Kidney Week

Abstract: FR-PO1097

Activation of the Alternative Complement Pathway Predicts Renal Outcome in Patients with Lupus Nephritis

Session Information

• Glomerular Diseases: Clinical, Outcomes, Trials - II
  October 26, 2018 | Location: Exhibit Hall, San Diego Convention Center
  Abstract Time: 10:00 AM - 12:00 PM

Category: Glomerular Diseases

• 1203 Glomerular Diseases: Clinical, Outcomes, and Trials

Authors

• Kim, Hyunwoo, Jeju National University Hospital, Jeju City, Korea (the Republic of)

Hyunwoo Kim,

• Kim, Jinseok, Jeju National University Hospital, Jeju City, Korea (the Republic of)

Jinseok Kim,

Background

The aim of this study was to clarify the glomerular activation of complement pathways in patients with lupus nephritis, and to elucidate the association between these complement activation types and clinical outcomes.

Methods

We enrolled 100 patients with biopsy-proven lupus nephritis from 2003 to 2016 from the lupus cohort at the Busan Paik Hospital and the Jeju National University Hospital in Korea. The patients were divided into two groups based on the patterns of glomerular complements deposits: The presence of C4 and C1q deposits with C3 deposits in the glomerulus was considered to be the evidence for the activation of the classical pathway (group I, n=83) and glomerular C3 deposition without C4 and C1q deposits was considered as a marker for the activation of the alternative pathway (group II, n=17). The study endpoint was progression of kidney dysfunction defined as the decline rate of estimated glomerular filtration rate (GFR) of more than 1 ml/min/1.73 m² per year.

Results

The mean age of the patients was 32.9 ± 10.7 years. Ten patients were male, 34 patients were hypertensive, 24 patients had a GFR < 60 ml/min/1.73 m², and 38 patients had nephrotic range of proteinuria at the time of kidney biopsy. Compared to the group I patients, those in group II were older (31.1 ± 10.1 vs. 41.5 ± 9.5 years, p <0.001), more hypertensive (29% vs. 59%, p=0.020), and more male dominant (6% vs. 29%, p=0.003). Considering histopathologic features, group I patients had higher glomerular deposition of IgG and IgA than those in group II. Endocapillary hypercellularity and fibrinoid necrosis were also more frequently found in group I patients compared with those in group II. The median follow-up time was 4.3 years (interquartile range: 2.6–7.6 years). The rate of decline in estimated GFR was greater in group II patients than in group I patients (-5.7 ml/min/1.73 m² per year vs. 1.4 ml/min/1.73 m² per year; p=0.034).

Conclusion

This study showed that the patients with the alternative complement activation had poor renal outcome compared to the patients with the classical complement pathway, suggesting that the alternative complement activation may play a pathogenic role in the progression of lupus nephritis.