Specific organization for in‐hospital belatacept infusion to avoid nosocomial transmission during the SARS‐CoV‐2 pandemic

International audienceThe first cases of Severe Acute Respiratory Syndrome coronavirus 2 (SARS‐CoV‐2) occurred in France in early February and in our region (Southwest France) in early March 2020

Pharmacodynamic effects of cinacalcet after kidney transplantation: once- versus twice-daily dose.

International audienceBACKGROUND: In the setting of kidney transplantation, cinacalcet has been given, mainly, once daily, but also twice daily. The aims of this prospective study were to assess the acute pharmacodynamic effect of cinacalcet administrated once or twice daily to kidney transplant patients with normal renal function and persisting hypercalcaemia due to hyperparathyroidism and to evaluate 1-year efficacy and tolerance of cinacalcet given at a dose of 30 mg b.i.d. METHODS: Eleven patients, who received a transplant 6 (6-59) months previously, were included in the study. A first kinetic was done after administration of 60 mg of cinacalcet at 8 a.m. After a washout period of 1 week, the second kinetic was performed with cinacalcet given at 30 mg b.i.d within a 12-h period. RESULTS: During both kinetics, serum calcium (sCa), ionized calcium (sCa(2+)), albumin-corrected Ca and parathyroid hormone (PTH) levels decreased significantly. At 24 h after the second kinetic, sCa(2+) was significantly lower. After 1 year of cinacalcet treatment, given at the dose of 30 mg b.i.d., there was a significant decrease in sCa, sCa(2+), PTH levels and calcium x phosphorus (Ph) product. In contrast, Ph levels increased significantly. There was no significant change in renal function. CONCLUSION: Once- or twice-daily acute administration of cinacalcet to kidney-transplant patients has similar efficacy. One-year administration of cinacalcet, given as two daily doses, is safe and efficient

Humoral and Cellular Immune Responses of Solid Organ Transplant Patients on Belatacept to Three Doses of mRNA-Based Anti-SARS-CoV-2 Vaccine

Background: Two doses of anti-SARS-CoV-2 mRNA-based vaccines are poorly immunogenic in solid organ transplant recipients (SOT). Methods: In total, 68 belatacept-treated SOT recipients followed at the Toulouse University Hospital were investigated. They were given three injections of the BNT162b2 mRNA COVID-19 vaccine. Their humoral response was assessed by determining anti-spike antibodies and neutralizing antibodies. The T-cell responses were assessed using an enzyme-linked immunospot assay that measured the interferon-γ produced by specific SARS-CoV-2 T-cells in a subgroup of 17 patients. Results: Only 23.5% of these patients developed a detectable anti-spike response. Moreover, the cellular and the humoral responses were well correlated. Patients with no humoral response were also without a detectable cellular response. Those belatacept-treated patients who developed an Anti-SARS-CoV-2 humoral response were younger, had been transplanted for longer, and had a higher lymphocyte count and a better glomerular filtration rate than those with no response. Finally, patients on tacrolimus plus belatacept produced a lower immune response. Conclusions: Belatacept-treated SOT recipients have a reduced immune response to anti-SARS-CoV-2 mRNA vaccination. The vaccine should be given quite separately from the belatacept infusion to improve immunogenicity. Studies to assess whether switching to another immunosuppressive regimen can improve the post-vaccination immune response would be useful

Humoral and Cellular Immune Responses of Solid Organ Transplant Patients on Belatacept to Three Doses of mRNA-Based Anti-SARS-CoV-2 Vaccine

International audienceBackground: Two doses of anti-SARS-CoV-2 mRNA-based vaccines are poorly immunogenic in solid organ transplant recipients (SOT). Methods: In total, 68 belatacept-treated SOT recipients followed at the Toulouse University Hospital were investigated. They were given three injections of the BNT162b2 mRNA COVID-19 vaccine. Their humoral response was assessed by determining anti-spike antibodies and neutralizing antibodies. The T-cell responses were assessed using an enzyme-linked immunospot assay that measured the interferon-γ produced by specific SARS-CoV-2 T-cells in a subgroup of 17 patients. Results: Only 23.5% of these patients developed a detectable anti-spike response. Moreover, the cellular and the humoral responses were well correlated. Patients with no humoral response were also without a detectable cellular response. Those belatacept-treated patients who developed an anti-SARS-CoV-2 humoral response were younger, had been transplanted for longer, and had a higher lymphocyte count and a better glomerular filtration rate than those with no response. Finally, patients on tacrolimus plus belatacept produced a lower immune response. Conclusions: Belatacept-treated SOT recipients have a reduced immune response to anti-SARS-CoV-2 mRNA vaccination. The vaccine should be given quite separately from the belatacept infusion to improve immunogenicity. Studies to assess whether switching to another immunosuppressive regimen can improve the post-vaccination immune response would be useful

Anti-Human Leukocyte Antigen Immunization After Early Allograft Nephrectomy

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Do kidney histology lesions predict long-term kidney function after liver transplantation?

International audienceHistological renal lesions observed after liver transplantation are complex, multifactorial, and interrelated. The aims of this study were to determine whether kidney lesions observed at five yr after liver transplantation can predict long-term kidney function. Ninety-nine liver transplant patients receiving calcineurin inhibitor (CNI)-based immunosuppression, who had undergone a kidney biopsy at 60 ± 48 months post-transplant, were included in this follow-up study. Kidney biopsies were scored according to the Banff classification. Estimated glomerular filtration rate (eGFR) was assessed at last follow-up, that is, 109 ± 48 months after liver transplantation. eGFR decreased from 92 ± 33 mL/min at transplantation to 63 ± 19 mL/min after six months, to 57 ± 17 mL/min at the kidney biopsy, to 54 ± 24 mL/min at last follow-up (p < 0.0001). At last follow-up, only three patients required renal replacement therapy. After the kidney biopsy, 13 patients were converted from CNIs to mammalian target of rapamycin inhibitors, but no significant improvement in eGFR was observed after conversion. Elevated eGFR at six months post-transplant and a lower fibrous intimal thickening score (cv) observed at five yr post-transplant were the two independent predictive factors for eGFR ≥60 mL/min at nine yr post-transplant. Long-term kidney function seems to be predicted by the kidney vascular lesions

Mass spectrometry detection of G3m and IGHG3 alleles and follow-up of differential mother and neonate IgG3.

International audienceMass spectrometry (MS) analysis for detection of immunoglobulins (IG) of the human IgG3 subclass is described that relies on polymorphic amino acids of the heavy gamma3 chains. IgG3 is the most polymorphic human IgG subclass with thirteen G3m allotypes located on the constant CH2 and CH3 domains of the gamma3 chain, the combination of which leads to six major G3m alleles. Amino acid changes resulting of extensive sequencing previously led to the definition of 19 IGHG3 alleles that have been correlated to the G3m alleles. As a proof of concept, MS proteotypic peptides were defined which encompass discriminatory amino acids for the identification of the G3m and IGHG3 alleles. Plasma samples originating from ten individuals either homozygous or heterozygous for different G3m alleles, and including one mother and her baby (drawn sequentially from birth to 9 months of age), were analyzed. Total IgG3 were purified using affinity chromatography and then digested by a combination of AspN and trypsin proteases, and peptides of interest were detected by mass spectrometry. The sensitivity of the method was assessed by mixing variable amounts of two plasma samples bearing distinct G3m allotypes. A label-free approach using the high-performance liquid chromatography (HPLC) retention time of peptides and their MS mass analyzer peak intensity gave semi-quantitative information. Quantification was realized by selected reaction monitoring (SRM) using synthetic peptides as internal standards. The possibility offered by this new methodology to detect and quantify neo-synthesized IgG in newborns will improve knowledge on the first acquisition of antibodies in infants and constitutes a promising diagnostic tool for vertically-transmitted diseases