Glomerular Hematuria and the Utility of Urine Microscopy: A Review

Introducing a Software-Based Template for Standardized Structured Reports of Urinary Cytology and Its Impact on Turnaround Time in a Tertiary Center

INTRODUCTION

Standardized pathology reports enhance completeness and readability, contributing to the overall improvement in the management of patients. The standardization of urine cytology reporting has gained widespread acceptance with the use of the Paris system (TPS) for reporting urinary cytology, primarily focused on detecting high-grade urothelial carcinoma (HGUC). The next phase at the Institute of Pathology, Medical Faculty, University of Ljubljana, was the implementation of TPS, including standardized additional findings on non-neoplastic changes, into a software-based standardized structured reporting (SBSSR) system.

METHODS

The implementation of SBSSR for urinary cytology at the Institute of Pathology, Faculty of Medicine, University of Ljubljana, Ljubljana, Slovenia, began in March 2023. Before daily usage, the SBSSR template was tested and approved by all cytopathology team members. An informative briefing for clinicians was organized to facilitate inter-specialty communication. To assess the impact of the SBSSR system on reporting efficiency, the turnaround time was tracked from the receipt of the cytology sample in the lab to the time of digital signature on its diagnostic report during two consecutive 11-month periods (04/01/2022-03/01/2023 and 04/01/2023-03/01/2024).

RESULTS

All team members easily adopted the new SBSSR for urinary cytology. Reports are generated, costs are calculated, and they are digitally signed in a single step. The adoption of SBSSR for urinary cytology led to the replacement of dictation and administrative tasks. The average turnaround time for urine cytology has been reduced from 1,8 days (based on 2843 samples) to 1,5 days (based on 3438 samples).

CONCLUSIONS

The introduction of SBSSR for urinary cytology increased the quality of patient care with a shorter time to diagnosis and a higher level of report clarity.

Two-year treatment experience with BI 655064, an antagonistic anti-CD40 antibody, in patients with active lupus nephritis: An exploratory, phase II maintenance trial

ObjectiveTo evaluate the long-term efficacy and safety of different doses of BI 655064 versus placebo added to standard of care during maintenance treatment for lupus nephritis (LN).Methods1293.13 was an exploratory, phase II maintenance trial. Patients were eligible for entry if they had completed 1 year of randomised treatment with BI 655064 (120, 180 or 240 mg) or placebo in the 1293.10 trial, responded to treatment at Year 1 (complete renal response [CRR], partial renal response or urinary protein/creatinine ratio ≤1) and consented to continue treatment. The primary endpoint was the proportion of patients with CRR without renal flares at Year 2. Secondary endpoints included change from baseline in Safety of Estrogens in Lupus Erythematosus National Assessment-Systemic Lupus Erythematosus Disease Activity Index (SELENA-SLEDAI) scores and safety/tolerability.Results69/121 patients (57.0%) from the 1293.10 trial entered 1293.13. The adjusted proportion of patients with CRR decreased in all groups between Year 1 (BI 655064: 53.4%-72.7%; placebo: 71.4%) and Year 2 (BI 655064: 48.2%-59.5%; placebo: 57.5%). At Year 2, mean decreases in total SELENA-SLEDAI scores were greatest with BI 655064 240 mg (-10.6 points), followed by 120 mg (-8.9 points), 180 mg (-7.2 points) and placebo (-5.3 points). SELENA-SLEDAI non-renal scores decreased at Year 1 (BI 655064: -3.0 to -3.4; placebo: -1.8); this pattern remained with BI 655064 during Year 2 (-2.4 to -4.1), whereas placebo returned to near-baseline scores (-0.4). Over 2 years of treatment, almost all patients (97.1%) experienced ≥1 adverse event (AE). Compared with the other groups, higher rates of serious AEs (42.9% vs 23.1%-33.3%)-mainly driven by serious infections (23.8% vs 7.7%-14.3%)-and severe AEs (47.6% vs 13.3%-28.6%) were reported with BI 655064 240 mg.ConclusionsThis exploratory, phase II maintenance trial failed to demonstrate the benefits of BI 655064 on renal outcomes in the treatment of LN. However, some benefits in total and non-renal SELENA-SLEDAI scores were observed.

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.

Clinical and immunological biomarkers can identify proliferative changes and predict renal flares in lupus nephritis

BACKGROUND

Kidney involvement is frequent in SLE, with proliferative lupus nephritis (LN) forms and nephritic flares being key predictors of poor outcomes. Conflicting results have been reported for anti-C1q antibodies among the serological markers. Our purpose was to assess the value of immunological tests (C3,C4 complement fractions, anti-DNA and antiC1q antibodies) in predicting histological classes and flares of lupus nephritis (LN).

METHODS

For histological class prediction, we evaluated the immunological tests performed on the day of kidney biopsy by linear and multiple regression analyses. For flare prediction, univariable and multivariable Cox analyses were made at baseline, 6, and 12 months.

RESULTS

Of 61 participants in the study, 47 had proliferative (III, IV) and 14 non-proliferative LN (II, V) at kidney biopsy. In proliferative LN, anti-DNA (p = 0.0186) and anti-C1q antibodies (Ab) (p = 0.0050) were significantly higher, and serum C3 and C4 lower (p = 0.0026; p = 0.0212) compared to non-proliferative LN. At multiple regression analysis, the best association to differentiate proliferative from non-proliferative LN was the number of urinary erythrocytes (OR 3.2292; CI 1.2585-8.2858; p = 0.0148) and anti-C1qAb (OR 1.0288; CI 1.0016-1.0568; p = 0.0380). Of 53 patients evaluated for flare predictions, followed for 60.69 (37.20-78.704) months, 10 (18.86%) had a renal flare at 28.19 months (24.84-39.38, range:16.3-55.8) from therapy initiation. At univariable analysis, anti-C1qAb (p = 0.0340, p = 0.0005) and no-use hydroxychloroquine (p = 0.0313, p = 0.0276) predicted flares at baseline and six months. Anti-C1qAb (p = 0.0047), non-use hydroxychloroquine (p = 0.0252), anti-C1qAb ≥ 40UA (p = 0.0047), 24/h proteinuria (p = 0.0185), and proteinuria ≥ 0.5 g/day (p = 0.0216) predicted flares at 12 months. At multivariable analysis, anti-C1q > 40UA (OR 9.0721; CI 0.9146-42.9882; p = 0.0057) and non-use of hydroxychloroquine (OR 0.1742 CI 0.0445-0.6823; p = 0.0126) were the independent predictors of renal flares.

CONCLUSION

Immunological tests can differentiate proliferative from non-proliferative LN, but anti-C1qAb and urinary erythrocytes had the best predictive power. Only persistent high anti-C1qAb at 1 year and non-use of hydroxychloroquine seem to predict renal flares.

Epidemiology of kidney biopsy from regional referral center in Romania: 10-year review

PURPOSE

To provide epidemiologic data on kidney biopsy from Romania.

METHODS

Retrospective observational study of kidney biopsy records for adult patients from a referral center in the north-western part of Romania, reported for 2014-2023.

RESULTS

556 biopsies were performed, corresponding to an incidence of 12 biopsies/m person-year with over 50% increase over the last reported year. Optimal core for optic microscopy was available in 81.4%, immunofluorescence was performed in 86.3%, and electron microscopy in 35.2% of patients. The mean age at biopsy was 47.12 years, and 53.8% were males. Indications for kidney biopsy were nephrotic syndrome in 63.1% of patients, nephritic in 25.9% of patients, asymptomatic urinary abnormalities in 2.9%, acute kidney injury/ rapid progressive renal failure in 3.6%, and chronic kidney disease in 1.4%. The most frequent diagnostic categories were membranous nephritis (14.7%), IgA nephropathy (13.9%), focal segmental glomerulosclerosis (11,1%), minimal change disease (12,2%), lupus nephritis (10,9%), vasculitis (7.6%), and membranoproliferative glomerulonephritis (8%). The age of diagnosis increased for IgA Nephropathy over time while it decreased for membranous nephritis.

CONCLUSIONS

Our study adds data for the completion of the kidney biopsy map in our region.

Unleashing the power of urine‑based biomarkers in diagnosis, prognosis and monitoring of bladder cancer (Review)

Bladder cancer (BCa) is a prevalent malignant neoplasm of the urinary tract with high incidence rate, frequent recurrence and rapid disease progression. Conventional approaches for diagnosing, prognosticating and monitoring BCa often rely on invasive procedures such as cystoscopy and tissue biopsy, which are associated with high costs and low patient compliance for follow‑up. Liquid biopsies have advantages, such as being non‑invasive, real‑time, and reproducible, in obtaining diverse biomarkers derived from cellular, molecular, proteomic and genetic signatures in urine or plasma samples. Although plasma‑based biomarkers have been clinically validated, urine provides greater specificity for directly assessing biological materials from urological sources. The present review summarizes advancements and current limitations in urinary protein, genetic and epigenetic biomarkers for disease progression and treatment response of BC, compares performance and application scenarios of urine and blood biomarkers and explores how urinary biomarkers may serve as an alternative or complementary tool to traditional diagnostic methods. The integration of urine‑based or plasma‑based biomarkers into existing diagnostic workflows offers promising avenues for improving accuracy and efficiency of diagnosis in the management of BCa. Notably, the emergence of synthetic biomarkers and urine metabolites, combined with artificial intelligence or bioinformatic technologies, has promise in the screening of potential targets. Continued research and validation efforts are needed to translate these findings into routine clinical practice, ultimately improving patient outcomes and decreasing the burden of BCa.

UF-5000 urinary erythrocyte parameters versus urinary aberrant erythrocytes and acanthocytes for diagnosing IgA glomerular hematuria

This study evaluated the diagnostic value of the automated UF-5000 parameters and compared it with that of aberrant erythrocytes and acanthocytes classified by microscopy for identifying IgA glomerular hematuria to propose a predictive model for clinical use. It also compared correlations between erythrocyte parameters and malformed erythrocytes. Urine samples from 53 biopsy-proven IgA hematuria cases and 143 non-IGA nephropathic hematuria cases as controls were analyzed. The ratio of small red blood cells to nonlysed red blood cells (UF-sRBC%) and lysed red blood cells (lysed RBCs) showed good diagnostic performance for IgA glomerular hematuria (area under the curve [AUC] = 0.857 [P = 0.000] and AUC = 0.860 [P = 0.000], respectively). Combining UF-sRBC%, lysed RBCs, and urine protein dry chemistry improved the diagnostic accuracy (AUC = 0.967; positive predictive value [PPV] = 91.89%; negative predictive value [NPV] = 93.10%; P = 0.000). This approach surpassed traditional microscopy for aberrant erythrocytes (AUC = 0.895; PPV = 62.27%; NPV = 88.66%; P = 0.008) and acanthocytes (AUC = 0.868; PPV = 72.97%; NPV = 83.65%; P = 0.006). The erythrocyte size index was negatively correlated with the proportion of urinary aberrant erythrocytes (r = - 0.787; P = 0.000). The UF-5000 erythrocyte parameters facilitate rapid identification of IgA nephropathy and could replace manual microscopy.

Urine Sediment Evaluation

Sample cases and questions with discussion of urinary sediment findings and their application in patient care.

Glomerular Hematuria as a Predictor of Renal Prognosis in Malignant Hypertension Patients with Thrombotic Microangiopathy: A Propensity Score-Matched Analysis of a Biopsy-Based Cohort Study

Introduction

Malignant hypertension (mHTN) is a hypertensive emergency. Thrombotic microangiopathy (TMA) is a widespread complication of mHTN. Few studies have evaluated whether glomerular hematuria provides prognostic information for renal dysfunction in patients with mHTN-associated TMA.

Methods

This observational cohort study included 292 patients with mHTN-associated TMA based on renal biopsy. Propensity-score matching (PSM) analysis was conducted to adjust for clinical characteristics in a comparison between with and without glomerular hematuria. Cox regression was employed to identify risk factors for renal prognosis.

Results

A total of 70 patients with glomerular hematuria were compared to 222 patients with non-glomerular hematuria. After PSM, 67 pairs of patients with mHTN-associated TMA were matched. Patients with glomerular hematuria exhibited lower serum albumin levels, higher 24-h proteinuria, and a higher prevalence of glomerular sclerosis than those with non-glomerular hematuria. Glomerular hematuria was independently associated with deteriorated renal function compared with non-glomerular hematuria (HR: 0.51; 95% CI: 0.29-0.89, p = 0.019). This association remained significant after PSM (HR: 0.51; 95% CI: 0.28-0.91, p = 0.022). Additionally, glomerular hematuria was independently associated with renal replacement therapy (RRT) (HR: 3.14; 95% CI: 2.06-5.66, p < 0.001). This difference remained significant after PSM comparison (HR: 2.41; 95% CI: 1.34-4.33, p = 0.003). Furthermore, despite intensive blood pressure control, patients with glomerular hematuria experienced a higher incidence of RRT and a poorer recovery in renal function, specifically a 25% reduction of creatinine levels, compared to patients with non-glomerular hematuria.

Conclusion

Glomerular hematuria is significantly associated with an increased risk of adverse renal outcomes in patients with mHTN-associated TMA.

Lupus nephritis: Biomarkers

Lupus nephritis (LN) or renal involvement of systemic lupus erythematosus (SLE), is a common manifestation occurring in at least 50 % of SLE patients. LN remains a significant source of morbidity, often leading to progressive renal dysfunction and is a major cause of death in SLE. Despite these challenges, advances in the understanding of the pathogenesis and genetic underpinnings of LN have led to a commendable expansion in available treatments over the past decade. This chapter provides a foundation for the understanding LN pathogenesis, diagnosis, and epidemiology, and guides the reader through recent advances in biomarkers, genetic susceptibility of this intricate condition.

Urinary renal tubular epithelial cells and casts as predictors of renal outcomes in patients with biopsy-proven diabetic nephropathy

BACKGROUND

Urine sediment examination is a time-tested and non-invasive diagnostic tool. This study investigated the characteristics of urine sediment and its association with severity and renal outcomes in diabetic nephropathy (DN) patients.

METHODS

A total of 201 biopsy-proven diabetic nephropathy patients (according to the pathological classification of diabetic nephropathy proposed by the Renal Pathology Society in 2010) who underwent manual urine sediment microscopic examination were included. We compared the clinicopathological characteristics of diabetic nephropathy patients with and without urinary renal tubular epithelial cells (RTECs) or renal tubular epithelial cell casts. The predictive value of urinary renal tubular epithelial cells or renal tubular epithelial cell casts for renal outcomes in diabetic nephropathy was analyzed.

RESULTS

Fifty of 201 (24.9%) diabetic nephropathy patients had renal tubular epithelial cells or renal tubular epithelial cell casts in urine sediment. Diabetic nephropathy patients with renal tubular epithelial cells or renal tubular epithelial cell casts in urine sediment had a significantly higher level of proteinuria [6.0 (3.1, 9.7) vs. 3.6 (1.8, 6.8) g/24 h, p = 0.001], higher serum creatinine [227.9 (151.6, 338.1) vs. 177.0 (104.4, 288.4) μmol/L, p = 0.016] and lower estimated glomerular filtration rate (eGFR) [25.8 (15.8, 44.8) vs. 35.7 (19.9, 65.0) mL/min/1.73 m2, p = 0.025] than those without. Cox regression analysis demonstrated that the presence of urinary renal tubular epithelial cells or renal tubular epithelial cell casts was independently associated with the development of end-stage kidney disease (ESKD) in diabetic nephropathy patients [HR 1.670, 95% CI (1.042, 2.676), p = 0.033]. Adding the presence of urinary renal tubular epithelial cells or renal tubular epithelial cell casts to the predictive model could improve the effectiveness of the model for predicting the risk of ESKD within one year after renal biopsy.

CONCLUSIONS

The presence of urinary renal tubular epithelial cells or renal tubular epithelial cell casts was associated with more severe kidney injury and worse renal outcomes in patients with diabetic nephropathy, thus perhaps providing a noninvasive biomarker for predicting diabetic nephropathy.

Machine learning-based 2-year risk prediction tool in immunoglobulin A nephropathy

BACKGROUND

This study aimed to develop a machine learning-based 2-year risk prediction model for early identification of patients with rapid progressive immunoglobulin A nephropathy (IgAN). We also assessed the model's performance to predict the long-term kidney-related outcome of patients.

METHODS

A retrospective cohort of 1,301 patients with biopsy-proven IgAN from two tertiary hospitals was used to derive and externally validate a random forest-based prediction model predicting primary outcome (30% decline in estimated glomerular filtration rate from baseline or end-stage kidney disease requiring renal replacement therapy) and secondary outcome (improvement of proteinuria) within 2 years after kidney biopsy.

RESULTS

For the 2-year prediction of primary outcomes, precision, recall, area-under-the-curve, precision-recall-curve, F1, and Brier score were 0.259, 0.875, 0.771, 0.242, 0.400, and 0.309, respectively. The values for the secondary outcome were 0.904, 0.971, 0.694, 0.903, 0.955, and 0.113, respectively. From Shapley Additive exPlanations analysis, the most informative feature identifying both outcomes was baseline proteinuria. When Kaplan-Meier analysis for 10-year kidney outcome risk was performed with three groups by predicting probabilities derived from the 2-year primary outcome prediction model (low, moderate, and high), high (hazard ratio [HR], 13.00; 95% confidence interval [CI], 9.52-17.77) and moderate (HR, 12.90; 95% CI, 9.92-16.76) groups showed higher risks compared with the low group. From the 2-year secondary outcome prediction model, low (HR, 1.66; 95% CI, 1.42-1.95) and moderate (HR, 1.42; 95% CI, 0.99-2.03) groups were at greater risk for 10-year prognosis than the high group.

CONCLUSION

Our machine learning-based 2-year risk prediction models for the progression of IgAN showed reliable performance and effectively predicted long-term kidney outcome.

Current urinalysis practices in Belgian laboratories towards the 2023 EFLM European urinalysis guideline

OBJECTIVES/BACKGROUND

We aimed to investigate routine urinalysis practices in Belgian laboratories and verify these findings against the 2023 European Federation of Clinical Chemistry and Laboratory Medicine (EFLM) European Urinalysis Guideline.

METHODS

A questionnaire was developed to collect information on pre- to postanalytical aspects of urine test strip and particle analysis. The questionnaire was distributed by Sciensano to all Belgian laboratories, licensed to perform urine particle analysis.

RESULTS

Sixty-six percent of the Belgian laboratories (75/113) participated. The responding laboratories served physicians in private (25%), hospital (60%) and university hospital (15%) setting. All laboratories performed test strip and particle analysis, predominantly automatically (97% and 96%, respectively). In addition, most laboratories (87%) used intelligent verification criteria to optimize diagnostic accuracy. Almost all laboratories (≥90%) screened and reported a minimal biochemistry panel (glucose, protein, pH, ketones) and particle count (red and white blood cells). Independent of the technology, a notable variability was observed regarding medical cut-off values and advanced particle differentiation and reporting. Internal quality control was extensively performed for urine test strip (91%) and particle analysis (96%), while external QC was less common (32% and 36%, respectively). Consequently, only few laboratories were ISO15189 accredited for urine test strip (15%) and particle analysis (17%).

CONCLUSION

There is considerable variability in current urinalysis performed in Belgian laboratories. The 2023 EFLM urinalysis guideline has the potential to guide clinical laboratories towards improving their urinalysis practices. Additional efforts are required to implement these recommendations into clinical practice in Belgium.

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.

A Cross-Sectional Survey to Identify Sociodemographic Factors Associated with the Frequency of Urinalysis in a Representative Sample of Adults in Poland, 2024

A general urine test is considered one of the basic diagnostic tests using in healthcare. This study aimed to analyze sociodemographic factors associated with the frequency of urine testing in Poland. This cross-sectional survey was conducted using computer-assisted web interviewing (CAWI) between 1 March and 4 March 2024. A representative sample of 1113 adults in Poland (aged 18-86 years, 52.5% of whom were females) took part in the study. The survey showed that 46.3% of adults in Poland had a urinalysis in the last 12 months. One-fifth (20.7%) of the participants had a urinalysis more than a year ago but not more than 2 years ago. Moreover, 26.7% had a urinalysis performed 2-3 years ago. Among all participants, female gender (OR = 1.31 [1.01-1.68]; p < 0.05), being aged 70 years and over (OR = 2.22 [1.23-4.02]; p < 0.01), having children (OR = 1.45 [1.01-2.09]; p < 0.05), and having urologic diseases (OR = 2.34 [1.79-3.02]; p < 0.001) were significantly associated with having urinalysis in the last 12 months. Among respondents without urologic diseases, female gender (OR = 1.33 [1.02-1.74]; p < 0.05), being aged 60 years and over (p < 0.05), and being married (OR = 1.45 [1.09-1.94]; p < 0.05) were significantly associated with having a urinalysis in the last 12 months. There was no significant impact of educational level, occupational status, or financial situation on the frequency of urinalysis.

The efficacy and safety of hydroxychloroquine versus leflunomide in patients with IgA nephropathy: a single-center experience

PURPOSE

To date, our understanding of IgA nephropathy (IgAN) pathophysiology has remained incomplete; therefore, treatment remains largely empiric, and the efficacy and safety of immunosuppressants remain controversial. We aimed to assess the efficacy and safety of hydroxychloroquine and leflunomide therapy in a retrospective cohort of patients with IgAN.

METHODS

We screened the IgAN registration database in our department, and a total of 159 kidney patients with biopsy-confirmed IgAN were enrolled, with 57 patients receiving hydroxychloroquine plus a renin-angiotensin system inhibitor (hydroxychloroquine group), 52 patients receiving leflunomide plus a renin-angiotensin system inhibitor (leflunomide group), and 50 patients receiving only a renin-angiotensin system inhibitor (renin-angiotensin system inhibitor-only group). Changes in proteinuria, hematuria, and the estimated glomerular filtration rate (eGFR), as well as adverse events, were analyzed during the follow-up period.

RESULTS

At the end of 6-month follow-up, proteinuria significantly decreased by 70.36 (57.54, 79.33)%, 57.29 (46.79, 67.29)% and 41.20 (25.76, 48.94)% in the hydroxychloroquine, leflunomide and renin-angiotensin system inhibitor-only groups, respectively, compared to baseline (all P values < 0.001). Hematuria significantly decreased by 71.07 (56.48, 82.47)% in the leflunomide group (P < 0.001). The eGFR improved by 3.72 ± 2.97%, 3.16 ± 2.00% and 1.91 ± 2.41%, respectively, in the hydroxychloroquine, leflunomide and renin-angiotensin system inhibitor-only groups, but without statistical significance. No serious adverse events occurred during the follow-up period.

CONCLUSION

Both hydroxychloroquine combined with a renin-angiotensin system inhibitor and leflunomide combined with a renin-angiotensin system inhibitor were more effective than a renin-angiotensin system inhibitor alone in improving proteinuria in IgAN patients. Hydroxychloroquine was more effective in reducing proteinuria, and leflunomide showed superiority in reducing hematuria. Our results need to be verified in large-scale randomized controlled trials.

A nomogram predicting the histologic activity of lupus nephritis from clinical parameters

BACKGROUND

The 2021 clinical guidelines of the Kidney Disease: Improving Global Outcomes emphasize the importance of the histological activity index (AI) in the management of lupus nephritis (LN). Patients with LN and a high AI have poor renal outcomes and high rates of nephritic relapse. In this study we constructed prediction models for the AI in LN.

METHODS

The study population comprised 337 patients diagnosed with LN using kidney biopsy. The participants were randomly divided into training and testing cohorts. They were further divided into high-activity (AI >2) and low-activity (AI ≤2) groups. This study developed two clinical prediction models using logistic regression and least absolute shrinkage and selection operator (LASSO) analyses with laboratory test results collected at the time of kidney biopsy. The performance of models was assessed using 5-fold cross-validation and validated in the testing cohort. A nomogram for individual assessment was constructed based on the preferable model.

RESULTS

Multivariate analysis showed that higher mean arterial pressure, lower estimated glomerular filtration rate, lower complement 3 level, higher urinary erythrocytes count and anti-double-stranded DNA seropositivity were independent risk factors for high histologic activity in LN. Both models performed well in the testing cohort regarding the discriminatory ability to identify patients with an AI >2. The average area under the curve of 5-fold cross-validation was 0.855 in the logistic model and 0.896 in the LASSO model. A webtool based on the LASSO model was created for clinicians to enter baseline clinical parameters to produce a probability score of an AI >2.

CONCLUSIONS

The established nomogram provides a quantitative auxiliary tool for distinguishing LN patients with a high AI and helps physicians make clinical decisions in their comprehensive assessment.

Microscopic urinary particle detection by different YOLOv5 models with evolutionary genetic algorithm based hyperparameter optimization

The diagnosis of kidney disease often involves analysing urine sediment particles. Traditionally, urinalysis was performed manually by collecting urine samples and using a centrifuge, which was prone to manual errors and relied on labour-intensive processes. Automated urine sediment microscopy, based on machine learning models, requires segmentation and feature extraction, which can hinder model performance due to intrinsic characteristics of microscopic images. Deep learning models based on convolutional neural networks (CNNs) often rely on a large number of manually annotated data, making the system computationally complex. This study propose an advanced deep learning model based on YOLOv5, which offers faster performance and requires comparatively less data. The proposed model used five variants of the YOLOv5 model (YOLOv5n, YOLOv5s, YOLOv5m, YOLOv5l, and YOLOv5x) to detect six categories of urine particles (erythrocyte, leukocyte, crystals, cast, mycete, epithelial cells) from microscopic urine sediment images. The dataset involved 5376 images of urine sediments with 6 particles. There are 30 sets of hyperparamreteres are employed in the YOLOv5 model. To optimize the hyperparameters and fine-tune with the urine sediment dataset and for training each model, the system employed a genetic algorithm (GA) based on evolutionary principles named as Evolutionary Genetic Algorithm (EGA). Among the six categories of detected particles mycete achieved maximum performance with a mAP of 97.6 % and crystals achieved minimum performance with a mAP of 81.7 % with YOLOv5x model compared to other particles. To optimize the hyperparameters for training each model, the system employed a genetic algorithm (GA) based on evolutionary principles named as Evolutionary Genetic Algorithm (EGA). Among all the models, YOLOv5l and YOLOv5x performed the best. YOLOv5l achieved a mean average precision (mAP) of 85.8 % while YOLOv5x achieved a mAP of 85.4 % at an IoU threshold of 0.5. The detection speed per image was 23.4 ms for YOLOv5l and 28.4 ms for YOLOv5x. The proposed method developed a faster and better automated microscopic model using advanced deep learning techniques to detect urinary particles from microscopic urine sediment images for kidney disease identification. The method demonstrated strong performance in urinalysis.

Discrepant guidelines in the evaluation of hematuria

PURPOSE

To assess discrepancies in current imaging recommendations for hematuria among North American societies: American College of Radiology (ACR), American Urological Association (AUA), and Canadian Urological Association (CUA).

METHODS

The latest available ACR Appropriateness Recommendations, AUA guidelines, and CUA guidelines were reviewed. AUA and CUA guidelines imaging recommendations by variants and level of appropriateness were converted to match the style of ACR. Imaging recommendations including modality, anatomy, and requirement for contrast were recorded.

RESULTS

Clinical variants included microhematuria without risk factors, microhematuria with risk factors, gross hematuria, and microhematuria during pregnancy. CUA recommends ultrasound kidneys as the first-line imaging study in the first 3 variants; pregnancy is not explicitly addressed. For hematuria without risk factors, ACR does not routinely recommend imaging, while AUA recommends shared decision-making to decide repeat urinalysis versus cystoscopy with ultrasound kidneys. For hematuria with risk factors and gross hematuria, ACR recommends CT urography; MR urography can also be considered in gross hematuria. AUA further stratifies intermediate- and high-risk patients, for which ultrasound kidneys and CT urography are recommended, respectively. For pregnancy, ACR and AUA both recommend ultrasound kidneys, though AUA additionally recommends consideration of CT or MR urography after delivery.

CONCLUSION

There is no universally agreed upon algorithm for diagnostic evaluation. Discrepancies centered on the role of upper tract imaging with ultrasound versus CT. Prospective studies and/or repeat simulation studies that apply newly updated guidelines are needed to further clarify the role of imaging, particularly for patients with microhematuria with no and intermediate risk factors.

Pregnancy outcomes in systemic lupus erythematosus: experience from a Caribbean center

BACKGROUND

Systemic Lupus Erythematosus (SLE) is a chronic autoimmune multi-system disorder frequently affecting black women of childbearing age. No published data exist on the obstetric outcomes in a Caribbean population.

OBJECTIVE

We analyzed pregnancy outcomes in an Afro-Caribbean cohort of women with SLE at a tertiary university hospital.

METHODS

A retrospective cohort study was performed of all pregnant women with SLE prior to pregnancy from January 1990 to December 2021 at the University Hospital of the West Indies (UHWI), Jamaica. Maternal rheumatologic, obstetric, fetal/neonatal data were analyzed. Descriptive statistical analyses were performed. To determine if outcomes were associated with various factors, Spearman's rho was followed by logistic regression analysis to estimate unadjusted odds ratios with statistical significance at p < 0.05.

RESULTS

A total of 56 pregnancies in 47 women were identified with SLE. Live births were 87.5%, with 10.7% spontaneous miscarriages and no neonatal deaths. Prednisone was the most used drug in 67.9% of patients. 85% of women had an adverse outcome with an adverse fetal outcome occurring in 55% of cases. Prednisone was associated with an adverse fetal/neonatal outcome (Spearman's rho = 0.38; p = .004).

CONCLUSION

In this first Caribbean series on SLE in pregnancy, reasonably successful pregnancy outcomes are achievable in Afro-Caribbean women managed in multidisciplinary centers.

Pitfalls in the diagnosis of hematuria

Detection of hemoglobin (Hb) and red blood cells in urine (hematuria) is characterized by a large number of pitfalls. Clinicians and laboratory specialists must be aware of these pitfalls since they often lead to medical overconsumption or incorrect diagnosis. Pre-analytical issues (use of vacuum tubes or urine tubes containing preservatives) can affect test results. In routine clinical laboratories, hematuria can be assayed using either chemical (test strips) or particle-counting techniques. In cases of doubtful results, Munchausen syndrome or adulteration of the urine specimen should be excluded. Pigmenturia (caused by the presence of dyes, urinary metabolites such as porphyrins and homogentisic acid, and certain drugs in the urine) can be easily confused with hematuria. The peroxidase activity (test strip) can be positively affected by the presence of non-Hb peroxidases (e.g. myoglobin, semen peroxidases, bacterial, and vegetable peroxidases). Urinary pH, haptoglobin concentration, and urine osmolality may affect specific peroxidase activity. The implementation of expert systems may be helpful in detecting preanalytical and analytical errors in the assessment of hematuria. Correcting for dilution using osmolality, density, or conductivity may be useful for heavily concentrated or diluted urine samples.

Renal Manifestations of Drug Reaction with Eosinophilia and Systemic Symptoms (DRESS) Syndrome: A Systematic Review of 71 Cases

Unlike other adverse drug reactions, visceral organ involvement is a prominent feature of drug reaction with eosinophilia and systemic symptoms (DRESS) syndrome and correlates with mortality. The aim of this study was to systematically review cases published in PubMed-indexed, peer-reviewed journals in which patients had renal injury during the episode of DRESS syndrome (DS). We found 71 cases, of which 67 were adults and 56% were males. Female sex was associated with higher mortality. Chronic kidney disease (CKD) was present in 14% of patients who developed acute kidney injury (AKI) during DS. In 21% of cases, the kidneys were the only visceral organ involved, while 54% of patients had both liver and kidney involvement. Eosinophilia was absent in 24% of patients. The most common classes of medication associated with renal injury in DS were antibiotics in 34%, xanthine oxidase inhibitors in 15%, and anticonvulsants in 11%. Among antibiotics, vancomycin was the most common culprit in 68% of patients. AKI was the most common renal manifestation reported in 96% of cases, while isolated proteinuria or hematuria was present in only 4% of cases. In cases with AKI, 88% had isolated increase in creatinine and decrease in glomerular filtration (GFR), 27% had AKI concomitantly with proteinuria, 18% had oliguria, and 13% had concomitant AKI with hematuria. Anuria was the rarest manifestation, occurring in only 4% of patients with DS. Temporary renal replacement therapy was needed in 30% of cases, and all but one patient fully recovered renal function. Mortality of DS in this cohort was 13%, which is higher than previously reported. Medication class, latency period, or pre-existing CKD were not found to be associated with higher mortality. More research, particularly prospective studies, is needed to better recognize the risks associated with renal injury in patients with DS. The development of disease-specific biomarkers would also be useful so DS with renal involvement can be easier distinguished from other eosinophilic diseases that might affect the kidney.

Urinary Sediment Microscopy and Correlations with Kidney Biopsy: Red Flags Not To Be Missed

BACKGROUND

Urinary sediment is a noninvasive laboratory test that can be performed by an automated analyzer or manually by trained personnel. Manual examination remains the diagnostic standard because it excels at differentiating isomorphic from dysmorphic red blood cells and identifying other urinary particles such as renal tubular epithelial cells (RTECs), lipids, crystals, and the composition of casts. This study aimed to investigate the prevalence of a complete profile of urinary sediment particles and its associations with histologic lesions on kidney biopsy, regardless of diagnosis.

METHODS

This was a single-center, observational retrospective study of 131 patients who had contemporary manual urinary sediment evaluation and kidney biopsy. A comprehensive set of urinary particles and histologic lesions were quantified, and their associations were analyzed.

RESULTS

In our samples, we found an elevated frequency of findings suggestive of proliferative kidney disease and a low frequency of particles evoking urologic damage. The association of histologic lesions and urinary particles was explored with a multivariate model. We identified urinary sediment characteristics that independently correlated with the presence of some histologic lesions: urinary lipids with mesangial expansion (OR=2.86; 95% confidence interval [95% CI], 1.3 to 6.3), mesangial hypercellularity (OR=2.44; 95% CI, 1.06 to 5.58), and wire loops and/or hyaline deposits (OR=2.89; 95% CI, 1.13 to 7.73); Urinary renal tubular epithelial cells with endocapillary hypercellularity (OR=3.17; 95% CI, 1.36 to 7.39), neutrophils and/or karyorrhexis (OR=4.51; 95% CI, 1.61 to 12.61), fibrinoid necrosis (OR=4.35; 95% CI, 1.48 to 12.74), cellular/fibrocellular crescents (OR=5.27; 95% CI, 1.95 to 14.26), and acute tubular necrosis (OR=2.31; 95% CI, 1.08 to 4.97).

CONCLUSIONS

In a population of patients submitted to kidney biopsy, we found that the presence of some urinary particles (renal tubular epithelial cells, lipids, and dysmorphic erythrocytes), which are seldom reported by automated analyzers, is associated with active proliferative histologic lesions. In this regard, manual urinary sediment evaluation may help to shape the indications for performing a kidney biopsy.