Management of myeloma-associated renal dysfunction in the era of novel therapies

Exosomal miR-21-5p derived from multiple myeloma cells promote renal epithelial-mesenchymal transition through targeting TGF-β/SMAD7 signalling pathway

The prognosis of multiple myeloma (MM) patients combined with renal insufficiency is poor. Renal fibrosis is an important pathological cause for MM patients combined with renal insufficiency. It is reported that epithelial-mesenchymal transition (EMT) of renal proximal tubular epithelial cells is an important mechanism in renal fibrosis. We speculated that EMT might play an important role in the renal insufficiency of MM with unclear mechanism. MM cells derived exosomes could affect the function of targeted cells by delivering microRNAs (miRNAs). Literature has shown that the expression of miR-21 is closely related to EMT. In this research, we found that co-culture of HK-2 cells (human renal proximal tubular epithelial cells) and exosomes derived from MM cells promoted the EMT of HK-2 cells, resulting in the down-regulation of epithelial-related marker (E-cadherin), and up-regulation of stroma-related marker (Vimentin). Meanwhile, the expression of SMAD7, one of the downstream targets in the TGF-β signalling pathway, was suppressed and the expression of TGF-β was increased. After transfecting the inhibitor of miR-21 in MM cells, the expression of miR-21 in exosomes secreted by MM cells was significantly decreased, and the co-culture of these treated exosomes and HK-2 cells inhibited the EMT of HK-2 cells. In conclusion, these findings showed that exosomal miR-21 derived from MM cells could promote renal EMT through targeting TGF-β/SMAD7 signalling pathway.

Hemodiafiltration with ultrafiltrate regeneration reduces free light chains without albumin loss in multiple myeloma patients

Background

Acute kidney injury (AKI) occurs in 12–20% of multiple myeloma (MM) patients. Several studies have shown a reduction of free light chains (FLC) using hemodialysis with High-Cut-Off membranes. However, this technique entails albumin loss. Hemodiafiltration with ultrafiltrate regeneration is a technique that includes a process of adsorption. The aim of this study was to evaluate the effectiveness of hemodiafiltration with ultrafiltrate regeneration in reducing FLC levels without causing albumin loss.

Methods

This is an observational study (2012 to 2018) including nine patients with MM (5 kappa, 4 lambda) and AKI. All patients were treated with chemotherapy and hemodiafiltration with ultrafiltrate regeneration. Blood Samples (pre and post-dialysis) and ultrafiltrate were collected pre and post-resin at 5 min after initiation of the session and 5 min before the end of the procedure.

Results

The serum levels of kappa and lambda were reduced by a 57.6 ± 10% and 33.5 ± 25% respectively. Serum albumin concentration remained unchanged after the procedure. In the ultrafiltrate, the mean FLC reduction ratio shortly after initiation of the dialysis procedure was: 99.2 and 97.06% for kappa and lambda respectively, and only 0.7% for albumin; and at the end of the session the percent reduction was: 63.7 and 33.62% for kappa and lambda respectively, and 0.015% for albumin. Patients clinical outcome was: 33.3% recovered renal function, 22.2% died during the first year and 44.4% required maintenance dialysis.

Conclusions

Hemodiafiltration with ultrafiltrate regeneration reduces FLC levels without producing a significant loss of albumin; and, FLC removal is maintained throughout the session. Therefore, hemodiafiltration with ultrafiltrate regeneration may be considered an effective adjunctive therapy in patients with MM.

The Emerging Role of Innate Immunity in Chronic Kidney Diseases

Renal fibrosis is a common fate of chronic kidney diseases. Emerging studies suggest that unsolved inflammation will progressively transit into tissue fibrosis that finally results in an irreversible end-stage renal disease (ESRD). Renal inflammation recruits and activates immunocytes, which largely promotes tissue scarring of the diseased kidney. Importantly, studies have suggested a crucial role of innate immunity in the pathologic basis of kidney diseases. This review provides an update of both clinical and experimental information, focused on how innate immune signaling contributes to renal fibrogenesis. A better understanding of the underlying mechanisms may uncover a novel therapeutic strategy for ESRD.

Toxicity and survival outcomes of autologous stem cell transplant in multiple myeloma patients with renal insufficiency: an institutional comparison between two eras

Autologous stem cell transplant (ASCT) is a feasible treatment option for multiple myeloma (MM) patients with renal insufficiency; however, these patients tend to experience higher rates of drug toxicity and transplant-related mortality (TRM) during ASCT. Recent adoption of bortezomib-based induction regimens and dose reduction of melphalan during conditioning may improve outcomes in this population. In this single center retrospective study, we compared the toxicity and survival outcomes of 96 MM patients with renal insufficiency undergoing ASCT between two eras: 1998-2007 and 2008-2016. The proportion of dialysis dependent patients was similar in both groups (49 and 45%). We found no TRM in those transplanted more recently as compared with 13% in the older era of ASCT. There were significantly more high grade (grades 3-4) toxicities in the older era of ASCT including high grade electrolyte abnormalities, mucositis, delirium, and bleeding. Patients transplanted more recently had significantly higher overall response rate (ORR) as well as deeper responses to ASCT (≥VGPR in 79% vs 39%). Progression-free survival (PFS) was prolonged by 26 months in the more recent era compared with the older era. Overall, improvements in treatment regimens have resulted in reduced TRM and toxicities for patients with renal insufficiency undergoing ASCT.

Renal Dysfunction and Recovery following Initial Treatment of Newly Diagnosed Multiple Myeloma

Introduction

Renal insufficiency (RI) in Multiple Myeloma (MM) portends a higher tumor burden and worse prognosis. Reversal of RI in newly diagnosed MM (NDMM) improves patient outcomes, but it is unknown if there is a disparity in renal recovery in NDMM between African Americans (AA) and non-African Americans.

Methods

A retrospective chart review was conducted of 690 patients with NDMM at Rush University Medical Center from 2005 to 2016. 118 patients (59 AA and 59 non-AA) with NDMM and an estimated glomerular filtration rate (eGFR) < 90 mL/min/1.73 m² at the time of diagnosis were identified and analyzed. The time to best renal response and best eGFR achieved during initial myeloma therapy were tabulated.

Results

Median eGFR at the time of diagnosis was similar between the AA and non-AA groups (47.89 versus 51.95, p=0.56). Median absolute change in eGFR after initial therapy was significantly higher in the AA (+33.64) versus the non-AA group (+21.07, p=0.00183). This difference remained whether the baseline eGFR at diagnosis was <90 or <60 mL/min/1.73 m².

Discussion

AA patients with NDMM treated in the era of novel agents have greater improvement in renal function in comparison to non-AA patients, regardless of myeloma response. The biological underpinnings for this disparity require further investigation.

Bortezomib overcomes the negative prognostic impact of renal impairment in a newly diagnosed elderly patient with multiple myeloma: A case report

Multiple myeloma (MM) is a common B-cell hematological malignancy in the clinic. Bortezomib is the first-in-class proteasome inhibitor that has been approved for the treatment of patients with MM in the bone marrow. The present study report the case of an 83-year-old man who showed marked weakness, fatigue and a poor appetite. The patient was admitted to the Department of Nephrology due to severe renal impairment (RI). Immunofixation electrophoresis indicated a λ light chain-positive status. There were 19.2% plasmablasts and proplasmacytes in the bone marrow. Positivity for the cell surface markers cluster of differentiation (CD)13, CD33, CD38 and human leukocyte antigen-antigen D-related was detected by flow cytometry. The patient was diagnosed with MM, λ light chain type, stage IIIB, and received bortezomib and dexamethasone regimen chemotherapy. RI was improved following the chemotherapy, and plasmablasts and proplasmacytes were almost eliminated. The Hb level was maintained at ~90 g/l. Overall, the present case report suggests that bortezomib may be safe and effective for elderly patients, even those >80 years of age, with severe RI.

Safety Outcomes for Autologous Stem Cell Transplant in Multiple Myeloma

Systems have been put in place in the Mayo Clinic Stem Cell Transplantation program to reduce day-100 all-cause mortality. Currently our mortality has been reduced to 0.3%. Patients can undergo transplant as an outpatient, with a median hospital duration of 0 days and only 25% of patients requiring a hospital stay of 5 days or greater. Outpatient transplantation is safe and reduces patient-incurred costs.

Lenalidomide is effective and safe for the treatment of patients with relapsed multiple myeloma and very severe renal impairment

Patients with multiple myeloma (MM) and severe renal impairment (SRI) have shorter survival than MM patients without renal failure. Although lenalidomide is a highly active drug, this immunomodulatory agent is frequently neglected in this context due to its predominant renal clearance and, consequently, an increased risk of toxicity. This risk might be overcome with the proper lenalidomide dose adjustment to renal function. This study evaluates the outcomes of 23 relapsed MM patients with SRI (baseline creatinine clearance (CrCl) <30 mL/min) treated with lenalidomide-dexamethasone (LenDex), including 56 % (13 patients) under hemodialysis. The median CrCl at start of LenDex was 19 mL/min; an overall response rate (partial response or better) of 56 % was obtained, with a median follow-up from start of LenDex of 52 months (8-79). The median time until maximal response was 4 months, and in 58 % (7/12), the response was longer than 2 years. Nine percent had renal improvement, but all the 13 patients on hemodialysis remained under treatment. LenDex was interrupted in three cases because of adverse events (infections and cutaneous events); 78 % of the patients were on thromboprophylaxis with aspirin. It is important to notice that, after initial dose adjustment of therapy, there should be a continuous process of dose adjustment, taking into account variations in renal function. Furthermore, lenalidomide dose adjustment should be made according to the individual tolerance, even with stable renal function. LenDex dose adjustment, according to these principles, does not negatively impact response and improves treatment tolerance. It has a clear potential to treat this group of patients and to induce long duration of responses [event-free survival (EFS) 20.5 m and overall survival (OS) 42.6 m].

Immunosuppressive Medications

Immunosuppressive agents are commonly used in the nephrologist's practice in the treatment of autoimmune and immune-mediated diseases and transplantation, and they are investigational in the treatment of AKI and ESRD. Drug development has been rapid over the past decades as mechanisms of the immune response have been better defined both by serendipity (the discovery of agents with immunosuppressive activity that led to greater understanding of the immune response) and through mechanistic study (the study of immune deficiencies and autoimmune diseases and the critical pathways or mutations that contribute to disease). Toxicities of early immunosuppressive agents, such as corticosteroids, azathioprine, and cyclophosphamide, stimulated intense investigation for agents with more specificity and less harmful effects. Because the mechanisms of the immune response were better delineated over the past 30 years, this specialty is now bestowed with a multitude of therapeutic options that have reduced rejection rates and improved graft survival in kidney transplantation, provided alternatives to cytotoxic therapy in immune-mediated diseases, and opened new opportunities for intervention in diseases both common (AKI) and rare (atypical hemolytic syndrome). Rather than summarizing clinical indications and clinical trials for all currently available immunosuppressive medications, the purpose of this review is to place these agents into mechanistic context together with a brief discussion of unique features of development and use that are of interest to the nephrologist.

Bortezomib-based therapy combined with high cut-off hemodialysis is highly effective in newly diagnosed multiple myeloma patients with severe renal impairment

Multiple myeloma (MM) is often associated with renal insufficiency (RI) which adversely influences the prognosis. Several studies demonstrated that bortezomib can improve both renal function and outcome. We prospectively evaluated 21 newly diagnosed MM patients with severe renal impairment secondary to tubular-interstitial damage, most of them due to myeloma kidney, who were primarily treated with bortezomib-based therapy combined with high cut-off hemodialysis (HCOD). The median serum creatinine level at baseline was 6.44 mg dL(-1) and calculated median estimated glomerular filtration rate (eGFR), according to Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) creatinine equation, was 8 mL/min/1.73 m(2) . Serum free light chain (sFLC) median concentration was 6,040 mg L(-1) . Post induction and best stringent complete response rates were 19 and 38%, respectively. Responses were fast, occurring within a median of 1.4 months. The combination of bortezomib and HCOD led to a prompt and remarkable (>90%) decrease in sFLC levels. Sixteen patients (76%) became dialysis independent within a median of 32 days. With a median follow up of 17.2 months, the 3-year PFS and OS were 76 and 67%, respectively. No early deaths were observed. This study demonstrates that incorporation of bortezomib into induction therapy combined with HCOD is a highly effective strategy in rescuing renal function and improving outcomes in patients with MM and RI.

Prognostic Significance of Initial Serum Albumin and 24 Hour Daily Protein Excretion before Treatment in Multiple Myeloma

Renal failure is a common morbidity in multiple myeloma (MM). Although proteinuria has been increasingly reported in malignancies, it is not routinely used to refine risk estimates of survival outcomes in patients with MM. Here we aimed to investigate initial serum albumin and 24-hour daily protein excretion (24-h DPE) before treatment as prognostic factors in patients with MM. We conducted a retrospective analysis of 102 patients with myeloma who were ineligible for haematopoietic stem cell transplantation between October 2000 and December 2012. Initial proteinuria was assessed before treatment by quantitative analysis of 24-hour urine samples. The demographic and laboratory characteristics, survival outcome, and significance of pre-treatment 24-h DPE and albumin in the new staging system of MM were analyzed. Pre-treatment proteinuria (>300 mg/day) was present in 66 patients (64.7%). The optimal cut-off value of 24-h DPE before treatment was 500 mg/day. Analysis of the time-dependent area under the curve showed that the serum albumin and 24-h DPE before treatment were better than 24-h creatinine clearance rate and β2-microglobulin. A subgroup analysis showed that an initial excess proteinuria (24-h DPE ≥ 500 mg) was associated with poor survival status (17.51 vs. 34.24 months, p = 0.002). Furthermore, initial serum albumin was an independent risk factor on multivariate analysis (<2.8 vs. ≥ 2.8, hazard ratio = 0.486, p = 0.029). Using the A-DPE staging system, there was a significant survival difference among patients with stage I, II, and III MM (p < 0.001). Initial serum albumin and 24-h DPE before treatment showed significant prognostic factors in patients with MM, and the new A-DPE staging system may be utilized instead of the International Staging System. Its efficacy should be evaluated by further large prospective studies.

Percentage of urinary albumin excretion and serum-free light-chain reduction are important determinants of renal response in myeloma patients with moderate to severe renal impairment

Reversal of renal dysfunction significantly affects the prognosis of multiple myeloma (MM) with renal impairment (RI). There is no reliable test for predicting reversibility of RI in MM patients. We postulated that MM with high albuminuria may reflect glomerular disease that is difficult to reverse. Here, we examined the impact of urinary albumin excretion. We retrospectively analyzed 279 patients admitted to our hospital from April 2000 to December 2013. Clinical variables and laboratory data that may affect myeloma treatment response were extracted. The results were examined for relationship to renal response by univariate and multivariate analysis. RI (estimated glomerular filtration rate ≦50 ml/min per 1.73 m(2)) was observed in 116 patients (46%) and renal responses of renal complete response, renal partial response, renal minor response and no response were obtained in 46 (40%), 15 (13%), 13 (11%) and 42 (36%) patients, respectively. Although renal recovery was significantly associated with Durie-Salmon 1 or 2 (P=0.02), myeloma response better than very good partial response (P=0.03), involved free light-chain (iFLC) reduction from baseline 80% at day 12 (P=0.005), ≧95% at day 21 (P<0.001) and urinary albumin ≦25% on admission (P<0.001) on univariate analysis, only reduction of iFLC 95% at day 21 (P=0.015) and urinary albumin ≦25% (P=0.007) remained significant for any renal response. Our observation indicates that increased urinary albumin excretion >25% and reduction of iFLC ≦95% on day 21 were associated with favorable renal recovery in MM patients with RI, and were considered as negative predictors for renal response.

Case report on renal failure reversal in lambda chain multiple myeloma with bortezomib and dexamethasone

Renal failure (RF) reversal in multiple myeloma (MM) is associated with an improved prognosis. Light chain myeloma, serum creatinine (SCr) > 4 mg/dL, extensive proteinuria, early infections, and certain renal biopsy findings are associated with lower rates of RF reversal. Our patient is a 67-year-old female with multiple poor prognostic factors for RF reversal who demonstrated a rapid renal response with bortezomib and dexamethasone (BD) regimen. She presented initially with altered mental status. On exam, she appeared lethargic and dehydrated and had generalized tenderness. She had been taking ibuprofen as needed for pain for a few weeks. Labs showed a white cell count—18,900/μL with no bandemia, hemoglobin 10.8 gm/dL, potassium—6.7 mEq/L, bicarbonate—15 mEq/L, blood urea nitrogen—62 mg/dL, SCr—5.6 mg/dL (baseline: 1.10), and corrected calcium—11.8 mg/dL. A rapid flu test was positive. Imaging studies were unremarkable. Her EKG showed sinus tachycardia and her urinalysis was unremarkable. The unexplained RF in an elderly individual in conjunction with hypercalcemia and anemia prompted a MM work-up; eventually, lambda variant MM was diagnosed. An immediate (4 days) renal response defined as 50% reduction in SCr was noticed after initiation of the BD regimen.

Plasmablastic myeloma presenting as rapidly progressive renal failure in a young adult

Multiple myeloma (MM) is a condition where there is malignant proliferation of plasma cells. There is a strong correlation with age, peaking at 60-70 years. The clinical course in adolescents and young individuals is generally indolent and the survival is longer. We report a case of a 28-year-old male, who was diagnosed to have plasmablastic myeloma, an atypical variant of MM with a poor prognosis, presenting as rapidly progressive renal failure. He was given induction chemotherapy and then underwent autologous peripheral blood stem cell transplantation.

Bortezomib before and after autologous stem cell transplantation overcomes the negative prognostic impact of renal impairment in newly diagnosed multiple myeloma: a subgroup analysis from the HOVON-65/GMMG-HD4 trial

Renal impairment is frequent in patients with multiple myeloma and is correlated with an inferior prognosis. This analysis evaluates the prognostic role of renal impairment in patients with myeloma treated with bortezomib before and after autologous stem cell transplantation within a prospective randomized phase III trial. Eight hundred and twenty-seven newly diagnosed myeloma patients in the HOVON-65/GMMG-HD4 trial were randomized to receive three cycles of vincristine, adriamycin, dexamethasone (VAD) or bortezomib, adriamycin, dexamethasone (PAD) followed by autologous stem cell transplantation and maintenance with thalidomide 50 mg daily (VAD-arm) or bortezomib 1.3 mg/m(2) every 2 weeks (PAD-arm). Baseline serum creatinine was less than 2 mg/dL (Durie-Salmon-stage A) in 746 patients and 2 mg/dL or higher (stage B) in 81. In myeloma patients with a baseline creatinine ≥ 2 mg/dL the renal response rate was 63% in the VAD-arm and 81% in the PAD-arm (P=0.31). The overall myeloma response rate was 64% in the VAD-arm versus 89% in the PAD-arm with 13% complete responses in the VAD-arm versus 36% in the PAD-arm (P=0.01). Overall survival at 3 years for patients with a baseline creatinine ≥ 2 mg/dL was 34% in the VAD-arm versus 74% in the PAD-arm (P<0.001) with a progression-free survival rate at 3 years of 16% in the VAD-arm versus 48% in the PAD-arm (P=0.004). Overall and progression-free survival rates in the PAD-arm were similar in patients with a baseline creatinine ≥ 2 mg/dL or <2 mg/dL. We conclude that a bortezomib-containing treatment before and after autologous stem cell transplantation overcomes the negative prognostic impact of renal impairment in patients with newly diagnosed multiple myeloma. The trial was registered at www.trialregister.nl as NTR213 and at www.controlled-trials.com as ISRCTN 64455289.

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.

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.