Glomerular Hematuria and the Utility of Urine Microscopy: A Review.

Evaluation of hematuria and microscopic examination of urine sediment are commonly used tools by nephrologists in their assessment of glomerular diseases. Certain morphological aspects of urine red blood cells (RBCs) seen by microscopy may help in identifying the source of hematuria as glomerular or not. Recognized signs of glomerular injury are RBC casts or dysmorphic RBCs, in particular acanthocytes (ring-shaped RBCs with protruding blebs). Despite being a highly operator-dependent test, urine sediment examination revealing these signs of glomerular hematuria has demonstrated specificities and positive predictive values ranging between 90%-100% for diagnosing glomerular disease, although sensitivity can be quite variable. Hematuria is a commonly used tool for diagnosing patients with proliferative glomerulonephritis such as IgA nephropathy, antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis, and lupus nephritis, sometimes even as a surrogate for kidney involvement. Studies examining the role for hematuria in monitoring and predicting adverse outcomes in these diseases have shown inconsistent results, possibly due to inconsistent definitions that often fail to consider specific markers of glomerular hematuria such as dysmorphic RBCs, acanthocytes, or RBC casts. A consensus definition of what constitutes glomerular hematuria would help standardize use in future studies and likely improve the diagnostic and prognostic value of hematuria as a marker of glomerulonephritis.

Prognostic Significance of Urinary Biomarkers in Patients Hospitalized With COVID-19.

RATIONALE & OBJECTIVE: Acute kidney injury (AKI) is common in patients with coronavirus disease 2019 (COVID-19) and associated with poor outcomes. Urinary biomarkers have been associated with adverse kidney outcomes in other settings and may provide additional prognostic information in patients with COVID-19. We investigated the association between urinary biomarkers and adverse kidney outcomes among patients hospitalized with COVID-19. STUDY DESIGN: Prospective cohort study. SETTING & PARTICIPANTS: Patients hospitalized with COVID-19 (n=153) at 2 academic medical centers between April and June 2020. EXPOSURE: 19 urinary biomarkers of injury, inflammation, and repair. OUTCOME: Composite of KDIGO (Kidney Disease: Improving Global Outcomes) stage 3 AKI, requirement for dialysis, or death within 60 days of hospital admission. We also compared various kidney biomarker levels in the setting of COVID-19 versus other common AKI settings. ANALYTICAL APPROACH: Time-varying Cox proportional hazards regression to associate biomarker level with composite outcome. RESULTS: Out of 153 patients, 24 (15.7%) experienced the primary outcome. Twofold higher levels of neutrophil gelatinase-associated lipocalin (NGAL) (HR, 1.34 [95% CI, 1.14-1.57]), monocyte chemoattractant protein (MCP-1) (HR, 1.42 [95% CI, 1.09-1.84]), and kidney injury molecule 1 (KIM-1) (HR, 2.03 [95% CI, 1.38-2.99]) were associated with highest risk of sustaining primary composite outcome. Higher epidermal growth factor (EGF) levels were associated with a lower risk of the primary outcome (HR, 0.61 [95% CI, 0.47-0.79]). Individual biomarkers provided moderate discrimination and biomarker combinations improved discrimination for the primary outcome. The degree of kidney injury by biomarker level in COVID-19 was comparable to other settings of clinical AKI. There was evidence of subclinical AKI in COVID-19 patients based on elevated injury biomarker level in patients without clinical AKI defined by serum creatinine. LIMITATIONS: Small sample size with low number of composite outcome events. CONCLUSIONS: Urinary biomarkers are associated with adverse kidney outcomes in patients hospitalized with COVID-19 and may provide valuable information to monitor kidney disease progression and recovery.

Evaluation of the detection ability of uropathogen morphology and vaginal contamination by the Atellica UAS800 automated urine microscopy analyzer and its effectiveness.

BACKGROUND: To help combat the worldwide spread of multidrug-resistant Enterobacterales, which are responsible for many causes of urinary tract infection (UTI), we evaluated the ability of the Atellica UAS800 automated microscopy system, the only one offering the capability of bacterial morphological differentiation, to determine its effectiveness. METHODS: We examined 118 outpatient spot urine samples in which pyuria and bacteriuria were observed using flow cytometry (training set: 81; cross-validation set: 37). The ability of the Atellica UAS800 to differentiate between bacilli and cocci was verified. To improve its ability, multiple logistic regression analysis was used to construct a prediction formula. RESULTS: This instrument's detection sensitivity was 106 CFU/ml, and reproducibility in that range was good, but data reliability for the number of cocci was low. Multiple logistic regression analysis with each explanatory variable (14 items from the Atellica UAS800, age and sex) showed the best prediction formula for discrimination of uropathogen morphology was a model with 5 explanatory variables: number of bacilli (p < 0.001), squamous epithelial cells (p = 0.004), age (p = 0.039), number of cocci (p = 0.107), and erythrocytes (p = 0.111). For a predicted cutoff value of 0.449, sensitivity was 0.879 and specificity was 0.854. In the cross-validation set, sensitivity was 0.813 and specificity was 0.857. CONCLUSIONS: The Atellica UAS800 could detect squamous epithelial cells, an indicator of vaginal contamination, with high sensitivity, which further improved performance. Simultaneous use of this probability prediction formula with urinalysis results may facilitate real-time prediction of uropathogens and vaginal contamination, thus providing helpful information for empiric therapy.

Assessment of Significant Bacteriuria, Bacterial Profile and Pyuria among Pregnant Women with Urinary Tract Symptoms in Enugu, South-Eastern Nigeria: A Cross-Sectional Study.

BACKGROUND: Urinary tract symptoms are common in pregnancy; thus, symptom-based diagnosis of urinary tract infection (UTI) might not be accurate. Such women are often exposed to antibiotics without urine culture and antibiotics sensitivity. Identification of pyuria on urine microscopy of pregnant women with urinary tract symptoms may predict significant bacteriuria and guide such women's treatment in under-resourced settings. METHODS: A cross-sectional study of 233 consecutive consenting pregnant women with UTI symptoms at theantenatal clinic of the University of Nigeria Teaching Hospital ItukuOzalla, Nigeria. Participants' mid-stream urine specimens were sent for microscopy, culture, and antibiotics sensitivity. Data analysis was descriptive and inferential at 95% confidence level. RESULTS: The prevalence of symptomatic UTI among pregnant women with urinary tract symptoms was 33.5% (78/233). Coliform bacilli were the most common isolates (82.0%) from participants' urine. Ceftriaxone and ampicillin-cloxacillin had the highest (76.9%) and least (12.8%) sensitivity, respectively. Using urine culture as the standard, pyuria on microscopy showed a sensitivity of 43.6% and a specificity of 93.5% for predicting symptomatic UTI. CONCLUSION: The prevalence of UTI among pregnant women with urinary tract symptoms was low, and the most common isolate was coliform bacilli. Though pyuria had reasonably good accuracy for diagnosing symptomatic UTI, it should not be used for this purpose because of the risks associated with misdiagnosis.

CONTEXTE: Les symptômes des voies urinaires sont fréquents pendant la grossesse; ainsi, le diagnostic basé sur les symptômes de l'infection des voies urinaires (IVU) pourrait ne pas être exact. Ces femmes sont souvent exposées à des antibiotiques sans culture d'urine ni sensibilité aux antibiotiques. L'identification de la pyurie par microscopie urinaire chez les femmes enceintes présentant des symptômes des voies urinaires peut prédire une bactériurie importante et orienter le traitement de ces femmes dans les milieux défavorisés. BUT: Déterminer la prévalence des infections urinaires chez les femmes enceintes présentant des symptômes des voies urinaires et évaluer l'exactitude de la pyurie pour prédire les infections urinaires symptomatiques pendant la grossesse à Enugu, au Nigéria. MÉTHODES: Une étude transversale de 233 femmes enceintes consentantes consécutives présentant des symptômes d'infection urinaire à la clinique prénatale de l'hôpital universitaire d'Ituku, à Ozalla, au Nigéria. Les échantillons d'urine à mi-parcours des participants ont été envoyés pour microscopie, culture et sensibilité aux antibiotiques. L'analyse des données était descriptive et inférentielle à un niveau de confiance de 95. RÉSULTATS: La prévalence des infections urinaires symptomatiques chez les femmes enceintes présentant des symptômes des voies urinaires était de 33,5% (78/233). Les bacilles coliformes étaient les isolats les plus courants (82,0%) des urines des participants. La ceftriaxone et l'ampicilline-cloxacilline avaient respectivement la sensibilité la plus élevée (76,9%) et la moins élevée (12,8%). En utilisant la culture d'urine comme norme, la pyurie à la microscopie a montré une sensibilité de 43,6% et une spécificité de 93,5% pour prédire les infections urinaires symptomatiques. CONCLUSION: La prévalence des infections urinaires chez les femmes enceintes présentant des symptômes des voies urinaires était faible et l'isolat le plus courant était les bacilles coliformes. Bien que la pyurie ait une précision raisonnablement bonne pour diagnostiquer une infection urinaire symptomatique, elle ne doit pas être utilisée à cette fin en raison des risques associés à un diagnostic erroné. MOTS CLÉS: Grossesse, infection symptomatique des voies urinaires, culture d'urine, microscopie d'urine.

Urine Sediment Examination in the Diagnosis and Management of Kidney Disease: Core Curriculum 2019.

Automated urine technology and centralized laboratory testing are becoming the standard for providing urinalysis data to clinicians, including nephrologists. This trend has had the unintended consequence of making examination of urine sediment by nephrologists a relatively rare event. In addition, the nephrology community appears to have lost interest in and forgotten the utility of provider-performed urine microscopy. However, it is critical to remember that urine sediment examination remains a time-honored test that provides a wealth of information about the patient's underlying kidney disease. This test performs very favorably as a urinary "biomarker" for a number of acute kidney diseases. When used properly, urine sediment findings alert health care providers to the presence of kidney disease, while also providing diagnostic information that often identifies the compartment of kidney injury. Urine sediment findings may also guide therapy and assist in prognostication. In this review of the role of urine sediment examination in the diagnosis and management of kidney disease, we seek to help experienced nephrologists maintain their competency in performing this test and encourage ongoing training of nephrology fellows and others less experienced in such analyses.

Accuracy of urinary symptoms and urine microscopy in diagnosing urinary tract infection in women.

BACKGROUND: Women with urinary tract infections (UTIs) often present with urinary complaints such as frequency of micturition, dysuria, foul-smelling urine and other non-specific symptoms like fever. Physicians may order urine microscopy to guide empirical antibiotic prescription. However, the performance of this approach has not been assessed. OBJECTIVES: This study aimed to determine the accuracy of UTI symptoms and urine microscopy associated with culture-positive UTI in Asian women. METHODS: A cross-sectional study of adult women who presented with UTI-related symptoms was conducted at three public primary care clinics in Singapore. Demographic data and information on their symptoms were collected, followed by urine microscopy and culture to diagnose UTI. The sensitivity, specificity, positive (PPV), negative predictive values (NPV), accuracy (ACC) and area under curve (AUC) of combinations of symptom and urine investigations were analysed in association with culture-positive UTI, which was regarded as a benchmark. RESULTS: Data on 564 women (73.9% Chinese, 11.5% Malay, 8.2% Indian) were analysed, of which 259 (45.9%) had culture-positive UTI. Frequency and foul-smelling urine, pyuria (WBC ≥10/hpf) and semi-quantitative bacterial count (≥2+) were significantly associated with positive urine culture. The ACC and AUC for single or multiple urinary and/or general symptoms were low. Urine pyuria (minimally >10/hpf) alone or in combination with symptoms and/or semi-quantitative bacterial count achieved high sensitivity (>85%) and PPV, NPV, ACC and AUC of >70%. CONCLUSION: Urinary symptoms have limited accuracy in diagnosing culture-positive UTI. Concurrent urine microscopy showing presence of pyuria and/or bacterial count increased the diagnostic accuracy of culture-positive UTI.

Performance of automated urine analyzers using flow cytometric and digital image-based technology in routine urinalysis.

The purpose of this study was to evaluate the analytical performances of Sysmex UF-5000 and Dirui FUS-200 and to compare the results with manual microscopy and between each other. Two hundred fifty urine samples were analyzed for evaluation. Mid-stream specimens were studied sequentially using Dirui FUS-200 and Sysmex UF-5000, and also with manual microscopy within one hour. The physical and chemical components of urinalysis, and sediment results were investigated. The precision results of the FUS-200 and UF-5000 for WBCs, RBCs, and ECs were acceptable. The both analyzers demonstrated good linearity (r > 0.97), with no carry-over. The comparisons of FUS-200 and UF-5000 with manual microscopy for RBCs, WBCs, and ECs on 250 samples exhibited good agreement with little bias (R > 0.780). Only, the moderate agreements were obtained for calcium oxalate for both analyzers (R = 0.512, and 0.648, respectively). The sensitivities of the FUS-200 and UF-5000 were 75.8% and 86.8%, with specificities of 92.3% and 87.8% for WBCs, for RBCs the sensitivities were 91.1%, and 84.4% with specificities of 82.2%, and 89.6% for both analyzers. Kappa values of the UF-5000 were higher than FUS-200 for WBCs, RBCs, ECs, and calcium oxalate. The FUS-200 and UF-5000 urine analyzers, are both accurate, very precise systems and can be safely used in clinical laboratories. However, due to the technological characteristics of the UF-5000 analyzer, its positive impacts on the morphologic recognition and enumeration of RBCs and WBCs should be taken into account, particularly in university hospital laboratories with high patient volumes.

Current practice on the management of pre-operative urine dipstick results in women undergoing gynaecological surgery in Wales.

A survey was circulated to consultant gynaecologists across Wales, to evaluate the management of pre-operative urine dipstick results. Questions were based on NICE guideline 171, regarding the management of urinary incontinence in women. Six respondents never checked their patient's urine dipstick results. Of the remaining 37 respondents, 70% always check and 30% sometimes check. Overall, 37.1% cancelled surgery when a urine dipstick was positive for either nitrite or leukocyte-esterase (LE). A significantly larger proportion cancelled surgery when symptomatic for urinary tract infection (p< 0.001), and when nitrite and LE positive compared to only LE positive (p< 0.05). This survey provides evidence that gynaecological operations are potentially being cancelled unnecessarily based on a screening test with limited sensitivity and specificity. Further research is needed into the outcomes of gynaecological surgery in women symptomatic of urinary tract infection to provide guidance on the use of pre-operative urinalysis and the management of test results. Impact statement What is already known on this subject? The strongest risk factor for postoperative urinary tract infections (UTIs) is a pre-operative recurrent UTI (Nygaard et al. 2011 ). This is the reason behind the urine dipstick being part of the pre-operative checklist for gynaecological surgery. Traditionally, a suspected UTI would mean postphoning surgery whilst treating the UTI. It is known that the sensitivity of the nitrite test and leukocyte-esterase test when used alone is low and cannot rule out UTI in most patients (Mambatta et al. 2015 ). Urine culture is therefore suggested for all patients with a suspected UTI (John et al. 2006 ). To our knowledge, there are no data available on whether we should be postphoning gynaecological surgery based on a urine dipstick result. What the results of this study add? Overall, 37.1% of respondents cancelled surgery when a pre-operative urine dipstick was positive for either nitrite or leukocyte-esterase. This provides evidence of variation in the practice of using the urine dipstick in women undergoing gynaecological surgery in Wales. These cancellations are potentially unnecessarily. Furthermore, 14% of respondents did not use a urine dipstick and the majority did not act on an abnormal results, implying clinicians have a low confidence in the test as a screening tool. What the implications are of these findings for clinical practice and/or further research? We propose removing the urine dipstick as a pre-operative screening test. Asymptomatic bacteriuria is common in women and routine screening for UTI pre-operatively will therefore inevitably lead to unnecessary intervention (i.e. cancellation). Further research is needed into the outcomes of gynaecological surgery in women symptomatic of UTI to be able to provide guidance on the use of pre-operative urinalysis and management of the test results.

Comparison of ELISA and Urine Microscopy for Diagnosis of Schistosoma haematobium Infection.

BACKGROUND: Schistosoma haematobium which causes urogenital schistosomiasis (UGS) is highly prevalent in African countries. Urine microscopy (UM) is the first-line diagnostic method of UGS. Enzyme-linked immunosorbent assay (ELISA) is a common method for screening many parasite infections primarily or alternatively. The present study established an in-house diagnostic system by ELISA and evaluated its diagnostic efficacy in comparison with UM for screening UGS in White Nile State, Republic of Sudan, 2011-2013. METHODS: A total of 490 participants were screened by UM or ELISA, and 149 by both. The in-house ELISA system was established employing soluble egg antigen of S. haematobium and the cut-off absorbance was set at 0.270. RESULTS: Of the 149 subjects, 58 participants (38.9%) were positive by UM, 119 (79.9%) were positive by ELISA and 82 (55.0%) showed consistently positive or negative results by both methods. The diagnostic sensitivity of ELISA was 94.8% and specificity was 29.7% based on UM results. The ELISA positive serum samples also cross-reacted with egg antigens of Schistosoma mansoni and Schistosoma japonicum. CONCLUSION: We have established in-house ELISA for screening serum immunoglobulin (Ig) G antibodies by employing soluble egg antigen of S. haematobium for diagnosis of UGS with 94.8% sensitivity and 29.7% specificity. The ELISA system can supplement the conventional diagnosis by UM.

Harnessing basic and clinic tools to evaluate SGLT2 inhibitor nephrotoxicity.

Sodium-glucose cotransporter-2 (SGLT2) inhibitors are a new class of medications that target the transporter that reabsorbs ~90% of glucose in the S1 segment of the proximal convoluted tubule. As a result, SGLT2 inhibition increases urinary glucose excretion, effectively lowering plasma glucose levels. In addition to reducing hemoglobin A1c levels, these drugs also lower body weight, blood pressure, and uric acid levels in Type 2 diabetes mellitus (T2DM) patients. Importantly, empagliflozin has been observed to slow progression of kidney disease and reduce dialysis requirements in T2DM patients. However, the Food and Drug Administration (FDA) Adverse Events Reporting System (FAERS) has collected over 100 cases of acute kidney injury (AKI) for canagloflozin and dapagliflozin since their approval. Of the 101 patients, 96 required hospitalization, 22 required intensive care unit admission, and 15 underwent hemodialysis. The FDA now requires that AKI be listed as a potential side effect of the SGLT2 inhibitors along with cautious prescription of these drugs with other medications, such as renin-angiotensin-system antagonists, diuretics, and NSAIDs. It is unclear, however, whether this FAERS reported "AKI" actually represents structural kidney injury, as randomized, controlled trials of these drugs do not describe AKI as an adverse event despite coprescription with RAS blockers and diuretics. As a result of this FDA warning, diabetic patients with early-stage CKD may not be prescribed an SGLT2 inhibitor for fear of AKI. Thus, it is imperative to ascertain whether the reported AKI represents true structural kidney injury or a functional decline in glomerular filtration rate. We propose using readily available clinical tools with experimental biomarkers of kidney injury and kidney-on-a-chip technology to resolve this question and provide solid evidence about the AKI risk of these drugs for healthcare providers.

Kidney Injury and Repair Biomarkers in Marathon Runners.

BACKGROUND: Investigation into strenuous activity and kidney function has gained interest given increasing marathon participation. STUDY DESIGN: Prospective observational study. SETTING & PARTICIPANTS: Runners participating in the 2015 Hartford Marathon. PREDICTOR: Completing a marathon. OUTCOMES: Acute kidney injury (AKI) as defined by AKI Network (AKIN) criteria. Stage 1 AKI was defined as 1.5- to 2-fold or 0.3-mg/dL increase in serum creatinine level within 48 hours of day 0 and stage 2 was defined as a more than 2- to 3-fold increase in creatinine level. Microscopy score was defined by the number of granular casts and renal tubular epithelial cells. MEASUREMENTS: Samples were collected 24 hours premarathon (day 0), immediately postmarathon (day 1), and 24 hours postmarathon (day 2). Measurements of serum creatinine, creatine kinase, and urine albumin were completed, as well as urine microscopy analysis. 6 injury urine biomarkers (IL-6, IL-8, IL-18, kidney injury molecule 1, neutrophil gelatinase-associated lipocalin, and tumor necrosis factor α) and 2 repair urine biomarkers (YKL-40 and monocyte chemoattractant protein 1) were measured. RESULTS: 22 marathon runners were included. Mean age was 44 years and 41% were men. 82% of runners developed an increase in creatinine level equivalent to AKIN-defined AKI stages 1 and 2. 73% had microscopy diagnoses of tubular injury. Serum creatinine, urine albumin, and injury and repair biomarker levels peaked on day 1 and were significantly elevated compared to day 0 and day 2. Serum creatine kinase levels continued to significantly increase from day 0 to day 2. LIMITATIONS: Small sample size and limited clinical data available at all time points. CONCLUSIONS: Marathon runners developed AKI and urine sediment diagnostic of tubular injury. An increase in injury and repair biomarker levels suggests structural damage to renal tubules occurring after marathon. The results of our study should be validated in larger cohorts with longer follow-up of kidney function.

Advances in Urine Microscopy.

Urine microscopy is an important tool for the diagnosis and management of several conditions affecting the kidneys and urinary tract. In this review, we describe the automated instruments, based either on flow cytometry or digitized microscopy, that are currently in use in large clinical laboratories. These tools allow the examination of large numbers of samples in short periods. We also discuss manual urinary microscopy commonly performed by nephrologists, which we encourage. After discussing the advantages of phase contrast microscopy over bright field microscopy, we describe the advancements of urine microscopy in various clinical conditions. These include persistent isolated microscopic hematuria (which can be classified as glomerular or nonglomerular on the basis of urinary erythrocyte morphology), drug- and toxin-related cystalluria (which can be a clue for the diagnosis of acute kidney injury associated with intrarenal crystal precipitation), and some inherited conditions (eg, adenine phosphoribosyltransferase deficiency, which is associated with 2,8-dihydroxyadenine crystalluria, and Fabry disease, which is characterized by unique urinary lamellated fatty particles). Finally, we describe the utility of identifying "decoy cells" and atypical malignant cells, which can be easily done with phase contrast microscopy in unfixed samples.

Comparison of the Automated cobas u 701 Urine Microscopy and UF-1000i Flow Cytometry Systems and Manual Microscopy in the Examination of Urine Sediments.

BACKGROUND: The cobas u 701, a new automated image-based urine sediment analyzer, was introduced recently. In this study, we compared its performance with that of UF-1000i flow cytometry and manual microscopy in the examination of urine sediments. METHODS: Precision, linearity, and carry-over were determined for the two urine sediment analyzers. For a comparison of the method, 300 urine samples were examined by the automated analyzers and by manual microscopy using a KOVA chamber. RESULTS: Within-run coefficients of variation (CVs) for the control materials were 7.0-8.8% and 1.7-5.7% for the cobas u 701 and UF-1000i systems, respectively. Between-run CVs were 8.5-9.8% and 2.7-5.4%, respectively. Both instruments showed good linearity and negligible carry-over. For red blood cells (RBC), white blood cells (WBC), and epithelial cells (EPI), the overall concordance rates within one grade of difference among the three methods were good (78.6-86.0%, 88.7-93.8%, and 81.3-90.7%, respectively). The concordance rate for casts was poor (66.5-68.9%). CONCLUSION: Compared with manual microscopy, the two automated sediment analyzers tested in this study showed satisfactory analytical performances for RBC, WBC, and EPI. However, for other urine sediment particles confirmation by visual microscopy is still required.

Babesiosis-induced acute kidney injury with prominent urinary macrophages.

Babesia is an obligate intracellular erythrocyte parasite that can infect humans. Severe symptomatic disease from massive hemolysis and multiorgan system failure, including acute kidney injury (AKI), occurs. Acute tubular injury from a combination of volume depletion and heme pigment toxicity from profound hemolysis is the most common cause of AKI. We present a case of severe babesiosis complicated by dialysis-requiring AKI with the unique finding of large macrophages containing engulfed erythrocyte fragments in urine sediment. This urinary finding raised the possibility of another diagnosis distinct from acute tubular injury. Subsequent kidney biopsy demonstrated infection-associated acute interstitial nephritis.

Review of Recent Prevalence of Urogenital Schistosomiasis in Sub-Saharan Africa and Diagnostic Challenges in the Field Setting.

Human schistosomiasis is one of neglected tropical diseases that remain highly prevalent in sub-Saharan Africa (SSA). Human schistosomiasis is mainly caused by two species, Schistosoma haematobium and S. mansoni, leading to urogenital and intestinal schistosomiasis, respectively. The World Health Organization (WHO) recommends mass drug administration (MDA) with praziquantel as the primary method of global intervention. Currently, MDA with praziquantel covers over half of the target population in endemic SSA countries. However, an accurate diagnosis is crucial for monitoring and evaluating the effectiveness of MDA. The standard diagnosis of both urogenital and intestinal schistosomiasis relies on the microscopic identification of eggs. However, the diagnostic sensitivity of this approach is low, especially for light or ultra-light infections. This is because Schistosoma eggs are laid inside of the venous plexus of the urinary bladder or mesenteric vein, where the adult flukes live. Approximately half of the eggs circulate in the blood vessels or are packed in neighboring tissues, while the remaining half are expelled into the lumen of the urinary bladder or intestine intermittently when the blood vessels are ruptured. In the field setting, the accuracy of any diagnostic method is critical for proper management of the intervention. The present article reviews the recent prevalence of urogenital schistosomiasis in SSA and highlights the practical limitations of diagnostic methods such as urine microscopy, urine reagent strips, molecular diagnosis, and ultrasound scanning in the field setting. Despite continuous global efforts to eliminate schistosomiasis over the past 20 years, many areas still remain endemic in SSA. No single diagnostic approach achieves acceptable sensitivity and specificity in the field setting. Therefore, any field survey should employ a combination of these methods based on the purpose of the study to accurately monitor and evaluate urogenital schistosomiasis. Based on diagnostic values and a cost-benefit analysis, a urine reagent strip test can replace urine microscopy in the field setting. The WHO criteria by ultrasound diagnosis should be updated including the echogenic snow sign and contour distortion.

Urinary bacterial profile and antibiotic susceptibility pattern among pregnant women in Rahima Moosa Mother and Child Hospital, Johannesburg.

BACKGROUND: Urinary tract infection (UTI) in pregnancy is associated with significant morbidity for both the mother and the foetus. The aim of this study was to determine the prevalence of UTI, urinary bacterial susceptibility, and resistance patterns among pregnant women with a possible UTI at Rahima Moosa Mother and Child Hospital (RMMCH) in Johannesburg. METHODS: In this retrospective study, we analysed mid-stream urine culture and antibiotic susceptibility data from both inpatients and outpatients of pregnant women who attended RMMCH from January 2017 to December 2017. Data were collected from patients' files and then matched with urine microscopy, sensitivity and culture (MC&S) results from the National Health Laboratory Services (NHLS) data. RESULTS: Urine microscopy, cultures and sensitivities were performed on 1984 specimens belonging to pregnant women who presented with symptoms and/or signs of a UTI. A total of 333 patients (16.8%) had positive bacterial cultures. Escherichia coli (E. coli) was the commonest bacterial isolate (49.9%). Other microorganisms isolated included Klebsiella species (14.4%), Enterococcus faecalis (12.9%) and coagulase-negative staphylococci (CoNS); (8.9%). Approximately 98% of organisms were sensitive to cephalexin. Cefuroxime (95.2%), ceftriaxone/cefotaxime (94.4%) and nitrofurantoin (81.9%) demonstrated antimicrobial effectiveness as indicated. Most isolates were resistant to ampicillin/amoxicillin (84.4%), Trimethoprim/Sulfamethoxazole (55.6%) and amoxicillin-clavulanic acid (50.2%). CONCLUSION: E. coli was the commonest pathogen causing UTIs in pregnancy with Enterococcus faecalis increasing in prevalence. The choice of antimicrobial therapy in pregnancy should be determined according to sensitivity and resistance and foeto-maternal safety.

Association between urine microscopy and severe acute kidney injury in critically ill patients following non-cardiac surgery: a prospective cohort study.

BACKGROUND: Acute kidney injury (AKI) is a common and adverse complication following non-cardiac surgery. Evidence have shown urine microscopy could help early detection, differentiating the causes and predicting the progression of AKI. However, little evidence is available on AKI after non-cardiac surgery. Thus, we investigated the association between urine microscopy and severe AKI in critically ill patients after non-cardiac surgery. METHODS: This was a single-center prospective cohort study. The primary outcome was severe AKI, defined as stage 2 or 3 according to maximal KDIGO criteria within 7 days following non-cardiac surgery. Urine microscopy immediately, 6 and 12 hours after surgical intensive care unit (SICU) admission were examined and graded by a urine microscopy score (UMS) based on the observed quantification of renal tubular cells and casts in the sediment. Then, multivariate Logistic regression models were used to analyze the associations between UMS and postoperative severe AKI. RESULTS: From May 20, 2019 to November 24, 2020, 661 patients were enrolled with 147 patients (22.2%) developing postoperative severe AKI. Multivariate Logistic regression model showed elevated UMS (≥1) 6 and 12 hours after SICU admission were independently associated with postoperative severe AKI (OR 2.200, 95% CI: 1.182-4.095, P=0.013 and OR 2.949, 95% CI: 1.657-5.248, P<0.001, respectively). Furthermore, higher UMS 6 hours after SICU admission demonstrated correlation with greater risk of severe AKI with OR 3.887 (95% CI: 1.430-10.563) for UMS ≥3 and OR 2.429 (95% CI: 1.237-4.770) for UMS =1-2. The specificity and sensitivity of UMS ≥1 for severe AKI was 93.8% (95% CI: 91.7-95.9%) and 15.6% (95% CI: 9.7-21.5%), respectively. While the negative and positive predictive value was 79.5% (95% CI: 76.3-82.7%) and 41.8% (95% CI: 28.8-54.8%), respectively. In addition, patients with higher UMS (≥3, 1-2 and 0) had significantly more postoperative complications and longer SICU stay; and they also showed a trend toward other adverse postoperative outcomes. CONCLUSIONS: Early urine microscopy was independently associated with severe AKI in critically ill patients following non-cardiac surgery with higher UMS related to greater risk. TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT03880110.

Concomitant Identification of Muddy Brown Granular Casts and Low Fractional Excretion of Urinary Sodium in AKI.

Background: Fractional excretion of urinary sodium (FENa) is a widely utilized clinical test to evaluate acute kidney injury (AKI). A low FENa (<1%) is deemed consistent with prerenal azotemia and inconsistent with acute tubular injury (ATI). Muddy brown granular casts (MBGC) on microscopic examination of urinary sediment (MicrExUrSed) are highly suggestive of ATI. We hypothesized that there is poor concordance between the presence of MBGC and FENa in ATI. Methods: We conducted a prospective observational study in patients with AKI seen during inpatient consultation. We extracted patients who underwent assessment of percentage of low power fields (LPFs) with MBGC by MicrExUrSed and concomitant measurement of FENa. Diagnostic concordance between MBGC and FENa and their individual prognostic value were examined. Results: Our cohort included 270 patients, 111 (41%) of whom were women. Median age was 61 years (range 27-92 years), and median serum creatinine was 3.7 mg/dl ( range1.2-22.0 mg/dl). MBGC were found in 49% (133/270). FENa <1% (inconsistent with ATI) was found in 50/133 (38%), 38/115 (33%), and 16/45 (36%) of those with >0%, ≥10%, and ≥50% LPFs with MBGC, respectively. Concordance between FENa and MBGC for ATI diagnosis was deemed fair (estimated κ-coefficient=0.2), and poor (κ=-0.11) within a subgroup of patients with preexisting chronic kidney disease (n=139). In patients with biopsy-proven ATI (n=49), MBGC had 100% specificity and 100% positive predictive value for ATI. MBGC were associated with greater risk for ≥50% increase in creatinine from baseline at discharge (acute kidney disease [AKD]). Conclusions: About two of five patients with MBGC identified by MicrExUrSed presented with FENa <1%. Presence of MBGC was consistent with ATI, as verified by biopsy, and were predictive of AKD. These data suggest that the sole reliance in low FENa to exclude ATI should be abandoned, and MicrExUrSed should be pursued for AKI diagnosis.

How Reliable Is Automated Urinalysis in Acute Kidney Injury?

OBJECTIVE: Examination of urine sediment is crucial in acute kidney injury (AKI). In such renal injury, tubular epithelial cells, epithelial cell casts, and dysmorphic red cells may provide clues to etiology. The aim of this study was to compare automated urinalysis findings with manual microscopic analysis in AKI. METHODS: Samples from patients diagnosed with AKI and control patients were included in the study. Red blood cells, white blood cells, renal tubular epithelial cells/small round cells, casts, and pathologic (path) cast counts obtained microscopically and by a UF1000i cytometer were compared by Spearman test. Logistic regression analysis was used to assess the ability to predict AKI from parameters obtained from the UF1000i. RESULTS: There was poor correlation between manual and automated analysis in AKI. None of the parameters could predict AKI using logistic regression analysis. However, the increment in the automated path cast count increased the odds of AKI 93 times. CONCLUSION: Automated urinalysis parameters are poor predictors of AKI, and there is no agreement with manual microscopy.

Urine Microscopy for Internal Medicine Residents: A Needs Assessment and Implementation of Virtual Teaching Sessions.

Background: Although urine microscopy is an important step in the initial evaluation of a patient with kidney disease, internal medicine residents have minimal exposure to this technique during their training. The goal of this study was to understand knowledge of and attitudes toward urine microscopy among internal medicine residents and to implement virtual urine microscopy teaching sessions. Methods: A voluntary, anonymous, online survey was sent to all of the categorical internal medicine residents (n=131) training at the Icahn School of Medicine at Mount Sinai (ISMMS). The survey included 13 questions to assess attitudes toward, experience with, and clinical interpretation of urine microscopy specimens. In response to the survey results, we implemented virtual urine microscopy teaching sessions using video conferencing software that incorporated real-time urine sediment analysis with nephrology fellows and attending nephrologists. Results: The survey response rate was 45% (59 of 131). Forty-seven percent (28 of 59) of respondents reported performing urine microscopy at least once during their training, and 75% (44 of 59) of respondents did not feel comfortable performing urine microscopy. The majority of residents (92%; 54 of 59) reported they felt urine microscopy was very helpful or somewhat helpful in the evaluation of patients with AKI. Overall, 41% of responses to clinical interpretation questions were considered correct. Following survey completion, virtual urine microscopy sessions were held monthly and well received by the participants. Conclusions: Our study found that internal medicine residents perceive urine microscopy as a helpful diagnostic tool, although lack the skills to perform and interpret urine microscopy sediments. Virtual educational sessions using video conferencing software are a technically feasible approach to teaching urine microscopy to internal medicine residents. Future studies include a study of the effect of these sessions on learning of urine microscopy. Podcast: This article contains a podcast at https://www.asn-online.org/media/podcast/K360/2021_01_28_KID0006282020.mp3.