Mehmet Senes

Can routine automated urinalysis reduce culture requests

OBJECTIVES There are a substantial number of unnecessary urine culture requests. We aimed to investigate whether urine dipstick and microscopy results could accurately rule out urinary tract infection (UTI) without urine culture. DESIGN AND METHODS The study included a total of 32,998 patients (11,928 men and 21,070 women, mean age: 39 ± 32 years) with a preliminary diagnosis of UTI and both urinalysis and urinary culture were requested. All urine cultures were retrospectively reviewed; association of culture positivity with a positive urinalysis result for leukocyte esterase (LE) and nitrite in chemical analysis and pyuria (WBC) and bacteriuria in microscopy was determined. Diagnostic performance of urinalysis parameters for detection of UTI was evaluated. RESULTS In total, 758 (2.3%) patients were positive by urine culture. Out of these culture positive samples, ratios of positive dipstick results for LE and nitrite were 71.0% (n=538) and 17.7% (n=134), respectively. The positive microscopy results for WBC and bacteria were 68.2% (n=517) and 78.8% (n=597), respectively. Negative predictive values for LE, nitrite, bacteriuria and WBC were very close to 100%. CONCLUSIONS Most of the samples have no or insignificant bacterial growth. Urine dipstick and microscopy can accurately rule out UTI. Automated urinalysis is a practicable and faster screening test which may prevent unnecessary culture requests for majority of patients.

Urinary 8-hydroxy-2′-deoxyguanosine level and plasma paraoxonase 1 activity with Alzheimer’s disease

Abstract Background: Alzheimer’s disease (AD) is the most frequent cause of dementia and age is the most important risk factor for AD. Aging is associated with increased free radical production and oxidative stress plays an important role in the pathogenesis of AD. 8-Hydroxy-2′-deoxyguanosine (8-OHdG) is a biomarker indicating oxidative DNA damage. Paraoxonase 1 (PON1) is a high-density lipoprotein (HDL)-associated antioxidant enzyme and prevents especially oxidation of low-density lipoproteins. The aim of this study is to measure urinary 8-OHdG levels and serum PON1 activity in patients with AD. Methods: A total of 21 elderly patients diagnosed with moderate AD (10 men and 11 women, aged 76±7.8 years) were included in the study. A total of 20 healthy elderly volunteers (11 men and nine women, aged 81±7.2 years) were enrolled as a control group. Levels of urinary 8-OHdG, serum PON1 activity and lipid profile were determined in patients and controls. Results: Urinary 8-OHdG levels were significantly increased, but serum PON1 activity was significantly decreased in patients compared to controls. Lipid profile did not show a difference between the groups. There was a negative correlation between 8-OHdG levels and PON1 activity only in the patient group (r=–0.536). Analytical performance characteristics of the methods used were satisfactory. Conclusions: In this study, evidence of increased oxidative DNA damage was determined in AD patients as well as decreased serum PON1 activity. Oxidant stress and oxidative DNA damage are important pathological processes in AD. The biomarkers, urinary 8-OHdG level and serum PON1 activity can be used to determine and monitor the status of patients with AD.

What should be the laboratory approach against isolated prolongation of a activated partial thromboplastin time

This study is a retrospective evaluation of patients who were subject to mixing study in our laboratory due to prolonged APTT. The preliminary diagnoses, clinical manifestations, and results of additional ordered tests were reviewed. The study aims to investigate whether repeating APTT test with a different assay prior to performing mixed study in patients with prolonged APTT would be a better alternative algorithmic approach in order to save both time and costs.

Tumor marker requests in a general teaching Turkish hospital

Serum tumor markers may be requested inappropriately by clinicians. In this retrospective study, we aimed to investigate the appropriateness of TM requests in our hospital. Patients in the study were identified from the TM requests for 3 months between June–August 2004, using the laboratory database. A total of 2249 patients (1351 men, 898 women) were included in the study and there were 6570 TM requests. The number of requests were 1050 (16%) for Carbohydrate Antigen 19-9, 993 (15.1%) for Cancer Antigen 125, 941 (14.3%) for Prostate Specific Antigen, 921 (14%) for free PSA, 925 (14.1%) for Cancer Antigen 15-3, 788 (12%) for Alphafetoprotein, 730 (11.1%) for Carcinoembryonic Antigen and 222 (3.4%) for AFP/Human Chorionic Gonadotrophin. Our findings support the idea that for the evidence-based use of TM requests the education of clinical staff is required. Clear clinical guidelines including recommendations about the appropriate use of TM can be useful for this education process. Careful audit studies are also useful to determine the impact of these guidelines on the practice of evidence-based laboratory medicine.

Falsely Elevated Glucose Concentrations in Peritoneal Dialysis Patients Using Icodextrin

Peritoneal dialysis (PD) is used as an alternative to hemodialysis in end‐stage renal disease (ESRD). Icodextrin has been used as a hyperosmotic agent in PD. The aim of the study was to assess two different point‐of‐care testing (POCT) glucose strips, affected and not affected by icodextrin, with serum glucose concentrations of the patients using and not using icodextrin.

Is Turkish MEFV Mutations Spectrum Different Among Regions

Familial Mediterranean fever (FMF) is an autosomal recessive inherited inflammatory disease. The gene responsible for the disease, called MEFV, encodes a protein called pyrin or marenostrin. According to recent data, MEFV mutations are not the only cause of FMF, but genetic analysis of MEFV gene is needed for confirming the diagnosis of FMF. In the present study, we aimed to evaluate the molecular testing results of MEFV mutations.

Urinary methylmalonic acid levels in patients with acute ischemic stroke.

OBJECTIVES Vitamin B-12 and folate deficiency are common, especially in people aged 55 or over, and accompanied by elevated methylmalonic acid (MMA) and homocysteine concentrations. The aims of the study were to investigate the relationship between serum vitamin B-12, homocysteine, folate, erythrocyte folate and urinary MMA in patients with ischemic stroke, and to develop a simple screening HPLC method for the measurement of urinary MMA. DESIGN AND METHODS Twenty-eight patients aged 55 years and over with ischemic stroke and 23 age- and sex- matched healthy controls were included in the study. Serum vitamin B-12 and folate were measured by immunoassay; serum total homocysteine and urinary MMA concentrations by HPLC. RESULTS There was no significant difference in vitamin B-12, folate and homocysteine concentrations between the patient and control groups. Urinary MMA concentrations and erythrocyte folate levels were significantly higher in patients than controls. There was a significantly negative correlation between vitamin B-12 and MMA. CONCLUSIONS Increased urinary MMA excretion is associated with ischemic stroke and it may more robustly reflect vitamin B-12 deficiency in patients with ischemic stroke. The method used in this study is eligible for routine urinary MMA measurements.

Biological variation estimates of prothrombin time, activated partial thromboplastin time, and fibrinogen in 28 healthy individuals

Although tests of global hemostasis prothrombin time (PT) and activated partial thromboplastin time (aPTT) should not be used for prediction of bleeding risk, these tests are often used by many clinicians in daily practice particularly as a preoperative screening test. Robust biological variation (BV) data are needed for safe clinical applications of these tests. In this study, a stringent protocol was followed to estimate the BVs for PT, aPTT, and fibrinogen levels.

Higher Pentraxin-3 Levels are Associated With Inflammation in Familial Mediterranean Fever.

Circulating levels of Pentraxin‐3 (PTX3) have been shown to increase in several inflammatory conditions. However, there is no information about the levels of PTX3 in patients with familial Mediterranean fever (FMF). This study was designed to evaluate the serum PTX3 levels in patients with FMF during attack and free‐attack periods.

Serum soluble fas ligand levels in familial Mediterranean fever

Abstract Introduction: Fas/FasL system plays an important role in the regulation of cell life and death, and circulating levels of sFasL have been shown to increase in some inflammatory conditions. However, there is no sufficient information about the levels of sFasL in patients with FMF. This study was designed to evaluate the serum sFasL levels in patients with FMF during attack and attack-free periods. Methods: Twenty-five FMF patients in attack and forty-four in free-attack period, and 20 age-, sex-, and BMI-matched healthy controls were included in this study. Participants with any chronic diseases were excluded. Blood samples were obtained within the first 24 h of the attack period and between febrile attacks, and levels of WBC, ESR, Fibrinogen, hsCRP and sFasL were determined. Results: The levels of traditional acute phase reactants during the attack were significantly higher than the attack-free and controls (p < 0.05). The serum sFasL levels in the FMF study groups did not differ from the control group (0.70 ± 0.08 vs. 0.73 ± 0.12; 0.70 ± 0.08 vs. 0.83 ± 0.14; 0.73 ± 0.12 vs. 0.83 ± 0.14, respectively, p > 0.05). Moreover, the sFasL levels during the attack were not significantly different from those in attack-free patients (0.70 ± 0.08 vs. 0.83 ± 0.14, p > 0.05). Conclusion: In this study, we demonstrated that serum sFasL levels were not markedly affected in FMF and cannot be used as a supportive marker to differentiate attacks from attack-free periods. However, further studies are needed to determine its usefulness as a marker in clinical practice.