Abstract: FR-PO0680
Humoral Response to SARS-CoV-2 mRNA Vaccination in Nephrology Patients Receiving Immunosuppressive Therapy
Session Information
- Glomerular Diseases: Clinical, Outcomes, and Therapeutics Research - ANCA/FSGS
October 23, 2026 | Location: Exhibit Hall A, Convention Center
Abstract Time: 10:00 AM - 12:00 PM
Category: Glomerular Diseases
- 1402 Glomerular Diseases: Clinical, Outcomes, and Therapeutics
Authors
- Kotwica-Strzalek, Ewa, Wojskowy Instytut Medyczny - Panstwowy Instytut Badawczy, Warsaw, Masovian Voivodeship, Poland
- Niemczyk, Stanislaw, Wojskowy Instytut Medyczny - Panstwowy Instytut Badawczy, Warsaw, Masovian Voivodeship, Poland
Background
Patients receiving immunosuppressive therapy (IST) are at risk for reduced vaccine immunogenicity. We assessed anti-spike (anti-S) IgG response after mRNA SARS-CoV-2 vaccination in patients receiving IST.
Methods
In this study, 60 patients receiving IST were compared with 60 age and sex matched controls. Indications for IST included glomerular diseases and systemic vasculitis. Regimens included glucocorticoids (GKS), rituximab/cyclophosphamide, calcineurin inhibitors, mycophenolate mofetil, azathioprine, and combinations thereof. Participants received mRNA vaccines available in Poland during the study period: BNT162b2 (Comirnaty) or mRNA-1273 (Spikevax). Anti-S IgG (WHO-standardized IU/mL) was measured 4-8 months after primary mRNA vaccination. Seronegativity was defined as IgG <39 IU/mL.
Results
Anti-S IgG levels were lower in patients receiving IST than in controls (median 124 [7-2931] vs 302 [34-3043] IU/mL; mean 495±743 vs 639±814 IU/mL; p=0.012). Non-response was more frequent in patients receiving IST (23.3%, 14/60) than in controls (5.0%, 3/60). Among non-responders, the most common patterns were GKS alone (28.6%) and GKS plus calcineurin inhibitor/MMF/azathioprine (28.6%). In the immunosuppression group, anti-S IgG was inversely correlated with age (Spearman R=-0.274, p=0.034), with no significant association for creatinine or eGFR. Infection after two vaccine doses was more frequent in patients receiving IST than in controls (13.3% vs 3.3%, p=0.048). Higher anti-S IgG was associated with lower odds of infection before completion of the vaccination cycle (OR 0.999 per 1 IU/mL; 95% CI 0.999-1.00). No severe post-vaccination COVID-19 occurred: no COVID-19-related hospitalizations or deaths were observed.
Conclusion
Immunosuppressive therapy is associated with weaker humoral response and higher non-response rates after mRNA SARS-CoV-2 vaccination. These data support risk-adapted vaccination strategies and closer post-vaccination monitoring in immunosuppressed nephrology patients.
Acknowledgment
The study protocol was approved by the Bioethics Committee at the Military Institute of Medicine in Warsaw (resolution no. 29/WIM/2021, dated 18 August 2021). This work was funded by a statutory project of the Military Institute of Medicine. The figure included in this abstract was generated using Codex (OpenAI), and AI-assisted support was used only for figure generation and language editing.
Funding
- Government Support – Non-U.S.