Multiple myeloma with acute light chain cast nephropathy

A rare case of IgA lambda multiple myeloma in a 32-year-old woman with t(14;16) translocation associated with kidney injury and non-albumin proteinuria

BACKGROUND

Multiple myeloma (MM) is a malignant disorder characterized by monoclonal differentiated plasma cells. While it is more commonly diagnosed in elderly individuals, it can also affect younger populations, though with a lower incidence.

CASE PRESENTATION

Here, we present the case of a 32-year-old woman diagnosed with IgA lambda MM. She presented with fatigue, nausea, acute kidney injury (AKI) with a rapid increase in creatinine, and anemia. A kidney biopsy was done to rule out a rapidly progressive glomerular disease and a diagnosis was thus reached. A genetic workup revealed t(14;16) translocation and an extra copy of TP53. The patient received aggressive intravenous steroids and intravenous fluid resuscitation, resulting in an improvement in renal function. Treatment with daratumumab in combination with bortezomib, thalidomide, and dexamethasone was initiated and well tolerated. Despite the generally poor prognosis of IgA MM, our case emphasizes the importance of considering MM in young patients with unexplained kidney injury.

CONCLUSION

Early recognition and prompt intervention are essential in managing MM patients, especially in those with high-risk cytogenetic abnormalities. This case serves as a reminder for clinicians to maintain a high index of suspicion for MM, even in younger populations, when presented with unexplained kidney injury.

The Urine Light Chain/eGFR Quotient as a Tool to Rule out Cast Nephropathy in Myeloma-Associated Kidney Failure

Kidney involvement with resulting kidney failure leads to increased mortality in patients with multiple myeloma (MM). Cast nephropathy (CN), in particular, if left untreated, quickly leads to kidney failure requiring dialysis and has a very poor prognosis for the affected patient. The gold standard for diagnosing kidney involvement is a kidney biopsy. However, due to bleeding risk, this cannot be done in every patient. We recently reported that a quotient of urine light chain (LCurine) to glomerular filtration rate (eGFR) is a non-invasive diagnostic tool for patients with kidney involvement in MM. But this quotient has not yet been tested in everyday clinical practice. In this study, our LCurine/eGFR ratio was tested on 67 patients in two centers. Enrollment took place between January 2019 and September 2023. A total of 18 of the 67 patients had CN. With the threshold defined in our initial paper, we were able to show a sensitivity of 100% with a specificity of 85.7% for CN in patients with MM. As a result, the LCurine/eGFR quotient recognizes 100% of all CN and can therefore detect this group, which has a very poor prognosis, without the need for a kidney biopsy.

Monoclonal immunoglobulin crystalline nephropathies

Monoclonal Ig crystalline nephropathies are rare lesions resulting from precipitation of monoclonal Igs in the kidney as crystalline inclusions. They can be categorized into lesions with predominant intracellular crystals (light chain [LC] proximal tubulopathy, LC crystal-storing histiocytosis, and LC crystalline podocytopathy) and lesions with predominant extracellular crystals (crystalglobulin-induced nephropathy and crystalline variant of LC cast nephropathy). The majority of these lesions are associated with low tumor burden lymphoproliferative disorders, with the exception of crystalline variant of LC cast nephropathy. Extrarenal involvement (e.g., skin and cornea) is frequent. Kidney biopsy is the cornerstone for diagnosis, which often requires electron microscopy and antigen retrieval. A thorough hematologic workup and evaluation of extrarenal involvement is mandatory for management. Treatment of these lesions is with clone-directed therapy, with the goal of achieving hematologic very good partial response or complete response, which preserves or improves kidney function. In vitro and in vivo studies, animal models, and novel sequencing techniques have been invaluable tools to understand the pathogenesis of LC proximal tubulopathy and can be used to increase our limited knowledge of the pathogenesis of the other monoclonal Ig crystalline nephropathies. This review provides an update on the pathology, renal and hematologic characteristics, extrarenal manifestations, prognosis, treatment, and pathogenesis of monoclonal Ig crystalline nephropathies.

Serum Free Light Chain Kinetics Is Predictive of Renal Response in Myeloma Patients With Renal Impairment-An ALLG Trial of Carfilzomib-Dexamethasone Therapy in Frontline and Relapse

BACKGROUND AND PURPOSE

Renal impairment (RI) confers adverse prognosis in myeloma; its reversal and avoidance of dialysis are crucial. We investigated whether serum free light chain (SFLC) measurements can predict renal outcome, to enable change in therapy to optimize prognosis and avoid dialysis.

PATIENTS AND METHODS

We investigated 36 myeloma patients (17 newly diagnosed [ND]; 19 relapsed refractory [RR]; with median of 5 prior lines) with eGFR 15-40 ml/min treated with carfilzomib (Cfz)-dexamethasone to determine whether SFLC kinetics can predict renal outcomes, and assess efficacy and tolerability.

RESULTS

The change in involved SFLC at Cycle 2 Day 1 was significantly correlated with renal function; for every one log10 reduction in involved SFLC, eGFR increased by 9.0-15.0 mL/min at cycles 2-4, with SFLC reduction of 54%-78%. At a median follow-up of 30.6 months, renal outcomes were favorable-CRrenal 25%, MRrenal 36%. Disease responses (ND 100%, RR 75%), progression-free survival (ND 32.2 months, RR 11.1 months) and overall survival (ND not reached, RR 42.0 months) were comparable to patients without RI. There was significant toxicity, including Cfz-related cardiac impairment of 20% within a cohort with high co-morbidity, and a high incidence of infections.

CONCLUSION

We propose that one log10 reduction in involved SFLC at Cycle 2 Day 1 is an appropriate target for reducing the risk of dialysis in myeloma patients with RI; below this threshold patients may benefit from a change in therapy. While Cfz-dexamethasone achieved favorable renal and disease outcomes, toxicity can be significant in this vulnerable cohort.

Multiple Myeloma as a Potential Cause of Low Complements in Patients With Acute Kidney Injury

Multiple myeloma (MM) is a plasma cell malignancy belonging to the class of monoclonal gammopathies that leads to end-organ damage myeloma events that encompass anemia, the presence of lytic bone lesions, hypercalcemia, and renal insufficiency. However, there are very few reported cases of patients with low complements in the context of MM and renal failure. Traditionally, low complements in glomerular disease are associated with conditions such as membranoproliferative glomerulonephritis, cryoglobulinemia, systemic lupus erythematous, and post-infectious glomerulonephritis. Despite its rarity, physicians should maintain a high degree of suspicion and consider MM as a potential cause of low complements in patients with renal injury. In this case report, we present a patient with a history of MM associated with acute kidney injury with hypocomplementemia, an atypical presentation of myeloma in MM.

The role of therapeutic plasma exchange in plasma cell disorders

Therapeutic plasma exchange (TPE) is an extracorporeal technique where patient's plasma containing pathogenic substances is separated and removed from the whole blood, while the cellular component is returned to the patient mixed with replacement solution via an apheresis machine. Due to its ability to remove pathogenic substances from plasma including immunoglobulins, TPE has proven efficacious in the management of various disorders across different medical disciplines, including plasma cell dyscrasias, which are characterized by the abundant secretion of non-functional immunoglobulins produced by an abnormally proliferating plasma cell clone. This review summarizes the current indications of TPE in plasma cell-related disorders and discusses its application, safety, and therapeutic effects.

Pharmacotherapy considerations in patients who develop acute kidney injury during anti-cancer therapy

INTRODUCTION

Acute kidney injury (AKI) frequently develops in patients receiving cancer therapy and requires a wide differential diagnosis due to possible role of unique cancer and drug-related factors, in addition to common pre- and post-renal causes. Rapid development of new molecular targeted anti-cancer drugs and immunotherapies has opened unprecedented possibilities of treatment at the price of an increased spectrum of renal side effects.

AREAS COVERED

The present review aims at providing a state-of-the-art picture of AKI in cancer patient (PubMed and Embase libraries were searched from inception to January 2024), with a focus on differential diagnosis and management of diverse clinical settings. Reports of parenchymal AKI due to glomerular, microvascular, tubular and interstitial damage have been constantly increasing. Complex electrolyte and acid-base disorders can coexist. The role of renal biopsy and possible therapeutic approaches are also discussed.

EXPERT OPINION

Onconephrology has become an important subspecialty of clinical nephrology, requiring constantly updated skills and a high degree of interdisciplinary integration to tackle diagnostic challenges and even therapeutic and ethical dilemmas. Integrated onconephrological guidelines and availability of biomarkers may provide new tools for management of this unique type of patients in the near future.

Unusual Coincidence: Concurrent Cast Nephropathy and Lymphoma Infiltration in an Influenza A-Associated Acute Kidney Injury

Acute kidney injury (AKI) poses a substantial challenge in the management of lymphoma patients and is frequently associated with diverse causative factors. Herein, we report an illustrative case involving a 47-year-old male with influenza A infection who developed severe AKI, which was incongruent with his medical history. Laboratory investigations disclosed aberrant immunoglobulin levels and urinary protein excretion, prompting further evaluation. A renal biopsy revealed the presence of infiltrating lymphoid cells and cast nephropathy, raising suspicion of an underlying hematological disorder. A comprehensive diagnostic workup, including positron emission tomography imaging and bone marrow biopsy, culminated in the definitive diagnosis of splenic marginal zone lymphoma. This case highlights the crucial significance of including lymphoma-associated kidney disorders in the evaluation of unexplained AKI, particularly when encountering unconventional clinical and laboratory results. Swift and precise intervention is of utmost importance in attaining positive results in these rare and complex clinical situations. This study underscores the persistent concern of AKI in lymphoma patients, with lymphocytic infiltration and cast nephropathy as notable elements contributing to the intricate nature of this condition.