Session Information
Date: Sunday, November 5, 2017
Title: Systemic Lupus Erythematosus – Clinical Aspects and Treatment Poster I: Biomarkers and Outcomes
Session Type: ACR Poster Session A
Session Time: 9:00AM-11:00AM
Background/Purpose: Tubulointerstitial inflammation (TI) has been shown to have prognostic significance in renal outcome of lupus nephritis. Considering that the type of protein excreted in urine is different between glomerular disease and tubulointerstitial disease, we aimed to determine whether non-albumin proteinuria is associated with severity of TI in lupus nephritis.
Methods : We included patients with biopsy-confirmed lupus nephritis at a tertiary medical center in Korea from January 2000 to February 2017. Patients were included if their urine protein/creatinine ratio (uPCR) and urine albumin/creatinine ratio (uACR) were simultaneously measured. All included patients met the ACR criteria for classification of systemic lupus erythematosus. Clinical and laboratory variables including C3 and C4 levels as well as anti-double strand DNA (anti-dsDNA) antibody titers were collected. Non-albumin proteinuria was calculated by subtracting uACR from uPCR (uPCR – uACR). Renal pathology including International Society of Nephrology/Renal Pathology Society (ISN/RPS) classification 2003, activity and chronicity indices, and severity of TI was reviewed. Logistic regression analysis was performed to identify the clinical and laboratory parameters associated with TI severity.
Results: Of the total 36 patients, 27 (75%) had no -to -mild TI and 9 (25%) had moderate -to -severe TI. 31 (86.1%) had proliferative type glomerulonephritis (class III ¡¾ V and IV ¡¾ V) and 5 (13.9%) had non-proliferative type glomerulonephritis (class II and V). In logistic regression analysis, the following factors were significantly associated with moderate -to -severe TI: uPCR (odds ratio [OR] 1.599, 95% confidence interval [CI] 1.025-2.494, p = 0.039) and non-albumin proteinuria (uPCR – uACR) (OR 3.558, 95% CI 1.147-11.038, p = 0.028).
Conclusion: In lupus nephritis, non-albumin proteinuria, as assessed by the difference between uPCR and uACR, was associated with severity of TI, to a more relevant degree than uPCR alone. Thus, measuring non-albumin proteinuria can be a valuable non-invasive method for assessing the severity of TI in lupus nephritis.
Table 1. Factors associated with TI severity
|
|
Odds ratio |
95% CI |
P value |
|
Age |
1.034 |
0.988-1.082 |
0.148 |
|
Female |
4.706 |
0.511-43.361 |
0.172 |
|
uACR |
1.596 |
0.921-2.764 |
0.095 |
|
uPCR |
1.599 |
1.025-2.494 |
0.039 |
|
uAPR |
0.154 |
0.004-6.650 |
0.330 |
|
uPCR – uACR |
3.558 |
1.147-11.038 |
0.028 |
|
Cr |
5.235 |
0.645-42.506 |
0.121 |
|
C3 |
1.007 |
0.964-1.052 |
0.748 |
|
C4 |
0.942 |
0.750-1.182 |
0.604 |
|
Anti-dsDNA |
0.946 |
0.850-1.054 |
0.314 |
|
GN activity index |
1.086 |
0.883-1.336 |
0.435 |
|
GN chronicity index |
1.000 |
0.283-3.528 |
>0.999 |
|
ISN/RPS class (proliferative GN) |
N/A |
N/A |
>0.999 |
To cite this abstract in AMA style:
Kwon OC, Hong S, Lee JS, Ghang B, Lim DH, Seo WJ, Kim YG, Lee CK, Yoo B. Clinical Significance of Non-Albumin Proteinuria for Severity Assessment of Tubulointerstitial Inflammation in Lupus Nephritis [abstract]. Arthritis Rheumatol. 2017; 69 (suppl 10). https://acrabstracts.org/abstract/clinical-significance-of-non-albumin-proteinuria-for-severity-assessment-of-tubulointerstitial-inflammation-in-lupus-nephritis/. Accessed .« Back to 2017 ACR/ARHP Annual Meeting
ACR Meeting Abstracts - https://acrabstracts.org/abstract/clinical-significance-of-non-albumin-proteinuria-for-severity-assessment-of-tubulointerstitial-inflammation-in-lupus-nephritis/