Arterial Embolization of Polycystic Kidneys for Heterotopic Transplantation

Introduction: The purpose of this study was to evaluate the efficacy of polycystic kidney embolization, performed to reduce kidney volume before heterotopic kidney transplantation, as this technique could be an alternative to pretransplant nephrectomy. Materials and Methods: All patients who underwent pretransplant embolization of polycystic kidneys were included in a prospective register from June 2014 to February 2020. All patients underwent computed tomography (CT) scan with volumetric reconstruction (OsiriX, Bernex, Switzerland) before embolization and were then followed up at 3 and 6 months after embolization. Primary outcome was percentage of kidney volume reduction. Secondary outcomes were 30 day mortality and morbidity. Results: Thirty-one embolizations performed on 29 patients (medium age = 55.6; 62.1% male) were included between June 2014 and February 2020. All patients were under dialysis before embolization (9 peritoneal dialysis and 20 hemodialysis). Technical success was observed in 96.8% of cases. Mean procedural time was 65 minutes (range = 35–106 minutes) and mean length of in-hospital stay was 3.8 days (range = 3–6 days). A volume reduction allowing a kidney transplant was obtained for 28 patients (96.5%). The mean volume reduction was 39.9% (range = 6.01–68.2). The main observed complication was postembolization pain in 10 cases (32.2%). One patient needed complementary nephrectomy due to insufficient volume reduction. Twenty-three patients (79.3%) received renal transplant during follow-up with a mean delay of 19.5 month (range = 4–54). Conclusion: Polycystic kidney embolization is an effective and safe minimally invasive technique. It can be proposed as the first-choice technique for kidney transplant recipients as an alternative to pretransplantation nephrectomy.

Anti-SARS-CoV-2 Antibody Level among Renal Transplant Recipients: A Case Report from Nepal

Globally, SARS-CoV-2 has caused significant public health burden, mainly in patients with underlying comorbidities including both communicable and noncommunicable diseases. Solid organ transplant recipients under immunesupressive medication are also amongst the high risk group. There is only sparse data on immunity against SARS-CoV-2 infection among renal transplant recipients. In this case report, we present the level of anti-SARS-CoV-2 antibody of three kidney transplant recipients after vaccination against COVID-19 virus. All three cases had received two doses of Oxford-AstraZeneca COVID-19 vaccine AZD1222 (ChAdOx1). Serological analysis showed protective level of circulating antibodies in the blood of all three cases. Although two out of three patients in the study acquired COVID-19 infection after immunization, they recovered with mild clinical course. Hence, we conclude that despite immune-suppressed status of transplant recipients, COVID-19 vaccination could protect them against severe illness.

Temporary hold of mycophenolate boosts SARS-CoV-2 vaccination-specific humoral and cellular immunity in kidney transplant recipients

Transplant recipients exhibit an impaired protective immunity after SARS-CoV-2 vaccination, potentially caused by mycophenolate (MPA) immunosuppression. Recent data from autoimmune patients suggest that temporary MPA hold might significantly improve booster vaccination outcomes. We applied a fourth dose of SARS-CoV-2 vaccine during temporary (5 weeks) MPA hold to 29 kidney transplant recipients, who had not mounted a humoral immune-response to previous vaccinations. Seroconversion until day 32 after vaccination was observed in 76% of patients, associated with acquisition of virus neutralizing capacity. Interestingly, 21/25 (84%) CNI-treated patients responded, but only 1/4 Belatacept-treated patients. In line with humoral responses, counts and relative frequencies of spike receptor binding domain (RBD) specific B cells were significantly increased on day 7 after vaccination, with an increase in RBD specific CD27++CD38+ plasmablasts. Whereas overall proportions of spike-reactive CD4+ T cells remained unaltered after the fourth dose, frequencies were positively correlated with specific IgG levels. Importantly, antigen-specific proliferating Ki67+ and in vivo activated PD1+ T cells significantly increased after re-vaccination during MPA hold, whereas cytokine production and memory differentiation remained unaffected. In summary, MPA hold was safe and augmented all arms of immunity during booster vaccination, suggesting its implementation in vaccination protocols for clinically stable transplant recipients.