Stopping renin-angiotensin system blockers after acute kidney injury and risk of adverse outcomes: parallel population-based cohort studies in English and Swedish routine care.

BACKGROUND: The safety of restarting angiotensin-converting enzyme inhibitors (ACEI) or angiotensin II receptor blockers (ARB) after acute kidney injury (AKI) is unclear. There is concern that previous users do not restart ACEI/ARB despite ongoing indications. We sought to determine the risk of adverse events after an episode of AKI, comparing prior ACEI/ARB users who stop treatment to those who continue. METHODS: We conducted two parallel cohort studies in English and Swedish primary and secondary care, 2006-2016. We used multivariable Cox regression to estimate hazard ratios (HR) for hospital admission with heart failure (primary analysis), AKI, stroke, or death within 2 years after hospital discharge following a first AKI episode. We compared risks of admission between people who stopped ACEI/ARB treatment to those who were prescribed ACEI/ARB within 30 days of AKI discharge. We undertook sensitivity analyses, including propensity score-matched samples, to explore the robustness of our results. RESULTS: In England, we included 7303 people with AKI hospitalisation following recent ACEI/ARB therapy for the primary analysis. Four thousand three (55%) were classified as stopping ACEI/ARB based on no prescription within 30 days of discharge. In Sweden, we included 1790 people, of whom 1235 (69%) stopped treatment. In England, no differences were seen in subsequent risk of heart failure (HR 1.10; 95% confidence intervals (CI) 0.93-1.30), AKI (HR 0.90; 95% CI 0.77-1.05), or stroke (HR 0.99; 95% CI 0.71-1.38), but there was an increased risk of death (HR 1.27; 95% CI 1.15-1.41) in those who stopped ACEI/ARB compared to those who continued. Results were similar in Sweden: no differences were seen in risk of heart failure (HR 0.91; 95% CI 0.73-1.13) or AKI (HR 0.81; 95% CI 0.54-1.21). However, no increased risk of death was seen (HR 0.94; 95% CI 0.78-1.13) and stroke was less common in people who stopped ACEI/ARB (HR 0.56; 95% CI 0.34-0.93). Results were similar across all sensitivity analyses. CONCLUSIONS: Previous ACEI/ARB users who continued treatment after an episode of AKI did not have an increased risk of heart failure or subsequent AKI compared to those who stopped the drugs.

Guidance for post-discharge care following acute kidney injury: an appropriateness ratings evaluation.

BACKGROUND: Acute kidney injury (AKI) is associated with poor health outcomes, including increased mortality and rehospitalisation. National policy and patient safety drivers have targeted AKI as an example to ensure safer transitions of care. AIM: To establish guidance to promote high-quality transitions of care for adults following episodes of illness complicated by AKI. DESIGN & SETTING: An appropriateness ratings evaluation was undertaken using the RAND/UCLA Appropriateness Method (RAM). The Royal College of General Practitioners (RCGP) AKI working group developed a range of clinical scenarios to help identify the necessary steps to be taken following discharge of a patient from secondary care into primary care in the UK. METHOD: A 10-person expert panel was convened to rate 819 clinical scenarios, testing the most appropriate time and action following hospital discharge. Specifically, the scenarios focused on determining the appropriateness and urgency for planning: an initial medication review; monitoring of kidney function; and assessment for albuminuria. RESULTS: Taking no action (that is, no medication review; no kidney monitoring; or no albuminuria testing) was rated inappropriate in all cases. In most scenarios, there was consensus that both the initial medication review and kidney function monitoring should take place within 1-2 weeks or 1 month, depending on clinical context. However, patients with heart failure and poor kidney recovery were rated to require expedited review. There was consensus that assessment for albuminuria should take place at 3 months after discharge following AKI. CONCLUSION: Systems to support tailored and timely post-AKI discharge care are required, especially in high-risk populations, such as people with heart failure.

Immunological risk stratification and tailored minimisation of immunosuppression in renal transplant recipients.

BACKGROUND: The efficacy and safety of minimisation of immunosuppression including early steroid withdrawal in kidney transplant recipients treated with Basiliximab induction remains unclear. METHODS: This retrospective cohort study reports the outcomes from 298 consecutive renal transplants performed since 1st July 2010-June 2013 treated with Basiliximab induction and early steroid withdrawal in low immunological risk patients using a simple immunological risk stratification and 3-month protocol biopsy to optimise therapy. The cohort comprised 225 low-risk patients (first transplant or HLA antibody calculated reaction frequency (CRF ≤50% with no donor specific HLA antibodies) who underwent basiliximab induction, steroid withdrawal on day 7 and maintenance with tacrolimus and mycophenolate mofetil (MMF), and 73 high-risk patients who received tacrolimus, MMF and prednisolone for the first 3 months followed by long term maintenance immunosuppression with tacrolimus and prednisolone. High-risk patients not undergoing 3-month protocol biopsy were continued on triple immunosuppression. RESULTS: Steroid withdrawal could be safely achieved in low immunological risk recipients with IL2 receptor antibody induction. The incidence of biopsy-proven acute rejection was 15.1% in the low-risk and 13.9% in the high-risk group (including sub-clinical rejection detected at protocol biopsy). One- year graft survival was 93.3% and patient survival 98.5% in the low-risk group, and 97.3 and 100% respectively in the high-risk group. Graft function was similar in each group at 1 year (mean eGFR 61.2 ± 23.4 mL/min low-risk and 64.6 ± 19.2 mL/min high-risk). CONCLUSIONS: Immunosuppression regimen comprising basiliximab induction, tacrolimus, MMF and prednisolone with early steroid withdrawal in low risk patients and MMF withdrawal in high risk patients following a normal 3-month protocol biopsy is effective in limiting acute rejection episodes and produces excellent rates of patient survival, graft function and complications.

Hepatitis B virus related membranous glomerulonephritis and proteinuria treated with lamivudine and tenofovir.

Membranous glomerulonephritis is the most common histological renal lesion associated with hepatitis B virus (HBV) infection. The authors describe here a case of a patient presenting with the nephrotic syndrome and HBV infection but without progressive liver disease. The use of lamivudine and tenofovir resulted in arrest of proteinuria and stabilisation of renal function.

The isoprostane 8-iso-PGF2alpha suppresses monocyte adhesion to human microvascular endothelial cells via two independent mechanisms.

Isoprostanes, produced in vivo by non-enzymatic free-radical-induced lipid peroxidation, are markers of oxidative stress. Elevated serum and urine levels of 8-iso-PGF2alpha have been reported in a variety of diseases, many of which are characterized by early perivascular inflammatory infiltrates. It has been suggested that, in addition to being markers of oxidative stress, isoprostanes may have pathogenic functions. In this study, we investigated the potential role of 8-iso-PGF2alpha in inflammation, focusing on its effects on adhesion of monocytes to microvascular endothelial cells, an early event in the inflammatory response. In monocyte adhesion assays, 8-iso-PGF2alpha (>10(-8) M) suppressed both basal and TNF-alpha-induced monocyte adhesion to quiescent or proliferating human dermal (HMEC) and rat renal microvascular endothelial cells. In contrast, 8-iso-PGF2alpha stimulated monocyte adhesion to human umbilical vein endothelial cells (HUVEC) as also reported by others. 8-Iso-PGF2alpha had no effect on the viability (Trypan Blue exclusion) of U937 monocytes or HMEC. 8-Iso-PGF2alpha also had no effect on HMEC surface expression of ICAM-1 or VCAM-1. Exposure of HMEC to 8-iso-PGF2alpha for 1-2 h was sufficient to reduce monocyte adhesion to the cell surface, and this effect was independent of de novo protein synthesis by HMEC. The effect of 8-iso-PGF2alpha was mimicked by a thromboxane receptor (TP) agonist (U46619) and blocked by a TP antagonist (SQ29548), indicating a TP-mediated process. Signal transduction pathway inhibitors (SB203580, curcumin, and PD98059) implicated p38 and JNK, but not ERK, in 8-iso-PGF2alpha-induced suppression of monocyte adhesion. In addition to a direct effect, conditioned medium (CM) transfer experiments suggest that 8-iso-PGF2alpha induces a secondary mediator, which also suppresses monocyte adhesion but via an alternative mechanism initiated between 3-4 h, which is TP-independent, requires new protein synthesis, and is primarily dependent on activation of p38. The data show that 8-iso-PGF2alpha can suppress the attachment of monocytes to HMECs via two independent pathways, indicating a potential anti-inflammatory effect of 8-iso-PGF2alpha in the microvasculature.

Treatment of idiopathic membranoproliferative glomerulonephritis with mycophenolate mofetil and steroids.

BACKGROUND: Treatment of adults with idiopathic membranoproliferative glomerulonephritis (IMPGN) is often unrewarding with approximately 60% of patients progressing to end-stage renal failure within 10 years. Although children with IMPGN may respond to steroid therapy, there is no significant benefit to treating adult IMPGN patients with immunosuppression. METHODS: Outcome measures in five patients with IMPGN who were treated with oral prednisolone and mycophenolate mofetil (MMF) (treatment group) were compared with six patients with IMPGN who did not receive immunosuppression (control group). RESULTS: There was no significant difference between either group in baseline clinical characteristics or systolic and diastolic blood pressure during observation. In the treatment group, there was a significant reduction in proteinuria from a baseline of 5.09 to 1.97 g/24 h (P = 0.003) at 6 months, 1.96 g/24 h (P = 0.003) at 12 months and 2.59 g/24 h (P = 0.015) at 18 months. There was no significant change in proteinuria over 18 months in the control group. Serum creatinine concentration and creatinine clearance did not change significantly over 18 months in the treatment group. In the control group, there were significant changes in serum creatinine and creatinine clearance over 18 months [baseline 103 to 159 micromol/l (P = 0.004) and baseline 108 to 67 ml/min (P > 0.001), respectively] when compared to baseline, although the differences were not significant when the two groups were compared directly. CONCLUSIONS: This preliminary study suggests that in the short term, the combination of MMF and prednisolone can significantly reduce proteinuria and may preserve renal function in patients with IMPGN.

Acute transplant rejection induced by blood transfusion reaction to the Kidd blood group system.

Many renal transplant centres now try to avoid blood transfusion prior to renal transplantation, to avoid alloimmunization due to antibody production against donor antigens usually present on contaminating white cells. Post- or peri-operative transfusions are usually not considered to present problems, since the patient is heavily immunosuppressed. We present a patient who suffered a rare transfusion reaction, that we believe may have initiated a severe vascular rejection of a kidney transplant, probably mediated by Kidd blood group antigens.

Transjugular kidney biopsy.

BACKGROUND: Most previous studies demonstrating the feasibility of transjugular kidney biopsy have used a modified Colapinto aspiration biopsy needle. We present 25 high-risk patients, with contraindications to percutaneous renal biopsy, who underwent transjugular kidney biopsy using a transvenous side-cut needle. This technique is easier to learn and can be performed by an interventional radiologist with transjugular liver biopsy experience and equipment. The needle is designed for optimal cortical sampling but has a high incidence of capsular perforation. Elective coil embolization was used in selected patients to reduce the risk of bleeding. METHODS: We retrospectively reviewed the indications for obtaining renal histology, based on clinical presentation, and the specific indications for transjugular biopsy. Transjugular kidney biopsy was assessed for sampling effectiveness and adequacy, the impact of histology on patient management, and technique complication rates. RESULTS: Renal tissue was obtained in 23 cases, with diagnostic biopsies in 21 of 23 (91.3%). A mean of 3.5 cores were obtained with 9.9 glomeruli per procedure for light microscopy (range, 0 to 32), 2.2 (range, 1 to 7) for electron microscopy, and adequate tissue for immunoflorescence available in 11 of 23 biopsies. Histology influenced patient management in all 23 cases. Capsular perforation was recorded in 73.9% (17 of 23) of cases with 6 undergoing elective coil embolization. Two major complications occurred, both in patients with multiple risk factors for bleeding. One required coil embolization of an arterio-calyseal system fistula. A further patient developed renal vein thrombosis 6 days after a failed transjugular kidney biopsy. CONCLUSION: Transjugular kidney biopsy provides a histological diagnosis in high-risk patients, making an important contribution to patient management.

Peroxynitrite-induced oxidation of plasma lipids is enhanced in stable hemodialysis patients.

BACKGROUND: The relationship between end-stage renal disease (ESRD), hemodialysis, and oxidative stress is controversial. To determine whether ESRD causes oxidative stress, we measured basal levels of plasma F2-isoprostanes as a marker of lipid peroxidation in vivo, and peroxynitrite-stimulated formation of F2-isoprostanes, as a marker of the oxidizibility of plasma lipids in vitro, before and after routine hemodialysis. METHODS: Total plasma F2-isoprostanes were measured by gas chromatography-mass spectrometry (GC-MS) before and after the oxidation of plasma lipids with the peroxynitrite-generating compound, 3-morpholino-sydnonimine (SIN-1), in 23 patients with ESRD patients undergoing regular hemodialysis, and 14 controls. Plasma vitamin E concentrations were measured by high-performance liquid chromatography (HPLC). RESULTS: There was no difference in basal plasma concentrations of F2-isoprostanes in the ESRD group prior to hemodialysis, 246 +/- 20 pg/mL, compared to controls, 252 +/- 28 pg/mL, or immediately on completion of hemodialysis, 236 +/- 14 pg/mL. Incubation of control plasma with SIN-1 caused the formation of F2-isoprostanes with plasma concentrations increasing to 987 +/- 54 pg/mL at 6 hours. The formation of F2-isoprostanes stimulated by SIN-1 was markedly enhanced in the plasma obtained from patients undergoing hemodialysis at 1861 +/- 174 pg/mL, P < 0.001, and SIN-1-induced formation of F2-isoprostanes was further increased in plasma obtained immediately after hemodialysis at 2437 +/- 168 pg/mL, P < 0.001. Incubation of plasma with SIN-1 resulted in the net consumption of vitamin E. CONCLUSION: Although basal plasma F2-isoprostanes were similar in patients with ESRD compared with controls, the presence of oxidative stress in patients with ESRD was unmasked when the plasma was stressed by peroxynitrite generated from SIN-1, and this was enhanced further by hemodialysis.