The severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) has a major impact on transplant recipients, with mortality rates up to 20%. Therefore, the effect of established messenger RNA (mRNA)-based SARS-CoV-2 vaccines have to be evaluated for solid organ transplant patients (SOT) since they are known to have poor responses after vaccination. We investigated the SARS-CoV-2 immune response via SARS-CoV-2 IgG detection in 23 renal transplant recipients after two doses of the mRNA-based SARS-CoV-2 vaccine BNT162b2 following the standard protocol. The antibody response was evaluated once with an anti-SARS-CoV-2 IgG CLIA 15.8 +/− 3.0 days after the second dose. As a control, SARS-CoV-2 IgG was determined in 23 healthcare workers (HCW) and compared to the patient cohort. Only 5 of 23 (22%) renal transplant recipients were tested positive for SARS-CoV-2 IgG antibodies after the second dose of vaccine. In contrast, all 23 (100%) HCWs were tested positive for antibodies after the second dose. Thus, the humoral response of renal transplant recipients after two doses of the mRNA-based vaccine BNT162b2 (Pfizer-BioNTech, Kronach, Germany) is impaired and significantly lower compared to healthy controls (22% vs. 100%; p = 0.0001). Individual vaccination strategies might be beneficial in these vulnerable patients.

Introduction: Systemic lupus erythematosus (SLE) is an autoimmune disease accompanied by a disturbed T-cell balance skewed towards effector T-cells, in particular Th17-cells. The novel cytokine interleukin-21 (IL-21) is suggested to be crucial for triggering T-cell responses towards IL-17 producing cells. Thus, we aimed to investigate the ability of T-cells to produce IL-21 and IL-17 in SLE patients. Methods: Peripheral blood of 34 SLE patients and 18 healthy controls (HC) was stimulated with phorbol myristate acetate (PMA) and calcium ionophore (Ca-Io). Percentages of IL-21- and IL-17A expressing T-cells were analysed by flow cytometry. The expression levels of the transcription factors B-cell lymphoma-6 (BCL-6) and factors retinoid-related orphan receptor (ROR-γt) were assessed in T-cells by real-time RT-PCR and flow cytometry. Additionally, IL-21 receptor (IL-21R) expression on B- and T-cells of patients and HC was analyzed. Results: Significantly increased percentages of IL-21 expressing CD4⁺ T-cells and CD8⁺ T-cells were found in SLE patients as compared to HC. The percentages of IL-21⁺ CD4⁺ T-cells and CD8⁺ T-cells correlated significantly with the percentages of IL-17A⁺ CD4⁺ T-cells and CD8⁺ T-cells, respectively. The relative expression of BCL-6 and ROR-γt did not differ between SLE patients and HC. IL-21R expression occurred mainly on B-cells and was not different comparing SLE patients and HC. Conclusions: This study demonstrates an increased proportion of IL-21⁺ T-cells in SLE patients correlating with the proportion of IL-17⁺ T-cells. This suggests a pivotal role of IL-21 in the pathogenesis of SLE.

The purpose of this study was to investigate the use of the short‐acting insulin secretion drug repaglinide in new‐onset diabetes mellitus (NODM) after renal transplantation. Twenty‐three Caucasian patients with NODM after renal transplantation were selected to receive repaglinide therapy and were followed for at least 6 months. A control group treated with rosiglitazone was chosen for comparison. Successful repaglinide treatment was defined as a significant improvement of blood glucose concentrations and HbA1c <7% in the absence of glucosuria and without the need for the addition of further anti‐diabetic agents. After 6 months of treatment with repaglinide, 14 of the 23 patients were successfully treated. Mean HbA1c decreased from 7.6 ± 0.6% to 5.8 ± 0.6% in 14 patients treated successfully. In nine patients, hyperglycemia persisted, and they were switched to insulin treatment (HbA1c 8.5 ± 2.9% at the beginning to 7.4 ± 2.2%). Mean serum creatinine levels, cyclosporine A and tacrolimus blood levels did not change significantly following institution of repaglinide therapy. The rate of successful treatment and the degree of HbA1c decrease were similar compared to rosiglitazone‐treated control patients. The data from our observational study indicate that repaglinide can be an effective treatment option in Caucasian patients with NODM after renal transplantation.