Kidney Week

Abstract: SA-PO946

Correlation of Immunoglobulin A/Complement Factor 3 (IgA/C3) Ratio with the Clinico-Histological Characteristics and Outcome in IgA Nephropathy

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

• Swamy, Anitha, All India Institute of Medical Sciences, New Delhi, India

Anitha Swamy,

• Barwad, Adarsh, All India Institute of Medical Sciences, New Delhi, Delhi, India

Adarsh Barwad,

• Singh, Geetika, All India Institute of Medical Sciences, New Delhi, Delhi, India

Geetika Singh,

• Subbiah, Arunkumar, All India Institute of Medical Sciences, New Delhi, Delhi, India

Arunkumar Subbiah,

• Yadav, Raj Kanwar, All India Institute of Medical Sciences, New Delhi, Delhi, India

Raj Kanwar Yadav,

• Mahajan, Sandeep, All India Institute of Medical Sciences, New Delhi, Delhi, India

Sandeep Mahajan,

• Bhowmik, Dipankar M., All India Institute of Medical Sciences, New Delhi, Delhi, India

Dipankar M. Bhowmik,

• Agarwal, Sanjay K., All India Institute of Medical Sciences, New Delhi, Delhi, India

Sanjay K. Agarwal,

• Bagchi, Soumita, All India Institute of Medical Sciences, New Delhi, Delhi, India

Soumita Bagchi,

Background

IgAN is a heterogenous disease and has an aggressive clinical course in Asians. The serum IgA/C3 ratio at biopsy has been shown to correlate well with the prognosis of IgAN in few studies. We conducted this study to evaluate this non-invasive biomarker in our patients.

Methods

In an ambispective study we evaluated the baseline serum IgA and C3 levels, and IgA/C3 ratio in patients with biopsy proven primary IgAN and eGFR ≥ 30 ml/min/1.73m². For the patients recruited retrospectively, the same was determined from serum samples stored in a biorepository at the time of kidney biopsy. The ratio was evaluated in relation to the clinical severity at the time of presentation in terms of eGFR and proteinuria and histological severity assessed using the Oxford classification. We also assessed the role of the baseline IgA/C3 ratio as a prognostic biomarker in this cohort. The primary outcome assessed was renal survival which was defined as absence of > 40% decline in eGFR and/or progression to end stge renal disease. Remission of proteinuria was defined as urinary protein creatinine ratio(UPCR) <1g/g with stable renal function(≤ 25% decline in eGFR).

Results

106 patients with a median follow-up period of 17.3 months with a median serum creatinine of 1.3 (0.4-2.6) mg/dl at presentation were analyzed. 46 patients (43.4%) had a baseline eGFR < 60 ml/min/1.73m². The mean UPCR at baseline was 2.1 ±1.6 g/g with 18 patients (17.0%) having nephrotic range proteinuria. The median IgA/C3 ratio in the population was 2.5 (0.79-4.75). The serum IgA/C3 ratio at baseline did not corelate with the baseline eGFR, proteinuria and the MEST-C characteristics. The ratio did not predict the primary outcome or the remission of proteinuria.

Conclusion

Future studies with larger sample size, milder cases, longer follow up period and a serial measurement of IgA/C3 are warranted for better clarification of any possible role of this biomarker in IgAN in our population.