Light-chain removal by plasmapheresis in myeloma-associated renal failure

Early Light Chains Removal and Albumin Levels with a Double Filter-Based Extracorporeal Treatment for Acute Myeloma Kidney

Renal impairment in Multiple Myeloma (MM) represents one of the most important factors that influences patient survival. In fact, before the introduction of modern chemotherapy, less than 25% of patients with acute kidney injury (AKI) and MM who required dialysis recovered sufficient renal function to become independent from dialysis, with a median overall survival of less than 1 year. There are many other factors involved in determining patient survival. In this study we aimed to investigate the role of double filter-based extracorporeal treatment for removal of serum free light chains (sFLC) in acute myeloma kidney (AKI for MM) and to evaluate patient overall survival. All patients received Bortezomib-based chemotherapy and extracorporeal treatment for sFLC removal. For each session 2 dialyzers of the same kind were used. The dialytic dose was not related to the degree of renal function but to the removal of sFLC. The factors that have been found to be significantly associated with lower mortality were reduction of sFLC at day 12 and day 30, >50% reduction of sFLC at day 30, number of sessions and independence from dialysis. Among baseline characteristics, albumin level was statistically associated with the patients’ outcome. Our analysis highlights the importance of the early treatment for removal of sFLC in AKI for MM. These results indicate that the early removal of sFLC can improve patient’s outcome.

The Increasing Role of Kappa Free Light Chains in the Diagnosis of Multiple Sclerosis

Free light chains (FLC) are a promising biomarker to detect intrathecal inflammation in patients with inflammatory central nervous system (CNS) diseases, including multiple sclerosis (MS). The diagnostic use of this biomarker, in particular the kappa isoform of FLC ("KFLC"), has been investigated for more than 40 years. Based on an extensive literature review, we found that an agreement on the correct method for evaluating KFLC concentrations has not yet been reached. KFLC indices with varying cut-off values and blood-CSF-barrier (QAlbumin) related non-linear formulas for KFLC interpretation have been investigated in several studies. All approaches revealed high diagnostic sensitivity and specificity compared with the oligoclonal bands, which are considered the gold standard for the detection of intrathecally synthesized immunoglobulins. Measurement of KFLC is fully automated, rater-independent, and has been shown to be stable against most pre-analytic influencing factors. In conclusion, the determination of KFLC represents a promising diagnostic approach to show intrathecal inflammation in neuroinflammatory diseases. Multicenter studies are needed to show the diagnostic sensitivity and specificity of KFLC in MS by using the latest McDonald criteria and appropriate, as well as standardized, cut-off values for KFLC concentrations, preferably considering non-linear formulas such as Reiber's diagram.

The Impact of Immunomodulatory Treatment on Kappa Free Light Chains as Biomarker in Neuroinflammation

Background: Kappa free light chains (KFLC) are a promising new biomarker to detect neuroinflammation. Still, the impact of pre-analytical effects on KFLC concentrations was not investigated. Methods: KFLC concentrations were measured in serum and cerebrospinal fluid (CSF) of patients with a newly diagnosed multiple sclerosis (MS) or clinically isolated syndrome (CIS) before (n = 42) or after therapy with high-dose methylprednisolone (n = 65). In prospective experiments, KFLC concentrations were analyzed in the same patients in serum before and after treatment with high-dose methylprednisolone (n = 16), plasma exchange (n = 12), immunoadsorption (n = 10), or intravenous immunoglobulins (n = 10). In addition, the influence of storage time, sample method, and contamination of CSF with blood were investigated. Results: Patients diagnosed with MS/CIS and treated with methylprednisolone showed significantly lower KFLC concentrations in serum as untreated patients. Repeated longitudinal investigations revealed that serum KFLC concentrations continuously decreased after each application of methylprednisolone. In contrast, other immune therapies and further pre-analytical conditions did not influence KFLC concentrations. Conclusion: Our results show prominent effects of steroids on KFLC concentrations. In contrast, various other pre-analytical conditions did not influence KFLC concentrations, indicating the stability of this biomarker.

Guidelines on the Use of Therapeutic Apheresis in Clinical Practice - Evidence-Based Approach from the Writing Committee of the American Society for Apheresis: The Eighth Special Issue

The American Society for Apheresis (ASFA) Journal of Clinical Apheresis (JCA) Special Issue Writing Committee is charged with reviewing, updating and categorizing indications for the evidence-based use of therapeutic apheresis (TA) in human disease. Since the 2007 JCA Special Issue (Fourth Edition), the committee has incorporated systematic review and evidence-based approaches in the grading and categorization of apheresis indications. This Eighth Edition of the JCA Special Issue continues to maintain this methodology and rigor in order to make recommendations on the use of apheresis in a wide variety of diseases/conditions. The JCA Eighth Edition, like its predecessor, continues to apply the category and grading system definitions in fact sheets. The general layout and concept of a fact sheet that was introduced in the Fourth Edition, has largely been maintained in this edition. Each fact sheet succinctly summarizes the evidence for the use of TA in a specific disease entity or medical condition. The Eighth Edition comprises 84 fact sheets for relevant diseases and medical conditions, with 157 graded and categorized indications and/or TA modalities. The Eighth Edition of the JCA Special Issue seeks to continue to serve as a key resource that guides the utilization of TA in the treatment of human disease.

Myeloma light chain cast nephropathy, a review

Multiple Myeloma is a plasma cell proliferative disorder that commonly involves the kidney. Renal impairment is a serious complication during the course of the disease that is associated with increased morbidity and mortality. Light chain cast nephropathy is the predominant pattern of renal injury in Multiple Myeloma. This review article focuses on the pathophysiology and diagnostic approach of myeloma cast nephropathy. The management of precipitating factors as well as anti-plasma cell treatment modalities in the context of renal impairment are also discussed.

Rapid reduction of extremely high kappa free light chains in a patient with myeloma cast nephropathy

This report describes a patient with light chain myeloma and acute renal injury. Serum kappa free light chain (FLC) was extremely elevated, >33,000 mg/dL. Treatment with therapeutic plasma exchange (TPE) started day 2 for biopsy-confirmed cast nephropathy. Bortezomib-containing chemotherapy was initiated on day 5, and hemodialysis for tumor lysis syndrome on day 7. TPE alone decreased kappa FLC >70% by day 5, indicating direct FLC removal was successful in this patient. A total of 25 TPE procedures were performed in a 31-day hospitalization. Hemodialysis was discontinued after 3 months, and the patient's renal function and kappa FLC remain stable. Although the use of TPE for FLC removal is controversial, recent evidence supports its use as adjuvant therapy for acute renal injury secondary to myeloma cast nephropathy. TPE can be effective for rapidly reducing FLC; however, several TPE procedures might be required to reduce the risk of hemodialysis dependency.

Guidelines on the Use of Therapeutic Apheresis in Clinical Practice-Evidence-Based Approach from the Writing Committee of the American Society for Apheresis: The Seventh Special Issue

The American Society for Apheresis (ASFA) Journal of Clinical Apheresis (JCA) Special Issue Writing Committee is charged with reviewing, updating, and categorizing indications for the evidence-based use of therapeutic apheresis in human disease. Since the 2007 JCA Special Issue (Fourth Edition), the Committee has incorporated systematic review and evidence-based approaches in the grading and categorization of apheresis indications. This Seventh Edition of the JCA Special Issue continues to maintain this methodology and rigor to make recommendations on the use of apheresis in a wide variety of diseases/conditions. The JCA Seventh Edition, like its predecessor, has consistently applied the category and grading system definitions in the fact sheets. The general layout and concept of a fact sheet that was used since the fourth edition has largely been maintained in this edition. Each fact sheet succinctly summarizes the evidence for the use of therapeutic apheresis in a specific disease entity. The Seventh Edition discusses 87 fact sheets (14 new fact sheets since the Sixth Edition) for therapeutic apheresis diseases and medical conditions, with 179 indications, which are separately graded and categorized within the listed fact sheets. Several diseases that are Category IV which have been described in detail in previous editions and do not have significant new evidence since the last publication are summarized in a separate table. The Seventh Edition of the JCA Special Issue serves as a key resource that guides the utilization of therapeutic apheresis in the treatment of human disease. J. Clin. Apheresis 31:149-162, 2016. © 2016 Wiley Periodicals, Inc.

Amyloidosis: A cancer-derived paraproteinemia and kidney involvement

Amyloidosis is the general term describing the extracellular tissue deposition of fibrils composed of low molecular weight subunits of a variety of proteins. There are multiple different human protein precursors of amyloid fibrils. Amyloid deposits are stained using Congo Red and show typical apple-green birefringence in polarized microscopy. Nowadays, a novel technique LMD/MS technique or laser microdissection combined with mass spectrometry help to diagnose amyloidosis. Amyloidosis of the kidney is typically classified as being either one of two types: AL or AA. Less common is the hereditary amyloidosis. Clinical manifestations are usually determined by the type of precursor protein, the tissue distribution, and the amount of amyloid deposition. Renal manifestation is usually present as asymptomatic proteinuria or clinically apparent nephrotic syndrome. In some patients clinical presentation include impaired kidney function with no or mild proteinuria. Patients with renal amyloidosis who progress to end-stage renal disease (ESRD) can be treated with either dialysis or renal transplantation. Diagnosis of amyloidosis is prerequisite to consider treatment options to avoid unnecessary chemotherapy. Treatment of amyloidosis is aimed at decreasing the precursors of fibrillary proteins and/or decrease in synthesis/deposition of amyloid fibrils. It depends upon the type of amyloidosis and cause of excess fibril production.

Acute liver failure due to primary amyloidosis in a nephrotic syndrome: a swiftly progressive course

AL amyloidosis is a clonal plasma cell proliferative disorder characterised by extracellular tissue deposits of insoluble fibrils derived from κ or λ immunoglobulin light chains. The most common organs affected by AL amyloidosis are the kidney, presenting with nephrotic syndrome and/or progressive renal dysfunction, and the heart, with restrictive cardiomyopathy. Hepatic deposition of fibrils occurs in half the cases but the liver is rarely the predominantly affected organ. The most common presentation of hepatic amyloidosis is hepatomegaly with elevated alkaline phosphatase. Acute liver failure with cholestasis and jaundice is a rare complication, with a prevalence of approximately 5%, and is usually associated with a worse prognosis. We report a case of a 39-year-old man admitted to our nephrology department with an unusual presentation of primary amyloidosis with nephrotic syndrome and acute liver failure, complicated by obstructive cholestasis resulting in death 2 months after diagnosis.

Current Trends of Renal Impairment in Multiple Myeloma

BACKGROUND

Renal impairment (RI) is a common complication of multiple myeloma (MM). Around 50% of patients with MM have RI at presentation, and up to 5% require dialysis treatment. Severe acute kidney injury (AKI) as a cause of RI is a particular challenge as historically the survival of patients who sustain this complication and require dialysis is very poor. However, in this current period, survival is improving and the focus is on optimum use of novel chemotherapies and the evaluation of extra-corporeal therapies for removal of serum immunoglobulin light chains.

SUMMARY

RI in patients with MM is commonly associated with excess monoclonal free light chain (FLC) production; myeloma cast nephropathy is the predominant renal pathology in patients presenting with severe RI secondary to AKI. The majority of patients have mild to moderate RI and recover renal function. However, patients with more severe RI, in particular those with a requirement for dialysis, are less likely to recover renal function. Rapid diagnosis and prompt institution of anti-myeloma therapy is an important determinant of renal function recovery, through targeting early and sustained reduction of involved monoclonal FLC. Novel agents are associated with excellent disease response, and bortezomib is now widely used as a first-line agent in the management of MM in patients with severe RI. Extended haemodialysis using high cut-off dialysers is more effective for extracorporeal removal of FLC than plasma exchange, and clinical trials are in process. High-dose chemotherapy with autologous stem cell transplantation does have a role in patients with severe RI but requires careful patient selection.

KEY MESSAGES

RI is very common in patients with MM, and renal function recovery is associated with improved clinical outcomes. We summarise the epidemiology of MM in the UK, present the impact of RI and renal function recovery on patient outcome, and describe the current management of MM in western countries.

FACTS FROM EAST AND WEST

(1) A serum creatinine level >2 mg/dl has been reported in 16, 21, 24, and 33% of patients with MM in cohort studies from Japan, Europe, China, and Korea, respectively. A creatinine clearance rate <30 ml/min was observed in 30 and 15% of patients in Chinese and Western MM cohorts, respectively. The commonest cause of severe RI in patients with MM is myeloma cast nephropathy. (2) The efficacy of novel treatments (bortezomib, carfilzomib, thalidomide, and lenalidomide) has predominantly been assessed in Western patients. Bortezomib and dexamethasone are the current standard of care for MM and severe RI in the West. Severe RI is not a contraindication to autologous stem cell transplantation (ASCT). Most of the data are from the West; there are case reports from China describing good outcomes with ASCT. The removal of FLC by high-cut-off hemodialysis is under evaluation in randomized controlled trials (RCTs) in the West. Studies in this area are not yet conducted in China. In China, new treatments, such as bortezomib, are more widely used than before, and favorable results are being reported; however, RCT studies are still needed in this area to confirm the efficacy and safety of this and other novel treatments.

Plasmapheresis in cast nephropathy: yes or no?

PURPOSE OF REVIEW

Renal failure is a frequent complication of multiple myeloma and portends a poor prognosis. Plasmapheresis has been suggested as an adjunct to chemotherapy to halt or reverse renal injury associated with multiple myeloma. The purpose of this article is to review the rationale for using plasmapheresis for this indication and then provide a discussion of the evidence regarding its use.

RECENT FINDINGS

The outcome of patients with multiple myeloma has improved considerably in recent years, mostly owing to the introduction of new highly effective chemotherapeutic agents. However, patients with renal failure who do not recover independent renal function continue to have very poor prognosis. Recent evidence now indicates that an early and sustained reduction in circulating free light chains (FLCs) is associated with improved renal recovery in patients with myeloma kidney. Extracorporeal removal of FLCs with plasmapheresis, or other techniques, can achieve rapid and sustained reduction in serum FLC concentration in patients with acute myeloma kidney. Unfortunately, there is currently no convincing evidence in the literature that the addition of mechanical removal of FLC to standard chemotherapy translates into clinical benefits for patients.

SUMMARY

Plasmapheresis is theoretically attractive as a means of rapidly lowering serum FLC burden in the hope of reducing nephrotoxicity in patients with multiple myeloma. However, the role of plasmapheresis in improving renal prognosis and patient survival remains to be demonstrated.

Lenalidomide and dexamethasone for acute light chain-induced renal failure: a phase II study

We prospectively evaluated the activity and tolerance of lenalidomide-dexamethasone in 35 patients with acute light chain-induced renal failure. The lenalidomide dose was adapted to the estimated glomerular filtration rate and dexamethasone was given at high dose in cycle one and at low dose thereafter. Four patients died within the first two cycles, and five discontinued therapy leaving 26 patients for the per-protocol analysis. Responses were observed in 24/35 (68.6%) patients of the intent-to-treat population. Complete response was noted in seven patients (20%), very good partial response in three patients (8.6%), partial response in 14 patients (40%), and minimal response in one patient (2.9%). Renal response was observed in 16 (45.7%) patients: five (14.2%) achieved complete, four (11.4%) partial and seven (20%) minor renal responses. Five of 13 patients who were dialysis dependent at baseline became dialysis independent. The median time to myeloma and to renal response was 28 days for both parameters, while the median time to best myeloma and best renal response was 92 and 157 days, respectively. The median estimated glomerular filtration rate increased significantly in patients with partial response or better from 17.1 mL/min at baseline to 39.1 mL/min at best response (P=0.001). The median progression-free and overall survival was 5.5 and 21.8 months, respectively, in the intent-to-treat population and 12.1 and 31.4 months, respectively, in the per-protocol group. Infections, cardiotoxicity, anemia and thrombocytopenia were the most frequent toxicities. In conclusion, the lenalidomide-dexamethasone regimen achieved rapid and substantial myeloma and renal responses. The trial was registered under EUDRACT number 2008-006497-15.

Kidney disease and multiple myeloma

Kidney injury is a common complication of multiple myeloma and other plasma cell dyscrasias, and it is associated with increased mortality. Multiple pathogenic mechanisms can contribute to kidney injury in the patient with myeloma, some of which are the result of nephrotoxic monoclonal Ig and some of which are independent of paraprotein deposition. The pathogenic mechanisms that underlie paraprotein-related kidney disease are increasingly well understood. A novel assay allowing the quantification of free light chains in the serum has aided the diagnosis of new onset disease and allowed for the earlier detection of relapse. Novel myeloma agents have shown considerable promise in reversing renal failure in some patients and improving outcomes. Stem cell transplantation remains a mainstay of management for younger patients with myeloma who are suitable candidates for intensive therapy, whereas the role of new drugs, plasma exchange, and kidney transplantation continues to evolve.

Novel renal replacement strategies for the elimination of serum free light chains in patients with kappa light chain nephropathy

Multiple myeloma (MM) is a malignancy with excessive production of monoclonal proteins. At disease presentation 30% of MM patients have significant renal impairment which may progress to renal failure requiring dialysis. Besides chemotherapy extracorporeal elimination procedures such as plasma exchange have been applied as adjuvant strategies to eliminate free light chains from circulating blood, however the efficacy was poor with older techniques. We report about a highly efficient method to eliminate serum free light chain (sFLC) using a newly designed protein leaking membrane in patients suffering from sFLC induced acute renal failure. The protein leaking membrane (HCO 1100) is characterized by increased pore size facilitating elimination of middle molecules such as sFLC kappa (22.5 kD). The HCO 1100 membrane was applied in a hemodialysis and hemodiafiltration mode and compared to standard procedures (high flux hemodialysis, hemodiafiltration and plasma exchange). Hemodiafiltration with the protein leaking membrane HCO 1100 was superior to all other extracorporeal replacement strategies in eliminating sFLC-kappa from circulating blood. A median blood reduction rate of 40.8% (range 13.9% - 66.4%) was achieved during hemodiafiltration. The corresponding peak clearance rate was 25 ml/min. Importantly, the poorest elimination rate was achieved by plasma exchange followed by standard high flux hemodialysis. Extracorporeal elimination strategies with the protein leaking membrane HCO 1100 may be a promising adjuvant treatment strategy for patients with sFLC nephropathy requiring dialysis. Hemodiafiltration and to lesser extend also hemodialysis with the HCO 1100 hemofilter are able to eliminate substantial amounts of sFLC kappa in MM patients.

Early Application of High Cut-Off Haemodialysis for de-Novo Myeloma Nephropathy is Associated with Long-Term Dialysis-Independency and Renal Recovery

Background

Multiple myeloma (MM) is a haematological malignancy associated with kidney injury resulting from cast nephropathy, which can be caused by monoclonal free light chains (FLC). It has been demonstrated that early reduction of FLC can lead to a higher proportion of patients recovering renal function with a better outcome, especially if high cut-off haemodialysis (HCO-HD) combined with chemotherapy is used.

Patients and Methods

In this study, four cases with MM nephropathy were treated with HCO-HD and chemotherapy at a single institution during the period from August 2009 to August 2011. All of the patients presented with acute renal failure and high serum FLC. All patients underwent a bone marrow biopsy to confirm the diagnosis of MM, according to the WHO criteria. Three patients had de novo MM and one patient had relapsed light chain myeloma disease. All patients underwent HCO-HD concomitantly with specific myeloma therapy once the diagnosis or relapse of MM was established.

Results

After a medial follow up of 26 months, (range, 13–36) our data showed that all patients had a significant decrease in serum FLC through HCO-HD, proving the effectiveness of HCO-HD in managing MM. De-novo MM patients restored their renal function and achieved low-level FLC early in the treatment and became dialysis-independent. One patient with relapsed myeloma remained dialysis-dependent.

Conclusion

In summary, our study suggests that in myeloma nephropathy associated with light-chain MM, HCO-HD should be initiated as early as possible. At the same time a specific MM treatment should be initiated to gain control of the disease and salvage the kidneys in order to achieve dialysis-independency. Further randomized trials to confirm our results are warranted.

Endotoxemia after high cutoff hemodialysis for treatment of patient with multiple myeloma can be prevented by using ultrapure dialysate: a case report

To report endotoxemia presented in a case with multiple myeloma (MM) treated by high cutoff hemodialysis (HCO-HD) being prevented by using ultrapure dialysate. A female inpatient with MM received six times HCO-HD (HCO 2100 dialyzer) within 3 weeks after initiation of a chemotherapy based on vincristine+epirubicin+dexamethasone protocol. Conventional dialysate was used in the first three times and then changed to ultrapure dialysate due to elevation of body temperature after HCO-HD. Free light chains (FLC) and endotoxin levels in blood and dialysate were monitored. After six times HCO-HD, her serum FLC λ decreased from 4689 mg/L to 492.7 mg/L, with a trend of decline of serum creatinine. The clearance, reduction ratio, and removal amount of FLC λ was 38.4 mL/min, 71.0-85.2%, and 9.06-18.02 g, respectively, in the setting of dialysate flow rate 500 mL/min, while in the setting of dialysate flow rate 200 mL/min, the removal efficacy of FLC λ was lower than the former. A rise of body temperature up to 38.5°C after treatment and endotoxemia (endotoxin levels 0.122 EU/mL) was found when using conventional dialysate (endotoxin levels 0.112-0.145 EU/mL), but not seen after changing to ultrapure dialysate. Combined with appropriate chemotherapy, HCO-HD can effectively remove and reduce blood FLC. Attention should be paid to the endotoxemia and the rise of temperature after treatment when conventional dialysate is used, which can be prevented by using ultrapure dialysate.

The rationale and evidence base for the direct removal of serum-free light chains in the management of myeloma kidney

Myeloma kidney (cast nephropathy) causing severe acute kidney injury occurs in up to 10% of patients with multiple myeloma. The lesion is caused by exposure of the kidneys to high serum levels of free clonal immunoglobulin light chains (LCs) and is associated with very high morbidity and mortality. The current focus on the management of this complication is on early and aggressive treatment to rapidly reduce the serum levels of the immunoglobulin LC clone and protect the kidneys from continuing injury. This has promoted intense interest in the role of direct (extracorporeal) removal of free LCs from serum by plasma exchange or high cut-off (protein permeable) hemodialysis. However, it remains uncertain whether direct removal provides an additional measurable clinical benefit over the current standard of care; rapid institution of treatment with a dexamethasone- and bortezomib-based chemotherapy regime. In this article, we review the rationale for direct removal of free LCs and the current clinical evidence base for plasma exchange and high cut-off hemodialysis.

Novel approaches for reducing free light chains in patients with myeloma kidney

Myeloma kidney is a tubulointerstitial pathology that accounts for approximately 80-90% of severe acute kidney injury in patients with multiple myeloma. Unless there is rapid intervention, progressive irreversible damage from interstitial fibrosis and tubular atrophy occurs. Work over the past decade has demonstrated that an early sustained reduction in serum concentrations of pathogenic monoclonal free light chains (FLCs) leads to improved renal recovery rates. In turn, an early improvement in renal function is associated with improved patient survival. An early reduction in FLC levels should therefore become standard of care, although the optimum mechanisms to achieve this depletion of FLCs remain to be determined. To provide a coordinated, cross-disciplinary approach to research in this disease, the International Kidney and Monoclonal Gammopathy Research Group was formed. In this Review, we address the current state of knowledge in the management of myeloma kidney.

Complete remission of lambda light chain myeloma presenting with acute renal failure following treatment with bortezomib and steroids

About one in five people with multiple myeloma produce only light chains. Patients with lambda light chain disease have a three times worse prognosis than kappa light chain disease. We report a case of lambda light chain deposition disease in a 35-year-old female who presented with acute renal failure requiring hemodialysis. She had complete recovery and is now in complete remission following treatment with bortezomib and steroids.

Recent advances in the pathogenesis and management of cast nephropathy (myeloma kidney)

Multiple myeloma is an incurable plasma cell malignancy that is often accompanied by renal failure; there are a number of potential causes of this, of which cast nephropathy is the most important. Renal failure is highly significant in myeloma, as patient survival can be stratified by the severity of the renal impairment. Consequently, there is an ongoing focus on the pathological basis of cast nephropathy and the optimal treatment regimens in this setting, including effective chemotherapy regimens to reduce light chain production and emerging extracorporeal techniques to remove circulating light chains. This paper bridges recent advances in the pathogenesis and management of cast nephropathy in multiple myeloma.

High cut-off dialysis membranes: current uses and future potential

The removal of larger uremic toxins by conventional dialysis membranes is restricted by their molecular weight cut-offs. The recent availability of a new generation of hemodialysis membranes with molecular weight cut-offs closer to that of the native kidney (65 kDa) has led to work assessing their potential utility across several different clinical scenarios. Initially designed to remove proinflammatory cytokines in patients with severe sepsis syndrome, clinicians are now using these membranes for the treatment of myeloma kidney and rhabdomyolysis. Further early pilot studies have demonstrated a potential utility for the removal of larger middle molecules in the population with end-stage renal failure. The purpose of this review was to summarize the current evidence base for the use of high cut-off hemodialysis membranes and discuss their future clinical relevance.

Evaluation of blood purification and bortezomib plus dexamethasone therapy for the treatment of acute renal failure due to myeloma cast nephropathy

Aggressive removal of circulating free light chains (FLC) by blood purification accompanied by chemotherapy is a promising approach for the treatment of acute renal failure due to myeloma cast nephropathy. Plasma exchange has been performed to remove serum FLC; in order to examine an alternative strategy we performed hemodiafiltration using protein-leaking dialyzers for the treatment of dialysis-dependent acute renal failure due to myeloma cast nephropathy. In the first case with κ-light chain cast nephropathy, the pre-treatment serum creatinine was 9.65 mg/dL, and the serum κ-FLC was 27100 mg/L. Plasma exchange or hemodiafiltration was performed from Monday to Friday during the first several weeks. Chemotherapy was started with high-dose dexamethasone and then switched to bortezomib plus dexamethasone. The mean removal rates of κ-FLC were 45.8% (one plasma volume) and 66.9% (one-and-a-half plasma volumes) by plasma exchange. The removal rates of κ-FLC by hemodiafiltration (66.9%, FB210UHβ; 71.6%, PES210Dα; 75.2%, FXS220) were comparable to those by plasma exchange. In the second case with λ-light chain cast nephropathy, the pre-treatment serum creatinine was 4.14 mg/dL, and the serum λ-FLC was 4140 mg/L. The mean removal rates of λ-FLC were 60.2% (FXS140) and 64.2% (FB210UHβ) by hemodiafiltration. Both cases became dialysis-independent. The combination of an intense blood purification regimen and bortezomib plus dexamethasone therapy appears to be an efficient approach to renal recovery. Hemodiafiltration using protein-leaking dialyzers could become an alternative to plasma exchange as a method of removing FLC.

Modelled cost-effectiveness of high cut-off haemodialysis compared to standard haemodialysis in the management of myeloma kidney

BACKGROUND

Approximately 10-20% of multiple myeloma patients experience dialysis-dependent renal failure. This is principally due to myeloma kidney, a tubulointerstitial injury caused by high circulating concentrations of monoclonal free light chains. Studies have found that between 3% and 37% of patients with myeloma kidney requiring dialysis recover renal function. In-vivo studies indicate that extended haemodialysis using high cut-off dialysers (HCO-HD) can remove significant quantities of free light chains and is associated with a renal recovery rate of 63-74% in these patients.

OBJECTIVE

The objective of this study was to assess the cost-effectiveness of HCO-HD compared to standard HD in the management of myeloma kidney.

METHODS

The study used a lifetime Excel-based decision tree model that followed all patients from treatment of the initial presentation with myeloma kidney requiring dialysis to death. It was populated with published clinical data, United Kingdom costs and expert opinion, using a National Health Service perspective and 3.5% annual discounting.

RESULTS

HCO-HD was dominant to standard HD, meaning it was both more effective (greater life years and quality adjusted life years) and less costly, due to a greater increase in the proportion of patients recovering renal function. The model projected lifetime costs of £31,345 per patient for patients treated with standard haemodialysis only and £24,845 for the new treatment (discounted). The model predicted an average survival of 19.92 months for patients on standard HD and 33.90 months for the new therapy (discounted).

CONCLUSIONS

The analysis found that treatment of myeloma kidney using an extended schedule of HCO-HD may substantially improve renal recovery in multiple myeloma patients compared to standard HD, resulting in greater life expectancy and cost savings due to avoided chronic dialysis. Limitations of the study include those common to rare diseases including small study sizes and limited natural history data.

Guidelines on the use of therapeutic apheresis in clinical practice--evidence-based approach from the Apheresis Applications Committee of the American Society for Apheresis

The American Society for Apheresis (ASFA) Apheresis Applications Committee is charged with a review and categorization of indications for therapeutic apheresis. Beginning with the 2007 ASFA Special Issue (fourth edition), the subcommittee has incorporated systematic review and evidence-based approach in the grading and categorization of indications. This Fifth ASFA Special Issue has further improved the process of using evidence-based medicine in the recommendations by refining the category definitions and by adding a grade of recommendation based on widely accepted GRADE system. The concept of a fact sheet was introduced in the Fourth edition and is only slightly modified in this current edition. The fact sheet succinctly summarizes the evidence for the use of therapeutic apheresis. The article consists of 59 fact sheets devoted to each disease entity currently categorized by the ASFA as category I through III. Category IV indications are also listed.

Kidney disease associated with plasma cell dyscrasias

Plasma cell dyscrasias are frequently encountered malignancies often associated with kidney disease through the production of monoclonal immunoglobulin (Ig). Paraproteins can cause a remarkably diverse set of pathologic patterns in the kidney and recent progress has been made in explaining the molecular mechanisms of paraprotein-mediated kidney injury. Other recent advances in the field include the introduction of an assay for free light chains and the use of novel antiplasma cell agents that can reverse renal failure in some cases. The role of stem cell transplantation, plasma exchange, and kidney transplantation in the management of patients with paraprotein-related kidney disease continues to evolve.

Presentation and survival of patients with severe acute kidney injury and multiple myeloma: a 20-year experience from a single centre

BACKGROUND

Myeloma is the second most common haematological malignancy and is a cause of severe acute kidney injury (serum creatinine >or=500 micromol/L) that has long been associated with a poor prognosis, although previous series have been small.

METHODS

We have therefore documented the natural history of all 107 patients referred to a large regional renal unit over a 20-year period and investigated factors associated with survival over a long period of time using Cox regression methods.

RESULTS

Three factors were found to be significantly and independently associated with survival: use of chemotherapy [hazard ratio (HR) 0.21, 95% CI: 0.08-0.46, P < 0.001], serum albumin (HR 0.49, 95% CI: 0.29-0.82, P = 0.02 for >or=35 g/L versus <35 g/L) and dialysis independence (HR 0.43, 95% CI: 0.24-0.76, P = 0.005). However, survival was not found to be better for patients presenting in the second decade compared to the first (HR 0.88, 95% CI: 0.52-1.50, P = 0.65).

CONCLUSIONS

This analysis highlights the need for clinical trials of novel chemotherapy regimens in this complicated group of patients. Furthermore, whether strategies to restore or preserve dialysis-independent renal function provide additional benefit to effective chemotherapy also requires further investigation. The advent of efficacious low toxicity chemotherapy (such as thalidomide and bortezomib) and new dialysis techniques to remove free light chains may radically alter the outcome of this group of patients.

Light chains: heavy burden in kidney transplantation

Plasma cell dyscrasias are frequently encountered malignancies which are often associated with kidney disease through the production of monoclonal immunoglobulin (Ig). Recent advances in the field include the availability of an assay for free light chains, the introduction of new agents which more effectively target malignant plasma cells, and refinements in the application of stem-cell transplantation. Well-selected patients with plasma cell dyscrasias whose monoclonal Ig is well controlled may be candidates for kidney transplantation. Kidney transplant patients with allograft dysfunction from recurrent or de novo monoclonal Ig deposition can be successfully identified and treated with these new approaches.

Treatment of acute renal failure secondary to multiple myeloma with chemotherapy and extended high cut-off hemodialysis

BACKGROUND AND OBJECTIVES

Extended hemodialysis using a high cut-off dialyzer (HCO-HD) removes large quantities of free light chains in patients with multiple myeloma. However, the clinical utility of this method is uncertain. This study assessed the combination of chemotherapy and HCO-HD on serum free light chain concentrations and renal recovery in patients with myeloma kidney (cast nephropathy) and dialysis-dependent acute renal failure.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

An open-label study of the relationship between free light chain levels and clinical outcomes in 19 patients treated with standard chemotherapy regimens and HCO-HD.

RESULTS

There were sustained early reductions in serum free light chain concentrations (median 85% [range 50 to 97]) in 13 patients. These 13 patients became dialysis independent at a median of 27 d (range 13 to 120). Six patients had chemotherapy interrupted because of early infections and did not achieve sustained early free light chain reductions; one of these patients recovered renal function (at 105 d) the remaining 5 patients did not recover renal function. Patients who recovered renal function had a significantly improved survival (P < 0.012).

CONCLUSION

In dialysis-dependent acute renal failure secondary to myeloma kidney, patients who received uninterrupted chemotherapy and extended HCO-HD had sustained reductions in serum free light chain concentrations and recovered independent renal function.

Serum free-light chain removal by high cutoff hemodialysis: optimizing removal and supportive care

In multiple myeloma the predominant cause of irreversible renal failure is cast nephropathy, secondary to excess kappa or lambda serum free light chains (FLCs). These molecules are efficiently cleared by hemodialysis (HD) using the Gambro HCO 1100 dialyzer. To optimize the removal of FLCs by this dialyzer we have studied the effect of dialyzers in series, dialyzer change, and hemodiafiltration in 14 patients with multiple myeloma and renal failure. The clearance rates of both kappa FLCs and lambda FLCs were significantly increased on two dialyzers from 19 (7.3-34)-15.3 (9-28) mL/min to 47 (17-79)-35.5 (20-57) mL/min, respectively. Clearance rates of both FLCs decreased over the course of the dialysis sessions (both P < 0.001). Changing the dialyzer during a HD session increased lambda FLC clearance rates (22.5 [6-41] to 37.6 [9-52] mL/min; P < 0.001) and decreased kappa FLC clearance rates (39.6 [9-72] to 19 [8-59] mL/min; P < 0.003). Ultrafiltration during HD increased the clearance rates of kappa FLCs (R 0.52, P < 0.01) but not lambda FLCs (R -0.25; P < 0.076). Hemodiafiltration increased the clearance rates of both kappa (19 [SD 6.8] to 32 [SD 9.8] mL/min) and lambda FLCs (15 [SD 7.8] to 20 [SD 7.7] mL/min). Albumin replacement requirements for 8 h of HD increased from 12 g for a single dialyzer to 45 g for two dialyzers in series (P < 0.001). Different protocols are required to optimize the removal of kappa and lambda FLCs in patients with myeloma and renal failure.

Plasma exchange for myeloma kidney: cast(s) away?

Leung et al. (this issue) present a retrospective study of 40 patients. Observations in 14/40 led to the suggestion of restitution of plasma exchange for light-chain responsive, biopsy-proven myeloma kidney until a better randomized control trial (RCT) is constructed. A careful analysis of their study and a recent RCT suggest little difference in outcome between plasma exchange and control groups. The analysis supports restitution of a better RCT of plasma exchange for myeloma kidney rather than off-label use.

Efficient Removal of Immunoglobulin Free Light Chains by Hemodialysis for Multiple Myeloma:In VitroandIn VivoStudies

Of patients with newly diagnosed multiple myeloma, approximately 10% have dialysis-dependent acute renal failure, with cast nephropathy, caused by monoclonal free light chains (FLC). Of these, 80 to 90% require long-term renal replacement therapy. Early treatment by plasma exchange reduces serum FLC concentrations, but randomized, controlled trials have shown no evidence of renal recovery. This outcome can be explained by the low efficiency of the procedure. A model of FLC production, distribution, and metabolism in patients with myeloma indicated that plasma exchange might remove only 25% of the total amount during a 3-wk period. For increasing FLC removal, extended hemodialysis with a protein-leaking dialyzer was used. In vitro studies indicated that the Gambro HCO 1100 dialyzer was the most efficient of seven tested. Model calculations suggested that it might remove 90% of FLC during 3 wk. This dialyzer then was evaluated in eight patients with myeloma and renal failure. Serum FLC reduced by 35 to 70% within 2 hr, but reduction rates slowed as extravascular re-equilibration occurred. FLC concentrations rebounded on successive days unless chemotherapy was effective. Five additional patients with acute renal failure that was caused by cast nephropathy then were treated aggressively, and three became dialysis independent. A total of 1.7 kg of FLC was removed from one patient during 6 wk. Extended hemodialysis with the Gambro HCO 1100 dialyzer allowed continuous, safe removal of FLC in large amounts. Proof of clinical value now will require larger studies.