[Tixagevimab-cilgavimab as pre-exposure prophylactic treatment against SARS-CoV-2 in kidney transplantation patients]. / Tixagevimab-cilgavimab como tratamiento profiláctico preexposición frente a SARS-CoV-2 en pacientes trasplantados renales.

INTRODUCTION: It has been reported that after vaccination with RNAm or viral vectors from SARS-CoV-2 a significant number of solid organ transplant recipients do not develop an effective immune response. In this scenario, the use of tixagevimab-cilgavimab was approved by the European Medicines Agency for COVID-19 prophylaxis in immunocompromised patients in March 2022. We present our experience with a group of kidney transplant recipients who received prophylactic treatment with tixagevimab-cilgavimab. MATERIAL AND METHODS: Prospective study from a cohort of kidney transplant recipients who had been previously vaccinated with 4 doses and did not achieve a satisfactory immune response to vaccination, presenting antibody titers lower than 260 BAU/mL when measured by ELISA. A total of 55 patients who received a single dose of 150mg of tixagevimab and 150mg of cilgavimab between May and September of 2022 were included in this study. RESULTS: No immediate or severe adverse reactions, including worsening of kidney function, were observed after administering the drug or during follow up. All patients who had received the drug 3 months prior presented positive antibody titers (>260 BAU/mL). Seven patients were diagnosed with COVID, and one of those patients had to be admitted to the hospital and died 5 days later from infectious complications and a suspected diagnosis of bacterial coinfection. CONCLUSIONS: In our experience, all kidney transplant recipients reached antibody titers higher than 260 BAU/mL 3 months after receiving prophylactic treatment with tixagevimab-cilgavimab with no severe or irreversible adverse reactions.

[Tixagevimab-cilgavimab as pre-exposure prophylactic treatment against SARS-CoV-2 in kidney transplantation patients]. / Tixagevimab-cilgavimab como tratamiento profiláctico preexposición frente a SARS-CoV-2 en pacientes trasplantados renales.

Introduction: It has been reported that after vaccination with RNAm or viral vectors from SARS-CoV-2 a significant number of solid organ transplant recipients do not develop an effective immune response. In this scenario, the use of tixagevimab-cilgavimab was approved by the European Medicines Agency for COVID-19 prophylaxis in immunocompromised patients in March 2022. We present our experience with a group of kidney transplant recipients who received prophylactic treatment with tixagevimab-cilgavimab. Material and methods: Prospective study from a cohort of kidney transplant recipients who had been previously vaccinated with 4 doses and did not achieve a satisfactory immune response to vaccination, presenting antibody titers lower than 260 BAU/mL when measured by ELISA. A total of 55 patients who received a single dose of 150 mg of tixagevimab and 150 mg of cilgavimab between May and September of 2022 were included in this study. Results: No immediate or severe adverse reactions, including worsening of kidney function, were observed after administering the drug or during follow up. All patients who had received the drug 3 months prior presented positive antibody titers (> 260 BAU/mL). Seven patients were diagnosed with COVID, and one of those patients had to be admitted to the hospital and died 5 days later from infectious complications and a suspected diagnosis of bacterial coinfection. Conclusions: In our experience, all kidney transplant recipients reached antibody titers higher than 260 BAU/mL 3 months after receiving prophylactic treatment with tixagevimab-cilgavimab with no severe or irreversible adverse reactions.

Defining a Methylation Signature Associated With Operational Tolerance in Kidney Transplant Recipients.

Operational tolerance after kidney transplantation is defined as stable graft acceptance without the need for immunosuppression therapy. However, it is not clear which cellular and molecular pathways are driving tolerance in these patients. We performed genome-wide analysis of DNA methylation in peripheral blood mononuclear cells from kidney transplant recipients with chronic rejection and operational tolerance from the Genetic Analysis of Molecular Biomarkers of Immunological Tolerance (GAMBIT) study. Our results showed that both clinical stages diverge in 2737 genes, indicating that each one has a specific methylation signature associated with transplant outcome. We also observed that tolerance is associated with demethylation in genes involved in immune function, including B and T cell activation and Th17 differentiation, while in chronic rejection it is associated with intracellular signaling and ubiquitination pathways. Using co-expression network analysis, we selected 12 genomic regions that are specifically hypomethylated or hypermethylated in tolerant patients. Analysis of these genes in transplanted patients with low dose of steroids showed that these have a similar methylation signature to that of tolerant recipients. Overall, these results demonstrate that methylation analysis can mirror the immune status associated with transplant outcome and provides a starting point for understanding the epigenetic mechanisms associated with tolerance.

A Current Review of the Etiology, Clinical Features, and Diagnosis of Urinary Tract Infection in Renal Transplant Patients.

Urinary tract infection (UTI) represents the most common infection after kidney transplantation and remains a major cause of morbidity and mortality in kidney transplant (KT) recipients, with a potential impact on graft survival. UTIs after KT are usually caused by Gram-negative microorganisms. Other pathogens which are uncommon in the general population should be considered in KT patients, especially BK virus since an early diagnosis is necessary to improve the prognosis. UTIs following kidney transplantation are classified into acute simple cystitis, acute pyelonephritis/complicated UTI, and recurrent UTI, due to their different clinical presentation, prognosis, and management. Asymptomatic bacteriuria (ASB) represents a frequent finding after kidney transplantation, but ASB is considered to be a separate entity apart from UTI since it is not necessarily a disease state. In fact, current guidelines do not recommend routine screening and treatment of ASB in KT patients, since a beneficial effect has not been shown. Harmful effects such as the development of multidrug-resistant (MDR) bacteria and a higher incidence of Clostridium difficile diarrhea have been associated with the antibiotic treatment of ASB.

Levels of anti-CMV antibodies are modulated by the frequency and intensity of virus reactivations in kidney transplant patients.

Anti-CMV (cytomegalovirus) antibody titers are related to immune alterations and increased risk of mortality. To test whether they represent a marker of infection history, we analyzed the effect of viral reactivations on the production of specific antibodies in kidney transplant patients. We quantified CMV-DNAemia and antibody titers in 58 kidney transplant patients before transplantation and during a follow-up of 315 days (standard deviation, SD: 134.5 days). In order to calculate the intensity of the infection, we plotted the follow-up time of the infection on the x-axis and the number of DNA-CMV copies on the y-axis and calculated the area under the curve (CMV-AUC). The degree of T-lymphocyte differentiation was analyzed with flow cytometry, the cells were labelled with different monoclonal antibodies in order to distinguish their differentiation state, from naive T-cells to senescent T-cells. Peak viremia was significantly higher in patients experiencing a primary infection (VI) compared to patients experiencing viral reactivation (VR). Our data indicate that the overall CMV viral load over the course of a primary infection is significantly higher than in a reactivation of a previously established infection. Whereas patients who experienced an episode of CMV reactivation during the course of our observation showed increased levels of CMV-specific antibodies, patients who did not experience CMV reactivation (WVR) showed a drop in CMV antibody levels that corresponds to an overall drop in antibody levels, probably due to the continuing immunosuppression after the renal transplant. We found a positive correlation between the CMV viremia over the course of the infection or reactivation and the CMV-specific antibody titers in the examined patients. We also observed a positive correlation between anti-CMV titers and T-cell differentiation. In conclusion, our data show that anti-CMV antibody titers are related to the course of CMV infection in kidney transplant patients.

Hemorragia alveolar difusa unilateral en paciente con granulomatosis con poliangitis / Unilateral diffuse alveolar hemorrhage in a patient with granulomatous polyangiitis

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