Humoral immunity to SARS-CoV-2 in kidney transplant recipients and dialysis patients: IgA and IgG patterns unraveled after SARS-CoV-2 infection and vaccination.

BACKGROUND: Infection with SARS-CoV-2 in high-risk groups such as kidney transplant and dialysis patients is shown to be associated with a more serious course of the disease. Four years after the start of the COVID-19 pandemic, crucial knowledge on the immune responses in these patient groups is still lacking. Therefore, this study aimed at investigating the humoral immune response after a SARS-CoV-2 infection compared to vaccination as well as the evolution of immunoglobulins over time. METHODS: Kidney transplant recipients, patients on haemodialysis or on peritoneal dialysis and healthy controls were included in this longitudinal multicenter study. SARS-CoV-2 anti-RBD, anti-NP and anti-S1S2 immunoglobulin G (IgG) and A (IgA) as well as the neutralizing antibody capacity were measured. RESULTS: Kidney transplant recipients had a significantly better humoral response to SARS-CoV-2 after infection (86.4%) than after a two-dose mRNA vaccination (55.8%) while seroconversion was comparable in patients on haemodialysis after infection (95.8%) versus vaccination (89.4%). In individuals without prior COVID-19, the IgG levels after vaccination were significantly lower in kidney transplant recipients when compared to all other groups. However, the IgA titres remained the highest in this patient group at each time point, both after infection and vaccination. A history COVID-19 was associated with higher antibody levels after double-dose vaccination in all patient categories and, while decreasing, titres remained high six months after double-dose vaccination. CONCLUSION: Kidney transplant recipients had a more robust humoral response to SARS-CoV-2 following infection compared to a two-dose mRNA vaccination, while patients on haemodialysis exhibited comparable seroconversion rates. Notably, individuals with prior COVID-19 exhibited higher IgG levels in response to vaccination. Hybrid immunity is thus the best possible defence against severe COVID-19 disease and seems also to hold up for these populations. Next, it is not clear whether the higher IgA levels in the kidney transplant recipients is beneficial for neutralizing SARS-CoV-2 or if it is a sign of disease severity.

Indolent renal involvement with BRAFV600E mutation: Erdheim-Chester, a rare disease with a wide spectrum of clinical manifestations.

We present the case of a patient with three-year indolent bilateral ureteral and perirenal masses. Clinical presentation, radiological context, and histopathological findings with detection of BRAF V600E mutation confirmed the diagnosis of Erdheim-Chester disease (ECD). A review of current knowledge regarding diagnosis, clinical assessment, management, and treatment of ECD is also presented.

COVID-19 Outbreak in a Hemodialysis Center: A Retrospective Monocentric Case Series.

BACKGROUND: The rapid worldwide spread of COVID-19 has posed a serious threat to patients treated with kidney replacement therapy (KRT). Moreover, the impact of the disease on hemodialysis centers, the patients, and the health care workers is still not completely understood. OBJECTIVE: We present the analysis of a COVID-19 outbreak in a hemodialysis center in Belgium and report the incidence, clinical course, and outcome of the disease. DESIGN: A retrospective cross-sectional cohort study. SETTING: A hemodialysis center during the COVID-19 outbreak. PATIENTS: A total of 62 patients on maintenance hemodialysis at a tertiary care center in Belgium attended by 26 health care workers. MEASUREMENTS: Baseline patients' characteristics were retrieved. The incidence, clinical course, and outcome were reported. The differences between COVID-19 survivors and nonsurvivors were assessed along with the differences between COVID-19-hospitalized and nonhospitalized patients. The incidence of the disease and outcome of health care workers were also reported. METHODS: Proportions for categorical variables were compared using the Fisher exact test and χ2. The Mann-Whitney rank sum test was used to compare continuous variables. Univariate analysis and a binomial logistic regression were used to explore variables as predictors of death. RESULTS: Between March 6 and April 14, 2020, 40 of 62 (65%) patients tested positive for severe acute respiratory syndrome beta coronavirus 2 (SARS-CoV-2) along with 18 of 26 (69%) health care professionals. Twenty-five (63%) of the infected patients were hospitalized with a median time for hospitalization-to-discharge of 8 (interquartile range [IQR] = 4-12) days. Eleven (28%) COVID-19-related deaths were recorded with a median time for onset of symptoms-to-death of 9 (IQR = 5-14) days. Lymphocytopenia was prevalent among the cohort and was found in 9 of 11 (82%) reported deaths (P = .4). There was no influence of the use of angiotensin-converting enzyme inhibitors or angiotensin II receptor blockers on COVID-19-related deaths (P = .3). Advanced age, cardiovascular disease (CVD), and obstructive sleep apnea syndrome were all found to be significantly related to death. Of the 18 infected health care professionals, 13 (72%) were symptomatic and 2 (11%) were hospitalized. There was no reported death among the health care workers. LIMITATIONS: Limited follow-up time compared with the course of the disease along with a small sample size. CONCLUSIONS: Patients treated with KRT show a high mortality rate secondary to COVID-19. CVD and age are shown to impact survival. Proactive measures must be taken to prevent the spread of the virus in such facilities. TRIAL REGISTRATION: Not applicable as this is a retrospective study.

COVID-19 Pneumonia Mimicking Immunotherapy-Induced Pneumonitis on 18F-FDG PET/CT in a Patient Under Treatment With Nivolumab.

Within a few months, coronavirus disease 2019 (COVID-19) has become a pandemic with more than 2 million patients infected and a high mortality rate. Early detection of COVID-19 in oncologic patients is crucial in order to rapidly apply isolation measures and avoid nosocomial spread. However, early diagnosis may be challenging, especially in cancer patients under treatment with immunotherapy as drug-induced pneumonitis can present similar clinical and radiological features. We describe the findings of a SARS-CoV-2 infection on PET/CT with F-FDG in a 51-year-old man with metastatic renal cell carcinoma under treatment with nivolumab.

Interaction of renal failure and dyslipidaemia in the development of calcific aortic valve disease in rats.

OBJECTIVE: Calcific aortic valve disease (CAVD) is currently the most common heart valve disease worldwide and is known to be an active process. Both renal failure and dyslipidaemia are considered to be promoting factors for the development of valvular calcifications. The aim of this study is to prospectively evaluate the respective contribution and interaction of renal failure and dyslipidaemia on CAVD in a rat model, using echocardiography and compared with histology. METHODS AND RESULTS: Sixty-eight male Wistar rats were prospectively divided in eight groups, each fed a different diet to induce renal failure alone and combined with hyperlipidaemia or hypercholesterolemia. CAVD was detected and quantified by calibrated integrated backscatter of ultrasound (cIB) and compared with the histological calcium score. The study follow-up was 20 weeks. At the end of the study, the cIB value and the calcium score of the aortic valve were significantly increased in the group with isolated renal failure but not with dyslipidaemia. The combination of renal failure with high cholesterol or high-fat diet did not significantly increase calcifications further. CONCLUSIONS: Renal failure alone does induce aortic valve calcifications in a rat model of CAVD, whereas dyslipidaemia alone does not. The combination of renal failure with dyslipidaemia does not increase calcification further. These findings suggest that a combination of atherosclerotic and calcifying factors is not required to induce aortic valve calcifications in this model.

Primary high-dose intradermal hepatitis B vaccination in hemodialysis: cost-effectiveness evaluation at 2 years.

Reinforced hepatitis B (HB) vaccination schedules have been tested in nonresponsive hemodialysis (HD) patients. Primary high-dose intradermal (ID) vaccination in HD has been proposed in one study with higher seroconversion rate, but no cost analysis was made. The aim of this prospective study was to confirm this previous report and focus on a cost-effectiveness evaluation of the thorough vaccination with a maintenance program. Thirty-five chronic incident HD patients received primary ID HB vaccination with a reinforced schedule (20 microg Engerix-B every 2 weeks). Revaccination with a monthly single ID dose of 20 microg was performed whenever anti-HBs titer fell under 20 IU/L and continued until a titer of 20 U/L was reached. Outcome measures were cumulative seroconversion rates, mean levels of anti-HBs, maintenance booster doses, rate of seroprotection at the end of the 2-year follow-up and subsequent costs. The present study was associated with an earlier peak of anti-HBs titer (3.9+/-1.7 months) and a higher cumulative seroconversion rate (96.9%) after 1 year. Moreover, a low-booster shot (17.4 microg) of ID Engerix-B/year/patient confers a 100% seroprotection for all responders for a second-year period. The mean cost of our schedule is 127.7 euro/patient for a 2-year period, revaccination included. This current study demonstrates that primary reinforced ID HB vaccination with a maintenance program for a 2-year period warrants the best cost-effectiveness ratio with rapid and sustained seroprotection in almost all HD patients.