# The Diagnostic Value of Cellular Phenotyping and Pathological Casts Using Urine Flow Cytometry in Children with Lupus Nephritis

## TL;DR

This study shows that urine flow cytometry can help diagnose lupus nephritis in children by analyzing specific cell and cast characteristics.

## Contribution

The study evaluates the diagnostic performance of DysRBC, RTECs, and PathCasts in children with lupus nephritis using urine flow cytometry.

## Key findings

- Dysmorphic RBCs showed excellent diagnostic performance with an AUC of 0.954.
- RTECs and PathCasts also demonstrated significant discriminatory ability, though less than DysRBCs.
- The results suggest these parameters could aid in diagnosing lupus nephritis in children.

## Abstract

Introduction: Dysmorphic RBC (DysRBC) as a marker of glomerular abnormalities is expected to have added value in screening for glomerular abnormalities along with other examinations, including renal tubular epithelial cells (RTECs) and pathological casts (PathCasts) that indicate tubular abnormalities in lupus nephritis (LN). Therefore, this study intended to assess the diagnostic performance of urinary cell and cast characteristics, including DysRBC, RTECs, and PathCast, as measured by the urine flow cytometry in lupus nephritic children. Methods: Urine samples from 317 patients (50.47% female and 49.53% male) were collected. The diagnostic value was evaluated using receiver operating characteristic (ROC) analysis. Results: The ROC analysis demonstrated that all parameters exhibited acceptable discriminatory performance, including %DysRBC (AUC = 0.954, p < 0.001), RTEC (AUC = 0.580, p = 0.001), and PathCast (AUC = 0.664, p = 0.001). Conclusions: DysRBC, RTECs, and PathCast may have added value in the diagnosis of LN in children, notably with excellent diagnostic value in distinguishing LN in %DysRBC. This promising result warrants evaluation with a large-scale site study.