Clinical value of the renal pathologic scoring system in complement-mediated thrombotic microangiopathy

Abstract

Objectives

This study was initiated to establish a renal thrombotic microangiopathy (TMA) scoring system based on clinical needs and investigate its predictive value for patients’ long-term outcomes.

Methods

Kidney biopsy-proven Complement-mediated TMA (C-TMA) patients from January 2000 to December 2017 in Peking University First Hospital were retrospectively studied. Both acute and chronic TMA-related lesions, including 15 pathologic indices, were semiquantitatively scored. The interobserver and intraobserver reproducibility and correlation between the pathologic indices and clinical parameters were analyzed. Furthermore, the patients were divided into 2 groups by dialysis use at baseline, and the association of these pathologic indices with their prognostic outcomes was assessed between the two groups.

Results

Ninety-two patients with renal biopsy-proven C-TMA were enrolled. All fifteen included pathology indices showed good or moderate interobserver and intraobserver reproducibility and correlated well with several clinical parameters. Several clinicopathological indices were worse in the dialysis group than in the nondialysis group, such as serum creatinine, hemoglobin, platelet count, and estimated glomerular filtration rate. Moreover, morphologic features in the dialysis group presented with more severe vascular lesions. Interstitial fibrosis and chronic tubulointerstitial lesions were related to a trend of high risk of continuous dialysis in the dialysis group. Based on univariate and multivariable Cox regression analysis, more severe glomerular lesions, including glomerular mesangiolysis, glomerular basement membrane double contours and glomerular mesangial proliferation, were identified as risk factors predicting worse prognosis.

Conclusions

Our renal C-TMA semiquantitative scoring system is reliable with good reproducibility and prognostic value in clinical practice, which needs further validation.

Keywords:

• TMA
• C-TMA
• microangiopathy
• kidney
• pathology

Acknowledgements

The authors thank Jin-Wei Wang for the statistical consultation.

Authors’ contributions

Fei-Fei Chen analyzed the statistics and drafted the manuscript. Xiao-Juan Yu developed the renal pathologic scoring system, collected the general and follow-up data of the patients, and evaluated the pathology. Hui Wang evaluated the pathology. Xu Zhang assisted evaluation of pathology. Ying Tan provided data of genetic tests. Ying Tan, Zhen Qu, Min Chen, and Ming-Hui Zhao reviewed the manuscript. Feng Yu designed the study and revised the manuscript. Zhen Qu and Su-Xia Wang provided intellectual content of importance to this work. Feng Yu had full access to all of the data and provided final approval of the submitted manuscript. All authors read and approved the manuscript.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Data availability

The datasets generated and/or analyzed during the current study are available from the corresponding author upon reasonable request.

Additional information

Funding

This work was supported by the National Natural Science Foundation of China (82000666), the Beijing Natural Science Foundation (7212114), and Peking University International Hospital Research Grant (No. YN2020ZD03).

This work was supported by the National Natural Science Foundation of China (82000666), the Beijing Natural Science Foundation (7212114), and Peking University International Hospital Resaearch Grant (No. YN2020ZD03).