The pathogenesis of renal injury and treatment in light chain deposition disease

Light chain deposition disease: pathogenesis, clinical characteristics and treatment strategies

Light chain deposition disease (LCDD) is a rare hematologic disorder characterized by the deposition of non-amyloid monoclonal light chains in several organs. Together with renal impairment is being the primary morbidity associated with this disease. Due to its rarity, randomized clinical trials lack to explore treatment strategies and there are no approved or universally accepted standard of care treatment options. We aimed to provide a systematic summary of histological and clinical aspects of LCDD and treatment options of available literature therapies strategies. Currently, drugs used to treat multiple myeloma are recommended when LCDD patients also presented multiple myeloma. Anyway, in patients with LCDD that is not associated to multiple myeloma, haematopoietic stem cell transplantation (ASCT) and chemotherapy with thalidomide, dexamethasone, bortezomib are also recommended. In eligible patients, bortezomib-based chemotherapy followed by ASCT appears to be an effective treatment option with durable hematologic remission and organ responses. Although it appears that the patients undergoing ASCT seem to achieve deeper and durable hematologic remissions and organ responses, no statistically significant superiority can be demonstrated over non-transplant or standard chemotherapy-based approaches. As retrieved by our review, bortezomib-based therapy appears to be favorable strategy as long as no dose modification is required for renal impairment, and early hematologic responses as a recovery of renal function. Encouraging data were also demonstrated by treatment lenalidomide or melpalan based. Moreover, new myeloma treatment strategies, as monoclonal antibody Daratumumab, seem to be effective in LCDD. Instead, renal allograft is not recommended, due to high incidence of relapse.

Daratumumab treatment for kidney-involved light chain deposition disease prevents renal function progression: a case report with 3 years of follow-up and review of the literature

Light chain deposition disease (LCDD) is a clonal plasma cell disorder characterized by the deposition of nonamyloid monoclonal light chains in multiple organs. It can affect various systems throughout the body, mainly the kidneys. Symptoms may include renal insufficiency, proteinuria, hematuria, and others. Due to the lack of effective treatment, LCDD patients with kidney involvement often progress to chronic kidney failure, ultimately requiring renal replacement therapy. Daratumumab, an anti-CD38 monoclonal antibody, is primarily used for the treatment of relapsed and refractory multiple myeloma. Recent studies have shown that daratumumab also has an encouraging effect on light-chain amyloidosis. Here, we report the case of an LCDD (κ chain) patient with proteinuria, renal insufficiency, and anemia who was followed up for 3 years, during which he received daratumumab treatment. After the daratumumab treatment, the hematologic response continued progressing to a complete response without any adverse effects and continuous renal function improvement at a low serum free light chain (sFLC) level. This case shows that daratumumab is effective at treating LCDD. For LCDD patients with kidney involvement, frequent monitoring and active control of free light chain levels are necessary, as reaching the lowest sFLC of < 20 mg/L may help to improve kidney function.

Lambda Light Chain Cast Nephropathy Caused by Splenic Marginal Zone Lymphoma

We report an interesting case of an elderly male patient with splenic marginal zone lymphoma with a monoclonal cluster of differentiation (CD)5+ B cells. The patient developed signs of renal injury and was evaluated via serum protein electrophoresis and immunofixation electrophoresis, which revealed monoclonal gammopathy with elevated free lambda light chain. However, a bone biopsy ruled out a diagnosis of multiple myeloma. Upon renal biopsy, the patient was diagnosed with lambda light chain cast nephropathy. However, the patient's condition further deteriorated, and the patient eventually expired. This case highlights light chain cast nephropathy as a rare yet serious complication of lymphomas and, in particular, splenic marginal zone lymphoma.

Antibodies gone bad - the molecular mechanism of light chain amyloidosis

Light chain amyloidosis (AL) is a systemic disease in which abnormally proliferating plasma cells secrete large amounts of mutated antibody light chains (LCs) that eventually form fibrils. The fibrils are deposited in various organs, most often in the heart and kidney, and impair their function. The prognosis for patients diagnosed with AL is generally poor. The disease is set apart from other amyloidoses by the huge number of patient-specific mutations in the disease-causing and fibril-forming protein. The molecular mechanisms that drive the aggregation of mutated LCs into fibrils have been enigmatic, which hindered the development of efficient diagnostics and therapies. In this review, we summarize our current knowledge on AL amyloidosis and discuss open issues.

Light Chain Deposition Disease: A Morphological Case Report

Light chain deposition disease (LCDD) is a rare condition associated with the overproduction and deposition of monoclonal light chain immunoglobulins. The kidneys are universally affected in LCDD, with the development of renal failure with nephrotic syndrome, microscopic hematuria, and proteinuria. Most cases are associated with a plasma cell neoplasm (multiple myeloma or plasmacytoma) or other lymphoproliferative disorders, with a reasonable number of cases also being idiopathic. Other organs can be affected in rare cases, without producing significant symptoms, predominantly the liver and heart. In this report, we discuss a case of a 72-year-old female presenting with the aforementioned symptoms. Percutaneous ultrasound-guided kidney biopsy revealed nodular sclerosis with periodic acid-Schiff stain (PAS)-positive, Congo red-negative, silver impregnation weakly-positive, and Masson's trichrome-positive (red reaction) deposits with ribbon-like changes together with light chain deposits in the tubular basement membranes. As LCDD was diagnosed, the patient was subjected to further tests, with multiple myeloma of the thoracic vertebrae also being diagnosed. The patient was started on myeloma treatment; however, she subsequently developed a severe lower limb infection that required amputation, after which she developed sepsis and expired.

Sjögren's syndrome as a cause of both lymphoid interstitial pneumonia and light chain deposition disease in a single patient

A man in his 70s presents with 12 months of progressive dyspnoea, sicca symptoms and Raynaud's phenomenon. Serological testing and tear duct biopsy confirm Sjögren's syndrome (SS). Bilateral nodular-cystic appearances highly suggestive of lymphoid interstitial pneumonia (LIP) are noted on high-resolution computed tomography (HRCT), supported by a 40% lymphocytosis on bronchoalveolar lavage.Biopsy of a non-characteristic additional pulmonary nodule diagnoses light chain deposition disease (LCDD). Extrapulmonary organ involvement is excluded. Pulmonary function tests are well-preserved, and the patient is kept under active surveillance without requiring immunomodulatory treatment.LIP and LCDD both have a strong association with SS. Identification of these disease associations is crucial as they may result in multiorgan involvement or progression to haematological malignancy. This is the first case published in the literature and highlights that a pragmatic approach to investigations can avoid unnecessary procedures, and that treatment may be guided by symptomology.

Masson Trichrome and Sulfated Alcian Blue Stains Distinguish Light Chain Deposition Disease From Amyloidosis in the Lung

Light chain deposition disease, characterized by nonamyloidogenic deposits of immunoglobulin light chains, is rare in the lung and possibly underdiagnosed due to low clinical suspicion and lack of readily accessible tests. We encountered a case of pulmonary light chain deposition disease (PLCDD) in which light chain deposits appeared crimson red with a Masson trichrome (MT) stain and salmon pink with a sulfated Alcian blue (SAB) stain. This prompted us to characterize a series of PLCDD cases and assess the utility of MT and SAB stains to distinguish them from amyloidosis. From the pathology archives of 2 institutions spanning 10 years, we identified 11 cases of PLCDD, including 7 diagnosed as such and 4 determined retrospectively. The deposits in all cases of PLCDD stained crimson red with MT and salmon pink with SAB, while the cases of pulmonary amyloid (n=10) stained blue-gray and blue-green, respectively. The immunoglobulin light chain nature of the deposits was confirmed in 10 of 11 cases by either immunofluorescence microscopy (n=5) or mass spectrometry (n=5). Transmission electron microscopy revealed osmiophilic, electron-dense deposits in all cases analyzed (n=3). An extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue type was diagnosed in 10 cases and 1 represented a plasma cell neoplasm. Our study highlights the importance of considering PLCDD in the differential diagnosis of amyloid-like deposits in the lung and the value of performing MT and SAB stains to distinguish between PLCDD and amyloidosis.

Understanding Mesangial Pathobiology in AL-Amyloidosis and Monoclonal Ig Light Chain Deposition Disease

Patients with plasma cell dyscrasias produce free abnormal monoclonal Ig light chains that circulate in the blood stream. Some of them, termed glomerulopathic light chains, interact with the mesangial cells and trigger, in a manner dependent of their structural and physicochemical properties, a sequence of pathological events that results in either light chain–derived (AL) amyloidosis (AL-Am) or light chain deposition disease (LCDD). The mesangial cells play a key role in the pathogenesis of both diseases. The interaction with the pathogenic light chain elicits specific cellular processes, which include apoptosis, phenotype transformation, and secretion of extracellular matrix components and metalloproteinases. Monoclonal light chains associated with AL-Am but not those producing LCDD are avidly endocytosed by mesangial cells and delivered to the mature lysosomal compartment where amyloid fibrils are formed. Light chains from patients with LCDD exert their pathogenic signaling effect at the cell surface of mesangial cells. These events are generic mesangial responses to a variety of adverse stimuli, and they are similar to those characterizing other more frequent glomerulopathies responsible for many cases of end-stage renal disease. The pathophysiologic events that have been elucidated allow to propose future therapeutic approaches aimed at preventing, stopping, ameliorating, or reversing the adverse effects resulting from the interactions between glomerulopathic light chains and mesangium.

An update to the pathogenesis for monoclonal gammopathy of renal significance

Monoclonal gammopathy of renal significance (MGRS) is characterized by the nephrotoxic monoclonal immunoglobulin secreted by an otherwise asymptomatic or indolent B cell or plasma cell clone, without hematologic criteria for treatment. These MGRS-associated diseases can involve one or more renal compartments, including glomeruli, tubules, and vessels. Hydrophobic residue replacement, N-glycosylated, increase in isoelectric point in monoclonal immunoglobulin (MIg) causes it to transform from soluble form to tissue deposition, and consequently resulting in glomerular damage. In addition to MIg deposition, complement deposition is also found in C3 glomerulopathy with monoclonal glomerulopathy, which is caused by an abnormality of the alternative pathway and may involve multiple factors including complement component 3 nephritic factor, anti-complement factor auto-antibodies, or MIg which directly cleaves C3. Furthermore, inflammatory factors, growth factors, and virus infection may also participate in the development of the diseases. In this review, for the first time, we discussed current highlights in the mechanism of MGRS-related lesions.