Abstract: PO0139
Humoral Response to Pfizer BNT162b2 in Peritoneal and Hemodialysis Patients: A Comparative Study
Session Information
- COVID-19: Vaccines, Diagnosis, and Treatment
November 04, 2021 | Location: On-Demand, Virtual Only
Abstract Time: 10:00 AM - 12:00 PM
Category: Coronavirus (COVID-19)
- 000 Coronavirus (COVID-19)
Authors
- Duarte, Rui A., Centro Hospitalar do Medio Tejo EPE Unidade de Torres Novas, Torres Novas, Santarém, Portugal
- Roldão, Marisa, Centro Hospitalar do Medio Tejo EPE Unidade de Torres Novas, Torres Novas, Santarém, Portugal
- Figueiredo, Cátia Raquel, Centro Hospitalar do Medio Tejo EPE Unidade de Torres Novas, Torres Novas, Santarém, Portugal
- Ferrer, Francisco, Centro Hospitalar do Medio Tejo EPE Unidade de Torres Novas, Torres Novas, Santarém, Portugal
- Gonçalves, Hernâni Martins, Centro Hospitalar do Medio Tejo EPE Unidade de Torres Novas, Torres Novas, Santarém, Portugal
- Sofia, Flora, Centro Hospitalar do Medio Tejo EPE Unidade de Torres Novas, Torres Novas, Santarém, Portugal
- Luz, Ivan Andrade, Centro Hospitalar do Medio Tejo EPE Unidade de Torres Novas, Torres Novas, Santarém, Portugal
Background
Generalized immunization against COVID19 has become the cornerstone in prevention of Sars-CoV-2. Maintenance dialysis patients (MDP) are at higher risk of both exposure and mortality. Efficacy and security of Pfizer BNT 162b2 vaccine is well documented for the general population, but not in MDP, particularly in peritoneal dialysis (PD) patients. This study aims to compare humoral response between HD and PD patients.
Methods
Observational prospective study including MDP on HD or PD program from a Portuguese middle-sized Nephrology Center, who received Pfizer-BNT162b2. Specific anti-Spike IgG was measured as arbitrary units per milliliter (AU/mL) on two separate occasions, corresponding to the first and second doses’ humoral response. The two groups were compared both for absolute value and number of non-responders (NR) after both inoculations. Demographic data was also obtained and compared.
Results
Of 73 patients enrolled, 67 were eligible for the final study: 42 HD and 25 PD patients. PD group developed significantly higher antibody titers both after first (Med 5.44 vs 0.99; p<0.01) and second dose (Med 170.43 vs 65.81; p<0.01). HD status was associated with non-responding after the first dose (Phi=0.383; p<0.01), but not after the second one (p=0.08). Age, Charlson Comorbidity Index and dialysis vintage were lower in the PD group (p<0.01; p=0.02; p<0.01, respectively).
Conclusion
This study demonstrated a better humoral response to immunization with Pfizer BNT162b2 in PD patients, when comparing to HD patients, after both inoculations. Both groups showed substantial humoral response after just one dose of the vaccine. Older age and higher comorbidity burden may explain the relative immunogenicity deficit.