Acute Kidney Injury Due to Ovarian Hyperstimulation Syndrome.

Ovarian hyperstimulation syndrome (OHSS) is a complication of assisted reproductive treatments such as in vitro fertilization (IVF). The pathophysiology of severe OHSS includes a humorally mediated capillary leak syndrome that is predominantly centered on the intra-abdominal space. Severe OHSS is frequently complicated by acute kidney injury (AKI), which can be due to any of a variety of mechanisms, each requiring a different management strategy. Mechanisms of AKI in severe OHSS include intravascular volume depletion, kidney edema due to capillary leak, intra-abdominal hypertension or compartment syndrome, and obstructive uropathy due to ovarian enlargement. We present a teaching case of severe OHSS complicated by AKI in a woman with underlying stage 4 chronic kidney disease. She had been undergoing IVF with plans to subsequently use a gestational carrier (surrogate) for pregnancy. We use this case to review the presentation and pathophysiology of OHSS complicated by AKI. In addition, we review the management of AKI in OHSS, in particular, the role of paracentesis and/or culdocentesis to manage tense ascites. Last, we highlight that similar cases may occur more frequently in the future given that IVF with subsequent use of a gestational carrier is increasingly being used for patients with comorbid conditions that can be exacerbated by pregnancy, such as advanced chronic kidney disease.

Safety Lapses Prior to Initiation of Hemodialysis for Acute Kidney Injury in Hospitalized Patients: A Patient Safety Initiative.

Background: Safety lapses in hospitalized patients with acute kidney injury (AKI) may lead to hemodialysis (HD) being required before renal recovery might have otherwise occurred. We sought to identify safety lapses that, if prevented, could reduce the need for unnecessary HD after AKI; Methods: We conducted a retrospective observational study that included consecutive patients treated with HD for AKI at a large, tertiary academic center between 1 September 2015 and 31 August 2016. Exposures of interest were pre-specified iatrogenic processes that could contribute to the need for HD after AKI, such as nephrotoxic medication or potassium supplement administration. Other outcomes included time from AKI diagnosis to initial management steps, including Nephrology referral; Results: After screening 344 charts, 80 patients were included for full chart review, and 264 were excluded because they required HD within 72 h of admission, were deemed to have progression to end-stage kidney disease (ESKD), or required other renal replacement therapy (RRT) modalities in critical care settings such as continuous renal replacement therapy (CRRT) or sustained low efficiency dialysis (SLED). Multiple safety lapses were identified. Sixteen patients (20%) received an angiotensin converting enzyme inhibitor or angiotensin receptor blocker after AKI onset. Of 35 patients with an eventual diagnosis of pre-renal AKI due to hypovolemia, only 29 (83%) received a fluid bolus within 24 h. For 28 patients with hyperkalemia as an indication for starting HD, six (21%) had received a medication associated with hyperkalemia and 13 (46%) did not have a low potassium diet ordered. Nephrology consultation occurred after a median (IQR) time after AKI onset of 3.0 (1.0⁻5.7) days; Conclusions: Although the majority of patients had multiple indications for the initiation of HD for AKI, we identified many safety lapses related to the diagnosis and management of patients with AKI. We cannot conclude that HD initiation was avoidable, but, improving safety lapses may delay the need for HD initiation, thereby allowing more time for renal recovery. Thus, development of automated processes not only to identify AKI at an early stage but also to guide appropriate AKI management may improve renal recovery rates.

Microparticle Formation in Peritoneal Dialysis: A Proof of Concept Study.

BACKGROUND: Injury to the mesothelial layer of the peritoneal membrane during peritoneal dialysis (PD) is implicated in loss of ultrafiltration capacity, but there are no validated biomarkers for mesothelial cell injury. Microparticles (MPs) are 0.1 to 1.0 µm membrane vesicles shed from the cell surface following injury and are sensitive markers of tissue damage. Formation of MPs in the peritoneal cavity during PD has not been reported to date. METHODS: We designed a single-center, proof of concept study to assess whether peritoneal solution exposure induces formation of mesothelial MPs suggestive of PD membrane injury. We examined MP levels in PD effluents by electron microscopy, nanoparticle tracking analysis (NTA), flow cytometry, procoagulant activity, and Western blot. RESULTS: NTA identified particles in the size range of 30 to 900 nm, with a mean of 240 (SE: 10 nm). MP levels increased in a progressive manner during a 4-hour PD dwell. Electron microscopy confirmed size and morphology of vesicles consistent with characteristics of MPs as well as the presence of mesothelin on the surface. Western blot analysis of the MP fraction also identified the presence of mesothelin after 4 hours, suggesting that MPs found in PD effluents may arise from mesothelial cells. CONCLUSIONS: Our results suggest that MPs are formed and accumulate in the peritoneal cavity during PD, possibly as a stress response. Assessing levels of MPs in PD effluents may be useful as a biomarker for peritoneal membrane damage.

CONTEXTE: Les lésions causées à la couche mésothéliale de la membrane péritonéale au cours d'une dialyse péritonéale (DP) sont impliquées dans la perte de capacité d'ultrafiltration. Toutefois, il n'existe aucun biomarqueur validé permettant la détection de ces lésions. Les microparticules (MP) sont des vésicules membranaires de 0,1 à 1,0 µm qui se détachent de la surface des cellules à la suite des lésions. Les microparticules sont sensibles aux marqueurs de dommages tissulaires. À ce jour, la formation de microparticules dans la cavité péritonéale au cours de la DP n'a pas été observée. MÉTHODOLOGIE: Nous avons conçu une étude de preuve de concept que nous avons menée dans un seul centre. Nous voulions déterminer si l'exposition à la solution de dialyse péritonéale induisait la formation de microparticules mésothéliales, ce qui pourrait indiquer la présence de dommages membranaires provoqués par la DP. Nous avons mesuré les taux de microparticules dans les effluents de la DP par microscopie électronique, par analyse du suivi individuel de particules (Nanoparticle Tracking Analysis­NTA), en cytométrie de flux, par la mesure de l'activité pro-coagulante et par Western Blot. RÉSULTATS: L'analyse par NTA a identifié des particules allant de 30 à 900 nanomètres, dont le diamètre moyen était de 240 ±10 nanomètres. Les taux de MP ont augmenté d'une façon progressive au cours des quatre heures que durait la DP. La microscopie électronique a confirmé la taille et la morphologie de vésicules conformes aux caractéristiques des MP, de même que la présence de mésothéline en surface. L'analyse par Western Blot de fragments de MP a également indiqué la présence de mésothéline après 4 heures, ce qui suggère que les microparticules recueillies dans les effluents de dialyse pourraient provenir de cellules mésothéliales. CONCLUSIONS: Nos résultats suggèrent que des microparticules sont formées au cours de la DP et qu'elles s'accumulent dans la cavité péritonéale, possiblement en réponse au stress. Par conséquent, la mesure des taux de microparticules dans les effluents de DP pourrait s'avérer un bon biomarqueur pour indiquer la présence de lésions dans la membrane péritonéale.

Renal pseudoaneurysm formation post allograft biopsy: a case report.

Renal pseudoaneurysm (PSA) is a rare complication post kidney transplant biopsy that accounts for less than 1% of allograft dysfunction. Imaging guidelines in the diagnosis of renal PSA have not yet been developed owing to the low occurrence and limited data availability. However, contrast-enhanced CT and magnetic resonance angiography (MRA) are the preferred modalities in detecting PSA owing to the high contrast and spatial resolution. However, magnetic resonance angiography is preferred since non-contrast imaging techniques can see blood flow patterns in renal PSA without the use of contrast media that may alter renal function. We present a rare complication in a 48-year-old male receiving a living related kidney transplant and found to have renal PSA post allograft biopsy. We review the clinical features, imaging and treatment outcome with the developed PSA in the transplanted kidney post allograft biopsy.

Rituximab use in adult primary glomerulopathy: where is the evidence?

Rituximab is a chimeric anti-CD20 antibody that results in depletion of B-cell lymphocytes. It is currently used in the treatment of a variety of autoimmune diseases, in addition to CD20-positive lymphomas. The use of rituximab in the treatment of the adult primary glomerular diseases has emerged recently, although not yet established as first-line therapy in international guidelines. In patients with steroid-dependent minimal change disease or frequently relapsing disease, and in patients with idiopathic membranous nephropathy (IMN), several retrospective and prospective studies support the use of rituximab to induce remission, whereas in idiopathic focal and segmental glomerulosclerosis (FSGS), the use of rituximab has resulted in variable results. Evidence is still lacking for the use of rituximab in patients with immunoglobulin A nephropathy (IgAN) and idiopathic membranoproliferative glomerulonephritis (MPGN), as only few reports used rituximab in these two entities. Randomized controlled trials (RCTs) are warranted and clearly needed to establish the definitive role of rituximab in the management of steroid-dependent and frequently relapsing minimal change disease, IMN, both as first-line and second-line treatment, and in MPGN. We await the results of an ongoing RCT of rituximab use in IgAN. Although current evidence for the use of rituximab in patients with idiopathic FSGS is poor, more RCTs are needed to clarify its role, if any, in the management of steroid-resistant or steroid-dependent FSGS.

CYTOMEGALOVIRUS INFECTION POST KIDNEY TRANSPLANT: What Should We Know Now?

Cytomegalovirus (CMV) remains one of the most important pathogen responsible for the morbidity and mortality of transplantation patients. The impact on recipients depends on the form of CMV infection knowing that 10% to 50% develop symptomatic disease while solid organ involvement if presumed (e.g. CMV nephritis) may have deleterious outcome and requires histopathology testing. Treatment with antivirals IV ganciclovir and valganciclovir is managed according to early diagnostic tools with quantitative nucleic acid testing (QNAT) and antigenemia that will indicate the extent of disease and monitor response to treatment. CMV prevention in particular conditions of high risk patients has proven to be beneficial, resistance to antivirals and CMV vaccines along with novel therapies are thoroughly discussed in this review describing the new perspectives of CMV infection management.

A Rare Cause of Reversible Renal Hemosiderosis.

Kidney failure secondary to renal hemosiderosis has been reported in diseases with intravascular hemolysis, like paroxysmal nocturnal hemoglobinuria, and valvular heart diseases. We present here a case of hemosiderin induced acute tubular necrosis secondary to intravascular hemolysis from Clostridium difficile infection with possible role of supratherapeutic INR. We discuss the pathophysiology, causes, and prognosis of acute tubular injury from hemosiderosis.