Kidney Week

Abstract: FR-PO806

SARS-CoV-2 Protein Deposition Enhances Renal Complement Activation and Aggravates Kidney Injury in Membranous Nephropathy after COVID-19

Session Information

• Glomerular Diseases: Inflammation and Immunology
  October 25, 2024 | Location: Exhibit Hall, Convention Center
  Abstract Time: 10:00 AM - 12:00 PM

Category: Glomerular Diseases

• 1401 Glomerular Diseases: Mechanisms, including Podocyte Biology

Authors

• Cheng, Hong, Beijing Anzhen Hospital Affiliated to Capital Medical University, Chaoyang-qu, Beijing, China

Hong Cheng, DrMed

• Wang, Guo-qin, Beijing Anzhen Hospital Affiliated to Capital Medical University, Chaoyang-qu, Beijing, China

Guo-qin Wang, MD

• Yang, Lei, Beijing Anzhen Hospital Affiliated to Capital Medical University, Chaoyang-qu, Beijing, China

Lei Yang, MS, DrPH

• Xu, Xiao-yi, Beijing Anzhen Hospital Affiliated to Capital Medical University, Chaoyang-qu, Beijing, China

Xiao-yi Xu, MD

• Guo, Weiyi, Beijing Anzhen Hospital Affiliated to Capital Medical University, Chaoyang-qu, Beijing, China

Weiyi Guo, MD, PhD

• Sun, Li-jun, Beijing Anzhen Hospital Affiliated to Capital Medical University, Chaoyang-qu, Beijing, China

Li-jun Sun

• Wang, Yan-yan, Beijing Anzhen Hospital Affiliated to Capital Medical University, Chaoyang-qu, Beijing, China

Yan-yan Wang, MD

• Cheng, Wenrong, Beijing Anzhen Hospital Affiliated to Capital Medical University, Chaoyang-qu, Beijing, China

Wenrong Cheng

• Ye, Nan, Beijing Anzhen Hospital Affiliated to Capital Medical University, Chaoyang-qu, Beijing, China

Nan Ye

• Kong, Lingqiang, Beijing Anzhen Hospital Affiliated to Capital Medical University, Chaoyang-qu, Beijing, China

Lingqiang Kong, MD

• Zhao, Xiaoyi, Affiliated Hospital of Chifeng University, Neimenggu, China

Xiaoyi Zhao

Background

COVID-19 has been reported to be associated with the occurrence and recurrence of membranous nephropathy (MN). The clinicopathological characteristics and complement system activation of MN after COVID-19 are unclear.

Methods

A total of 38 patients with biopsy-proven MN who developed new onset proteinuria after COVID-19 were enrolled in this study. One hundred patients with primary MN diagnosed before COVID-19 pandemic as control. Renal immunohistochemical staining for SARS-CoV-2 nucleocapsid protein was performed in 38 patients with MN after COVID-19. Serum membrane attack complex (MAC) was detected by enzyme-linked immunosorbent assay. Glomerular staining for the complement proteins in different pathways were detected by immunohistochemical.

Results

Thirteen of 38 patients had positive staining for SARS-CoV-2 nucleocapsid protein. Compared with control-patients, the clinical manifestations were more severe in patients after COVID-19. Patients with positive SARS-CoV-2 staining had a higher proportion of nephrotic syndrome, lower level of serum albumin, and greater severity of renal interstitial fibrosis than those of patients with negative SARS-CoV-2 staining. Serum MAC level and renal MAC staining intensity of MN after COVID-19 were significantly higher than those of control-patients. MAC expression in MN patients with positive SARS-CoV-2 staining was stronger than that in both control-patients and MN after COVID-19 with negative SARS-CoV-2 staining. Meanwhile, the expression trend of factor H was consistent with that of MAC.

Conclusion

Excessive activation of the complement system aggravated symptoms in MN after COVID-19. The complement alternative pathway might be involved in renal injury. Therapeutic strategy targeting the complement system may need to be considered.

Figure. The renal pathologic images of a patient with PLA2R-positive MN patient after COVID-19 who also is positive for SARS -COV-2 staining.