Obinutuzumab as treatment for ANCA-associated vasculitis.

OBJECTIVES: Rituximab is a standard of care therapy for patients with ANCA-associated vasculitis. When rituximab is contraindicated, or in the case of refractory disease, other treatments are needed. Obinutuzumab is another anti-CD20 antibody for the treatment of haematological malignancies that may induce a deeper B cell depletion compared with rituximab. This article reviews three cases of patients with ANCA-associated vasculitis who were treated with obinutuzumab due to their history of anaphylactic reactions to rituximab. METHODS: Case series of three patients with ANCA-associated vasculitis treated with obinutuzumab. RESULTS: One female patient with microscopic polyangiitis and two male patients with granulomatosis with polyangiitis received obinutuzumab. The treatment was well-tolerated in all patients despite previous anaphylactic reaction to rituximab. Treatment with obinutuzumab was effective in (i) inducing disease remission, (ii) inducing total B cell depletion, and (iii) resulting in undetectable serum titres of ANCA. All three patients were re-treated with obinutuzumab for maintenance of remission. CONCLUSION: Obinutuzumab appears to be a safe and efficacious therapy for patients with ANCA-associated vasculitis who have had refractory disease or a history of anaphylaxis to rituximab. Prospective studies comparing rituximab to obinutuzumab in ANCA-associated vasculitis patients are warranted.

Worsening membranous nephropathy in a patient with GIST treated with sunitinib.

Tyrosine kinase inhibitors (TKI) are anticancer agents widely used for a variety of malignancies including gastrointestinal stromal tumours (GIST). Although generally well-tolerated, TKIs have been associated with a number of adverse events including hypertension, proteinuria and nephrotic syndrome. We present the case of a 70-year-old patient with metastatic GIST on long-standing sunitinib who developed hypertension, oedema and hypoalbuminemia with a rising serum creatinine and was found to have nephrotic syndrome. Workup revealed elevated antiphospholipase A2 receptor (PLA2R) antibody IgG titres and a kidney biopsy confirmed PLA2R-positive membranous nephropathy without findings of thrombotic microangiopathy. Cessation of sunitinib led to reduction in anti-PLA2R antibody IgG titres while resumption, due to concern for cancer progression, led to worsening symptoms. Treatment with rituximab led to undetectable anti-PLA2R IgG titres. We highlight the importance of maintaining a systematic approach for evaluating nephrotic syndrome and provide a case showing that TKIs can exacerbate underlying nephrotic syndrome.

Bevacizumab-associated thrombotic microangiopathy treated with eculizumab: A case series and systematic review of the literature.

BACKGROUND: Bevacizumab is a recombinant monoclonal antibody against the vascular endothelial growth factor A (VEGF-A) ligand that is used in the management of various solid malignancies. The adverse effect profiles of angiogenesis inhibitors, such as bevacizumab, have become increasingly well characterized and include renal manifestations such as hypertension, proteinuria, and thrombotic microangiopathy. Eculizumab inhibits terminal-complement activation and is used to treat atypical hemolytic uremic syndrome. There has been growing usage of eculizumab to treat bevacizumab-associated thrombotic microangiopathy. MATERIALS AND METHODS: We performed a systematic review of the literature to identify full-text articles that describe the use of eculizumab for bevacizumab-associated thrombotic microangiopathy. RESULTS: Our systematic review identified 522 unique articles of which 5 were included in the final review. 9 cases, including 2 new cases presented in this review, were identified in which eculizumab was used in the management of bevacizumab-associated thrombotic microangiopathy. Hematologic parameters and kidney function stabilized or improved in all cases, and the 2 patients who required renal replacement therapy were able to discontinue dialysis. CONCLUSIONS: Given the findings of this systematic review, the use of eculizumab in the treatment of bevacizumab-associated thrombotic microangiopathy warrants further study, particularly in severe cases.

Deferasirox-associated Fanconi syndrome in adult patients with transfusional iron overload.

BACKGROUND AND OBJECTIVES: Deferasirox is an oral chelator approved for iron overload, which has a potential side effect of renal Fanconi syndrome, with proximal tubular dysfunction and tubular acidosis. Monitoring of renal function is recommended, though no standard for monitoring exists. We aim to describe cases of deferasirox-associated Fanconi syndrome in adults and the renal monitoring required to detect these findings. MATERIALS AND METHODS: We present a review of the literature and six cases from our institution of deferasirox-associated partial Fanconi syndrome in adult patients with transfusional iron overload secondary to ß-thalassemia or Diamond Blackfan Anaemia. RESULTS: While prior cases in the literature occurred at high doses of deferasirox, our series included patients on doses as low as deferasirox 10 mg/kg who had been aggressively chelated. All patients had resolution of laboratory abnormalities with drug interruption. CONCLUSION: Rather than chelating to normal iron levels, this series supports prior suggestions that deferasirox dose be reduced if ferritin <500-1000 ng/ml, and also supports dose reduction if liver iron content <3 mg iron per g dry weight or for those undergoing aggressive chelation with rapid decrease in iron. Monitoring with metabolic panel and urinalysis were sufficient to detect clinically significant proximal tubular dysfunction, but should be followed up with additional studies to confirm the diagnosis while deferasirox dose is decreased or held.

Nephrotoxicity From Molecularly Targeted Chemotherapeutic Agents.

The introduction of novel molecularly targeted therapies in the last 2 decades has significantly improved the patient survival compared to standard conventional chemotherapies. However, this improvement has been accompanied by a whole new spectrum of kidney adverse events. Although known as "targeted," many of these agents lack specificity and selectivity, and they have a tendency to inhibit multiple targets including those in the kidneys. Early detection and correct management of kidney toxicities is crucial to preserve kidney functions. The knowledge of these toxicities helps guide optimal and continued utilization of these potent therapies. The incidence, severity, and pattern of nephrotoxicity may vary depending on the respective target of the drug. Here, we review the mechanism of action, clinical findings of kidney adverse events, and their proposed management strategies.

Bortezomib Treatment for Refractory PLA2R-Positive Membranous Nephropathy.

Introduction: B-cell depletion has been shown to be an effective strategy for the majority of patients with membranous nephropathy (MN), and in PLA2R-positive MN, immunologic remission (improvement or elimination of measurable serum anti-PLA2R antibodies) precedes renal remission. Yet, cases exist of patients who do not achieve immunologic remission despite achieving peripheral B-cell depletion. This has led to the hypothesis that some patients have plasma cells that are responsible for producing anti-PLA2R antibodies. Case Presentation: A 66-year-old man with a past medical history of hypertension, hyperlipidemia, and cerebrovascular disease presented with nephrotic syndrome and was diagnosed with PLA2R-positive MN on kidney biopsy. He was refractory to multiple therapies including tacrolimus, and was resistant to rituximab despite having achieved B-cell depletion. He also did not enter into remission with plasmapharesis and cyclophosphamide. He then achieved immediate immunologic remission after treatment with the proteasome inhibitor bortezomib, which is used as first-line therapy for multiple myeloma. Discussion/Conclusion: This case suggests that considering the source of PLA2R antibody production could lead to individualized and targeted therapies for MN.

Hypertension in Cancer Patients and Survivors: Epidemiology, Diagnosis, and Management.

Cancer patients and survivors of cancer have a greater burden of cardiovascular disease compared to the general population. Much of the elevated cardiovascular risk in these individuals is likely attributable to hypertension, as individuals with cancer have a particularly high incidence of hypertension following cancer diagnosis. Treatment with chemotherapy is an independent risk factor for hypertension due to direct effects of many agents on endothelial function, sympathetic activity, and renin-angiotensin system activity as well as nephrotoxicity. Diagnosis and management of hypertension in cancer patients requires accurate blood pressure measurement and consideration of potential confounding factors, such as adjuvant treatments and acute pain, that can temporarily elevate blood pressure readings. Home blood pressure monitoring can be a useful tool to facilitate longitudinal blood pressure monitoring for titration of antihypertensive medications. Selection of antihypertensive agents in cancer patients should account for treatment-specific morbidities and target organ injury.

Warburg's effect on solid tumors.

Lactic acidosis is the result of imbalance between the systemic formation of lactate and its hepatic metabolism. In cancer patients, lactic acidosis is mainly associated with hematologic malignancies (leukemia and lymphomas) and the mechanism is known as Warburg's effect. We report a 76-year-old male known to have hypertension and coronary artery disease, who presented with abdominal distension and lactic acidosis. His initial evaluation showed multiple liver masses that were biopsied and the patient was diagnosed with undifferentiated carcinoma of unknown primary, involving the liver. The patient had progression of lactic acidosis leading to his death on day-15. As the lactic acidosis was not in the setting of hypoxia or hemodynamic instability, we made the diagnosis of malignancy-associated type B lactic acidosis, also known as the Warburg's effect. Warburg's effect can occur in solid cancer if the tumor involves the liver. It has bad prognostic implications. The use of intravenous bicarbonate as a temporary measure is of controversial benefit, as it can potentially worsen the metabolic acidosis and its use should be limited to patients with very low pH. In cancer patients, the use of lactatebased intravenous fluids can be potentially harmful and can increase the risk of tumor metastasis, at least in animal malignancy models.

Steroid withdrawal in kidney allograft recipients.

This review highlights the aggregate of knowledge obtained from the temporal trend of kidney transplant immune suppression. We will discuss the burden of steroid side effects and their impact on quality of life in kidney allograft recipients, which have led to minimizing steroid exposure. Issues arising since the inception of the concept of steroid withdrawal will be discussed, along with how they have continually led to a shift in research focus on this subject matter. The usefulness of surveillance biopsies and how further elucidation of the pathophysiology of interstitial fibrosis and tubular atrophy could contribute to improving long-term allograft outcomes will also be discussed. We will elaborate on the role of calcineurin inhibitor minimization alongside steroid withdrawal in improving long-term graft survival. Future expectations of subsequent studies with a view to improving overall kidney allograft outcomes by eliminating attendant problems associated with steroids will also be covered.

Belatacept: a new era of immunosuppression?

Full T-cell activation in alloimmunity requires the engagement of several costimulatory molecules. CTLA-4-Ig and its commercially available fusion proteins, belatacept and abatacept, are used to block CD80/86 and promote T-cell tolerance. Belatacept, a higher binding affinity molecule, is currently approved for clinical use in renal transplantation. The results of two Phase III clinical trials showed a similar patient/graft survival, with better renal function at a 3-year follow-up compared with conventional immunosuppression. There was a higher risk of early rejection and post-transplant lymphoproliferative disorder, especially with EBV-negative patients receiving kidneys from EBV-positive donors. Belatacept-treated groups had a better cardiovascular and metabolic profile. The authors review both preclinical and human studies of CTLA-4-Igs.

Diagnostic and prognostic stratification in the emergency department using urinary biomarkers of nephron damage: a multicenter prospective cohort study.

OBJECTIVES: This study aimed to determine the diagnostic and prognostic value of urinary biomarkers of intrinsic acute kidney injury (AKI) when patients were triaged in the emergency department. BACKGROUND: Intrinsic AKI is associated with nephron injury and results in poor clinical outcomes. Several urinary biomarkers have been proposed to detect and measure intrinsic AKI. METHODS: In a multicenter prospective cohort study, 5 urinary biomarkers (urinary neutrophil gelatinase-associated lipocalin, kidney injury molecule-1, urinary liver-type fatty acid binding protein, urinary interleukin-18, and cystatin C) were measured in 1,635 unselected emergency department patients at the time of hospital admission. We determined whether the biomarkers diagnosed intrinsic AKI and predicted adverse outcomes during hospitalization. RESULTS: All biomarkers were elevated in intrinsic AKI, but urinary neutrophil gelatinase-associated lipocalin was most useful (81% specificity, 68% sensitivity at a 104-ng/ml cutoff) and predictive of the severity and duration of AKI. Intrinsic AKI was strongly associated with adverse in-hospital outcomes. Urinary neutrophil gelatinase-associated lipocalin and urinary kidney injury molecule 1 predicted a composite outcome of dialysis initiation or death during hospitalization, and both improved the net risk classification compared with conventional assessments. These biomarkers also identified a substantial subpopulation with low serum creatinine at hospital admission, but who were at risk of adverse events. CONCLUSIONS: Urinary biomarkers of nephron damage enable prospective diagnostic and prognostic stratification in the emergency department.

Immunological aspects of pancreatic islet cell transplantation.

Type 1 diabetes mellitus (T1DM) is one of the most common diseases of childhood. Insulin discovery changed the clinical course of T1DM from an acutely fatal disease to a chronic disease, but this discovery was later found to be inefficient to control its long-term complications. Whole-pancreas and islet cell transplantation seem to provide a potential solution by restoring the normal physiology of glucose-insulin homeostasis. Although islet transplantation is less invasive than whole-pancreas transplantation, the insulin-free state after islet transplantation remained low (10%) at 5 years after surgery. Here, we will present the specific immunologic challenges that are specific to islet cell transplantation, including instant blood-mediated inflammatory reaction and the recurrence of autoimmunity. We will also briefly discuss the immunosuppressive regimens used and the recent radiologic techniques in the detection of engraftment and early rejection of islet cells.

Lupus cerebritis after visiting a tanning salon.

A 53-year-old female was admitted to the intensive care unit for lupus cerebritis; she had a 15-year history of stable lupus. Over the prior 1 to 2 months, the patient visited a tanning salon and this triggered the exacerbation of lupus. Her initial symptoms were cutaneous in the form of an erythematous rash. Within 2 weeks she started to have headaches and was admitted for seizure and psychosis. Ultraviolet A exposure in the tanning salon is known to exacerbate lupus by modulation of the immune system at the level of the skin. It has also been found that ultraviolet light can lead to the formation of antinuclear antibodies. This case illustrates the need to emphasize the danger of the tanning salon to patients with systemic lupus erythematous; the risk is not only cutaneous, it can also be systemic.