Renal outcome in multiple myeloma patients with cast nephropathy: a retrospective analysis of potential predictive values on clinical and renal outcome

OBJECTIVE

Cast nephropathy (CN) is the leading cause of acute kidney injury (AKI) in multiple myeloma (MM). Since it is sparsely documented why some patients with CN do achieve a renal response while others do not, we describe a single-center cohort of patients with multiple myeloma and biopsy-confirmed CN to evaluate potential markers of renal response.

METHODS

The data was collected as a retrospective, single-center analysis of CN-patients treated at the Medical University Vienna between 01/01/2004 and 01/01/2022. Baseline parameters and clinical outcome was compared between renal responders and non-responders.

RESULTS

Among 28 patients with CN, n = 23 were assessed for renal response (14 responders; 9 non-responders). Renal responders were younger (median age: 61 years; 77 years, p = 0.039), showed higher overall survival (153months; 58months, p = 0.044) and achieved hematologic response (≥PR) to first-line therapy (p = 0.029), and complete hematologic response (CR) at any time (p = 0.025) significantly more often. Further, we could show that rapid initiation of anti-myeloma therapy after initial presentation correlated significantly with renal response (median 9 days; 27 days, p = 0.016). Analyses of kidney biopsy specimens revealed that patients with a high IF/TA score showed end stage renal disease (dialysis ≥ 3 months) significantly more often (p = <0.001).

DISCUSSION

In summary, our data suggests, that a rapid start with systemic hematologic treatment in patients with MM and CN is crucial and achieving an early hematologic response is important for renal recovery. Moreover, achieving a deep hematologic response and subsequent renal recovery improves clinical outcome as reflected by an overall survival benefit.

Rituximab as add-on therapy in patients with resistant lupus nephritis who have failed induction or maintenance therapy with other agents: A real-world experience from a single center in Mumbai

BACKGROUND

Lupus nephritis (LN) is associated with poor outcomes and a significant risk of progression to end-stage renal disease (ESRD). Some patients with resistant LN do not respond adequately to current treatment options and need alternative strategies or therapies.

OBJECTIVE

The objective is to evaluate the efficacy and safety of rituximab as a re-induction therapy (Re-RTX) followed by maintenance therapy for patients with resistant LN.

METHODS

Twenty-four patients with resistant LN (failed initial induction therapy or severe relapse after remission) were analyzed. Re-RTX was co-administered with other immunosuppressants. The primary KDIGO criteria outcomes included renal response (complete and partial), disease progression, relapses, and infections.

RESULTS

The median age was 28 years (IQR 24.5-42), and the female-to-male ratio was 11:1. All patients had active LN, and 91.3% had proliferative LN. Baseline creatinine was 1.075 mg% (IQR 0.7-1.38), and mean urine protein-to-creatinine ratio (UPCR) was 4.9 (IQR 2.8-6.65). Of the patients receiving RTX as re-induction therapy, 66.6% (16/24) had failed initial induction therapy with other immunosuppressants, whereas 33.3% (8/24) had severe relapse during maintenance therapy.Re-RTX had a favorable renal response at 6 months, with 91.7% of the patients responding (20.8% complete response and 70.8% partial response). At 12 months, 58.3% of the patients maintained a renal response (25% complete response and 33.3% partial response). Approximately one-third of patients relapsed within a year.Fourteen patients (58.3%) continued RTX maintenance therapy with two different treatment regimens. At 6 months, Regimen-1 (500 mg every 6 months) resulted in a partial response in 43% (3/7) and relapse in 57% (4/7) of patients. Regimen 2 (1 g dose per year) achieved a complete response in 28.5% (2/7) and a partial response in 71.5% (5/7) with no relapses at 6 months.At a median follow-up of 29 months, adverse renal outcomes were observed in 29.16% of the patients with progression to advanced chronic kidney disease (CKD) or end-stage renal disease (ESRD). The overall use of Re-RTX was considered safe, with a reported infection prevalence of 16%, which is comparable to the existing data.

CONCLUSION

Re-RTX demonstrated efficacy and safety as an induction therapy for resistant LN. However, the response waned after 1 year, underscoring the need for optimized maintenance therapy.

Characterization of Serum Cytokine Profiles of Patients with Active Lupus Nephritis

Cytokines contribute to the pathogenesis of lupus nephritis (LN), yet their value as prognostic biomarkers is still debated. We aimed to describe the serum cytokines' profiles and prospectively assess correlations with disease features and renal response in a multicentric cohort of consecutive adult patients with biopsy-proven active LN. Cytokine associations with clinical and serological data were performed at LN diagnosis (T0), and at 3 (T3) and 6 months (T6) of follow up. Renal response according to EULAR definition was assessed at T3, T6 and T12. BAFF and interleukin (IL)-37 were measured by ELISA; IL-2, IL-10, IL-17A and IL-18 by a bead-based multiplex cytokine assay (Luminex). Thirty-nine patients with active LN (age 40.5 ± 15.6 years; F 71.8%; 84.6% proliferative LN) were enrolled, of whom twenty-nine displayed complete longitudinal records. At T0, we observed higher levels of IL-37 and IL-17 in proliferative vs. non-proliferative LN (IL-37: 0.0510 (0.0110-0.2300) vs. 0.0000 (0.0000-0.0397) ng/mL, p = 0.0441; IL-17: 2.0920 (0.5125-17.9400) vs. 0.0000 (0.0000-0.6025) pg/mL, p = 0.0026, respectively), and positive correlations between IL-10 and 24 h proteinuria (r = 0.416, p = 0.0249) and anti-dsDNA levels (r = 0.639, p = 0.0003). BAFF was higher in patients with low complement (p < 0.0001). We observed a sustained correlation between BAFF and IL-10 throughout T6 (r = 0.654, p = 0.0210). Higher baseline IL-37 and BAFF levels were associated with renal response at T3 and T6, respectively, while baseline IL-18 levels were higher in patients achieving response at T12. Our study highlights the complexity of the cytokine network and its potential value as a marker of active LN and renal response.

Challenges of defining renal response in ANCA-associated vasculitis: call to action?

Avoiding end-stage kidney disease in patients with anti-neutrophil cytoplasmic antibody-associated vasculitis (AAV) has a high therapeutic priority. Although renal response is a crucial measure to capture clinically relevant changes, clinal trials have used various definitions and no well-studied key surrogate markers to predict renal outcome in AAV exist. Differences in clinical features and histopathologic and therapeutic approaches will influence the course of kidney function. Its assessment through traditional surrogates (i.e. serum creatinine, glomerular filtration rate, proteinuria, hematuria and disease activity scores) has limitations. Refinement of these markers and the incorporation of novel approaches such as the assessment of histopathological changes using cutting-edge molecular and machine learning mechanisms or new biomarkers could significantly improve prognostication. The timing is favourable since large datasets of trials conducted in AAV are available and provide a valuable resource to establish renal surrogate markers and, likely, aim to investigate optimized and tailored treatment approaches according to a renal response score. In this review we discuss important points missed in the assessment of kidney function in patients with AAV and point towards the importance of defining renal response and clinically important short- and long-term predictors of renal outcome.

Severe renal impairment as an adverse prognostic factor for survival in newly diagnosed multiple myeloma patients

Background

Renal impairment (RI) is associated with poor survival in newly diagnosed multiple myeloma (MM) patients. Renal function recovery has been one of the main therapeutic goals in those patients.

Methods

The records from 393 newly diagnosed MM patients in our hospital between January 2012 and December 2016 were retrospectively analyzed. RI was defined as an eGFR < 40 mL/min according to the novel IMWG criteria. RI patients were categorized based on their renal function at diagnosis: severe RI: eGFR < 30 mL/min, and mild RI: 30 mL/min ≤ eGFR <40 mL/min. We explored whether RI, and particularly severe RI, was an adverse prognostic factor for survival, and investigated the impact of renal function recovery on survival.

Results

Severe RI, hemoglobin <100 g/L, LDH ≥ 245 U/L, hyperuricemia, 1q21 amplification, and lack of novel agent treatment were associated with decreased overall survival (OS). Severe RI patients with renal response had a median OS of 27 months compared with 18 months for those patients without renal response (P = .030), but their median OS was still significantly lower than that for patients without severe RI, which was 51 months. In severe RI patients, the overall renal response rate in bortezomib‐based regimens was significantly higher than that in nonbortezomib‐based regimens.

Conclusion

Our results suggest that severe RI is an adverse prognostic factor for survival in newly diagnosed MM patients, restoration of renal function may improve survival, and bortezomib‐based regimens may be the preferred treatment in patients with severe RI.

Peripheral Blood B Cell Depletion after Rituximab and Complete Response in Lupus Nephritis

BACKGROUND AND OBJECTIVES

Incomplete peripheral blood B cell depletion after rituximab in lupus nephritis might correlate with inability to reduce tubulointerstitial lymphoid aggregates in the kidney, which together could be responsible for inadequate response to treatment. We utilized data from the Lupus Nephritis Assessment with Rituximab (LUNAR) study to characterize the variability of peripheral blood B cell depletion after rituximab and assess its association with complete response in patients with lupus nephritis.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

We analyzed 68 participants treated with rituximab. Peripheral blood B cell depletion was defined as 0 cells/µl, termed "complete peripheral depletion," assessed over 78 weeks. Logistic regression was used to estimate the association between characteristics of complete peripheral depletion and complete response (defined as urine protein-to-creatinine ratio <0.5 mg/mg, and normal serum creatinine or an increase in creatinine <15%, if normal at baseline), assessed at week 78.

RESULTS

A total of 53 (78%) participants achieved complete peripheral depletion (0 cells/µl) in a median time of 182 days (interquartile range, 80-339).The median duration of complete peripheral depletion was 71 days (interquartile range, 14-158). Twenty-five (47%) participants with complete peripheral depletion achieved complete response, compared with two (13%) without. Complete peripheral depletion was associated with complete response (unadjusted odds ratio [OR], 5.8; 95% confidence interval [95% CI], 1.2 to 28; P=0.03). Longer time to achieving complete peripheral depletion was associated with a lower likelihood of complete response (unadjusted OR, 0.89; 95% CI, 0.81 to 0.98; P=0.02). Complete peripheral depletion lasting >71 days (the median) was associated with complete response (unadjusted OR, 4.1; 95% CI, 1.5 to 11; P=0.008).

CONCLUSIONS

There was substantial variability in peripheral blood B cell depletion in patients with lupus nephritis treated with rituximab from the LUNAR trial. Achievement of complete peripheral depletion, as well as the rapidity and duration of complete peripheral depletion, were associated with complete response at week 78.

PODCAST

This article contains a podcast at https://www.asn-online.org/media/podcast/CJASN/2018_09_06_CJASNPodcast_18_10_.mp3.

Intensive haemodialysis using PMMA dialyser does not increase renal response rate in multiple myeloma patients with acute kidney injury

Background

Intensive haemodialysis (IHD) in addition to bortezomib-based chemotherapy might be efficient to rapidly decrease serum immunoglobulin-free light chains removal in patients with multiple myeloma (MM) and to improve renal prognosis and survival.

Methods

The aim of this retrospective multi-centre study was to compare the efficacy (renal recovery rate) of IHD and of standard haemodialysis (SHD) in patients with MM and dialysis-dependent acute kidney injury (AKI), concomitantly treated with bortezomib-based chemotherapy.

Results

We selected 41 patients with MM and dialysis-dependent AKI, most likely due to myeloma cast nephropathy (MCN), and who were treated in eight French hospitals between January 2007 and June 2011. Patients were classified in two groups according to dialysis regimen: IHD [n = 21, with a mean of 11.3 dialysis sessions all with poly(methyl methacrylate) (PMMA) membranes for 13.2 days] and SHD (n = 20 patients, mostly three times per week, 31% with PMMA membrane). The main outcome was dialysis-independence at 3 months. At 3 months, 15 patients could stop dialysis: 8 (38.1%) in the IHD and 7 (35%) in the SHD group (P = 1). Moreover, 14 (56%) of the 25 patients who did show haematological response and only one of the 16 patients who did not were dialysis-independent (P = 0.002) at 3 months.

Conclusions

The results of this retrospective study did not show any clear renal benefit of IHD in patients with MM and MCN compared with SHD. Conversely, they underline the importance of the haematological response to chemotherapy for the renal response and patient prognosis.

Hematologic and renal improvement of monoclonal immunoglobulin deposition disease after treatment with bortezomib-based regimens

Monoclonal immunoglobulin deposition disease (MIDD) is characterized by non-organized immunoglobulin-fragments along renal basement membranes with subsequent organ deterioration. Treatment is directed against the immunoglobulin-producing clone. We treated 18 MIDD patients with bortezomib-based regimens (12 received bortezomib-dexamethasone, 6 bortezomib-dexamethasone with cyclophosphamide). Eleven (61%) patients achieved a hematologic response, but only 6 (33.3%) reached to a complete (CR) or very good partial response (VGPR). Regarding renal outcomes 77.8 and 55.6% had ≥30 and ≥50% reduction of proteinuria, respectively, but 33.3% ended up in end-stage renal disease (ESRD). Among patients with CR or VGPR, median eGFR improvement was 7.7 ml/min/1.73 m² and none progressed to ESRD, but no significant renal recovery was observed in patients achieving a partial response or less, with 50% progressing to dialysis. Pretreatment eGFR seems to influence renal prognosis. Bortezomib-based treatment is considered an effective approach in MIDD and reaching to a deep hematologic response (≥VGPR) conditionally controls further renal declining.

Kidney diseases associated with monoclonal immunoglobulin M-secreting B-cell lymphoproliferative disorders: a case series of 35 patients

BACKGROUND

Kidney diseases associated with immunoglobulin M (IgM) monoclonal gammopathy are poorly described, with few data for patient outcomes and renal response.

STUDY DESIGN

Case series.

SETTING & PARTICIPANTS

35 patients from 8 French departments of nephrology were retrospectively studied. Inclusion criteria were: (1) detectable serum monoclonal IgM, (2) estimated glomerular filtration rate (eGFR) < 60mL/min/1.73m(2) and/or proteinuria with protein excretion > 0.5g/d and/or microscopic hematuria, and (3) kidney biopsy showing monoclonal immunoglobulin deposits and/or lymphomatous B-cell renal infiltration. All patients received chemotherapy, including rituximab-based regimens in 8 cases.

PREDICTORS

Patients were classified into 3 groups according to renal pathology: glomerular AL amyloidosis (group 1; n=11), nonamyloid glomerulopathies (group 2; n=15, including 9 patients with membranoproliferative glomerulonephritis), and tubulointerstitial nephropathies (group 3; n=9, including cast nephropathy in 5, light-chain Fanconi syndrome in 3, and isolated tumor infiltration in 1).

OUTCOMES

Posttreatment hematologic response (≥50% reduction in serum monoclonal IgM and/or free light chain level) and renal response (≥50% reduction in 24-hour proteinuria or eGFR≥30mL/min/1.73m(2) in patients with glomerular and tubulointerstitial disorders, respectively).

RESULTS

Nephrotic syndrome was observed in 11 and 6 patients in groups 1 and 2, respectively. Patients in group 3 presented with acute kidney injury (n=7) and/or proximal tubular dysfunction (n=3). Waldenström macroglobulinemia was present in 26 patients (8, 12, and 6 in groups 1, 2, and 3, respectively). Significant lymphomatous interstitial infiltration was observed in 18 patients (4, 9, and 5 patients, respectively). Only 9 of 29 evaluable patients had systemic signs of symptomatic hematologic disease (2, 5, and 2, respectively). In groups 1, 2, and 3, respectively, hematologic response was achieved after first-line treatment in 3 of 9, 9 of 10, and 5 of 6 evaluable patients, while renal response occurred in 5 of 10, 9 of 15, and 5 of 8 evaluable patients.

LIMITATIONS

Retrospective study; insufficient population to establish the impact of chemotherapy.

CONCLUSIONS

IgM monoclonal gammopathy is associated with a wide spectrum of renal manifestations, with an under-recognized frequency of tubulointerstitial disorders.

Renal Insufficiency in newly-diagnosed multiple myeloma: analysis according to International Myeloma Working Group consensus statement

Renal impairment (RI) is one of the key clinical manifestations of symptomatic multiple myeloma. However, the incidence of RI and renal response to treatment are variable depending on their definition. A total of 379 patients newly-diagnosed and treated for symptomatic myeloma at the Samsung Medical Center between January 2000 and December 2011 were retrospectively reviewed. RI and renal response were assessed according to the recent International working group (IMWG) recommendations. Out of the 379 patients, renal insufficiency was present in 117 (30.8%) and was associated with adverse clinical parameters such as anemia, elevated beta-2 microglobulin (B2M), elevated lactate dehydrogenase (LDH), hypercalcemia, and more advanced disease by the International Staging System (ISS). Out of the 85 patients who were evaluable for renal response, 58 (68.2%) showed renal response and 46 (54%) had major renal response. Less advanced disease by the International Staging System and inclusion of high-dose dexamethasone as first-line treatment were independently predictive for major renal response. Median time-to-renal response was 5.5 months, and bortezomib-containing regimen, high-dose dexamethasone, and less advanced stage disease were associated with a more rapid renal response.

CONCLUSION

The incidence of RI in patients with newly-diagnosed multiple myeloma was 31%, and renal response was affected by the treatment and staging by the International Staging System.

The value of repeat kidney biopsy in quiescent Argentinian lupus nephritis patients

BACKGROUND

The duration of maintenance therapy after induction therapy for lupus nephritis has not been rigorously established. A common practice is to maintain immunosuppression for 1-2 years after complete remission, and longer for partial remission. The present work addresses whether a repeat kidney biopsy might be informative in deciding who should continue immunosuppression after complete or partial remission.

METHODS

The practice in a large Buenos Aires nephrology unit is to repeat a kidney biopsy before finalizing the decision to withdraw or continue immunosuppression. This work reports on a cohort of 25 Hispanic patients that had two or more kidney biopsies, the last occurring after at least 24 months of clinically quiescent disease.

RESULTS

Despite normalization of serum creatinine and reduction of proteinuria to <500 mg/d, 30% of patients still had significant activity at the last biopsy. Conversely, 60% of patients with ongoing proteinuria (500-1000 mg/d), or stable but abnormal serum creatinine, had no activity by biopsy. Univariate association analyses demonstrated that improvement in the activity index (AI) of the last biopsy was associated with choice of induction therapy (cyclophosphamide or mycophenolate), improvement in serum creatinine over the first six months of treatment, and improvement in complement component C4. By multivariate regression analyses, two AI prediction models emerged. Cyclophosphamide plus change in serum creatinine or cyclophosphamide plus change in C4 accounted for 50% of the improvement in AI.

CONCLUSION

These data suggest that a repeat biopsy may be useful in making the decision to withdraw or continue maintenance immunosuppression.