KRKeegan Rengel

Keegan Rengel

*This is an algorithmically generated author record based on publicly available information.

Current Organizations / Institutes

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Keegan Rengel has a total of 15 co-authors. Here are the top co-authors by number of shared publications:


Latest Publications

  • Open Access

    Differences in Responses of Immunosuppressed Kidney Transplant Patients to Moderna mRNA-1273 versus Pfizer-BioNTech

    by Dulat Bekbolsynov, Andrew Waack, Camryn Buskey, Shalmali Bhadkamkar, Keegan Rengel, Winnifer Petersen, Mary Lee Brown, Tanaya Sparkle, Dinkar Kaw, Fayeq Jeelani Syed, et al.

    Immunosuppressed kidney transplant (KT) recipients produce a weaker response to COVID-19 vaccination than immunocompetent individuals. We tested antiviral IgG response in 99 KT recipients and 66 healthy volunteers who were vaccinated with mRNA-1273 Moderna or BNT162b2 Pfizer-BioNTech vaccines. A subgroup of participants had their peripheral blood leukocytes (PBLs) evaluated for the frequency of T helper 1 (Th1) cells producing IL-2, IFN-γ and/or TNF-α, and IL-10-producing T-regulatory 1 (Tr) cells. Among KT recipients, 45.8% had anti-SARS-CoV-2 IgG compared to 74.1% of healthy volunteers (p = 0.009); also, anti-viral IgG levels were lower in recipients than in volunteers (p = 0.001). In terms of non-responders (≤2000 U/mL IgG), Moderna’s group had 10.8% and Pfizer-BioNTech’s group had 34.3% of non-responders at 6 months (p = 0.023); similarly, 15.7% and 31.3% were non-responders in Moderna and Pfizer-BioNTech groups at 12 months, respectively (p = 0.067). There were no non-responders among controls. Healthy volunteers had higher Th1 levels than KT recipients, while Moderna produced a higher Th1 response than Pfizer-BioNTech. In contrast, the Pfizer-BioNTech vaccine induced a higher Tr1 response than the Moderna vaccine (p < 0.05); overall, IgG levels correlated with Th1(fTTNF-α)/Tr1(fTIL-10) ratios. We propose that the higher number of non-responders in the Pfizer-BioNTech group than the Moderna group was caused by a more potent activity of regulatory Tr1 cells in KT recipients vaccinated with the Pfizer-BioNTech vaccine.


  • Open Access

    Differences in Response by Immunosuppressed Kidney Transplant Patients to Moderna mRNA-1273 versus Pfizer-BioNTech

    by Dulat Bekbolsynov, Andrew Leland Waack, Camryn Buskey, Shalmali Sandeep Bhadkamkar, Keegan Rengel, Winnifer Petersen, Mary Lee Brown, Tanaya Sparkle, Dinkar Kaw, Fayeq Jeelani Syed, et al.

    Immunosuppressed kidney transplant (KT) recipients respond weaker to COVID-19 vaccination than immunocompetent individuals. We tested antiviral IgG response in 99 KT-recipients and 66 healthy volunteers who were vaccinated with mRNA-1273 Moderna or BNT162b2 Pfizer-BioNTech vaccines. A subgroup of participants had their peripheral blood leukocytes (PBLs) evaluated for the frequency of T helper 1 (Th1) cells producing IL-2, IFN-γ and/or TNF-α, and IL-10-producing T-regulatory 1 (Tr) cells. Among KT-recipients, 45.8% had anti-SARS-CoV-2 IgG compared to 74.1% of healthy volunteers (p=0.009); also, anti-viral IgG levels were lower in recipients than in volunteers (p=0.001). When defined as non-responders (≤2,000 U/ml IgG), Moderna’s group had 10.8% and Pfizer-BioNTech’s group had 34.3% of non-responders at 6 months (p=0.023); similarly, 15.7% and 31.3% non-responders were in Moderna and Pfizer-BioNTech groups at 12 months, respectively (p=0.067). There were no non-responders among controls. Healthy volunteers had higher Th1 levels than KT recipients, while Moderna produced higher Th1 response than Pfizer-BioNTech. In contrast, Pfizer-BioNTech vaccine induced higher Tr1 response than Moderna vaccine (p<0.05); overall, IgG levels correlated with Th1(fTTNF-α)/Tr1(fTIL-10) ratios. We propose that the higher number of non-responders in Pfizer-BioNTech group than Moderna group was caused by more potent activity of regulatory Tr1 cells in KT-recipients vaccinated with Pfizer-BioNTech vaccine.