Kidney Week

Abstract: SA-PO944

Relevance of Serum A Proliferation-Inducing Ligand (APRIL) as a Biomarker in South Asian Prospective Longitudinal Observational IgA Nephropathy Cohort (GRACE-IgANI)

Session Information

• Glomerular Diseases: Translational Studies and Biomarkers
  November 04, 2023 | Location: Exhibit Hall, Pennsylvania Convention Center
  Abstract Time: 10:00 AM - 12:00 PM

Category: Glomerular Diseases

• 1402 Glomerular Diseases: Clinical, Outcomes, and Trials

Authors

• Alexander, Suceena, Christian Medical College Vellore, Vellore, Tamil Nadu, India

Suceena Alexander,

• Mani, Selvin Sundar Raj, Christian Medical College Vellore, Vellore, Tamil Nadu, India

Selvin Sundar Raj Mani,

• Varughese, Santosh, Christian Medical College Vellore, Vellore, Tamil Nadu, India

Santosh Varughese,

• Barratt, Jonathan, University of Leicester, Leicester, United Kingdom

Jonathan Barratt,

• John, George, Christian Medical College Vellore, Vellore, Tamil Nadu, India

George John,

Group or Team Name

• GRACE-IgANI.

Background

The role of serum APRIL as a biomarker in a prospective longitudinal South Asian IgAN cohort (GRACE-IgANI) and the impact of immunosuppression (IS) is not known.

Methods

Serum APRIL levels were measured in baseline and longitudinal sera (1year, 2year & 3year) in IgAN patients, and at baseline in disease controls and healthy controls by ELISA (R&D Systems; Catalog No: DY884B). Short course IS was given to patients with proteinuria ≥1g/day and/or renal impairment (73%). Composite outcome (CO) was defined as ≥50% fall in eGFR (CKD EPI) from baseline and/or eGFR <15ml/min/1.73m² or RRT/death.

Results

Lower baseline serum APRIL levels were diagnostic of IgAN in our cohort compared to disease controls and healthy controls (398 vs. 550 vs. 516 pg/mL, p=0.002). Serum APRIL levels had significant but weak positive correlation with baseline eGFR. MEST-C T1/T2 scores were significantly associated with lower baseline serum APRIL levels (T0: 490 vs. T1/T2: 372 pg/mL, p=0.007). In the treatment group I (low-risk group without IS), there was no significant association with CO at 3year. In the treatment group II (high-risk group with IS), there was significant association between lower serum APRIL levels at 1year, 2year, 3year and CO at 3year (1Y: 590 vs. 356 pg/mL, p<0.001; 2Y: 508 vs. 314 pg/mL, p=0.003; 3Y; 519 vs. 271, p<0.001) and the ROC curve of serum APRIL level at 1year showed good discrimination (AUC 0.75) for CO. There was a significant longitudinal increase in serum APRIL levels from baseline to 1year and which was sustained at 3year (Baseline: 414 vs. 1Y: 590 vs. 2Y: 508 vs. 3Y: 519 pg/mL, p<0.0001) in patients with favorable renal outcome.

Conclusion

Serum APRIL levels were an indepenpendent risk factor for progressive kidney disese in this cohort.

Funding

• Government Support – Non-U.S.