Macroglossia – Not Always AL Amyloidosis

Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 5007-5007 ◽  
Author(s):  
Andrew J Cowan ◽  
Martha Skinner ◽  
J. Mark Sloan ◽  
John L Berk ◽  
Carl J O'Hara ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Bone Marrow ◽  
Plasma Cell ◽  
Light Chain ◽  
Plasma Cells ◽  
Plasma Cell Dyscrasia ◽  
Al Amyloidosis ◽  
Amyloid Deposits ◽  
Immuno Electron Microscopy ◽  
Congo Red Staining

Abstract Abstract 5007 Introduction: Amyloidosis is characterized by extracellular deposition of abnormal insoluble fibrillar proteins. The two most frequent systemic amyloidoses are the light-chain (AL amyloidosis) and familial transthyretin (ATTR) forms. Clinical presentations often vary between the two types. Macroglossia is viewed as pathognomic of AL amyloidosis, and has not previously been described in patients with hereditary TTR amyloidosis. Here, we describe two cases of systemic amyloidosis with macroglossia in which immuno-electron microscopy diagnosed ATTR in one and AL in the other. Case Presentations: A 61 year old woman presented initially to her general internist with weight loss, difficulty swallowing, and tongue numbness. Her clinical exam revealed macroglossia and peripheral neuropathy. Tongue and axillary lymph node biopsies demonstrated amyloid deposits by Congo red staining. There was no evidence of renal, cardiac or other vital organ involvement. She had no evidence of a plasma cell dyscrasia with negative serum and urine immunofixation electrophoresis, normal serum free light chain concentration and ratio as well as polytypic plasma cells in the bone marrow. Immuno-electron microscopy using gold-labeled antibodies was performed on the tongue biopsy. The fibrils were immunoreactive with anti-TTR but not anti-kappa, anti-lambda, or anti-AA antibodies. DNA sequencing identified a known amyloidogenic T60A TTR mutation in exon 3 of chromosome 18, confirming the diagnosis of ATTR with amyloidotic polyneuropathy and macroglossia. The second case involved a 59 year old man with renal insufficiency. He complained of fatigue, weight loss, and tongue swelling. Physical examination was significant for macroglossia and submandibular gland enlargement. Tongue biopsy demonstrated amyloid deposits by Congo red staining. As in the previous case, markers of plasma cell dyscrasia with clonal plasma cells in the bone marrow, blood, and urine were absent. Immuno-electron microscopy of the tongue biopsy documented antibody reactivity to lambda light chain and not TTR, kappa light chain or AA proteins, confirming the diagnosis of AL amyloidosis. He subsequently underwent treatment with high dose intravenous melphalan followed by stem cell transplantation achieving a good clinical response sustained for 2 years to date. Discussion: While macroglossia is thought to be pathognomonic of AL amyloidosis, we report a case of macroglossia with fibrillar ATTR amyloid deposits diagnosed by immuno-electron microscopy. This is contrasted with a clinical presentation consistent with AL in which routine laboratory testing failed to identify evidence of a plasma cell dyscrasia. In both cases, electron microscopy demonstrated immunoreactivity for the fibrils of a single pathogenic protein. The first case was confirmed by DNA sequencing, and the second had a typical response to anti-plasma cell chemotherapy, in spite of the lack of identifiable markers of disease. Disclosures: No relevant conflicts of interest to declare.

Analysis of Vλ-Jλ expression in plasma cells from primary (AL) amyloidosis and normal bone marrow identifies 3r(λIII) as a new amyloid-associated germline gene segment

Blood ◽  
2002 ◽  
Vol 100 (3) ◽  
pp. 948-953 ◽  
Author(s):  
Vittorio Perfetti ◽  
Simona Casarini ◽  
Giovanni Palladini ◽  
Maurizio Colli Vignarelli ◽  
Catherine Klersy ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Light Chain ◽  
Amyloid Fibrils ◽  
Plasma Cells ◽  
Strong Association ◽  
Gene Segment ◽  
Variable Region ◽  
Plasma Cell Dyscrasia ◽  
Al Amyloidosis ◽  
Primary Amyloidosis

Abstract Primary (AL) amyloidosis is a plasma cell dyscrasia characterized by extracellular deposition of monoclonal light-chain variable region (V) fragments in the form of amyloid fibrils. Light-chain amyloid is rare, and it is not fully understood why it occurs in only a fraction of patients with a circulating monoclonal component and why it typically associates with λ isotype and λVI family light-chain proteins. To provide insights into these issues, we obtained complete nucleotide sequences of monoclonal Vλ regions from 55 consecutive unselected cases of primary amyloidosis and the results were compared with the light-chain expression profile of polyclonal marrow plasma cells from 3 healthy donors (a total of 264 sequences). We demonstrated that: (1) the λIII family is the most frequently used both in amyloidosis (47%) and in polyclonality (43%); (2) both conditions are characterized by gene restriction; (3) a very skewed repertoire is a feature of amyloidosis, because just 2 germline genes belonging to the λIII and λVI families, namely 3r (22% of cases, λIII) and 6a (20%, λVI), contributed equally to encode 42% of amyloid Vλ regions; (4) these same 2 gene segments have a strong association with amyloidosis if their prevalences are compared with those in polyclonal conditions (3r, 8.3%,P = .024; 6a, 2.3%, P = .0008, χ2 test); (5) the Jλ2/3 segment, encoding the fourth framework region, appears to be slightly overrepresented in AL (83% versus 67%, P = .03), and this might be related to preferential Jλ2/3 rearrangement in amyloid (11 of 12 cases) versus polyclonal 3r light chains (13 of 22 cases). These findings demonstrate that Vλ-Jλ expression is more restricted in plasma cells from amyloidosis than from polyclonal bone marrow and identify 3r as a new disease-associated gene segment. Overusage of just 2 gene segments,3r and 6a, can thus account for the λ light-chain overrepresentation typical of this disorder.

scholarly journals A Novel Case of Direct Antiglobulin Test-Negative Intravascular Hemolysis in a Patient with Smoldering Myeloma

Blood ◽  
2015 ◽  
Vol 126 (23) ◽  
pp. 4539-4539
Author(s):  
Selina Dobing ◽  
Nikolas Desilet ◽  
Irwindeep Sandhu ◽  
Lauren Bolster
Keyword(s):  
Multiple Myeloma ◽  
Bone Marrow ◽  
Plasma Cell ◽  
Light Chain ◽  
Plasma Cells ◽  
Case Reports ◽  
Alternative Pathway ◽  
Plasma Cell Dyscrasia ◽  
Intravascular Hemolysis ◽  
Lambda Light Chain

Abstract Objectives: 1. Describe a case of severe DAT-negative intravascular hemolysis in plasma cell dyscrasia. 2. Discuss a potential novel mechanism of light-chain mediated hemolysis. A 34-year old woman was admitted to hospital with fatigue and severe iron deficiency anemia (hemoglobin 47 g/dL, MCV 59 fL, ferritin 2 mcg/L). Her medical history included a presumptive diagnosis of paroxysmal nocturnal hemoglobinuria (PNH) from five years prior. She was transfused 2 units of red cells, started on oral iron and folate, and was discharged symptom-free with a hemoglobin of 71 g/dL. She returned three days later with abdominal pain, dark urine, and evidence of intravascular hemolysis. She was admitted for empiric treatment of PNH with high-dose glucocorticoids and therapeutic enoxaparin for presumed intra-abdominal thrombosis. Her flow cytometry, including granulocytes, was negative for PNH. Her direct antiglobulin test (DAT) was negative for IgG antibodies but positive for C3 complement. A thorough hemolysis workup was negative, including schistocytes and Donath Landsteiner testing. ADAMTS13 testing was uninterpretable due to high plasma free hemoglobin. Despite corticosteroids, brisk hemolysis continued with 10 units of RBCs required over 5 days to maintain a stable hemoglobin. Plasma free hemoglobin reached 1147 mg/L, prompting therapeutic plasmapheresis for renal protection by the end of day 5. She deteriorated clinically after her first plasmapheresis with acute confusion (GCS 10) and lactic acidosis. She was empirically treated for seizure with levetiracetam. CT and MRI scans of her brain and lumbar puncture were normal. Her consciousness improved with daily plasmapheresis. A bone marrow biopsy performed on day twelve of glucocorticoid therapy found monoclonal plasma cell proliferation of 15% with marked lambda light chain predominance (20:1) (Figure 1). Repeat bone marrow biopsy 3 months post-steroid therapy still revealed 10% clonal plasma cells. Hemolysis can be a rare presentation of plasma cell dyscrasia. Case reports of both autoimmune hemolytic anemia and microangiopathic hemolytic anemia associated with multiple myeloma exist. In our case, there was no evidence of a microangiopathic process, making thrombotic thrombocytopenic purpura (TTP) or atypical hemolytic-uremic syndrome (aHUS) unlikely. DAT was negative for IgG but did demonstrate C3 complement molecules bound to red cells. No previous case reports of complement-mediated hemolysis and multiple myeloma were found on literature review. We report the first in vivo association between complement-mediated hemolysis and plasma cell dyscrasia. Complement pathways bridge the innate and acquired immune systems by helping select cells to be targeted by the acquired immune system. The alternative complement pathway does not require an antigen-antibody interaction to become active; rather, it is controlled by direct binding of complement and regulated by cofactor molecules. Jokiranta et al. (J Immunol 1999) identified a monoclonal Ig-lambda dimer that efficiently activated the alternative pathway of complement, triggering complement molecules to enhance hemolysis of serum in vitro. This "miniautoantibody" specifically bound and blocked the function of complement factor H, inhibiting enzymatic inactivation of fluid-phase C3b with uncontrolled activation of the alternative pathway. It is possible that the relative immune dysfunction in this patient's plasma cell dyscrasia led to a disturbance in the alternate complement pathway, perhaps due to dimerization of abnormal lambda light chains, resulting in complement-mediated intravascular hemolysis. Glucocorticoids and plasmapheresis may have helped manage hemolysis in this case. By diagnostic criteria, this patient has smoldering myeloma, with urine monoclonal protein (1.2 g/24 hours), clonal bone marrow plasma cells (10-15%), and absence of myeloma-defining events. We have elected to manage her as such, with close observation. Further work-up performed for her plasma cell dyscrasia included a normal MRI of spine and pelvis. Over a year later, there has been no recurrence of hemolysis. Consideration will be given to treatment if she progresses to overt multiple myeloma. Figure 1. A. Aspirate showing abnormal plasma cells. B. Trephine CD138 stain. C. Trephine kappa light chain stain. D. Trephine lambda light chain stain. Figure 1. A. Aspirate showing abnormal plasma cells. B. Trephine CD138 stain. C. Trephine kappa light chain stain. D. Trephine lambda light chain stain. Disclosures Sandhu: Novartis: Consultancy, Honoraria; Amgen: Consultancy, Honoraria; Celgene: Consultancy, Honoraria; Janssen: Consultancy, Honoraria.

scholarly journals Coexistent Multiple Myeloma or Increased Bone Marrow Plasma Cells Define Equally High-Risk Populations in Patients With Immunoglobulin Light Chain Amyloidosis

2013 ◽  
Vol 31 (34) ◽  
pp. 4319-4324 ◽  
Author(s):  
Taxiarchis V. Kourelis ◽  
Shaji K. Kumar ◽  
Morie A. Gertz ◽  
Martha Q. Lacy ◽  
Francis K. Buadi ◽  
...  
Keyword(s):  
Multiple Myeloma ◽  
Bone Marrow ◽  
Plasma Cell ◽  
Light Chain ◽  
Plasma Cells ◽  
Survival Rates ◽  
Bone Lesions ◽  
Al Amyloidosis ◽  
Characteristic Analysis ◽  
Bone Marrow Plasma

Purpose There is consensus that patients with light chain (AL) amyloidosis with hypercalcemia, renal failure, anemia, and lytic bone lesions attributable to clonal expansion of plasma cells (CRAB criteria) also have multiple myeloma (MM). The aim of this study was to examine the spectrum of immunoglobulin AL amyloidosis with and without MM, with a goal of defining the optimal bone marrow plasma cell (BMPC) number to qualify as AL amyloidosis with MM. Patients and Methods We identified 1,255 patients with AL amyloidosis seen within 90 days of diagnosis between January 1, 2000, and December 31, 2010. We defined a population of patients with coexisting MM on the basis of the existence of CRAB criteria (AL-CRAB). Receiver operating characteristic analysis determined the optimal BMPC cut point to predict for 1-year mortality in patients with AL amyloidosis without CRAB to produce two additional groups: AL only (≤ 10% BMPCs) and AL plasma cell MM (AL-PCMM; > 10% BMPCs). Results Among the 1,255 patients, 100 (8%) had AL-CRAB, 476 (38%) had AL-PCMM, and 679 (54%) had AL only. Their respective median overall survival rates were 10.6, 16.2, and 46 months (P < .001). Because the outcomes of AL-CRAB and AL-PCMM were similar, they were pooled for univariate and multivariate analyses. On multivariate analysis, pooled AL-CRAB and AL-PCMM retained negative prognostic value independent of age, Mayo Clinic AL amyloidosis stage, prior autologous stem-cell transplantation, and difference between the involved and uninvolved free light chain. Conclusion Patients with AL amyloidosis who have more than 10% BMPCs have a poor prognosis, similar to that of patients with AL-CRAB, and should therefore be considered together as AL amyloidosis with MM.

scholarly journals P0508NEPHROTIC SYNDROME DUE TO HEAVY AND LIGHT CHAIN (AHL) AMYLOIDOSIS

2020 ◽  
Vol 35 (Supplement_3) ◽  
Author(s):  
Csilla Markóth ◽  
László Bidiga ◽  
Piroska Pettendi ◽  
Éva Rékasi ◽  
László Ujhelyi ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Nephrotic Syndrome ◽  
Plasma Cell ◽  
Heavy Chain ◽  
Light Chain ◽  
Kidney Biopsy ◽  
Kidney Diseases ◽  
Screening Tests ◽  
Renal Outcome ◽  
Plasma Cell Dyscrasia

Abstract Background and Aims Kidney diseases with heavy chain deposition are rare, including AHL amyloidosis also. The mutation/deletion of the constant domain (CH1/CH2) of the heavy chain causing high tissue affinity seems most likely in its pathogenesis. The very low serum level is responsible for the difficult diagnosis, which is often based on kidney biopsy or laser microdissection / mass spectrometry. Method Case study of a 76-year-old male patient, examined in January, 2019. Results Besides treatment for Ménière syndrome and benign prostatic hyperplasia there was no other important event in patient’s history. Significant proteinuria and microscopic haematuria were observed from May 2016, but eGFR was 70 ml/min/1,73 m2 at that time. By April, 2018 nephrotic range proteinuria (10 g/day) with full nephrotic syndrome developed. Screening tests for cancer were negative. Despite symptomatic treatment, half year later eGFR decreased to 27 ml/min/1,73 m2, therefore he was referred to nephrology. Serum protein electrophoresis verified IgG lambda (8,1 g/l) and free lambda (0,5 g/l) monoclonal light chains, and in addition the possibility of IgG heavy chain accumulation. Urine electrophoresis showed also IgG lambda (1720,1 mg/l), and free lambda light chain (552,1 mg/l) monoclonality. Serum free lambda and kappa light chain ratio was 0,06, complement serology was normal. Kidney biopsy was done, which showed IgG heavy and light chain restriction, Congo red stain positivity and apple green birefringence under the polarized microscope in the expanded mesangium, in the interstitium and along the tubular basement membrane and the blood vessels. The electron microscope detected fibrillary deposits (10 nm) in the same structures, therefore diagnosis of AHL amyloidosis was established. He had no extrarenal symptoms. Bone marrow aspiration flow cytometry verified 1,11% plasma cell accumulation, 93% of them had pathological immunphenotype. Bone marrow morphology assay showed 30-40% plasma cell infiltration, and chromosome assay detected monoallelic deletion of IgH and MAF and gains of 1q region, suggesting myeloma multiplex in the background of AHL amyloidosis. VCD (bortezomib-cyclophosphamide-dexamethason) treatment was started, so far he has received 8 cycles. He is asymptomatic, proteinuria decreased, kidney function stabilized, eGFR 23 ml/min/1,73 m2. Conclusion only about 20 cases of AHL amyloidosis have been reported in the literature so far. In the context of longstanding kidney failure with nephrotic syndrome, we should consider renal disease associated with plasma cell dyscrasia also. If case of an AHL amyloidosis caused by myeloma multiplex, effective anti-plasma cell therapy can improve the hematological and the renal outcome.

scholarly journals Recent Advances in the Diagnosis, Risk Stratification, and Management of Systemic Light-Chain Amyloidosis

2019 ◽  
Vol 141 (2) ◽  
pp. 93-106 ◽  
Author(s):  
Iuliana Vaxman ◽  
Morie Gertz
Keyword(s):  
Plasma Cell ◽  
Light Chain ◽  
Cell Clone ◽  
Proteasome Inhibitors ◽  
Clinical Manifestations ◽  
Al Amyloidosis ◽  
Amyloid Deposits ◽  
Protein Fibrils ◽  
Risk Patients ◽  
Intensive Search

The term amyloidosis refers to a group of disorders in which protein fibrils accumulate in certain organs, disrupt their tissue architecture, and impair the function of the effected organ. The clinical manifestations and prognosis vary widely depending on the specific type of the affected protein. Immunoglobulin light-chain (AL) amyloidosis is the most common form of systemic amyloidosis, characterized by deposition of a misfolded monoclonal light-chain that is secreted from a plasma cell clone. Demonstrating amyloid deposits in a tissue biopsy stained with Congo red is mandatory for the diagnosis. Novel agents (proteasome inhibitors, immunomodulatory drugs, monoclonal antibodies, venetoclax) and autologous stem cell transplantation, used for eliminating the underlying plasma cell clone, have improved the outcome for low- and intermediate-risk patients, but the prognosis for high-risk patients is still grave. Randomized studies evaluating antibodies that target the amyloid deposits (PRONTO, VITAL) were recently stopped due to futility and currently there is an intensive search for novel treatment approaches to AL amyloidosis. Early diagnosis is of paramount importance for effective treatment and prognosis, due to the progressive nature of this disease.

Localized AL Amyloidosis of the Breast: A Case Series.

Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 4906-4906
Author(s):  
Marjory Charlot ◽  
David C. Seldin ◽  
Carl O'Hara ◽  
Martha Skinner ◽  
Vaishali Sanchorawala
Keyword(s):  
Plasma Cell ◽  
Congo Red ◽  
Conflicts Of Interest ◽  
Amorphous Material ◽  
Case Series ◽  
Screening Mammography ◽  
Plasma Cell Dyscrasia ◽  
Al Amyloidosis ◽  
Palpable Mass ◽  
Amyloid Deposits

Abstract Abstract 4906 AL amyloidosis is characterized by widespread, progressive deposition of fibrillar amyloid protein derived from monoclonal immunoglobulin light chains, leading to organ failure and death. This disease is typically systemic, however, it can occur as a localized form. In localized amyloidosis, the deposits occur near the site of synthesis of the precursor protein and in some cases, plasma cells have been demonstrated histologically adjacent to the deposits. For unknown reasons, the tracheobronchial tree is the most common site for localized AL amyloidosis. Localized AL amyloidosis of the breast is a rare entity that has been described in the literature in isolated case reports. It can present as a palpable mass or as calcifications on routine screening mammography. We report here a case series of seven women (median age 63 years, range 46 to75) seen and evaluated at Boston University Medical Center from 1990-2008. We evaluated 1502 new patients with AL amyloidosis in this time period, making the incidence of localized AL amyloidosis of the breast to be 0.5% at a single referral center. All seven patients had abnormal screening mammography with calcifications, and biopsies that revealed Congo red positive amyloid deposits. Histologically, the amyloid deposits appeared as amorphous material in the stroma around the ducts and lobules in most patients; one patient had amyloid deposits in the ducts only, but not in the stroma. None of the patients had clinical or laboratory evidence of other organ involvement, all had negative Congo red staining of an abdominal fat pad aspirate, and all had a negative work up for a plasma cell dyscrasia or circulating paraprotein. The patients were treated with local excision of the regions of calcification or lumpectomy. Three out of seven patients underwent routine follow up within 6-12 months from the time of diagnosis with no evidence of disease recurrence or progression to systemic AL amyloidosis. One out of seven patients had bilateral and recurrent amyloidosis of the breasts and was found to have an associated stage I invasive ductal adenocarcinoma that was treated with lumpectomy and radiation. In summary, breast amyloidosis is rare, is not associated with a systemic plasma cell dyscrasia or amyloidosis in other organs, and can be treated surgically. Disclosures No relevant conflicts of interest to declare.

scholarly journals Quantitation of Monoclonal Plasma Cells in Bone Marrow Biopsies in Plasma Cell Dyscrasia

2003 ◽  
Vol 25 (4) ◽  
pp. 167-171 ◽  
Author(s):  
G. M. Markey ◽  
P. Kettle ◽  
T. C. M. Morris ◽  
N. Connolly ◽  
H. Foster
Keyword(s):  
Bone Marrow ◽  
Plasma Cell ◽  
Plasma Cells ◽  
Cell Mass ◽  
Observation Time ◽  
Plasma Cell Dyscrasia ◽  
Bone Marrow Biopsies ◽  
Colour Figure ◽  
Light Chain Immunoglobulin ◽  
Monoclonal Proteins

Direct measurement of monoclonal plasma cell mass in bone marrow biopsies may be a useful parameter to establish in plasma cell dyscrasia. In this study monoclonal plasma cells/mm2in light chain immunoglobulin immunostained archival bone marrow sections from 22 patients in whom a diagnosis of multiple myeloma (MM) had been excluded but who had monoclonal proteins were counted by two observers at light microscopic level. There was good correlation between the counts of the two observers. The levels of monoclonal plasma cells/mm2in biopsies were not related to the % counts in the aspirates taken at the same time as the biopsies. Three of seven patients with biopsy levels in excess of the polyclonal levels in patients without plasma cell dyscrasia developed progressive MM within the observation time. Monoclonal plasma cell levels/mm2of bone marrow biopsies can be measured and they provide a useful parameter for the assessment of patients with low volume plasma cell dyscrasia. Colour figure can be viewed onhttp://www.esacp.org/acp/2003/25‐4/markey.htm.

Correlation between serum levels of free light chain and phenotype of plasma cells in bone marrow in primary AL amyloidosis

Amyloid ◽  
2005 ◽  
Vol 12 (1) ◽  
pp. 33-40 ◽  
Author(s):  
Yasuhiro Shimojima ◽  
Masayuki Matsuda ◽  
Takahisa Gono ◽  
Wataru Ishii ◽  
Tomohisa Fushimi ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Light Chain ◽  
Plasma Cells ◽  
Serum Levels ◽  
Free Light Chain ◽  
Al Amyloidosis

scholarly journals In Vitro and inVivo Activity of Melflufen in Amyloidosis

Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 3100-3100 ◽  
Author(s):  
Ken Flanagan ◽  
Muntasir M Majumder ◽  
Romika Kumari ◽  
Juho Miettinen ◽  
Ana Slipicevic ◽  
...  
Keyword(s):  
Board Of Directors ◽  
Cell Lines ◽  
Plasma Cell ◽  
Light Chain ◽  
Research Funding ◽  
Plasma Cells ◽  
Al Amyloidosis ◽  
Advisory Committees

Background: Immunoglobulin light-chain (AL) amyloidosis is a rare disease caused by plasma cell secretion of misfolded light chains that assemble as amyloid fibrils and deposit on vital organs including the heart and kidneys, causing organ dysfunction. Plasma cell directed therapeutics, aimed at preferentially eliminating the clonal population of amyloidogenic cells in bone marrow are expected to reduce production of toxic light chain and alleviate deposition of amyloid thereby restoring healthy organ function. Melphalan flufenamide ethyl ester, melflufen, is a peptidase potentiated alkylating agent with potent toxicity in myeloma cells. Melflufen is highly lipophilic, permitting rapid cellular uptake, and is subsequently enzymatically cleaved by aminopeptidases within cells resulting in augmented intracellular concentrations of toxic molecules, providing a more targeted and localized treatment. Previous data demonstrating multiple myeloma plasma cell sensitivity for melflufen suggests that the drug might be useful to directly eliminate amyloidogenic plasma cells, thereby reducing the amyloid load in patients. Furthermore, the increased intracellular concentrations of melflufen in myeloma cells indicates a potential reduction in systemic toxicity in patients, an important factor in the fragile amyloidosis patient population. To assess potential efficacy in amyloidosis patients and to explore the mechanism of action, we examined effects of melflufen on amyloidogenic plasma cells invitro and invivo. Methods: Cellular toxicity and apoptosis were measured in response to either melflufen or melphalan in multiple malignant human plasma cell lines, including the amyloidosis patient derived light chain secreting ALMC-1 and ALMC-2 cells, as well as primary bone marrow cells from AL amyloidosis patients, using annexin V and live/dead cell staining by multicolor flow cytometry, and measurement of cleaved caspases. Lambda light chain was measured in supernatant by ELISA, and intracellular levels were detected by flow cytometry. To assess efficacy of melflufen in vivo, the light chain secreting human myeloma cell line, JJN3, was transduced with luciferase and adoptively transferred into NSG mice. Cell death in response to melflufen or melphalan was measured by in vivo bioluminescence, and serum light chain was monitored. Results: Melflufen demonstrated increased potency against multiple myeloma cell lines compared to melphalan, inducing malignant plasma cell death at lower doses on established light chain secreting plasma cell lines. While ALMC-1 cells were sensitive to both melphalan and melflufen, the IC50 for melphalan at 960 nM was approximately 3-fold higher than melflufen (334 nM). However, ALMC-2 cells were relatively insensitive to melphalan (12600 nM), but maintained a 100-fold increase in sensitivity to melflufen (121 nM). Furthermore, while 40% of primary CD138+ plasma cells from patients with diagnosed AL amyloidosis responded to melflufen treatment in vitro, only 20% responded to melphalan with consistently superior IC50 values for melflufen (Figure 1). Light chain secreting cell lines and AL amyloidosis patient samples were further analyzed by single cell sequencing. We further examined differential effects on apoptosis and the unfolded protein response in vitro in response to either melflufen or melphalan. This is of particular interest in amyloidosis, where malignant antibody producing plasma cells possess an increased requirement for mechanisms to cope with the amplified load of unfolded protein and associated ER stress. As AL amyloidosis is ultimately a disease mediated by secretion of toxic immunoglobulin, we assessed the effects of melflufen on the production of light chain invitro, measuring a decrease in production of light chain in response to melflufen treatment. Finally, we took advantage of a recently described adoptive transfer mouse model of amyloidosis to assess the efficacy of melflufen and melphalan in eliminating amyloidogenic clones and reducing the levels of toxic serum light chain in vivo. Conclusions: These findings provide evidence that melflufen mediated toxicity, previously described in myeloma cells, extends to amyloidogenic plasma cells and further affects the ability of these cells to produce and secrete toxic light chain. This data supports the rationale for the evaluation of melflufen in patients with AL amyloidosis. Figure 1 Disclosures Flanagan: Oncopeptides AB: Employment. Slipicevic:Oncopeptides AB: Employment. Holstein:Celgene: Consultancy; Takeda: Membership on an entity's Board of Directors or advisory committees; Adaptive Biotechnologies: Membership on an entity's Board of Directors or advisory committees; GSK: Consultancy; Genentech: Membership on an entity's Board of Directors or advisory committees; Sorrento: Consultancy. Lehmann:Oncopeptides AB: Employment. Nupponen:Oncopeptides AB: Employment. Heckman:Celgene: Research Funding; Novartis: Research Funding; Oncopeptides: Research Funding; Orion Pharma: Research Funding.

scholarly journals Should the Reporting of Bone Marrow Positivity for Amyloid Be Revised?: A Critical Assessment Based on 66 Biopsies From a Single Institution

2020 ◽  
Vol 144 (8) ◽  
pp. 967-973 ◽  
Author(s):  
Sara Javidiparsijani ◽  
Maria M. Picken
Keyword(s):  
Bone Marrow ◽  
Spatial Distribution ◽  
Plasma Cells ◽  
Treatment Options ◽  
Clinical Information ◽  
Al Amyloidosis ◽  
Significant Heterogeneity ◽  
Amyloid A ◽  
Amyloid Deposits ◽  
Amyloid Light Chain

Context.— Amyloidoses are rare but heterogeneous disorders for which diagnosis is contingent upon the detection of deposits by Congo red stain and amyloid protein typing determines the treatment options. Objective.— To address the reporting of bone marrow (BM) involvement by amyloid in relation to the spatial distribution of deposits and to explore whether the location of deposits may have clinical relevance. Design.— We examined 66 BM biopsies positive for amyloid with regard to the location and type of amyloid, the percentage and clonality of plasma cells, other organ involvement, and relevant clinical information. Results.— In 21 cases, amyloid deposits involved BM stroma, whereas 45 cases were nonstromal. All cases of stromal involvement were typed as amyloid light chain (AL) amyloidosis (or presumed AL), whereas nonstromal involvement was associated with at least 3 types of amyloidosis: AL, amyloid transthyretin (ATTR), and amyloid A (AA). The initial diagnosis of amyloidosis was made in a BM specimen in 21 of 66 cases (31.8%). Plasma cells ranged from 1% to 80% (mean, 13.4%; median, 8%; &lt;10% in 44 of 66 specimens [66.6%]) and were monoclonal in 58 of 66 cases (87.8%), and in 54 of 66 cases (81.8%) amyloid deposits were documented in at least one other organ. Conclusions.— This study demonstrates that there is significant heterogeneity in the spatial distribution of amyloid in BM biopsy specimens with medullary, extramedullary, purely vascular, or combined involvement. Whereas stromal deposits were associated exclusively with AL, nonstromal and purely vascular deposits were seen in at least 3 types of systemic amyloidosis (AL, AA, and ATTR). We discuss the reporting of BM biopsy tissue positivity for amyloid deposits.

Sign in / Sign up

Export Citation Format

Share Document