ABSTRACT
Purpose: Kidney transplant recipients (KTRs) have diminished immune response and protection after 2-dose mRNA COVID-19 vaccination. It is unknown if additional doses improve neutralization of variants of concern (VOC) in KTRs with prior poor seroresponse. Method(s): Adult KTRs with negative (<0.8 U/mL) or low (<=50 U/ml) anti-RBD Ig (Roche Elecsys anti-SARS-CoV-2-S) after 2-dose mRNA series were given a homologous 3rd dose (D3). Anti-RBD and VOC surrogate neutralization (%ACE2i) were measured 30 days post D3;responses were stratified by baseline anti-RBD. Reactogenicity, serial SARS-CoV-2 swabs, and donor-specific antibody (DSA) were assessed. Result(s): 81 KTRs (50% negative anti-RBD) received D3 (72% BNT162b2, 28% mRNA-1273) at median 167 days post D2 (Table). Median (IQR) anti-RBD increase was 410 (8-2309) U/mL with 69% (40% negative vs 98% low anti-RBD) achieving day 30 anti-RBD >50 U/ml (Fig1a). 22% remained seronegative. Non-response was associated with lower baseline lymphocyte count (median 770 vs 1160 cells/ uL;p=0.05) and IgG (median 779 vs 979 mg/dL;p<0.01), but not demographics, vaccine, or immunosuppressives. Median (IQR) delta variant %ACE2i increased from 6% (3-7) to 10% (4-22) (p<0.001), a 1% (0-5) increase in negative vs 13% (5-25) in low anti-RBD. %ACE2i was linearly associated with anti-RBD >=100 U/ mL (all VOC shown in Fig1b);64% of KTRs with anti-RBD >=250 U/mL had delta %ACE2i >20. There were 3 cases of mild-moderate COVID-19 >=7 days post-D3, with pre-infection anti-RBD <0.4, 22, 76 U/mL and delta %ACE2i 6, 9, and 16, respectively. There was no acute rejection, nor increased or de novo DSA. Conclusion(s): A 3rd mRNA vaccine dose increased anti-RBD and VOC neutralization in KTRs without inducing clinical alloimmunity, yet 45% with negative baseline anti-RBD remained seronegative without delta variant neutralization. Trials are ongoing to test immune response augmentation in this subgroup via temporary immunosuppression reduction or heterologous boosting.
ABSTRACT
Purpose: Kidney transplant recipients (KTRs) have poor outcomes compared to non-KTRs with acute COVID-19. To provide insight into management of immunosuppression (IS) during COVID-19, we studied immune signatures from the peripheral blood during and after COVID-19 infection from a multicenter KTR cohort. Method(s): Clinical data were collected by chart review. Paxgene blood RNA was polyA-selected and sequenced at enrollment Results: A total of 64 KTRs affected with COVID-19 were enrolled (31 Early cases (<4weeks from a positive SARS-CoV-2 PCR test) and 33 late cases). Out of the 64 patients, eight died and three encountered graft losses during follow-up. Among 31 early cases, we detected differentially expressed genes (nominal p-value < 0.01) in the blood transcriptome that were positively or negatively associated with the COVID-19 severity score (scale of 1 to 7 with increasing severity;Fig 1A). Enrichment analyses showed upregulation of neutrophil and innate immune pathways and downregulation of adaptive immune activation pathways with increasing severity score (Fig 1B). This observation was independent of lymphocyte count, despite reduction in immunosuppression (IS) in 75% of KTRs. Interestingly, compared with early cases, the blood transcriptome in late cases showed "normalization" of these enriched pathways after 4 weeks, suggesting return of adaptive immune system activation despite re-initiation of immunosuppression (Fig 1C). The latter analyses were adjusted for the severity score. Interestingly, similar pathway enrichment with worsening severity of COVID-19 was identifiable from a public dataset of non-KTRs (GSE152418), showing overlapped signatures for acute COVID-19 between KTRs and non-KTRs (overlap P<0.05) (Fig 1D). Conclusion(s): Blood transcriptome of COVID-KTRs shows marked decrease in adaptive immune system activation during acute COVID-19, even during IS reduction, which show recovery after acute illness. (Figure Presented).
ABSTRACT
Purpose: Kidney transplant recipients (KTRs) have poor outcomes vs non-KTRs with acute COVID-19. To provide insight into management of immunosuppression during acute COVID-19, we studied peripheral blood transcriptomes during and after COVID-19 from a multicenter KTR cohort. Method(s): Clinical data were collected by chart review. Paxgene blood RNA was polyA-selected and sequenced at enrollment. Result(s): A total of 64 KTRs with COVID-19 were enrolled (31 Early cases (<4weeks from a positive SARS-CoV-2 PCR test) and 33 late cases). Out of the 64 patients, eight died and three encountered graft losses during follow-up. Due to presence of mRNA reads in the blood transcriptome unmapped to the human genome, we aligned the mRNA short reads to the SARS-CoV-2 genome. Surprisingly, our strategy detected the SARS-Cov2 mRNA, especially Spike mRNA in 27 (87%) early cases, and 18 (54%) of late cases (Fig 1A and B). We then analyzed the raw reads from a public dataset of non-KTRs with Paxgene RNA (GSE172114). The SARS-CoV-2 Spike mRNA was detected in 2/47 (4.2%) critically ill COVID-19 cases and 0/25 noncritically ill cases in this non-KTR dataset (compared to KTRs, Chi-square P<0.001;Fig 1B). Among our KTRs, the amount of Spike mRNA was associated positively with the COVID-19 severity score (scale of 1 to 7 of increasing severity;Fig 1C) and inversely with time from initial positive PCR (Fig 1D). More interestingly, 7/64 patients had detectable Spike RNA-emia beyond 60 days after COVID-19 diagnosis. Of the 3 graft losses in our cohort, 2 occurred among these 7 patients. Conclusion(s): Blood transcriptome of KTRs with COVID-19 demonstrated a risk for persistent viremia with implications for pathogenesis of COVID-19 disease. This finding also supports using passive immune strategies in COVID-KTRs. (Figure Presented).