). CONCLUSION: Serum levels of TSP-1 and TSP-2 are determined to be higher in patients with TLE than in healthy subjects, and the resection of epileptogenic tissues decreases the serum levels of these molecules. Future studies should involve a higher number of patients with serial serum levels of TSP-1 and TSP-2 at the long-term follow-up to correlate with seizure outcome.

The use of preanalytical quality indicators: a Turkish preliminary survey study.

OBJECTIVES: The utilization of reliable quality indicators (QIs) proven to be suitable for monitoring and improvement tools is one of the best choices to minimize of the risk of errors in all laboratory processes called as total testing process (TTP). In 2008, a Working Group "Laboratory Errors and Patient Safety" (WG-LEPS) established by International Federation of Clinical Chemistry and Laboratory Medicine (IFCC) developed the Model of Quality Indicators (MQI) complying with requirements of the ISO 15189:2012 standard for laboratory accreditation. They have also been dealing with harmonizing the QIs in most laboratories worldwide since then. The present study was set out to investigate the frequency of using IFCC WG-LEPS' pre-QIs by Turkish laboratories and to assess the conformity of them, by taking into account Turkey's conditions. METHODS: A survey consisting nine questions was applied in 81 laboratories using SurveyMonkey. RESULTS: According to the survey results, most of the laboratories reported they have used pre-QIs in the quality standards of health prepared by Turkish Ministry of Health (MOH). A part of IFCC WG-LEPS' pre-QIs were being utilized by more than 80% of the laboratories, the rest of which only used by 10% of laboratories. CONCLUSIONS: The majority of the medical laboratories have been using the pre-QIs included in the guidelines of Quality Standards prepared by the MOH. The pre-QIs are partially compatible with IFCC WG-LEPS' pre-QIs. The definitions of IFCC WG-LEPS' pre-QIs may also be revised to make them more clear and understandable by IFCC WG-LEPS. The insufficiency of Health Information Management Systems (HIMS) limits the use of pre-QIs proposed by IFCC WG-LEPS. Finally, the education of relevant personnel about the use of HIMS and pre-QIs is very crucial to harmonize and to extend the use of IFCC WG-LEPS' pre-QIs in Turkish medical biochemistry laboratories.

Analysis of Prescribed Critical Values in Istanbul Training and Research Hospital Biochemistry Laboratory: Should Critical Values Be Repeated?

BACKGROUND: Clinically important critical values must be readily available to the clinician. Repeating critical values may cause a delay. In this study, we evaluated the requirement of repeating critical values. METHODS: We extracted initial and repeated critical values and reporting times for a six-month period via the hospital laboratory information management system. Ten parameters from our critical value list (glucose, urea, mag-nesium (Mg++), calcium (Ca++), sodium (Na+), potassium (K+), chloride (Cl-), white blood cells (WBC), platelets, hemoglobin) were evaluated. We assessed whether the difference between the first measurement of the initial critical value and the repeated measurement value exceeded total allowable error (TEa). RESULTS: Repeated critical values of Mg++, Ca++, WBC, platelets, and hemoglobin did not exceed TEa. However, repeated critical values of glucose, urea, Na+, K+, and Cl- did exceed TEa. In addition, parameters such as glucose and urea did not affect the clinical decision although their critical values exceeded the TEa. This study showed that critical values for Na+, K+, and Cl- may need to be repeated. CONCLUSIONS: Each laboratory should assess the requirement of repeating critical values under its own operating conditions and, accordingly, establish and implement a suitable policy.