GDF11 level and its effect on prognosis in patients with acute myeloid leukemia.

Acute myeloid leukemia (AML) is a hematologic malignancy characterized by the proliferation of CD34 positive self-renewing malignant hematopoietic stem cells. Previous studies have shown that the transforming growth factor beta (TGFß) pathway plays a role in AML pathogenesis, especially by affecting the microenvironment. Growth differentiation factor 11 (GDF11) is a member of the TGFß superfamily, involved in embryological development and known as rejuvenating factor. In this study, our aim was to determine the serum GDF11 level in patients with AML, to compare it with the control group, to determine its relationship with follistatin, vimentin, and E-cadherin levels, and to determine whether GDF11 influences AML prognosis. Serum GDF11, vimentin, follistatin, and E-cadherin levels of newly diagnosed or relapsed/refractory AML patients and age- and gender-matched control group were measured by enzyme-linked immunosorbent assay. Serum GDF11 level was higher in the patient group (263.87 ± 126.54 ng/L) compared to the control group (211.54 ± 61.47 ng/L; p = 0.035). GDF11 level did not change according to age, gender, hemoglobin level, and bone marrow blast rate. No correlation was found between GDF11 level, response rates, and survival status of the patients. A positive correlation was detected between GDF11, E-cadherin, and vimentin levels. As a conclusion, increased serum GDF11 levels in AML patients may be linked to the regeneration ability of leukemic stem cells. There is a need for studies investigating GDF11 expression in myeloblasts.

Characterizing upper extremity fine motor function in the presence of white matter hyperintensities: A 7 T MRI cross-sectional study in older adults.

BACKGROUND: White matter hyperintensities (WMH) are a prevalent radiographic finding in the aging brain studies. Research on WMH association with motor impairment is mostly focused on the lower-extremity function and further investigation on the upper-extremity is needed. How different degrees of WMH burden impact the network of activation recruited during upper limb motor performance could provide further insight on the complex mechanisms of WMH pathophysiology and its interaction with aging and neurological disease processes. METHODS: 40 healthy elderly subjects without a neurological/psychiatric diagnosis were included in the study (16F, mean age 69.3 years). All subjects underwent ultra-high field 7 T MRI including structural and finger tapping task-fMRI. First, we quantified the WMH lesion load and its spatial distribution. Secondly, we performed a data-driven stratification of the subjects according to their periventricular and deep WMH burdens. Thirdly, we investigated the distribution of neural recruitment and the corresponding activity assessed through BOLD signal changes among different brain regions for groups of subjects. We clustered the degree of WMH based on location, numbers, and volume into three categories; ranging from mild, moderate, and severe. Finally, we explored how the spatial distribution of WMH, and activity elicited during task-fMRI relate to motor function, measured with the 9-Hole Peg Test. RESULTS: Within our population, we found three subgroups of subjects, partitioned according to their periventricular and deep WMH lesion load. We found decreased activity in several frontal and cingulate cortex areas in subjects with a severe WMH burden. No statistically significant associations were found when performing the brain-behavior statistical analysis for structural or functional data. CONCLUSION: WMH burden has an effect on brain activity during fine motor control and the activity changes are associated with varying degrees of the total burden and distributions of WMH lesions. Collectively, our results shed new light on the potential impact of WMH on motor function in the context of aging and neurodegeneration.

Postmortem biochemistry in deaths from ischemic heart disease.

Ischemic heart disease (IHD) is one of the leading causes of morbidity and sudden cardiac death worldwide and is an important public health problem. The presence of ischemia in clinical applications can be detected by ECG, biochemical markers, and radiological methods. Myocardial infarction is also frequently encountered in forensic autopsies. Postmortem diagnosis is determined as a result of histopathological examinations and additional exclusionary examinations (toxicology, microbiology, etc.). However, routine histopathological examinations are insufficient, especially when death occurs in the early period of ischemia. It creates a problem for forensic pathologists and forensic medicine specialists in such cases of sudden cardiac death. Postmortem biochemistry is one of the important and promising disciplines in which forensic applications work in order to diagnose these cases correctly. The issue of whether biomarkers used in the diagnosis of myocardial infarction in clinical studies can be used reliably in postmortem cases has been discussed by forensic medicine researchers for some time. This manuscript aims to review and summarize biomarkers belonging to various categories that have been studied in IHD-related deaths, in biological fluids taken at autopsy, or in animal experiments. Our study shows that the postmortem use of biochemical markers in the diagnosis of IHD yields promising results. However, it should not be forgotten that postmortem biochemistry is different from clinical applications due to its dynamics and that the body causes unpredictable changes in markers in the postmortem process. Therefore, comprehensive studies are needed to evaluate the postmortem stability of these markers in different biological fluids, their significance among various causes of death, and whether they are affected by any variable (Cardiopulmonary resuscitation, Postmortem interval, medications, etc.) before they are routinely applied. It is suggested by the authors that the cut-off values of biomarkers whose significance has been proven by these studies should be determined and that they should be used in this way in routine applications.

The comparison of the suture materials on intestinal anastomotic healing: an experimental study.

BACKGROUND: This experimental comparative study was to evaluate the local effects of three different suture materials on in-testinal anastomosis healing. METHODS: Ethical approval was obtained from the University of Ethical Committee (E-60758568-020-176720). A prospective, experimental comparative analysis was conducted on 24 rats. They were divided into three equal groups; Group 1 underwent colonic anastomosis with Vicryl suture material, Group 2 underwent colonic anastomosis with polypropylene suture; and Group 3 underwent colonic anastomosis with polydioxanone (PDS) suture. The second operation underwent the 7th post-operative day. Adhesion score, anastomotic leakage, anastomotic bursting pressure, hydroxyproline levels, and histopathologic examination were evaluated. RESULTS: All animals survived, and no leakage, intestinal obstruction, or wound infection was observed during the experiment. The adhesion score was evaluated according to the Diamond classification and same in all groups. Median anastomotic bursting pressure was 125.75 mmHg (10-241) in the Vicryl group, 159.25 mmHg (113-190) in the polypropylene group, and 154.50 mmHg (20-212) in the PDS group. Hydroxyproline tissue concentrations were in the Vicryl group 1699.92±220.8 ng/mg (range: 1509.81-2186.47), in the polypropylene group 1126.24±607.12 ng/mg (range: 53.22-1815.63), and 1547.86±335.2 ng/mg (range: 973.66-1973.2) in PDS group. There was no difference among groups regarding the inflammatory response evaluated by histopathology. There was no statistical significance in all variables evaluated. CONCLUSION: This experimental study demonstrates that suture materials did not worsen tissue healing during intestinal anastomosis. Absorbable, slowly-absorbable, and non-absorbable suture materials could be used safely in every situation.

Plasma leucine-rich α-2-glycoprotein 1 - a novel marker of diabetic kidney disease in children and adolescents with type 1 diabetes mellitus?

BACKGROUND: Glomerular endothelial dysfunction and neoangiogenesis play a significant role in the pathogenesis of diabetic kidney disease (DKD). Leucine-rich α-2 glycoprotein 1 (LRG1) is a recently discovered protein that participates in the molecular pathway of inflammation and angiogenesis. We aimed to investigate efficacy of LRG1 to predict estimated glomerular filtration rate (eGFR) decrease in children and adolescents with type 1 diabetes mellitus (T1DM). METHODS: The study comprised 72 participants with diabetes duration for ≥ 2 years. At study initiation, LRG1, urine albumin, eGFR (cystatin C-based, and Schwartz), HbA1c, and lipid values were evaluated and diabetes-related clinical features and anthropometric measurements were collected. These results were compared with final control values after ≥ 1 year. Patients were divided into subgroups according to presence of albuminuria progression, eGFR decrease, and metabolic control parameters. RESULTS: There was positive correlation between LRG1 level and Schwartz and cystatin C-based eGFR decline (r = 0.360, p = 0.003; r = 0.447, p = 0.001, respectively), and negative correlation between final cystatin C-based eGFR and LRG1 (p = 0.01, r = -0.345). Patients with cystatin C-based eGFR decrease > 10% had significantly higher LRG1 levels (p = 0.03), however, LRG1 was not different between albuminuria progression subgroups. A 0.282 µg/ml increase in LRG1 correlated with a 1% decrease in eGFR in simple linear regression analysis (ß = 0.282, %CI 0.11-0.45, p = 0.001) and LRG1 was an independent predictor of GFR decline even in the presence of covariates. CONCLUSIONS: Our study supports the relationship between plasma LRG1 and eGFR decline and suggests LRG1 may be an early marker of DKD progression in children with T1DM. A higher resolution version of the Graphical abstract is available as Supplementary information.

Significance of postmortem biomarkers and multimarker strategy in sudden cardiac death.

The most common cause in the etiology of sudden cardiac death (SCD) is ischemic heart disease due to atherosclerosis. Postmortem diagnosis can be made by histopathological examinations, but routine histopathological examinations are limited, especially in the early period of postmortem ischemia. For this reason, many methods are being investigated for the postmortem diagnosis of ischemia, and postmortem biochemical studies are promising. In our study, we evaluated the biochemical markers; hs-cTnT, NT-proBNP, H-FABP, pentraxin-3, copeptin, ischemic modified albumin (IMA), and PAPP-A in postmortem serums. In forensic pathology practice, it was investigated whether it would be useful to go to the diagnosis by measuring more than one marker in a single biological fluid in SCD cases. The study included 35 sudden cardiac death cases and 24 control cases and as a result of our study, hs-cTnT, NT-proBNP, and H-FABP values were found to be significantly higher in the SCD group than in the control group. Within the scope of the multi-marker strategy, models were tried to be developed in which the markers were used together, and it was concluded that the model consisting of the myocardial ischemia marker hs-cTnT, the myocardial stress marker NT-proBNP, and the inflammation marker pentraxin 3 was the most accurate combination by correctly classifying the cases at a rate of 94.9%. As a result, it was thought that it would be appropriate to use the multi-marker strategy which is widely used in clinical applications, also in forensic medicine applications.

Evaluation of the Diagnostic Value of Hematologic Parameters and Ratios in SARS-CoV-2 VOC-202012/01 Mutant Population.

Introduction In this study, we set out to study possible differences between individuals with and without VOC 202012/01 variant by using less costly complete blood count analytes and quickly analyzing the samples and ratios derived from these analytes. For this purpose, we assessed neutrophil, lymphocyte, platelet, and Red Blood Cell Distribution Width-Standard Deviation (RDW-SD) levels among complete blood count parameters (CBC) (identification and count of red blood cell, neutrophil, eosinophil, basophil, lymphocyte, monocyte, platelet) as well as the neutrophil-lymphocyte ratio (NLR) and platelet-lymphocyte ratio (PLR). Methods A retrospective cross-sectional study was performed over the course of two months (from May to June 2021) on 212 patients who presented to the emergency department of a tertiary hospital with Covid-19 symptoms and took SARS-CoV2 PCR and CBC tests. The polymerase chain reaction (PCR)-confirmed SARS-CoV2 positive patients and their hospitalization data were gathered from the public health management system. Their VOC-202012/01 mutation status was also confirmed by this system. Results RDW-SD, RDW, NLR, and PLR indexes, as well as C-reactive protein (CRP), and lactate dehydrogenase (LDH) values, were higher in the patients with VOC-202012/01 mutation (p<0.0001) than those without mutation, while hemoglobin and hematocrit counts and ratio, as well as eosinophil and lymphocyte counts, remained lower in the patients with mutation (p<0.0001). Conclusion NLR and RLP ratios derived from hematological parameters and models based on these ratios and RDW-SD are cheaper and more widely used. Our study suggests that the hematological analytes, the ratios obtained from these analytes, and the models created through these ratios in patients presenting to the ED with COVID-19-like symptoms and having positive reverse transcription polymerase chain reaction (RT-PCR) test results were significantly different in those with and without the VOC-202012/01 mutation. The bottom line is that they can serve as reliable predictors in the assessment of patients with the VOC-202012/01 mutation.

Comparison of Serum Mitochondrial Open Reading Frame of the 12S rRNA-c (MOTS-c) Levels in Patients With Multiple Sclerosis and Healthy Controls.

Background Multiple sclerosis (MS) is a major global problem, and as its pathogenesis is understood more clearly, therapeutic options expand accordingly. The mitochondrial open reading frame of the 12S rRNA-c (MOTS-c) is a novel mitochondria-derived protein acting on metabolic homeostasis. In this study, we aimed to investigate the role of serum MOTS-c in the pathophysiology of the disease in MS patients and to discuss the mechanism of MOTS-c. Methodology In total, 43 patients diagnosed with relapsing-remitting MS and 41 healthy controls were enrolled in the study. MOTS-c, fasting blood glucose, insulin, Homeostatic Model Assessment for Insulin Resistance (HOMA-IR), lipid panel, and body mass index levels were assessed. Results The participants' MOTS-c levels remained significantly lower than that of the control group, while their fasting blood glucose and HOMA-IR values were higher. The multivariate logistic regression analysis established that increased MOTS-c levels could be a protective factor against the development of MS disease. The area under the receiver operating characteristic curve for MOTS-c was calculated as 0.782 (95% confidence interval = 0.684-0.879, p = 0.0001). Conclusions This study is the first to scrutinize MOTS-c levels in MS patients. We tried to provide clinical evidence that MOTS-c could act as a highly discriminative biomarker between MS patients and control groups, which may hold great promise for future therapeutic options.

Predictive Values of Coagulation Parameters to Monitor COVID-19 Patients.

Aims: In this study, we aim to unravel the relationship between coagulation parameters together with D-dimer and the severity of coronavirus disease (COVID-19) during hospitalization as well as hospitalization in the intensive care unit (ICU). Methods: This retrospective study was conducted in the Emergency Department (ED) of Pamukkale University Hospital (Denizli, Turkey) between March 1 and April 30, 2020. SARS-CoV-2 polymerase chain reaction (PCR) tests and laboratory tests, including international normalized ratio (INR), prothrombin time (PT), D-dimer, and activated thromboplastin time (APTT), were requested from 289 people presenting to the ED with symptoms of upper respiratory tract infection (URTI), such as cough, fever, and sore throat. Results: While 110 patients turned out to be polymerase chain reaction (PCR) positive, 181 individuals were PCR negative. The mean D-dimer level of the patient group was 147 ng/ml DDU (min: 9, max: 2948), and their mean PT level was found as 12.8 seconds (min: 10.3, max: 34.7). Besides, the mean APTT was 31.25 seconds (min: 19, max: 46.9), and the mean INR level was calculated as 1.09 (min: 0.88, max: 2.93). 35 of the patients were not hospitalized, while 43 were admitted to the Infectious Diseases, 20 to the Chest Diseases, and 12 to the ICU. Conclusions: It can be concluded from our findings that D-dimer, PT, and INR levels remained elevated in the COVID-19-diagnosed patients, but these parameters were unable to discriminate accurately between the patients with positive and negative SARS-CoV-2 results. Our findings also suggest that coagulation parameters might occupy a critical role in documenting clinical severity in patients with COVID-19 infection and requiring hospitalization.

Relationship between saliva opiorphin levels, pain threshold, and cutting number in adolescents with non suicidal self injury.

Various opinions have been suggested regarding non suicidal self-injury (NSSI) and pain relationship. Opiorphin is a recently found peptide that inhibits enkephaline-catabolizing enzymes. Analgesia caused by opiorphine has been demonstrated in animal experiments. No studies have examined the relationship between opiorphin and pain sensation until today. We aimed to investigate opiorphine and pain threshold among self-injuring adolescents. Adolescents aged 14-18 years were included in the study. The NSSI group consisted of 37 adolescents diagnosed with NSSI according to DSM-V Section 3, and the non-NSSI group consisted of 36 adolescents without any psychiatric disorder. We measured pain threshold with a pressure sensitive algometer device and analyzed saliva opiorphin levels by ELISA method. Mediation analysis was performed using Process Macro developed by Hayes. NSSI group had statistically significantly higher pain threshold and opiorphin levels than the non-NSSI group. There was a positive correlation between pain threshold values and opiorphin levels in the NSSI group. Also, a positive correlation between opiorphin levels and total cutting episode number was found. We searched for a probable relationship of pain threshold with episode number of each type of NSSI act. Accordingly, a positive correlation with two major act and a negative correlation with two minor act was shown. The opiorphine was found to be a mediator variable in the relationship between the pain threshold and the cutting number. The relationship between opiorphin, pain threshold and cutting number and their mediating effects with each other may highlight the pain-based biological origins of NSSI.

What is the best method for long-term survival analysis?

In the Cox proportional hazards regression model, which is the most commonly used model in survival analysis, the effects of independent variables on survival may not be constant over time and proportionality cannot be achieved, especially when long-term follow-up is required. When this occurs, it would be better to use alternative methods that are more powerful for the evaluation of various effective independent variables, such as milestone survival analysis, restricted mean survival time analysis (RMST), area under the survival curve (AUSC) method, parametric accelerated failure time (AFT), machine learning, nomograms, and offset variable in logistic regression. The aim was to discuss the pros and cons of these methods, especially with respect to long-term follow-up survival studies.

Serum Hepcidin and Prohepcidin Levels in Nonfebrile and Febrile Neutropenia.

OBJECTIVE: To compare the prohepcidin and hepcidin levels in the afebrile neutropenic period and neutropenic fever in patients with hematological malignancy. STUDY DESIGN: Descriptive study. PLACE AND DURATION OF STUDY: Department of Hematology, Pamukkale University Hospital, Denizli, Turkey, between January 2018 and December 2019. METHODOLOGY: Neutropenic patients were compared with a healthy control group. Prohepcidin and hepcidin serum levels were to be measured in neutropenic and control groups. When fever occurred in neutropenic group, serum was taken again and the same values were compared, in addition to procalcitonin and CRP values. RESULTS: Prohepcidin and hepcidin levels were found to be significantly higher in the neutropenic group (n = 53) than the control group [n = 44, (med:166.65 ng/ml, IQR:147.66 - 187.38 ng/ml vs. med:47.49 ng/ml, IQR:15.61 - 82.51 ng/ml; p <0.001); (med:315 ng/ml, IQR:314.92 - 315 ng/ml vs. med:26.61 ng/ml, IQR:4.69 - 66.83 ng/ml; p <0.001)]. No significant difference was found in terms of these two analyses (167.29 ± 29.31 ng/ml vs. 167.15 ± 27.61 ng/ml; p = 0.979; 296.21 ± 37.19 ng/ml vs 299.16 ± 37.68 ng/ml; p= 0.629) in the neutropenic fever period compared to the afebrile neutropenic period. In neutropenic fever patients, procalcitonin and CRP (C-reactive protein) were found significantly higher than the afebnile neutropenic group (0.7 ± 1.2 ng/ml vs. 0.25 ± 0.76 ng/ml; p = 0.034; 10.27 ± 9.93 mg/dl vs 2.61 ± 2.78 mg/dl; p <0.001). CONCLUSION: Although there was no significant difference between afebnile neutropenia and neutropenic fever in patients in terms of hepcidin and prohepcidin levels, higher levels were found in both groups compared to the control group. Key Words: Hepcidin, Prohepcidin, Neutropenia, Febrile neutropenia.

Frequency-dependent modulation of cerebellar excitability during the application of non-invasive alternating current stimulation.

BACKGROUND: it is well-known that the cerebellum is critical for the integrity of motor and cognitive actions. Applying non-invasive brain stimulation techniques over this region results in neurophysiological and behavioural changes, which have been associated with the modulation of cerebellar-cerebral cortex connectivity. Here, we investigated whether online application of cerebellar transcranial alternating current stimulation (tACS) results in changes to this pathway. METHODS: thirteen healthy individuals participated in two sessions of cerebellar tACS delivered at different frequencies (5Hz and 50Hz). We used transcranial magnetic stimulation to measure cerebellar-motor cortex (M1) inhibition (CBI), short-intracortical inhibition (SICI) and short-afferent inhibition (SAI) before, during and after the application of tACS. RESULTS: we found that CBI was specifically strengthened during the application of 5Hz cerebellar tACS. No changes were detected immediately following the application of 5Hz stimulation, nor at any time point with 50Hz stimulation. We also found no changes to M1 intracortical circuits (i.e. SICI) or sensorimotor interaction (i.e. SAI), indicating that the effects of 5Hz tACS over the cerebellum are site-specific. CONCLUSIONS: cerebellar tACS can modulate cerebellar excitability in a time- and frequency-dependent manner. Additionally, cerebellar tACS does not appear to induce any long-lasting effects (i.e. plasticity), suggesting that stimulation enhances oscillations within the cerebellum only throughout the stimulation period. As such, cerebellar tACS may have significant implications for diseases manifesting with abnormal cerebellar oscillatory activity and also for future behavioural studies.

Neutrophil to lymphocyte ratio, lymphocyte to monocyte ratio and platelet to lymphocyte ratio to predict the severity of COVID-19.

INTRODUCTION: In this study, we aimed to investigate and compare the prognostic impacts of C-reactive protein (CRP), white blood cell (WBC) count, neutrophil (NEU)-to-lymphocyte (LYM) ratio (NLR), platelet-to-lymphocyte ratio (PLR), Red Cell Distribution Width (RDW) biomarkers in laboratory-confirmed COVID-19 cases as well as to explore the most useful diagnostic biomarkers and optimal cutoff values in COVID-19 patients. METHODS: A total of 233 patients were admitted to Emergency Department (ED) of Pamukkale University Hospital during two months (March-April 2020) and underwent Sars CoV-2 PCR (Polymerase Chain Reaction), complete blood count (CBC), and CRP tests in sequence due to complaints of COVID-19. The laboratory results and demographic findings were collected from the public health management system retrospectively. The patients with positive Sars CoV-2 PCR test along with hospitalization data were also recorded. RESULTS: The CRP (p = 0.0001), lactate dehydrogenase (LDH) (p = 0.038), PLR (p = 0.0001) and NLR (p = 0.001) remained significantly higher in the patients with positive Sars CoV-2 PCR test result. By contrast, eosinophil (p = 0.0001), lymphocyte (p = 0.0001), platelet levels (p = 0.0001) were calculated as significantly higher in negative Sars CoV-2 patients. CONCLUSION: In the light of the obtained results, the CRP, LDH, PLR and NLR levels remained significantly higher in COVID-19 positive patients, while eosinophil, lymphocyte, and platelet levels were significantly elevated in COVID-19 negative patients.

Arterial stiffness measured by cardio-ankle vascular index is greater in non-obese young women with polycystic ovarian syndrome.

AIM: The association of metabolic abnormalities and polycystic ovarian syndrome (PCOS) has been documented, but few studies have focused on cardiovascular risk in these women. The aim of this study was to compare arterial stiffness by using the cardio-ankle vascular index (CAVI) in PCOS women with controls, and to evaluate whether any clinical or laboratory variables had independent associations with it. METHODS: A group of 160 women, matched for age and body mass index were recruited. Diagnosis of PCOS was made according to the Rotterdam criteria. Arterial stiffness using CAVI was evaluated in non-obese young woman, with and without PCOS. RESULTS: In the PCOS group (n = 80), 60 cases (75%) had findings of hyperandrogenism, 59 (73.8%) had ovulatory dysfunction, and 70 (87.5%) had an ultrasonographic appearance of polycystic ovaries. Women with PCOS had significantly higher mean CAVI values when compared to subjects without PCOS (5.78 ± 0.64 vs 5.28 ± 0.77, P < 0.001). Multiple regression analysis revealed that androgen excess was associated with increased arterial stiffness, independent of ovulatory dysfunction, polycystic ovaries, body mass index and age. CONCLUSION: This data suggests that vascular compliance is decreased in young women with PCOS. Androgen excess is independently associated with increased arterial stiffness.

68Ga-citrate positron emission tomography/computed tomography findings in an experimental model of acute appendicitis in rabbits.

OBJECTIVE: Acute appendicitis (AA) is a common urgent surgical situation of the gastrointestinal tract. Gallium-68 (68Ga)-citrate has been recently investigated as a radiopharmaceutical for infection and inflammation imaging. Aim of the study was to determine the effectiveness of 68Ga-citrate positron emission tomography/computed tomography (PET/CT) imaging in rabbits with experimentally induced AA. MATERIALS AND METHODS: In the AA group (n=6), the appendices of the rabbits were surgically ligated. The sham group (n=6) was used as control. Gallium-68-citrate was synthesized. All rabbits were imaged using 68Ga-citrate PET/CT at 36th following the establishment of experimental models, and at 36th h, all rabbits were appendectomised. Appendices were examined histopathologically. Blood samples were drawn from all rabbits at the beginning and end of the experimental process. Interleukin-6 (IL-6) and procalcitonin (Pct) levels were measured. Acute appendicitis was confirmed histopathologically and biochemically. RESULTS: Gallium-68-citrate PET/CT showed acute appendicitis in all rabbits. The sensitivity, specificity and accuracy of 68Ga-citrate PET/CT in AA were 100%, 83.3% and 91.7%, respectively. CONCLUSION: Acute appendicitis is accurately imaged in an experimental rabbit model by using 68Ga-citrate with PET/CT.

Assessment of Abbott Architect 25-OH vitamin D assay in different levels of vitamin D.

BACKGROUND: There is increasing requests of Vitamin D test in many clinical settings in recent years. However, immunoassay performance is still a controversial topic. Several diagnostic manufacturers have launched automated 25-hydroxyvitamin D (25-OH D) immunoassays in the past decade. We compared the performance of Abbott Architect 25-OH D Vitamin immunoassay with liquid chromatography-tandem mass spectrometry systems (LCMS/MS) to evaluate immunoassay performance, especially in deficient groups. METHODS: Eighty human serum samples were analyzed with Architect 25-OH D vitamin kit (Abbott Diagnostics, Lake Forest, IL, USA) and LC-MS/MS systems (Zivak Technology, Istanbul, Turkey). The results of the immunoassay method were compared with the LC-MS/MS using Passing-Bablok regression analysis, Bland-Altman plots and correlation coefficient analysis. We also evaluated results in four levels of D vitamin as a severe deficiency, deficiency, insufficiency, and sufficiency. RESULTS: Architect showed 9.59% bias from LC-MS/MS with smaller mean. Passing-Bablok regression analysis demonstrated the value of 0.95 slope and had a constant bias with an intercept value of -4.25. Concordance correlation coefficient showed moderate agreement with the value of 0.918 (95% CI 0.878-0.945). Two methods revealed good interrater agreement (kappa = 0.738). While the smallest bias determined in deficiency (9.95%) group, the biggest was in insufficiency (15.15%). CONCLUSIONS: Architect 25-OH D vitamin immunoassay can be used in routine measurements but had potential misclassification of vitamin D status in insufficient and deficient groups. Although there are recent standardization attempts in 25-OH D measurements, clinical laboratories must be aware of this method.

Determining biological variation of serum parathyroid hormone in healthy adults.

INTRODUCTION: Measurement of parathyroid hormone (PTH) is essential in the investigation and management of calcium metabolism disorders. To assess the significance of any assay result when clinical decision making biological variation (BV) of the measurand must be taken into consideration. The aim of the present study is determining the BV parameters for serum PTH. MATERIALS AND METHODS: Blood samples were taken at weekly intervals from 20 healthy subjects for ten weeks in this prospective BV study. Serum "intact PTH" concentrations were measured with electrochemiluminescence method. Biological variation parameters were estimated using the approach proposed by Fraser. RESULTS: The values of within-subject biological variation (CVI), between-subject biological variation (CVG), analytical variation (CVA), reference change value (RCV) and individuality index (II) for serum PTH were 21.1%, 24.9%, 3.8%, 59.4% and 0.8%, respectively. Within-subject biological variation and CVG were also determined according to gender separately; 18.5% and 24.0%; 26.2% and 18.6% for male and female, respectively. Calculated desirable precision and bias goals were < 10.6% and < 6.3%, respectively. CONCLUSION: This study may contribute to BV data on serum PTH as it includes a sufficient number of volunteers from both genders over an acceptable period of time. We do not recommend the usage of population-based reference intervals for serum PTH concentrations. Reference change value may be helpful for the evaluation of serial serum PTH results. Nonetheless, evaluation of data according to gender is necessary when setting analytical performance specifications.