Detection of Mycobacterium tuberculosis transrenal DNA in urine samples among adults in Peru.

Diagnosis of pulmonary tuberculosis (TB) relies on a sputum sample, which cannot be obtained from all symptomatic individuals. Mycobacterium tuberculosis (Mtb) transrenal DNA (trDNA) has been detected in urine, an easily obtainable, noninvasive, alternative sample type. However, reported sensitivities have been variable and likely depend on collection and assay procedures and aspects of trDNA biology. We analyzed three serial urine samples from each of 75 adults with culture-confirmed pulmonary TB disease in Lima, Peru for detection of trDNA using short-fragment real-time PCR. Additionally, we examined host, urine, and sampling factors associated with detection. Overall per-sample sensitivity was 38 % (95 % Confidence Interval [CI] 30-45 %). On an individual level (i.e., any of the three samples positive), sensitivity was 73 % (95 % CI: 62-83 %). Sensitivity was highest among samples from patients with smear-positive TB, 92 % (95 % CI: 62-100 %). Specificity from a single sample from each of 10 healthy controls was 100 % (95 % CI: 69-100 %). Adjusting our assay positivity threshold increased individual-level sensitivity to 88 % (95 % CI: 78-94 %) overall without affecting the specificity. We did not find associations between Mtb trDNA detection and individual characteristics or urine sample characteristics. Overall, our results support the potential of trDNA detection for TB diagnosis.

The applicability of the urine color scale in pediatric urology.

AIMS: To determine the level of agreement between healthcare professionals, patients and their parents/guardians in the interpretation of the urine color scale (UCS) in cases of urinary dysfunction, analyzing the applicability of the scale as a diagnostic tool determining the hydration status. METHODS: This was a cross-sectional study involving 5-17-year-old patients with lower urinary tract symptoms (LUTS) and enuresis. The study was conducted in a public healthcare referral center for pediatric urology in the Brazilian state of Bahia between October 2019 and March 2020. The Kolmogorov-Smirnov test was used to assess the distribution of the variables. Agreement was assessed using the kappa coefficient and weighted kappa. The z-test was used to determine significant differences between the kappa and weighted kappa. The statistical analysis was conducted using SPSS, version 14, and significance was established at p < 0.05. RESULTS: Forty-four patients were included. The kappa value was 32.4% (p = 0.000) for the agreement between healthcare professionals and patients, 41.9% (p = 0.000) for agreement between healthcare professionals and parents/guardians, and 25.0% (p = 0.001) for agreement between patients and parents/guardians. The weighted kappa was 70.6% (p = 0.000) for agreement between healthcare professionals and patients, 82.4% (p = 0.000) for agreement between healthcare professionals and parents/guardians, and 51.5% (p = 0.001) for agreement between patients and parents/guardians. There was a statistically significant difference in kappa values when the healthcare professionals were compared with the other groups. CONCLUSIONS: Although there were some inconsistencies in interpretation, the UCS proved to be a useful tool with which to evaluate patients' hydration status.

Antibiotic Overtreatment of Presumed Urinary Tract Infection Among Children with Spina Bifida.

OBJECTIVE: To identify factors associated with overtreatment of presumed urinary tract infection (UTI) among children with spina bifida using such criteria. STUDY DESIGN: A retrospective review of children with spina bifida (age <21 years) evaluated in the Emergency Department (ED) at a single institution was performed. Patients with a urinalysis (UA) performed who were reliant on assisted bladder emptying were included. The primary outcome was overtreatment, defined as receiving antibiotics for presumed UTI but ultimately not meeting spina bifida UTI criteria (≥2 urologic symptoms plus pyuria and urine culture growing >100k CFU/mL). The primary exposure was whether the components of the criteria available at the time of the ED visit (≥2 urologic symptoms plus pyuria) were met when antibiotics were initiated. RESULTS: Among 236 ED encounters, overtreatment occurred in 80% of cases in which antibiotics were initiated (47% of the entire cohort). Pyuria with <2 urologic symptoms was the most important factor associated with overtreatment (OR 9.6). Non-Hispanic White race was associated with decreased odds of overtreatment (OR 0.3). CONCLUSIONS: Overtreatment of presumed UTI among patients with spina bifida was common. Pyuria, which is not specific to UTI in this population, was the main driver of overtreatment. Symptoms are a cornerstone of UTI diagnosis among children with spina bifida, should be collected in a standardized manner, and considered in a decision to treat.

Surface-enhanced Raman Spectroscopy in urinalysis of hypertension patients with kidney disease.

Arterial hypertension (AH) is a multifactorial and asymptomatic disease that affects vital organs such as the kidneys and heart. Considering its prevalence and the associated severe health repercussions, hypertension has become a disease of great relevance for public health across the globe. Conventionally, the classification of an individual as hypertensive or non-hypertensive is conducted through ambulatory blood pressure monitoring over a 24-h period. Although this method provides a reliable diagnosis, it has notable limitations, such as additional costs, intolerance experienced by some patients, and interferences derived from physical activities. Moreover, some patients with significant renal impairment may not present proteinuria. Accordingly, alternative methodologies are applied for the classification of individuals as hypertensive or non-hypertensive, such as the detection of metabolites in urine samples through liquid chromatography or mass spectrometry. However, the high cost of these techniques limits their applicability for clinical use. Consequently, an alternative methodology was developed for the detection of molecular patterns in urine collected from hypertension patients. This study generated a direct discrimination model for hypertensive and non-hypertensive individuals through the amplification of Raman signals in urine samples based on gold nanoparticles and supported by chemometric techniques such as partial least squares-discriminant analysis (PLS-DA). Specifically, 162 patient urine samples were used to create a PLS-DA model. These samples included 87 urine samples from patients diagnosed with hypertension and 75 samples from non-hypertensive volunteers. In the AH group, 35 patients were diagnosed with kidney damage and were further classified into a subgroup termed (RAH). The PLS-DA model with 4 latent variables (LV) was used to classify the hypertensive patients with external validation prediction (P) sensitivity of 86.4%, P specificity of 77.8%, and P accuracy of 82.5%. This study demonstrates the ability of surface-enhanced Raman spectroscopy to differentiate between hypertensive and non-hypertensive patients through urine samples, representing a significant advance in the detection and management of AH. Additionally, the same model was then used to discriminate only patients diagnosed with renal damage and controls with a P sensitivity of 100%, P specificity of 77.8%, and P accuracy of 82.5%.

Contaminant Organism Growth in Febrile Infants at Low Risk for Invasive Bacterial Infection.

In this multicenter, cross-sectional, secondary analysis of 4042 low-risk febrile infants, nearly 10% had a contaminated culture obtained during their evaluation (4.9% of blood cultures, 5.0% of urine cultures, and 1.8% of cerebrospinal fluid cultures). Our findings have important implications for improving sterile technique and reducing unnecessary cultures.

Management of Urinary Tract Infection Symptoms in Older Women: A Survey of Practitioners.

IMPORTANCE: Urinary tract infection (UTI) is the most common bacterial infection for which empiric antibiotics are prescribed despite limited progression to urosepsis. More than half of antibiotics prescribed to older adults for a suspected UTI are considered unnecessary. OBJECTIVE: The aim of the study was to assess knowledge, attitudes, and practices regarding management of older women (>65 years) with symptoms attributed to UTIs among family and internal medicine providers. STUDY DESIGN: This cross-sectional study surveyed 330 primary care providers in November 2021 regarding management of UTI symptoms. The primary outcome was the proportion of primary care providers who felt safe waiting for urine culture results before prescribing antibiotics in older women. RESULTS: The response rate was 43.0% (n = 142) with the majority of primary care providers practicing medicine more than 15 years (56.3%). For the primary outcome, 26.1% (n = 37) of primary care providers felt safe waiting for a urine culture result before prescribing antibiotics, while 62.0% (n = 88) felt delaying antibiotics depended on multiple factors, and 9.2% (n = 13) felt it was never safe to delay antibiotics. Primary care providers that either never felt it was safe to delay antibiotics or felt that "it depends" on a variety of factors, attributed their antibiotics administration to concern for progression to sepsis (n = 50, 49.5%) or progression of symptoms (n = 28, 27.7%). A higher proportion of primary care providers practicing more than 15 years felt safe delaying antibiotics compared with primary care providers with less experience (33.8% vs 18.3%, P = 0.04), and 70.3% of those who felt safe delaying antibiotics had more than 15 years of experience. CONCLUSION: Primary care providers with more clinical experience have more comfort delaying antibiotics in older women with UTI symptoms.

Diagnosis of urinary tract infection in infants under 3 months with fever without a source: reliability of urinalysis and urine culture.

BACKGROUND: Urinary tract infection (UTI) is infants' most common serious bacterial infection. This study aimed to investigate the reliability of urianalysis (UA) to predict UTI, to specify the colony forming units (CFU)/ml threshold for diagnosis, and to identify variables that help suspect bacteremia in infants under 3 months with UTI. METHODS: We reviewed clinical records of children under 3 months hospitalized for a fever without source and recorded age, sex, days of fever pre-consultation, temperature and severity at admission, discharge diagnoses, laboratory tests, and treatments. According to the discharge diagnosis, we divided them into UTIs (-) and (+) with or without bacteremia. RESULTS: A total of 467 infants were admitted: 334 with UTI and 133 without UTI. In UTIs (+), the pyuria had a sensitivity of 95.8% and bacteria (+) 88.3%; specificity was high, especially for nitrites (96.2%) and bacteria (+) (92.5%). Positive predictive value (PPV) for nitrites was 95.9%, for bacteria 96.7%, and oyuria 92.5%. Escherichia coli was present in 83.8% of urine and 87% of blood cultures. UTIs with bacteremia had inflammatory urinalysis, urine culture > 100,000 CFU/ml, and higher percentage of C reactive protein (CRP) > 50 mg (p= 0.002); 94.6% of the urine culture had > 50,000 CFU. CONCLUSIONS: The pyuria and bacteria (+) in urine obtained by catheterization predict UTI. The cut-off point for diagnosis was ≥ 50,000 CFU/ml. No variables to suspect bacteremia were identified in this study.

INTRODUCCIÓN: La infección del tracto urinario (ITU) es una infección bacteriana grave frecuente en lactantes. El objetivo de este trabajo fue investigar la fiabilidad del análisis de orina (AO) para predecirla, precisar el umbral de unidades formadoras de colonias (UFC)/ml para el diagnóstico y buscar variables que ayuden a sospechar de bacteriemia en lactantes menores de 3 meses con ITU. MÉTODOS: Se revisaron fichas clínicas de lactantes menores de 3 meses hospitalizados por fiebre sin foco evidente, registrando edad, sexo, días de fiebre preconsulta, temperatura y gravedad al ingreso, diagnósticos de egreso, exámenes de laboratorio y tratamientos. Según diagnóstico de egreso, se separaron en ITU (-) y (+), con o sin bacteriemia. RESULTADOS: Ingresaron 467 lactantes: 334 con ITU y 133 sin ITU. En ITU (+), la sensibilidad de la piuria fue de 95.8% y bacterias (+) 88.3%; la especificidad fue alta para nitritos (96.2%) y bacterias (+) (92.5%). El valor predictivo positivo (VPP) fue de 95.9% para nitritos, 96.7% para bacterias y 92.5% para piuria. Escherichia coli se encontró en el 83.8% de los urocultivos (UC) (+) y en el 87% de los hemocultivos (+). Las ITU con bacteriemia presentaron elementos inflamatorios, UC con ≥ 100,000 UFC/ml y mayor porcentaje de proteína C reactiva (PCR) > 50 mg/l (p= 0.002); el 94.6% de los UC (+) tuvo ≥ 50,000 UFC/ml. CONCLUSIONES: La piuria y bacterias (+) en el AO son excelentes para pronosticar ITU en orina obtenida con sonda vesical y el punto de corte para el diagnóstico debe ser ≥ 50,000 UFC/ml. No encontramos señales que ayudaran a sospechar ITU con bacteriemia.

Usefulness of UF-5000 automatic screening system in UTI diagnosis.

We have evaluated the Sysmex UF-5000 cytometer use in microbiology for the screening of negative urines, looking for cut-off points to detect bacteria and leukocytes. The number of processed urines was 3569, the highest to date in these studies. The best general cut-off point has been 100 bact/µl, giving an area under the ROC curve of 0.868, a sensitivity of 96%, a specificity of 50%, 1.17% of false negatives, and saving 40% of cultures. The PPV and NPV have been 35.5 and 95.4 respectively. The leukocyte count has not been useful. Finally, we have evaluated urine screening usefulness, concluding that in laboratories such as ours (284 urines/working day) or smaller, it is not cost-effective.

Nitrite-negative results in urinary tract infection by Enterobacterales: does the nitrite dipstick test have low sensitivity?

Urinary tract infection (UTI) is one of the most common bacterial infections among humans. Urine culture is the gold standard diagnostic method for UTI; however, the dipstick test for nitrite is a widely used method signalling the presence of urinary nitrate-reducing bacteria. Unlike the gold standard, the dipstick test is easy to perform, while it is also less time-consuming and less expensive, and produces a result in a few minutes. This study investigates the sensitivity of the dipstick test for nitrite compared with the Griess test in urine samples from UTI caused by Enterobacterales species. We used the Griess test, which is the gold standard in nitrite measurement, to determine the sensitivity of the nitrite dipstick test. Semiquantitative urine culture was performed using standard procedures, and Enterobacterales identification was performed by manual conventional biochemical tests. In the first sample selection, 3 % (8/267) of urine samples suspected of UTI, analysed from March to April 2016, were nitrite-negative by dipstick test but positive for Enterobacterales in the urine culture. In the second sample selection, 5 % (2/44) of urine samples from October to December 2022 were also nitrite-negative but showed urine Enterobacterales isolation. All nitrite-negative dipstick results were consistent with the Griess test. Escherichia coli was the most prevalent bacterium, followed by Klebsiella pneumoniae, independent of sample selection. The dipstick test is a safe alternative for investigating nitrite in urine samples. We believe that the cause of nitrite-negative results is a lack of dietary nitrate, dilution of urine and exogenous interference (e.g. ascorbic acid). These findings support the idea that standard urine culture is necessary to rule out UTI.

Predictive model for urosepsis in patients with Upper Urinary Tract Calculi based on ultrasonography and urinalysis using artificial intelligence learning.

PURPOSE: To construct a predicting model for urosepsis risk for patients with upper urinary tract calculi based on ultrasound and urinalysis. MATERIALS AND METHODS: A retrospective study was conducted in patients with upper urinary tract calculi admitted between January 2016 and January 2020. The patients were randomly grouped into the training and validation sets. The training set was used to identify the urosepsis risk factors and construct a risk prediction model based on ultrasound and urinalysis. The validation set was used to test the performance of the artificial neural network (ANN). RESULTS: Ultimately, 1716 patients (10.8% cases and 89.2% control) were included. Eight variables were selected for the model: sex, age, body temperature, diabetes history, urine leukocytes, urine nitrite, urine glucose, and degree of hydronephrosis. The area under the receiver operating curve in the validation and training sets was 0.945 (95% CI: 0.903-0.988) and 0.992 (95% CI: 0.988-0.997), respectively. Sensitivity, specificity, and Yuden index of the validation set (training set) were 80.4% (85.9%), 98.2% (99.0%), and 0.786 (0.849), respectively. CONCLUSIONS: A preliminary screening model for urosepsis based on ultrasound and urinalysis was constructed using ANN. The model could provide risk assessments for urosepsis in patients with upper urinary tract calculi.

Long-term efficacy of complete trigonal electrofulguration for women with recurrent urinary tract infections.

INTRODUCTION AND OBJECTIVE: Recurrent urinary tract infections (R-UTIs) have a negative impact on quality of life and contribute to antimicrobial resistance. Long-term antibiotic therapy is the main treatment alternative but, in some cases, this approach may not be accepted by the patient, is ineffective or poorly tolerated. In selected women, electrofulguration (EF) of trigonal lesions has been shown to reduce urinary tract infection (UTI) episodes. METHODS: Between August 2006 and December 2017, 73 women with R-UTI had their data collected prospectively and analyzed. We evaluated the rate of UTIs during the initial 2 years of follow-up after fulguration based on symptoms and a positive urine culture. All patients failed with multiple antibiotic courses and were offered endoscopic electrofulguration of the entire trigonal and bladder neck mucosa with a rollerball probe. We present our long-term results using a strategy of complete fulguration of the trigone in women with R-UTIs. RESULTS: The median age was 64 years (range: 17-76 years) and the median follow-up time after EF was 4.2 years (range: 2.5-14 years). Overall, 70 patients (96%) remained free of UTI episodes during the first year of follow-up, at 2 years of follow-up, 57, 53% remained infection-free. Currently, UTIs are typically sparse, mild, and caused by multisensitive bacteria. CONCLUSIONS: Complete trigonal and bladder neck mucosal fulguration promoted a significant reduction of UTI episodes during the first 2 years of follow-up. Prospective controlled studies are needed to determine the role of EF in women with R-UTI.

Crystallurical profile in sheep after ammonium chloride supplementation / [Perfil cristalúrico em ovinos suplementados com cloreto de amônio]

Although urinary crystals are habitual components, urolithiasis formation is always preceded by these concretions. We aimed to identify the change in the crystalline profile in sheep supplemented with ammonium chloride. Twenty-five male sheep aged three months, feedlot and randomly distributed into three groups were used: Control Group (CG) n = 5 did not receive Ammonium Chloride; G200 Group (n=10) (200mg/kg) of Ammonium Chloride for 56 consecutive days; G500 Group (n=10) (500mg/kg) of Ammonium Chloride for 56 consecutive days, administered daily orally. Sampling times and clinical evaluation were performed at seven days, with M0 (immediately before Ammonium Chloride), M1 (seven days after) until M8, totaling 70 days of feedlot. Urine samples were performed to identify the presence, type, and quantity of crystals. There was an increase in crystalluria in all groups in relation to time due to dietary influence, mainly in the CG, which presented more crystals of amorphous calcium phosphate and calcium oxalate. In addition, the G500 Group presented a higher presence of urate/uric acid crystals after urinary acidification, which are closely related to urinary pH.

Apesar de cristais urinários serem componentes habituais, a formação de urolitíase é sempre precedida dessas concreções. O presente estudo objetivou identificar a mudança do perfil cristalúrico em ovinos suplementados com cloreto de amônio. Foram utilizados 25 ovinos, machos, com idade de três meses, confinados e distribuídos aleatoriamente em três grupos: grupo controle (GC) (n=5) não recebeu cloreto de amônio; grupo G200 (n=10) (200mg/kg) recebeu cloreto de amônio por 56 dias consecutivos; grupo G500 (n=10) (500mg/kg) recebeu cloreto de amônio por 56 dias consecutivos, administrados diariamente por via oral. Os momentos (M) de colheita de amostras e avaliação clínica foram realizados com intervalo de sete dias, sendo M0 (imediatamente antes da administração do cloreto de amônio), M1 (sete dias após) até M8, totalizando 70 dias de confinamento. As amostras de urina foram analisadas para se identificar a presença, o tipo e a quantidade de cristais. Houve aumento da cristalúria em todos os grupos em relação ao tempo por influência dietética, principalmente no GC, que apresentou mais cristais de fosfato de cálcio amorfo e oxalato de cálcio. Além disso, o grupo G500 apresentou maior presença de cristais de urato/ácido úrico após acidificação urinária, estando esses intimamente relacionados ao pH urinário.

Grapiprant or carprofen following ovariohysterectomy in the cat: analgesic efficacy, hematological, biochemical and urinalysis evaluation.

OBJECTIVES: This study aimed to compare the analgesic effect between carprofen and grapiprant every 12 or 24 h on postoperative pain in cats undergoing ovariohysterectomy, in addition to the effects on the hematological, biochemical and urinalysis variables. METHODS: A total of 32 female cats were randomly divided into three groups, according to the treatment administered with the first dose given orally 90 mins before surgery, as follows: CAR (cats received 4 mg/kg carprofen, n = 11); GRA1 (cats received 2 mg/kg grapiprant, n = 10); and GRA2 (cats received 2 mg/kg grapiprant q12h, n = 11). Pain was assessed by UNESP-Botucatu Multidimensional Composite Pain Scale (UNESP) and Glasgow Feline Composite Measure Pain Scale (GLASGOW) for cats preoperatively (baseline) and at 1, 3, 6, 8, 12 and 24 h after extubation. Venous blood was collected at baseline, and 12 and 24 h after the administration of carprofen or grapiprant to perform a complete blood count (CBC), the percentage of Heinz bodies and serum biochemistry (alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, gamma-glutamyltransferase, creatinine and urea). Urinalysis was performed at baseline and 24 h after extubation. Glucose levels were evaluated at baseline and 1 h postoperatively. RESULTS: Pain scores were not significantly different among groups in both scales, although pain was higher at 3 h in comparison with 24 h in all groups. In the GRA1 and GRA2 groups, 67% (14/21) of cats needed rescue analgesia compared with 18% (2/11) in the CAR group. Glucose increased from baseline to 1 h in the GRA1 and GRA2 groups. None of the CBC, serum biochemistry and urinalysis variables differed among groups. CONCLUSIONS AND RELEVANCE: Grapiprant did not promote adequate analgesia during the first 3 h postoperatively in cats undergoing ovariohysterectomy compared with carprofen, and no benefits were observed by administering grapiprant every 12 h.

Cell-in-cell phenomenon in urinary sediment: a case report.

The internalization of apoptotic cells by non-phagocytic cells has been observed in different tissues and could be an important mechanism for the elimination of dying cells. Here, we describe a probable event of phagocytosis of apoptotic cells mediated by urothelial cells in urinary sediment. A 90-years-old male patient was admitted unconscious to the hospital, visible signs included: pale skin and dry mucous membranes, presumptively diagnosed as dehydration. Blood test revealed anaemia (haemoglobin 130 g/L) and hyperglycaemia (glucose 7.8 mmol/L), urinalysis showed a picture of urinary tract infection (leukocyturia and bacteriuria). The microscopic analysis of urinary sediment revealed the presence of urothelial cells and leukocytes internalized in urothelial cells. Anti-CD68 (membrane marker of macrophages) was tested by immunocytochemistry and a negative result was observed. Based on the findings phagocytosis of apoptotic cells mediated by urothelial cells was identified. This phenomenon can be observed in urinary sediment and should not be confused with a neoplastic process since it is a physiological event of cell elimination.

Should asymptomatic bacteriuria be treated in lupus nephritis?

INTRODUCTION: The risk of infection in systemic lupus erythematosus (SLE) is associated with factors related to disease activity and immunosuppressive treatment. Recently, the persistence of asymptomatic bacteriuria (ASB) has been proposed as an environmental trigger for SLE and its flares, raising the question whether it should be treated systematically to reduce the risk of infection. To our knowledge, there is limited evidence on the screening and treatment of ASB in SLE. OBJECTIVE: The objective is to analyze the occurrence of infection and flare in patients with lupus nephritis with and without ASB. METHODS: A cross-sectional study of a cohort of patients with lupus nephritis during induction therapy with high-dose cyclophosphamide regimen was carried out between January 2018 and 2020, with a total of 37 patients investigated. Urine and blood samples from the two groups (with ASB and without ASB) where taken before the administration of cyclophosphamide. RESULTS: From the sampled 37 patients, 19 (51.4%) had ASB and 18 (48.6%) without ASB; both groups were well balanced in their demographics and clinical characteristics. No statistically significant association was found between the presence of ASB and the systemic lupus erythematosus disease activity index score (p = 0.604), and neither with the 24-h urine protein and leukocyte count (p > 0.177). Urinary tract infection occurred in 5.3% (1) of the patients with ASB, while 5.6% (1) of the patients in the group without ASB presented the infection, and the RR was 0.944 (0.06, 16.33) 95% CI; in addition, no statistically significant association was found between the presence of ASB and the occurrence of infection (p = 1,000). CONCLUSION: Our study did not find a statistically significant association of ASB with the occurrence of infection or disease activity. Further studies need it to clarify this, since treatment of ASB has been recognized as an important contributor to inappropriate antimicrobial use, which promotes emergence of antimicrobial resistance.

Use of Cotton Balls in Diapers for Collection of Urine Samples Impacts the Analysis of Routine Chemistry Tests: An Evaluation of Cotton Balls, Diapers, and Chemistry Analyzers.

OBJECTIVE: To evaluate the suitability of urine samples collected with cotton balls placed into diapers for routine laboratory chemistry analyses. STUDY DESIGN: Twenty pools of residual unpreserved urine samples were separated into control and treated aliquots. The treated samples were absorbed into 2 different brands of cotton balls, wrapped in 3 different brands of diapers, and incubated at 37°C for 1 hour. The urine-soaked cotton balls were placed into a syringe and expressed via plunger depression. Urine sodium, potassium, creatinine, urea, calcium, magnesium, inorganic phosphorus, albumin, and total protein were measured on all samples on 5 automated clinical chemistry platforms: Ortho Vitros 4600, Siemens Dimension Vista 500, Beckman Coulter AU5822, Roche Cobas 6000, and Abbott Architect c8000 at 5 separate hospital laboratories. Criteria used to exclude the presence of significant effects of urine from presoaked cotton balls in a diaper on the measurement of chemistry laboratory tests were R2 >0.95, slope of 0.9-1.1, and mean bias within ±10%. RESULTS: Albumin and total protein measurements demonstrated significant negative bias in urine from both brands of presoaked cotton balls with all brands of diapers on all 5 chemistry platforms compared with the control urine. We did not observe a significant effect of presoaking urine in cotton balls in a diaper on the measurement of sodium, inorganic phosphorus, and urea. The remaining tests demonstrated significant effects when measured in urine from presoaked cotton balls and/or diapers that were specific to the chemistry analyzer platform or diaper. CONCLUSIONS: Diaper and cotton ball-based urine collection significantly impacts the measurement of several common chemistry assays.

Association of Pyuria with Uropathogens in Young Children.

OBJECTIVE: To examine the association between uropathogens and pyuria in children <24 months of age. STUDY DESIGN: A retrospective study of children <24 months of age evaluated in the emergency department for suspected urinary tract infection (UTI) with paired urinalysis and urine culture during a 6-year period. Bagged urine specimens or urine culture growing mixed/multiple urogenital organisms were excluded. Analysis was limited to children with positive urine culture as defined by the American Academy of Pediatrics clinical practice guideline culture thresholds. RESULTS: Of 30 462 children, 1916 had microscopic urinalysis and positive urine culture. Urine was obtained by transurethral in-and-out catheterization in 98.3% of cases. Pyuria (≥5 white blood cells per high-powered field) and positive leukocyte esterase (small or more) on the urine dipstick were present in 1690 (88.2%) and 1692 (88.3%) of the children respectively. Children with non-Escherichia coli species were less likely to exhibit microscopic pyuria than children with E coli (OR 0.24, 95% CI 0.17-0.34) with more pronounced effect on Enterococcus and Klebsiella (OR 0.08, 95% CI 0.03-0.18 and OR 0.18, 95% CI 0.11-0.27 respectively). Similarly, positive leukocyte esterase was less frequently seen in non-E coli uropathogens compared with E coli. CONCLUSIONS: Pyuria and leukocyte esterase are not sensitive markers to identify non-E coli UTI in young children. More sensitive screening biomarkers are needed to identify UTI with these uropathogens.

Is routine 24-hour urine calcium measurement useful during the evaluation of primary hyperparathyroidism?

BACKGROUND: Primary hyperparathyroidism and familial hypocalciuric hypercalcemia have similar biochemical profiles, and calcium-to-creatinine-clearance ratio helps distinguish the two. Additionally, 24-hour urine calcium >400 mg/day indicates surgery and guidelines recommend obtaining 24-hour urine calcium preoperatively. Our aim was to assess how 24-hour urine calcium altered care in the evaluation of suspected primary hyperparathyroidism. METHODS: Consecutive patients assessed for primary hyperparathyroidism from 2018 to 2020 were reviewed. Primary hyperparathyroidism was diagnosed by 2016 American Association of Endocrine Surgeons Parathyroidectomy Guidelines criteria. 24-hour urine calcium-directed change in care was defined as familial hypocalciuric hypercalcemia diagnosis, surgical deferment for additional testing, or 24-hour urine calcium >400 mg/day as the sole surgical indication. RESULTS: Of 613 patients, 565 (92%) completed 24-hour urine calcium and 477 (84%) had concurrent biochemical testing to calculate calcium-to-creatinine-clearance ratio. 24-hour urine calcium was <100 mg/day in 9% (49/565) and calcium-to-creatinine-clearance ratio was <0.01 in 17% (82/477). No patient had confirmed familial hypocalciuric hypercalcemia, although 1 had a CASR variant of undetermined significance. When calcium-to-creatinine-clearance ratio was <0.01, familial hypocalciuric hypercalcemia was excluded by 24-hour urine calcium >100 mg/day (56%), prior normal calcium (16%), renal insufficiency (11%), absence of familial hypercalcemia (3%), normal repeat 24-hour urine calcium (10%), or interfering diuretic (1%). 24-hour urine calcium-directed change in care occurred in 25 (4%), including 4 (1%) who had genetic testing. Four-gland hyperplasia was more common with calcium-to-creatinine-clearance ratio <0.01 (17% vs calcium-to-creatinine-clearance ratio ≥ 0.01, 4%, P < .001), but surgical failure rates were equivalent (P = .24). CONCLUSION: 24-hour urine calcium compliance was high, and results affected management in 4%, including productive identification of hypercalciuria as the sole surgical indication in 2 patients. When calcium-to-creatinine-clearance ratio <0.01, clinical assessment was sufficient to exclude familial hypocalciuric hypercalcemia and only 1% required genetic testing. 24-hour urine calcium should be ordered judiciously during primary hyperparathyroidism assessment.

Desempeño comparativo de ecuaciones de estimación de excreción urinaria de creatinina / Comparative performance of urinary creatinine excretion estimating equations

BACKGROUND: 24-hour urine collection accuracy is generally evaluated based on the values of urine creatinine (UCr) excretion, usually using ranges adjusted by weight. UCr excretion depends on several factors. Equations to estimate UCr in 24-hour collection (UCr/24h) that consider these factors have been developed. However, these formulas have not been evaluated in a sample of Latinamerican origin. Aim: To evaluate the performance of the existing UCr/24 h estimation equations in a sample of Latinamerican origin. MATERIAL AND METHODS: 24-hour urine collections from 181 ambulatory patients were analyzed. Measured UCr/24h was compared with estimated UCr (eUCr) through the equations of Ix (CKD-EPI), Gerber-Mann, Goldwasser, Cockcroft-Gault, Rule, Walser, Kawasaki, Tanaka and Huidobro. Performance of the nine equations to estimate UCr/24h was evaluated with the Pearson correlation and Lin concordance coefficients, and Bland-Altman method. Bias, precision, and accuracy (percentage of collections within 30% of measured UCr or P30) were also calculated. RESULTSR: Measured UCr/24h in the 181 patients was 1236 + 378 mg. Correlation coefficient (Pearson) of the eUCr/24h with the equations of Walser, Ix and Huidobro and the measured UCr/24h was strongly positive. Rule and Kawasaki equations had the lowest positive correlation coefficients. Bias was similar using the formulas of Walser, Goldwasser, Kawasaki, Ix and Huidobro. Walser, Ix, Huidobro, Cockcroft-Gault and Goldwasser equations had good accuracy (P30 > 85%), while Gerber-Mann, Tanaka, Rule and Kawasaki formulas had a P30 < 65%. Conclusions: Walser, Ix and Huidobro equations had the best performance to estimate UCr/24h excretion in a population of latinamerican origin.

[A new equation to estimate daily natriuresis from parameters in plasma and spot urine sample in the Chilean population]. / Nueva ecuación para la estimación de la natriuresis diaria a partir de parámetros en plasma y orina aislada en población chilena.

BACKGROUND: Excessive sodium intake is associated with increased cardiovascular morbidity and mortality. Daily sodium intake is usually inferred from sodium excretion in a 24-hour urine collection, which is cumbersome and prone to errors. Different formulas have attempted to estimate 24-hour urinary sodium from a spot urine sample. Unfortunately, their concordances are insufficient and have not been tested in our population. AIM: To develop an equation to predict 24-hour urine sodium from parameters in plasma and spot urine samples. To validate the equation and compare it with other formulas in Chilean population. MATERIAL AND METHODS: Analysis of 24-hour urine collections, plasma sample and spot urine sample from 174 adult outpatients (81% females) with an estimated glomerular filtration rate (eGFR) ≥ 60 mL/min/1.73m2. These were collected between 2015 and 2019 using standardized methods and educating patients about the correct method to collect 24 h urine samples. In all these patients, creatinine and electrolytes were measured in plasma and urine. A new equation was developed using a multiple linear regression model. RESULTS: Twenty-four-hour urine sodium excretion was significantly correlated with age, weight, height, eGFR, plasma osmolarity, urine electrolytes and parameters obtained from spot urine sample, among others. The new equation had a linear correlation with 24-hour natriuresis of 0.91 and the concordance was 0.9. The predictive capacity of the new equation was better than the existing formulas. CONCLUSIONS: We developed a formula to accurately predict daily natriuresis in the Chilean population.