Monocyte/macrophage related biomarkers in assessment of lupus nephritis activity

Ranjan Gupta, Akhilesh Yadav, Amita AggarwalDepartment of Clinical Immunology, SGPGIMS, Lucknow

Disclosures: Funding by DBT to AA

Introduction

• Lupus nephritis (LN) affects almost 70% patients

• Limitations of conventional markers of LN:Proteinuria: damage vs activityActive sediment: reproducibilityRenal biopsy: invasive nature and associated risks

Quest to find new urinary biomarkers

Urinary Monocytes/Macrophages in LN

• Monocytes/MΦs: Most abundant urinary cells in LN

• MCP-1: Macrophage chemoattractantuMCP-1 surrogate marker for MΦs infiltration

Kopetschke et al. Arthritis Research & Therapy, 2015

Monocytes/Macrophages in renal biopsy

Olmes et al. Arthritis Research & Therapy, 2016

sCD163 in ANCA associated vasculitis

• sCD163:Glycosylated protein on monocytes/MΦsScavenger of Hb-Haptoglobin complexes

O’Reilly et al. J Am Soc Nephrol, 2016

Objectives

To evaluate MCP-1 and sCD163 as biomarkers of LN disease activity in a cross-sectional as well as longitudinal study

MethodsSLE patients: ACR 1997 criteriaExclusions: Pregnancy and infections

Baseline evaluation: SLEDAIUrine: active sediment, 24 hr. proteinuria, Spot U Pr/Cr ratioSerum and cell-free urine samples stored at -80oC

Active Non-Renal (ANR) Active Renal (AR) Inactive Disease (ID)

Treated as per ACR, 2012 guidelines

3 monthly follow-up visits for 1 year: SLEDAIUrine: active sediment, Spot U Pr/Cr ratioSerum and cell-free urine samples stored at -80oC

± renal biopsy

Controls: 20 healthy subjects and 20 rheumatoid arthritis patients

Results: Patients

Total patients: 117 (F:M – 109:8)

AR n=57

ANRn=23

ID n=37 Class III

n=16

Class IIN=5

Class Vn=7

Class VIn=1

Biopsy not donen=10

Class IVn=16

Baseline characteristics

Active Nephritis (AR)

Active Non-Renal (ANR)

Inactive Disease (ID)

Number 57 23 37

F:M 55:2 18:5 36:1

Median age (yrs) 27 (13 – 50) 29 (15 – 50) 28 (14 – 48)

rSLEDAI 8 (4 – 16) 0 (0) 0 (0)

SLEDAI 18 (6 – 28) 10 (5 – 20) 2 (0 – 4)

Low C3 45 10 2

Low C4 45 12 6

Anti-ds DNA (IU/ml) 200 (24 – >300) 185 (<6.25 – >300) 53.6 (<6.25 – >300)

UPr/UCr ratio 3.37 (0.3 – 20.25) 0.37 (0.04 – 1.46) 0.11 (0 – 10.69)

Serum Creatinine (mg/dl) 0.9 (0.4 – 3.87) 0.81 (0.6 – 1.25) 0.77 (0.4 – 1.3)

Urinary levels: Cross sectional analysisMCP-1 sCD163

Relationship with disease activity

MCP-1 sCD163

Serum levels: Cross sectional analysis

MCP-1 sCD163

Serum and urinary levels: correlation

Poor correlation between serum and urinary biomarker levels

MCP-1 sCD163

ROC analysis: AR vs ANR

AUCuMCP-1 – 0.75sMCP-1 – 0.31Anti-ds DNA – 0.6C3 – 0.65C4 – 0.61

AUCUrinary sCD163 – 0.72Serum sCD163 – 0.46Anti-ds DNA – 0.6C3 – 0.65C4 – 0.61

MCP-1 sCD163

Results: Longitudinal analysis

Baseline 3 months 6 months 9 months 12 months

Number 57 51 51 46 46

rSLEDAI 8 (4 – 16) 0 (0 – 12) 0 (0 – 4) 0 (0 – 8) 0 (0 – 8)

SLEDAI 18 (6 – 28) 2 (0 – 14) 2 (0 – 6) 2 (0 – 10) 2 (0 – 15)

Low C3 45 3 5 6 2

Low C4 45 15 14 9 7

Anti-ds DNA (IU) 200 (24 – >300)

87.9 (8.4 – >300)

53.75 (<6.25 – >300)

61.5 (<6.5 – 300)

63.8 (8 – 216.66)

UPr/UCr ratio 3.7 (0.3 – 20.25)

0.35 (0 – 13.55)

0.62 (0 – 3.98)

0.22 (0 – 6.98)

0.24 (0 – 6.25)

Serum Creatinine (mg/dl)

0.9 (0.4 – 3.87)

0.77 (0 – 4.12)

0.8 (0.56 – 1.7)

0.79 (0.4 – 1.3)

0.81 (0.4 – 1.3)

Urinary levels: Longitudinal analysisMCP-1 sCD163

Serum levels: Longitudinal analysisMCP-1 sCD163

Relapse & poor renal response

↓

↓

↓

↓

MCP-1 sCD163

↓ = Relapse of Nephritis

Discussion & Conclusion• Urinary MCP-1 & sCD163 levels:

Higher in renal disease compared to ANR & IDCorrelate with rSLEDAI and SLEDAINo association with serum MCP-1 & sCD163 levels

MCP-1 & sCD163 are produced locally in kidneys in LN• ROC analysis: perform better than conventional markers

• Renal inflammation M0 MΦs M2c MΦs1

Source: Urinary MCP-1 : Infiltrating Monocytes/MΦs & tubular

cells Urinary sCD163 : Infiltrating M2c MΦs

IL-6, IL-10M-CSF

MCP-1

1Endo N et al. Nephrol Dial Transplant, 2016

Discussion & Conclusion• With immunosuppression ↓Inflammation, cytokines and renal injury ↓Disease activity ↓uMCP-1 & sCD163 levels paralleling traditional

markers

• MCP-1/sCD163: ‘different elements of same process’

• uMCP-1 & sCD163 are potential biomarkers of LN Help differentiate LN from ANR diseaseLevels parallel renal activityMay predict relapse of LN

Acknowledgement: Support of our Lupus patients