Kidney Week

Abstract: SA-OR68

Noninvasive Assessment of the Presence or Absence of Histologic Activity in Kidney Biopsies from Patients with Lupus Nephritis

Session Information

• Glomerular Diseases: Clinical Advances
  October 26, 2024 | Location: Room 6D, Convention Center
  Abstract Time: 05:10 PM - 05:20 PM

Category: Glomerular Diseases

• 1402 Glomerular Diseases: Clinical, Outcomes, and Therapeutics

Authors

• Rojas-Rivera, Jorge Enrique, The Ohio State University Wexner Medical Center, Columbus, Ohio, United States

Jorge Enrique Rojas-Rivera, MD, MSc

• Mejia-Vilet, Juan M., Instituto Nacional de Ciencias Medicas y Nutricion Salvador Zubiran, Ciudad de Mexico, Ciudad de México, Mexico

Juan M. Mejia-Vilet, MD, MS, PhD

• Navarro Sanchez, Valeria, Instituto Nacional de Ciencias Medicas y Nutricion Salvador Zubiran, Ciudad de Mexico, Ciudad de México, Mexico

Valeria Navarro Sanchez, MD

• Rovin, Brad H., The Ohio State University Wexner Medical Center, Columbus, Ohio, United States

Brad H. Rovin, MD, FASN

Background

Withdrawal of immunosuppressive therapy for lupus nephritis (LN) may be considered if histologic activity completely resolves. Soluble urine CD163 (uCD163) is released from intra-renal macrophages and strongly correlates with the LN activity index (AI). We examined whether uCD163 could differentiate histologically active from quiescent LN, avoiding the need for a repeat kidney biopsy before withdrawing therapy.

Methods

Urine collected at the time of diagnostic kidney biopsy from Ohio (OSU, discovery, n=119) and Mexican (MEX, validation, n=113) LN cohorts was assessed for uCD163 by ELISA. The relationship between uCD163 and AI was tested by Spearman’s correlation. The ability of uCD163 to distinguish between the presence and absence of histologic activity was examined by receiver operating characteristic (ROC) analysis, and the strength of prediction by the area under the ROC curve (AUC).

Results

Table 1 shows the correlation between uCD163 and other commonly measured clinical parameters and components of the AI. uCD163 significantly associated with each AI component but correlated best with endocapillary hypercellularity. uCD163 distinguished the absence (AI=0) or presence (AI≥1) of biopsy histologic activity with AUCs of 0.778 (OSU) and 0.791 (MEX), and correctly classified 84% (OSU) and 93% (MEX) of patients. The AUCs to discriminate presence or absence of endocapillary hypercellularity were 0.805 (OSU) and 0.787 (MEX). The uCD193 cutoffs(Younden’s Index) to differentiate AI=0 from AI ≥1 were 8.82 (OSU) and 8.83 (MEX) ng/mg creatinine.

Conclusion

Urine soluble CD163 is a robust noninvasive biomarker that accurately differentiates LN patients with ongoing disease activity from those with histologic resolution of LN. We suggest uCD163 may be used in lieu of a repeat biopsy to manage immunosuppression withdrawal in LN.

Funding

• Other NIH Support