Αρχειοθήκη ιστολογίου

Πέμπτη 18 Αυγούστου 2022

Humoral response to heterologous prime‐booster vaccination in heart transplant recipients aged 18 to 70 years primed with a viral vector SARS‐CoV‐2 vaccine

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Abstract

Background

Solid organ transplant recipients have demonstrated a blunted immune response to standard 2-dose vaccination against SARS-CoV-2. This study sought to determine the humoral response to heterologous booster vaccination (viral vector vaccine dose 1 and 2 + mRNA booster).

Methods

Heart transplant recipients, aged 18 to 70 years of age who initially received two doses of the viral vector ChAdOx1 nCoV-19 vaccine followed by a BNT162b2 mRNA booster were recruited. A detectable antibody response in the absence of prior SARS-CoV-2 was the primary outcome measured. This was defined as an anti-spike titre of ≥0.8 U/mL on the Elecsys anti-SARS-CoV-2 S immunoassay.

Results

A total of 80 heart transplant patients (mean age 49±13 years, 28% female) were included. Blood samples were drawn at a median of 30 (IQR 28–33) days after the BNT162b2 mRNA booster. The frequency of a detectable antibody response increased from 37.5% (n = 30) after dose 2 to 56% (n = 45) post dose 3 (p<0.001). A non-detectable antibody response was significantly more common in recipients with a shorter time interval from transplantation (p<0.001), lower likelihood of cardiac allograft vasculopathy (p = 0.003) and in those prescribed a triple versus dual immunosuppressant regime (p = 0.009) and a tacrolimus versus cyclosporine based-regimen (p = 0.007).

Conclusion

Despite heterologous prime-booster vaccination 44% of this vulnerable population ultimately continue to have no detectable antibodies.

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Impact of antimetabolite discontinuation following cytomegalovirus or BK polyoma virus infection in kidney transplant recipients

alexandrossfakianakis shared this article with you from Inoreader

Abstract

Background

Development of cytomegalovirus (CMV) and BK polyoma virus (BKV) infection following kidney transplantation have been associated with allograft dysfunction and allograft loss. Reduction in immunosuppression is a mainstay of management yet has been associated with increased risk of rejection. According to international consensus guidelines, one approach to management of these viral infections is to discontinue the antimetabolite. Little is known surrounding long-term outcomes in these patients, and it remains unclear if consideration should be given to resuming the antimetabolite as variable re-escalation strategies have been reported. The objective was to describe episodes of rejection and identify risk factors for rejection following antimetabolite withdrawal after CMV or BKV DNAemia in kidney transplant recipients.

Methods

This single-center, retrospective review evaluated adult kidney transplant recipients with a serum CMV or BKV DNA PCR ≥ 500 copies/mL who underwent antimetabolite discontinuation. The primary outcome assessed was the incidence of biopsy-proven acute rejection (BPAR).

Results

159 patients were included. Overall, 14 patients (8.8%) experienced BPAR at a median of 1.6 years after antimetabolite discontinuation. Compared to CMV, discontinuation after BKV DNAemia was associated with a higher incidence of BPAR. Characteristics observed more frequently in patients with BPAR included younger age, female sex, higher initial viral load, and development of de novo donor-specific antibody (DSA).

Conclusion

These findings suggest that antimetabolite discontinuation after CMV or BKV DNAemia in kidney transplant recipients is a reasonable and safe approach. Further prospective studies investigating optimal immunosuppression management following CMV or BKV DNAemia in kidney transplant recipients are warranted.

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