Office or home versus 24-hour blood pressure measurement in stable kidney transplant recipients.

BACKGROUND AND HYPOTHESIS: The aim of this study was to quantify hypertension control and evaluate concordance between all commonly available blood pressure modalities in kidney transplant recipients (KTR). METHODS: For this prospective cross-sectional study 89 stable KTR were recruited at the Charité Transplant Outpatient Clinic. For each study participant office (manual office blood pressure 'MOBP' and automated office blood pressure 'AOBP'), 7-day home (HBPM) and 24-hour ambulatory blood pressure measurement (24h-ABPM) were performed. RESULTS: 80 of the 89 patients recruited had sufficient blood pressure recordings. Mean blood pressure for MOBP, AOBP, HBPM and 24h-ABPM was 129/73, 126/71, 131/85 and 130/81 mmHg, respectively. Uncontrolled hypertension, as defined by 24h-ABPM (mean ≥ 130/80 mmHg), was present in 53 (66%) patients. MOBP, AOBP and HBPM classified 19 (24%), 22 (28%) and 41 (51%) patients respectively as 'uncontrolled hypertensive'. The Bland-Altman plot showed good agreement between systolic MOBP, AOBP, HBPM and Daytime-ABPM (mean bias ± SD: -1 ± 13 mmHg, -4 ± 13 mmHg, 1 ± 10 mmHg, respectively). Uncontrolled nighttime hypertension was present in 74 (93%) KTR, with 71 (89%) patients showing a non-physiological dipping pattern. Moderate positive correlation between Daytime-ABPM/HBPM and Nighttime-ABPM (Pearson Correlation Coefficients: 0.62-0.73), followed by MOBP/AOBP (Pearson Correlation Coefficients: 0.49-0.59) was noted. eGFR and proteinuria displayed weak correlation with 24h-, Daytime- and Nighttime-ABPM (absolute values of Pearson Correlation Coefficients: 0.04-0.41). No robust association with either 24h-, Daytime- or Nighttime-ABPM was observed for volume status exams. CONCLUSIONS: Masked hypertension is highly prevalent in KTR, especially due to high rates of uncontrolled nighttime hypertension. HBPM shows the narrowest limits of agreement with Daytime-ABPM. Daytime-ABPM and HBPM show the highest, albeit clinically insufficient, correlation with Nighttime-ABPM. Systematic integration of 24h-ABPM into clinical practice, as proposed by the '2023 ESH Guidelines for the Management of arterial hypertension', should not be withheld for the KTR population. Clinical trials evaluating treatment of hypertension in KTR are urgently needed.

A 55-Year-Old Man with Recurrent Gastrointestinal Bleeding Due to Stricture of the Portal Vein Anastomotic Site 12 Years After Combined Pancreas and Kidney Transplantation.

BACKGROUND Varices of the upper gastrointestinal tract are due to portal hypertension and can result from occlusion of the portal venous system. This report is of a 55-year-old man with recurrent gastrointestinal bleeding due to stricture of the portal vein anastomotic site to inferior vena cava (IVC) 12 years after combined pancreas and kidney transplantation. CASE REPORT A 55-year-old man presented bleeding episodes requiring transfusion of more than 70 units of red blood cells (RBCs), complicated by bacterial and viral infection episodes including cytomegalovirus (CMV) reactivation and hepatitis E and transient impairment of function of the renal allograft. Endoscopy, computed tomography (CT) scan, and angiography revealed jejunal varices due to anastomotic stricture at the portal vein to IVC as the cause of the hemorrhage. Neither conservative therapy nor an anastomosis between the splenic vein of the graft and the internal iliac vein as a bypass could stop the life-threatening bleeding. During the recurrent bleeding, CD4 T lymphocytes were low, indicating immunodeficiency despite paused immunosuppressive therapy. After the hemorrhage resolved and immunosuppression was restarted, CD4 T lymphocyte levels normalized. Finally, to stop the hemorrhage and save the transplanted kidney and the patient's life, graft pancreatectomy was performed. Long-term damage to the renal transplant was not found. CONCLUSIONS This report is of a rare case of portal hypertension as a long-term complication of transplant surgery. Although acute venous thrombosis at the anastomotic site is a recognized postoperative complication of pancreatic transplant surgery, this case highlights the importance of post-transplant follow-up and diagnostic imaging.

Impact of Moderna mRNA-1273 Booster Vaccine on Fully Vaccinated High-Risk Chronic Dialysis Patients after Loss of Humoral Response.

The long-term effect of protection by two doses of SARS-CoV-2 vaccination in patients receiving chronic intermittent hemodialysis (CIHD) is an urging question. We investigated the humoral and cellular immune response of 42 CIHD patients who had received two doses of SARS-CoV-2 vaccine, and again after a booster vaccine with mRNA-1273 six months later. We measured antibody levels and SARS-CoV-2-specific surrogate neutralizing antibodies (SNA). Functional T cell immune response to vaccination was assessed by quantifying interferon-γ (IFN-γ) and IL-2 secreting T cells specific for SARS-CoV-2 using an ELISpot assay. Our data reveal a moderate immune response after the second dose of vaccination, with significantly decreasing SARS-CoV-2-specific antibody levels and less than half of the study group showed neutralizing antibodies six months afterwards. Booster vaccines increased the humoral response dramatically and led to a response rate of 89.2% for antibody levels and a response rate of 94.6% for SNA. Measurement in a no response/low response (NR/LR) subgroup of our cohort, which differed from the whole group in age and rate of immunosuppressive drugs, indicated failure of a corresponding T cell response after the booster vaccine. We strongly argue in favor of a regular testing of surrogate neutralizing antibodies and consecutive booster vaccinations for CIHD patients to provide a stronger and persistent immunity.

CD4+ T cell lymphopenia predicts mortality from Pneumocystis pneumonia in kidney transplant patients.

BACKGROUND: Pneumocystis jirovecii pneumonia (PcP) remains a life-threatening opportunistic infection after solid organ transplantation, even in the era of Pneumocystis prophylaxis. The association between risk of developing PcP and low CD4+ T cell counts has been well established. However, it is unknown whether lymphopenia in the context of post-renal transplant PcP increases the risk of mortality. METHODS: We carried out a retrospective analysis of a cohort of kidney transplant patients with PcP (n = 49) to determine the risk factors for mortality associated with PcP. We correlated clinical and demographic data with the outcome of the disease. For CD4+ T cell counts, we used the Wilcoxon rank sum test for in-hospital mortality and a Cox proportional-hazards regression model for 60-day mortality. RESULTS: In univariate analyses, high CRP, high neutrophils, CD4+ T cell lymphopenia, mechanical ventilation, and high acute kidney injury network stage were associated with in-hospital mortality following presentation with PcP. In a receiver-operator characteristic (ROC) analysis, an optimum cutoff of ≤200 CD4+ T cells/µL predicted in-hospital mortality, CD4+ T cell lymphopenia remained a risk factor in a Cox regression model. CONCLUSIONS: Low CD4+ T cell count in kidney transplant recipients is a biomarker for disease severity and a risk factor for in-hospital mortality following presentation with PcP.

Anatomy Revisited: Hemodialysis Catheter Malposition in the Left Ascending Lumbar Vein.

In selected cases, cuffed tunneled catheters via the iliac vein are implanted as a last resort access for hemodialysis. To monitor the correct position, sonography of the inferior vena cava (IVC) is sufficient in most cases. Position control using an X-ray of the abdomen is not routinely recommended when femoral catheters are implanted. In this report, we describe the case of a 59-year-old patient on chronic hemodialysis due to granulomatosis with polyangiitis and complex shunt history with multiple shunt occlusions and revisions. The implantation of an iliac-cuffed tunneled catheter led to complications because the catheter was malpositioned into the left ascending lumbar vein (ALV). It is important to be aware of potential incorrect positioning of dialysis catheters into the ALV. Due to the anatomical relation to the IVC, this happens more frequently on the left side than on the right side. In case of doubt, the correct placement of large-bore catheters via iliac access route should be verified by means of appropriate imaging before hemodialysis is performed.

Role of Nox4 in murine models of kidney disease.

Nox4 is a hydrogen peroxide-producing NADPH oxidase highly expressed in the kidney which has been linked to epithelial cell injury and diabetic-induced cellular dysfunction in cultured cells. The role of the enzyme for renal pathology in vivo, however, is unclear. To address this, three experimental animal models of renal injury (streptozotocin diabetes I, unilateral ureteral ligation (UUO), and 5/6 nephrectomy (5/6Nx)) were studied in either Nox4-inducible (Nox4(*/*)) or constitutive knockout (Nox4(-/-)) mice. Nox4 contributed more than 80% of diphenylene iodonium-sensitive H(2)O(2) formation of freshly isolated tubules determined by Amplex Red assay. In streptozotocin diabetes, acute deletion of Nox4 by tamoxifen-activated cre-recombinase increased albuminuria, whereas matrix deposition was similar between WT and Nox4(*/*) mice. Interestingly, renal Nox4 expression, mainly localized to tubular cells, decreased in the course of diabetes and this was not associated with a compensatory upregulation of Nox1 or Nox2. In the UUO model, renal expression of ICAM1, connective tissue growth factor, and fibronectin were higher in kidneys of Nox4(*/*) than control mice. Also in this model, levels of Nox4 decreased in the course of the disease. In the 5/6Nx model, which was performed in SV129 and SV129-Nox4(-/-) mice, no difference in the development of hypertension and albuminuria was found between the strains. Collectively, the first in vivo data of the kidney do not support the view that Nox4 is a main driver of renal disease. It rather appears that under specific conditions Nox4 may even slightly limit injury and disease progression.