Point-of-care image-based quantitative urinalysis with commercial reagent strips: Design and clinical evaluation.

Urinalysis is a useful test as an indicator of health or disease and as such, is a part of routine health screening. Urinalysis can be undertaken in many ways, one of which is reagent strips used in the general evaluation of health and to aid in the diagnosis and monitoring of kidney disease. To be effective, the test must be performed properly, and the results interpreted correctly. However, different light conditions and colour perception can vary between users leading to ambiguous readings. This has led to camera devices being used to capture and generate the estimated biomarker concentrations, but image colour can be affected by variations in illumination and inbuilt image processing. Therefore, a new portable device with embedded image processing techniques is presented in this study to provide quantitative measurements that are invariant to changes in illumination. The device includes a novel calibration process and uses the ratio of RGB values to compensate for variations in illumination across an image and improve the accuracy of quantitative measurements. Results show that the proposed calibration method gives consistent homogeneous illumination across the whole image. Comparisons against other existing methods and clinical results show good performance with a correlation to the clinical values. The proposed device can be used for point-of-care testing to provide reliable results consistent with clinical values.

Predictive performance of urinalysis for urine culture results according to causative microorganisms: an integrated analysis with artificial intelligence.

Urinary tract infections (UTIs) are pervasive and prevalent in both community and hospital settings. Recent trends in the changes of the causative microorganisms in these infections could affect the effectiveness of urinalysis (UA). We aimed to evaluate the predictive performance of UA for urinary culture test results according to the causative microorganisms. In addition, UA results were integrated with artificial intelligence (AI) methods to improve the predictive power. A total of 360,376 suspected UTI patients were enrolled from two university hospitals and one commercial laboratory. To ensure broad model applicability, only a limited range of clinical data available from commercial laboratories was used in the analyses. Overall, 53,408 (14.8%) patients were identified as having a positive urine culture. Among the UA tests, the combination of leukocyte esterase and nitrite tests showed the highest area under the curve (AUROC, 0.766; 95% CI, 0.764-0.768) for predicting urine culture positivity but performed poorly for Gram-positive bacteriuria (0.642; 0.637-0.647). The application of an AI model improved the predictive power of the model for urine culture results to an AUROC of 0.872 (0.870-0.875), and the model showed superior performance metrics not only for Gram-negative bacteriuria (0.901; 0.899-0.902) but also for Gram-positive bacteriuria (0.745; 0.740-0.749) and funguria (0.872; 0.865-0.879). As the prevalence of non-Escherichia coli-caused UTIs increases, the performance of UA in predicting UTIs could be compromised. The addition of AI technologies has shown potential for improving the predictive performance of UA for urine culture results.IMPORTANCEUA had good performance in predicting urine culture results caused by Gram-negative bacteria, especially for Escherichia coli and Pseudomonas aeruginosa bacteriuria, but had limitations in predicting urine culture results caused by Gram-positive bacteria, including Streptococcus agalactiae and Enterococcus faecalis. We developed and externally validated an AI model incorporating minimal demographic information of patients (age and sex) and laboratory data for UA, complete blood count, and serum creatinine concentrations. The AI model exhibited improved performance in predicting urine culture results across all the causative microorganisms, including Gram-positive bacteria, Gram-negative bacteria, and fungi.

Urinary Tract Infections: Core Curriculum 2024.

Urinary tract infections (UTIs) are some of the most commonly encountered infections in clinical practice. Accurate diagnosis and evidence-based treatment of UTIs will lead to better clinical care for many patients and limit unnecessary antibiotic use. Urinalysis and urine cultures are helpful tools in the diagnosis of UTIs; however, it is important to recognize their limitations. Differentiating between asymptomatic bacteriuria (ASB) and true UTI is important because antibiotics are unnecessary in most nonpregnant patients with ASB and can even potentially cause harm if prescribed. Choice and duration of antibiotics varies across the spectrum of UTI syndromes such as acute uncomplicated cystitis, pyelonephritis, prostatitis, and catheter-associated UTIs. The treatment approach also depends on patients' degree of immunosuppression and their genitourinary anatomy. Therefore, patients with urological obstruction or kidney transplants may require a specialized and multidisciplinary management approach. For individuals prone to frequent UTIs, some preventative measures can be utilized, yet there is often not a "one size fits all" approach.

Chronic Kidney Disease and Kidney Stone in a Wild Chimpanzee (Pan troglodytes verus) in Côte d'Ivoire.

An older wild female chimpanzee (Pan troglodytes) was found dead with a large calcium oxalate stone in the renal pelvis. Histopathological changes included glomerulosclerosis, interstitial nephritis and fibrosis, focal mineralization, and medial hypertrophy. Urinary albumin-creatinine-ratio showed increased values from 15 months before death. Causes of the kidney disease remain unconfirmed.

Atypical cells in urine sediment: a novel biomarker for early detection of bladder cancer.

OBJECTIVES: Atypical cells (Atyp.C), as a new parameter determined by an automated urine analyzer, can be suspected of being malignant tumor cells. We evaluated the extent to which the Atyp.C can predict the existence of malignant tumor cells. METHODS: A total of 3,315 patients (1,751 in the training cohort and 1,564 in the testing cohort) were recruited and divided into five groups, namely, primary bladder cancer (BCa), recurrent BCa, post-treatment monitoring of BCa, other urological tumors, and controls. Urine Atyp. C, bacteria, white blood cell, and red blood cell were measured by a Sysmex UF-5000 analyzer. We compared the Atyp.C values across the different groups, sexes, and tumor stages. The diagnostic performance of Atyp.C alone and in combination with other parameters for detecting BCa was evaluated using receiver operating characteristic (ROC) curve analysis. RESULTS: The Atyp.C value of the primary BCa group was significantly higher than that in the other groups, except recurrent BCa group. The Atyp.C value was closely related to tumor staging. Atyp.C combined with bacteria had the highest diagnostic performance for primary BCa [training cohort AUC: 0.781 (95 % CI: 0.761-0.801); testing cohort AUC: 0.826 (95 % CI: 0.806-0.845)]. The AUC value of diagnosed recurrent BCa by Atyp.C plus bacteria for the training cohort was 0.784 (95 % CI: 0.762-0.804). CONCLUSIONS: Atyp.C was high in primary BCa patients and the combination of bacteria and Atyp.C showed high predictive value for primary BCa, suggesting that Atyp.C may be a useful objective indicator for the early detection of BCa.

The EFLM European Urinalysis Guideline 2023.

BACKGROUND: The EFLM Task and Finish Group Urinalysis has updated the ECLM European Urinalysis Guidelines (2000) on urinalysis and urine bacterial culture, to improve accuracy of these examinations in European clinical laboratories, and to support diagnostic industry to develop new technologies. RECOMMENDATIONS: Graded recommendations were built in the following areas. MEDICAL NEEDS AND TEST REQUISITION: Strategies of urine testing are described to patients with complicated or uncomplicated urinary tract infection (UTI), and high or low-risk to kidney disease. SPECIMEN COLLECTION: Patient preparation, and urine collection are supported with two quality indicators: contamination rate (cultures), and density of urine (chemistry, particles). CHEMISTRY: Measurements of both urine albumin and α1-microglobulin are recommended for sensitive detection of kidney disease in high-risk patients. Performance specifications are given for urine protein measurements and quality control of multiproperty strip tests. PARTICLES: Procedures for microscopy are reviewed for diagnostic urine particles, including urine bacteria. Technologies in automated particle counting and visual microscopy are updated with advice how to verify new instruments with the reference microscopy. BACTERIOLOGY: Chromogenic agar is recommended as primary medium in urine cultures. Limits of significant growth are reviewed, with an optimised workflow for routine specimens, using leukocyturia to reduce less important antimicrobial susceptibility testing. Automation in bacteriology is encouraged to shorten turn-around times. Matrix assisted laser desorption ionization time-of-flight mass spectrometry is applicable for rapid identification of uropathogens. Aerococcus urinae, A. sanguinicola and Actinotignum schaalii are taken into the list of uropathogens. A reference examination procedure was developed for urine bacterial cultures.

Urinalysis is predictive for absence of urinary tract infection in men with and without catheters.

OBJECTIVES: To determine accuracy of negative urinalysis (UA) for predicting negative urine culture and the absence of urinary tract infection (UTI), and optimal urine culture growth cutoff for UTI diagnosis in men with and without urinary catheters. SUBJECTS AND METHODS: UAs with urine cultures within 1 week from adult men were identified and evaluated. Predictive values for the absence of UTI (absence of ≥1 of the following criteria: documentation of UTI diagnosis, antibiotic prescription, uropathogen presence on culture) were calculated. RESULTS: In total, 22 883 UAs were included. Negative UA had a high predictive value for negative urine culture (0.95, 95% confidence interval [CI]: 0.94-0.95) and absence of UTI (0.99, CI: 0.99-0.995) in the overall cohort. Negative UA also had a high predictive value for negative urine culture (0.93, CI: 0.90-0.95) and absence of UTI (0.99, CI: 0.98-0.999) in those with indwelling urinary catheters. The traditional threshold of culture growth of 100 000 colony-forming units (CFU)/mL did not capture 22% of UTIs. CONCLUSION: UA exhibits high predictive value for negative urine culture and absence of UTI in men, supporting a protocol wherein culture is only performed in the context of abnormal UA. The traditional 100 000 CFU/mL cut-off may have not captured a subset of UTI in the male population, and warrants further investigation.

Silver-based bimetallic nanozyme fabrics with peroxidase-mimic activity for urinary glucose detection.

The enhanced catalytic properties of bimetallic nanoparticles have been extensively investigated. In this study, bimetallic Ag-M (M = Au, Pt, or Pd) cotton fabrics were fabricated using a combination of electroless deposition and galvanic replacement reactions, and improvement in their peroxidase-mimicking catalytic activity compared to that of the parent Ag fabric was studied. The Ag-Pt bimetallic nanozyme fabric, which showed the highest catalytic activity and ability to simultaneously generate hydroxyl (•OH) and superoxide (O2•-) radicals, was assessed as a urine glucose sensor. This nanozyme fabric sensor could directly detect urinary glucose in the pathophysiologically relevant high millimolar range without requiring sample predilution. The sensor could achieve performance on par with that of the current clinical gold standard assay. These features of the Ag-Pt nanozyme sensor, particularly its ability to avoid interference effects from complex urinary matrices, position it as a viable candidate for point-of-care urinary glucose monitoring.

Machine learning-assisted image label-free smartphone platform for rapid segmentation and robust multi-urinalysis.

This study presents a groundbreaking approach for the early detection of chronic kidney disease (CKD) and other urological disorders through an image-label-free, multi-dipstick identification method, eliminating the need for complex machinery, label libraries, or preset coordinates. Our research successfully identified reaction pads on 187 multi-dipsticks, each with 11 pads, leveraging machine learning algorithms trained on human urine data. This technique aims to surpass traditional colourimetric methods and concentration-colour curve fitting, offering more robust and precise community screening and home monitoring capabilities. The developed algorithms enhance the generalizability of machine learning models by extracting primary colours and correcting urine colours on each reaction pad. This method's cost-effectiveness and portability are significant, as it requires no additional equipment beyond a standard smartphone. The system's performance rivals professional medical equipment without auxiliary lighting or flash under regular indoor light conditions, effectively managing false positives and negatives across various categories with remarkable accuracy. In a controlled experimental setting, we found that random forest algorithms, based on a Bagging strategy and applied in the HSV colour space, showed optimal results in smartphone-assisted urinalysis. This study also introduces a novel urine colour correction method, significantly improving machine learning model performance. Additionally, ISO parameters were identified as crucial factors influencing the accuracy of smartphone-based urinalysis in the absence of additional lighting or optical configurations, highlighting the potential of this technology in low-resource settings.

An updated approach to the evaluation of the urinary sediment.

Examination of the urinary sediment (U-sed) is an important non-invasive, rapid, and inexpensive tool for the diagnosis and surveillance over time of renal diseases. In this Educational Review, we describe first how to collect, prepare, and examine urine samples in order to obtain reliable results. Then, we describe the U-sed findings in isolated microscopic hematuria, glomerular diseases, acute interstitial nephritis, acute kidney injury, reactivation of the BK virus in kidney transplant recipients, and crystalluric genetic diseases.

Significance of scattered small echogenic foci floating in urinary bladder as ultrasonography finding in dogs.

BACKGROUND: Despite the prevalence of echogenic foci floating in the urinary bladder seen in ultrasonography in dogs, surprisingly little has been written on its significance, including its potential association with urinalysis. The objective of the study was to determine the diagnostic value of the echogenic foci floating in urinary bladders in dogs. RESULTS: - Cystosonography was performed on 45 dogs. Bladder contents were examined and divided into positive (containing echogenic particles) and negative (absent echogenic particles) groups according to the presence and absence of floating echogenic particles. Five mL of urine was collected via cystocentesis. Urine analysis and culture were done and the relationship between ultrasound evaluation and urinalysis results was investigated. In dogs with bladder echogenic particles in ultrasonography, the prevalence of hematuria, pyuria, bacteriuria, and lipiduria were 88.9%, 92.6%, 29.6%, and 70.3%, respectively. However, in dogs in which echogenic particles were not observed in their bladders, the prevalence of hematuria, pyuria, bacteriuria, and lipiduria was 77%, 50%, 5.5%, and 77%, respectively. There was a significant association between bladder debris and positive urine culture, with an odds ratio of 7.15 (95% confidence interval: 0.81-63.28) compared with matched controls. Furthermore, there was a significant relationship between the presence of floating echogenic particles with pyuria, and urine color ( p ≤ 0.05). CONCLUSION: In conclusion, the present results showed the detection of bladder debris on ultrasound can be a predictor for pyuria and positive urine culture in dogs.

Using the Sysmex UF-4000 urine flow cytometer for rapid diagnosis of urinary tract infection in the clinical microbiological laboratory.

BACKGROUND: Urinary tract infections are responsible for a significant worldwide disease burden. Performing urine culture is time consuming and labor intensive. Urine flow cytometry might provide a quick and reliable method to screen for urinary tract infection. METHODS: We analyzed routinely collected urine samples received between 2020 and 2022 from both inpatients and outpatients. The UF-4000 urine flow cytometer was implemented with an optimal threshold for positivity of ≥100 bacteria/µL. We thereafter validated the prognostic value to detect the presence of urinary tract infection (UTI) based on bacterial (BACT), leukocyte (WBC), and yeast-like cell (YLC) counts combined with the bacterial morphology (UF gram-flag). RESULTS: In the first phase, in 2019, the UF-4000 was implemented using 970 urine samples. In the second phase, between 2020 and 2022, the validation was performed in 42,958 midstream urine samples. The UF-4000 screen resulted in a 37% (n = 15,895) decrease in performed urine cultures. Uropathogens were identified in 18,673 (69%) positively flagged urine samples. BACT > 10.000/µL combined with a gram-negative flag had a >90% positive predictive value for the presence of gram-negative uropathogens. The absence of gram-positive flag or YLC had high negative predictive values (99% and >99%, respectively) and are, therefore, best used to rule out the presence of gram-positive bacteria or yeast. WBC counts did not add to the prediction of uropathogens. CONCLUSION: Implementation of the UF-4000 in routine practice decreased the number of cultured urine samples by 37%. Bacterial cell counts were highly predictive for the presence of UTI, especially when combined with the presence of a gram-negative flag.

The interval between the onset of increased blood pressure and proteinuria in preeclampsia and the contributing factors.

PURPOSE: New-onset proteinuria, as a pivotal sign of representative renal lesions in preeclampsia, is still the most common diagnostic tool for this condition and has been proven to be related to a significantly abnormal sFlt-1/VEGF ratio in circulation. At the same time, blood pressure control plays a vital role in the occurrence and evolution of proteinuria. Therefore, it is particularly helpful to investigate their interval, not only for performing urinalysis for protein more accurately but also for evaluating blood pressure as well as the aggravation of illness, as the related research is limited. METHODS: This retrospective study included 515 preeclampsia patients and 358 normotensive pregnant women who labored in the Second Hospital of Tianjin Medical University from January 2016 to January 2020. First, we described the onset circumstance of high blood pressure and proteinuria as well as the interval among the case group and the subgroups. Then, we determined whether there were significant differences in the basic information, laboratory test results, and newborns between the case and normal groups. Finally, multifactor ANOVA was used to determine the factors influencing the interval. RESULTS: 1. The two most common complications in preeclampsia were proteinuria (88.35%) and placental dysfunction (5.05%). Moreover, 72.04% of preeclampsia cases were diagnosed by abnormal blood pressure together with new-onset proteinuria. 2. The average interval between high blood pressure and proteinuria was 22 gestational days (from 0 to 106 days), and this interval was not significantly different between mild and severe PE (26 days vs. 21 days, P > 0.05) but significantly differed between early-onset and late-onset PE (9 days vs. 28 days, P < 0.05). 3. The number of prenatal visits, serum creatinine in the early trimester, gestational time and diastolic blood pressure value when increased blood pressure was initially detected may influence the interval between the onset of increased blood pressure and proteinuria. CONCLUSION: New-onset proteinuria was still the main parameter for identifying preeclampsia. The interval between increased blood pressure and proteinuria was probably related to the imbalance in the sFlt-1/VEGF ratio; therefore, we should pay attention to monitor proteinuria during the prenatal visits, especially for patients with a lower frequency of prenatal visits, higher serum creatinine in the early trimester, earlier onset and higher diastolic blood pressure at the initial onset of increased blood pressure.

On the Value of Measuring Recent Drug Use by Self-Reports and Urinalysis in Clinical Trials.

Background: Valid measurement of drug use in patients enrolled in clinical trials that treat substance use disorder is vital to determine the trial's outcome. Self-reports are often used but their validity has been studied with mixed results. Urinalysis may sometimes be employed as an alternative or supplement to self-reports. Objectives: This study examined how estimating drug use by either method would affect the results from a randomized clinical trial conducted in a methadone treatment program. At the initial Baseline interview and four follow-up interviews, participants were asked about their drug use history and provided a urine specimen for drug testing. Results: In most cases, the urinalyses detected more drugs than the patients had reported using. A major exception was heroin, whose use was an eligibility criterion for enrollment in the study and methadone treatment. Conclusions: The patients' self-reports would have led us to conclude that the use of heroin and fentanyl had declined from the initial Baseline interview to the final follow-up interview, while the urinalysis results indicated no change in exposure to heroin and an increase in exposure to fentanyl. Clinical trials would be well served to employ the use of biological tests in addition to self-reports to measure recent drug use and to accurately estimate the efficacy of the experimental protocols and patients' exposure to drugs.

Hepatic Biotransformation of Renal Clearable Gold Nanoparticles for Noninvasive Detection of Liver Glutathione Level via Urinalysis.

Renal clearable nanoparticles have been drawing much attention as they can avoid prolonged accumulation in the body by efficiently clearing through the kidneys. While much effort has been made to understand their interactions within the kidneys, it remains unclear whether their transport could be influenced by other organs, such as the liver, which plays a crucial role in metabolizing and eliminating both endogenous and exogenous substances through various biotransformation processes. Here, by utilizing renal clearable IRDye800CW conjugated gold nanocluster (800CW4-GS18-Au25) as a model, we found that although 800CW4-GS18-Au25 strongly resisted serum-protein binding and exhibited minimal accumulation in the liver, its surface was still gradually modified by hepatic glutathione-mediated biotransformation when passing through the liver, resulting in the dissociation of IRDye800CW from Au25 and biotransformation-generated fingerprint message of 800CW4-GS18-Au25 in urine, which allowed us to facilely quantify its urinary biotransformation index (UBI) via urine chromatography analysis. Moreover, we observed the linear correlation between UBI and hepatic glutathione concentration, offering us a noninvasive method for quantitative detection of liver glutathione level through a simple urine test. Our discoveries would broaden the fundamental understanding of in vivo transport of nanoparticles and advance the development of urinary probes for noninvasive biodetection.

Risk of CKD Following Detection of Microscopic Hematuria: A Retrospective Cohort Study.

RATIONALE & OBJECTIVE: Microscopic hematuria is an uncertain risk factor for chronic kidney disease (CKD). We investigated the association between persistent or single episodes of microscopic hematuria and the development of incident CKD, overall and separately among men and women. STUDY DESIGN: Retrospective cohort study. SETTING & PARTICIPANTS: A total of 232,220 Korean adults without CKD at baseline who underwent repeated regular health examinations at Kangbuk Samsung Health Study formed the study cohort. EXPOSURE: Microscopic hematuria was defined by≥5 red blood cells per high-power field. Participants were categorized into 1 of 4 groups according to the presence of hematuria at 2 consecutive examinations: (1) no hematuria at both examinations (reference group); (2) hematuria followed by no hematuria (regressed hematuria group); (3) no hematuria followed by hematuria (developed hematuria group); and (4) hematuria at both examinations (persistent hematuria group). OUTCOME: CKD was defined as an estimated glomerular filtration rate<60mL/min/1.73m2 or proteinuria (1+or more on dipstick examination). ANALYTICAL APPROACH: Semiparametric proportional hazards models were used to estimate hazard ratios. RESULTS: During a 4.8-year median follow-up period, 2,392 participants developed CKD. Multivariable-adjusted hazard ratios for incident CKD, comparing the regressed, developed, and persistent hematuria groups to the no-hematuria group were 1.85 (95% CI, 1.35-2.53), 3.18 (95% CI, 2.54-3.98), and 5.23 (95% CI, 4.15-6.59), respectively. The association between persistent hematuria and incident CKD was stronger in men than women (P for interaction<0.001), although a statistically significant association was observed in both sexes. LIMITATIONS: Lack of albuminuria and inability to consider specific glomerular diseases. CONCLUSIONS: Men and women with microscopic hematuria, especially persistent hematuria, may be at increased risk of CKD.

Major disparities in patient-reported adherence compared to objective assessment of adherence using mass spectrometry: A prospective study in a tertiary-referral hypertension clinic.

AIM: Many challenges exist in determining true rates of adherence to antihypertensive medications among individuals in a clinic setting. For the first time, we aimed to compare patient-reported antihypertensive adherence with objective evidence using mass spectrometry spot urinalysis in a tertiary referral clinic setting. METHODS: A prospective observational single-centre cohort study was performed in a tertiary referral hypertension clinic, encompassing antihypertensive initiation and persistence. Patients were referred with apparent treatment-resistant hypertension or for suspected secondary causes. Participants completed a self-reported assessment of antihypertensive adherence and provided a spot urine sample. The presence of antihypertensive medications and/or their respective metabolites was evaluated using high-performance liquid chromatography tandem mass spectrometry. Patients were determined to be adherent if they demonstrated both self-reported adherence and objective mass spectrometry evidence. RESULTS: Of all 105 eligible participants initially recruited, 73 (69.5%) met the eligibility criteria. Only 27.4% (95% confidence interval 0.2-0.4) of participants demonstrated true adherence to their self-reported antihypertensives, despite 75.3% (0.6-0.8) reporting adherence. Greatest medication adherence was achieved with angiotensin II receptor blockers (61%), with calcium-channel blockers and mineralocorticoid antagonists demonstrating least adherence (38%). CONCLUSION: In patients attending a tertiary hypertension clinic, the combined use of spot urine mass spectrometry and self-reporting identifies higher rates of nonadherence when compared to either modality alone. Both techniques should be combined for more accurate detection of medication adherence.

Calcium salt crystalluria in a captive chimpanzee (Pan troglodytes) population.

BACKGROUND: Urinalysis is a rapid, non-invasive method used to obtain diagnostic information on primates. While several studies have investigated dipstick and specific gravity values in chimpanzees, urine sediment analysis is often excluded. Crystalluria, observed during urine sediment analysis, can be benign or indicate renal pathologies. METHODS: In total, 665 urine samples from sanctuary-housed chimpanzees were analyzed over the course of 17 months for pH, specific gravity, time of collection, and crystalluria. RESULTS AND CONCLUSIONS: Calcium salt crystalluria was seen in 9.0% of the samples from 23.7% of the individuals in the study. Urinary pH and specific gravity were significantly higher in samples with crystalluria than in those lacking crystalluria, while time of collection did not differ between the two groups. While diet is the most likely cause of the crystalluria in this population, several medications could also cause urinary crystallization. Further exploration of the significance of calcium salt crystalluria in chimpanzees is warranted.

Urine transfer devices may impact urinary particle results: a pre-analytical study.

OBJECTIVES: Well-standardized procedures in the pre-analytical phase of urine diagnostics is of utmost importance to obtain reliable results. We investigated the effect of different urine collection methods and the associated urine transfer tubes on urine test strip and particle results. METHODS: In total, 146 selected urine samples were subdivided into three different collection containers and subsequently transferred into its accompanying transfer tube (BD, Greiner, Sarstedt vacuum and Sarstedt aspiration). As reference, the original urine sample was directly measured on the analyser. Both chemical test strip analysis (Sysmex UC-3500) and fluorescence flow cytometry particle analysis (Sysmex UF-5000) were performed on all samples. RESULTS: No statistically significant differences in test strip results were found between the studied transfer methods. On the contrary, transfer of urine samples to the secondary tubes affected their particle counts. Clinically significant reductions in counts of renal tubular epithelial cells and hyaline casts were observed using the BD and Greiner transfer tubes and in counts of pathological casts using the BD, Greiner and Sarstedt vacuum tubes. CONCLUSIONS: The results of this study indicate that the use of urine transfer tubes may impact counts of fragile urine particles. Clinical laboratories need to be aware about the variation that urine collection methods can induce on urine particle counts.

The relationship between abnormal urinalysis findings and appendicitis location.

AIMS: Acute appendicitis is a common cause of acute abdomen in general surgery and early diagnosis is crucial for prognosis. Abnormal urinalysis results have been associated with appendicitis in some studies, with reports of microscopic hematuria or pyuria in laboratory tests. The aim of this article is to evaluate the relationship between laboratory findings of hematuria, pyuria, and the location of acute appendicitis. METHODS: This retrospective study included 577 patients who underwent appendectomy for suspected acute appendicitis between January 1, 2018, and December 31, 2022, at the general surgery clinic of Samsun Training and Research Hospital. RESULTS: Among the 577 patients, 247 were female and 330 were male, with a median age of 34 years. A statistically significant difference was observed between appendicitis location and erythrocyte values (p = 0.009), specifically in paraileal and retrocecal locations. There was a statistically significant difference between appendicitis location and leukocyte values (p < 0.001), with significant differences found in paraileal, promontoric, and retrocecal locations. A statistically significant difference was observed between appendicitis location and leukocyte esterase values (p = 0.002), specifically in paraileal and retrocecal locations. DISCUSSION/CONCLUSION: Abnormal urinalysis findings are not uncommon in patients with acute appendicitis. Our study demonstrated a significant correlation between tit erythrocyte, tit leukocyte, and tit leukocyte esterase positivity with appendicitis locations. Therefore, we believe that pathological findings in urine tests of patients undergoing surgery with a preliminary diagnosis of appendicitis can provide valuable information to surgeons regarding the location of the appendix, ultimately aiding in optimizing the timing and cost of the operation.