Immunoglobulin light chain amyloidosis: recent molecular, clinical and therapeutic approach

AL amyloidosis is a rare disorder characterised by tissue deposition of a fibrillary proteinaceous material, formed from monoclonal immunoglobulin light (or exceptionally heavy) chains. Although it may complicate multiple myeloma or B-cell lymphomas, AL amyloidosis is often associated with a low burden of clonal plasma cells ("primitive" AL amyloidosis). The mechanisms involved in the formation of AL amyloid deposits remain unclear, but are probably related to structural peculiarities of monoclonal immunoglobulin light chains. AL amyloidosis is usually a systemic disease, often revealed by renal involvement, the most common complication of the disease. The longterm prognosis of AL amyloidosis is poor, mainly related to amyloid restrictive cardiomyopathy leading to congestive heart failure. Oral melphalan and prednisone is considered the standard treatment for AL amyloidosis, but with limited increase in the median survival. High-dose intra-venous melphalan with autologous stem cell transplantation is an effective treatment, aimed at eliminating the clonaly expanded plasma cells, which has been shown to induce complete hematologic remissions and to prolong survival. However, the tolerability of such treatment is low, limiting its use to selected patients. The development of new drugs, able to interfere with amyloid fibril deposition, may provide a new therapeutic approach.     

An unusual case of transient dermatological reaction to bortezomib in AL amyloidosis

We report an unusual dermatological reaction to bortezomib in a 61-year-old man with AL amyloidosis. Systemic AL amyloidosis is a rare complication of monoclonal gammopathy or myeloma in which abnormally unstable free light chains cause fibrillary deposits in organs leading to multisystem disease. The treatment of AL amyloidosis is directed at the underlying plasma cell dyscrasia and most regimes have been adapted from myeloma, but drug toxicity is more common in AL amyloidosis because of the more extensive nature of the disease. We report a patient who developed asymptomatic purple discolouration of the veins of his left arm several days after receiving the infusion in his left hand, although the infusion itself had been uncomplicated with no extravasation. The discolouration resolved completely within 2 weeks; there was recurrence on a subsequent dose of bortezomib but this also subsided spontaneously. This reaction may have been transient phlebitis or a local vasogenic reaction; its transient nature and the lack of systemic features suggest it is a benign phenomenon. There appears to be no indication for discontinuation of bortezomib treatment or dose alteration in such cases.     

Primary amyloidosis associated with IgD-lambda M-proteinemia

We describe here a case of primary AL amyloidosis associated with IgD monoclonal gammopathy of undetermined significance. A 73-year-old man was referred to our hospital with suspected multiple myeloma due to renal failure and urinary Bence Jones protein. Although serum electrophoresis revealed IgDlambda monoclonal protein, the bone marrow did not showed plasma cell proliferation. Systemic bone survey disclosed no lytic bone lesions. Because the patient had macroglossia and multiple ecchymosis in the face and neck, primary amyloidosis was suspected. Skin biopsy revealed extensive deposition of amyloid which was positively stained by Congo red dye. A diagnosis of primary AL amyloidosis associated with IgD monoclonal gammopathy was made. The patient was also complicated renal failure that eventually needed hemodialysis. To our knowledge, this is the first report of primary AL amyloidosis associated with IgD monoclonal gammopathy with undetermined significance.     

Monoclonal gammopathies of undetermined significance

The monoclonal gammopathies include multiple myeloma (MM), monoclonal gammopathy of undetermined significance (MGUS), primary systemic amyloidosis (AL), and Waldenstr?m's macroglobulinemia (WM). At Mayo Clinic, almost 60% of patients with a monoclonal gammopathy have MGUS. MGUS is characterized by the presence of a serum monoclonal protein value <3 g/dL, fewer than 10% plasma cells in the bone marrow, no or a small amount of monoclonal protein in the urine, and absence of lytic bone lesions, anemia, hypercalcemia, or renal insufficiency related to the plasma-cell proliferative process. During long-term follow-up of 241 patients with MGUS seen at Mayo Clinic from 1956 to 1970, MM, WM, AL, or a related disorder developed in 64. To confirm the findings, we conducted a population-based study on MGUS in the 11 counties of southeastern Minnesota from 1960 to 1994. The risk of progression to a malignant plasma-cell disorder was 1% per year.     

Primary amyloidosis (AL) in families

We report the occurrence of immunoglobulin-related amyloidosis (AL) in three separate families, each family having two members affected. None of the six patients had evidence to suggest the presence of familial amyloidosis (AF). Previously, immunoglobulin-related amyloidosis (AL) was considered to be a sporadic disease process. Because of the occasional familial occurrence of other monoclonal gammopathies such as monoclonal gammopathy of undetermined significance, multiple myeloma, and macroglobulinemia of Waldenstr?m, amyloidosis (AL) should be added to the list of immunopathies with a familial predisposition.     

Les amyloses cardiaques : état des lieux en 2022

The 3 main types of cardiac amyloidosis are linked to two protein precursors: AL amyloidosis secondary to free light chain deposits in the context of monoclonal gammopathy (mainly of undetermined significance or myeloma) and transthyretin amyloidosis (ATTR), comprising wild-type transthyretin amyloidosis (ATTRwt for wild type) and hereditary transthyretin amyloidosis (ATTRv for variant). These diseases are underdiagnosed and highly prevalent in common cardiac phenotypes in recent studies (heart failure with preserved ejection fraction, severe aortic stenosis, hypertrophic cardiomyopathy). Myocardial amyloid infiltration affects all cardiac structures and clinically promotes predominantly heart failure, conductive disorders and cardioembolic events. The search for extracardiac signs makes it possible to arouse diagnostic suspicion. Electrocardiogram, echocardiography and cardiac MRI can suspect cardiac amyloidosis. The diagnostic confirmation follows a simple algorithm including a systematic search for monoclonal gammapathy and a disphosphonate scintigraphy. Histological proof is necessary in case of AL or ATTR amyloidosis with concomitant monoclonal gammopathy in order to initiate specific treatment. Due to the late disease onset in ATTRv, genetic testing must be routine in all cases of ATTR. These diseases are no longer perceived as incurable since recent therapeutic innovations. A better knowledge of the disease is more than ever necessary.     

Immunoglobulin‐free light chain monomer‐dimer patterns help to distinguish malignant from premalignant monoclonal gammopathies: A pilot study

Multiple myeloma (MM) and AL amyloidosis (AL) are two malignant forms of monoclonal gammopathies. For the purposes of prognosis and treatment, it is important to distinguish these diseases from the premalignant forms of monoclonal gammopathies, such as monoclonal gammopathy of unknown significance (MGUS) and smoldering myeloma (SMM). Routine serum/urine tests for monoclonal protein are insufficient for differential diagnosis. Thus, invasive procedures, such as tissue aspiration or biopsy, are applied. In this study, we aimed at characterization of serum‐free light chain (FLC) monomer‐dimer patterns to distinguish the malignant from the premalignant forms of monoclonal gammopathies. A quantitative Western blotting was applied to estimate the FLC monomer and dimer levels in AL, MM, MGUS, and SMM patients, and in control subjects (healthy individuals and patients with AA amyloidosis). AL and MM patients displayed an abnormally increased dimerization of monoclonal FLC, accompanied by higher clonality values of FLC dimers, as compared to that of monomers. These abnormalities of FLC patterns were not observed in patients with MGUS, SMM, AA amyloidosis, and healthy individuals. Analysis of FLC patterns helped to differentiate AL and MM from MGUS and SMM, a goal difficult to achieve using routine serum tests. Also, our technique might serve as a complimentary diagnostic tool in the cases with suspected AL amyloidosis, where the diagnosis of MM is excluded, while the results of amyloid typing by routine immunohistochemical techniques are inconclusive. Am. J. Hematol. 89:882–888, 2014. © 2014 Wiley Periodicals, Inc.     

Hepatocyte growth factor measurement in AL amyloidosis

Hepatocyte growth factor (HGF) is a pro-angiogenic cytokine activated by tissue-type plasminogen activator (tPA) that might play a role in the progression of multiple myeloma (MM). Preliminary studies indicated that serum HGF levels were higher in patients with AL amyloidosis (AL) compared to those with MM. The aim of the present study was to determine whether HGF is a relevant marker of diagnosis and prognosis in AL. HGF serum levels were measured at diagnosis in patients with monoclonal gammopathy (MG) without AL (76 controls), or with biopsy-proven systemic AL (69 patients). HGF serum levels were significantly higher in patients with AL compared to controls, respectively, 11.2?ng/mL [min: 0.95–max: 200.4] versus 1.4?ng/mL [min: 0.82–max: 6.2] (p?<?0.0001). The threshold value of 2.2?ng/mL conferred optimal sensitivity (88%) and specificity (95%) to differentiate AL and monoclonal gammopathy of undetermined significance (MGUS) patients. Serum HGF concentrations were correlated positively with the severity of cardiac involvement and the serum level of monoclonal light chains. These data suggest that HGF measurement could be used in patients with MG to detect AL or to reinforce a clinical suspicion of AL and to guide indications for diagnostic tissue biopsies.     

Une maladie systémique mimant une polyarthrite rhumatoïde

IntroductionRare systemic diseases such as amyloidosis can mimic inflammatory rheumatic diseases. Because of their poor prognosis, physicians should rule them out at the onset of inflammatory rheumatism. We report a case of AL amyloidosis misdiagnosed as rheumatoid arthritis.Case reportA 71-year-old woman was referred for seronegative rheumatoid arthritis, resistant to three biologic therapies. She had an IgA lambda monoclonal gammopathy of undetermined significance (MGUS). The patient subsequently developed glomerular proteinuria. Abdominal fat and accessory salivary glands biopsies revealed amyloid light-chain (AL) amyloidosis. Treatment with bortezomib–cyclophosphamide–dexamethasone, led to complete hematologic, renal and rheumatologic remission. Ten months after treatment interruption, the patient had an articular and hematologic relapse.ConclusionAmyloid light-chain amyloidosis arthropathy is probably underdiagnosed. A review of amyloid arthropathy associated with multiple myeloma found that 33% of patients had been misdiagnosed with rheumatoid arthritis.     

Idiopathic AL amyloidosis and biclonal paraproteinemia: a case report and review of the literature.

A case of 79 year-old man suffering from nephrotic syndrome, infiltrative cardiomyopathy and sensitive neuropathy of the lower limbs, associated with biclonal gammopathy (IgG K and IgA A), is described. There was a history of non-insulin dependent diabetes mellitus and of two lung nodules considered as benign lesions on the basis of cytologic, hematologic and instrumental examination. A rectal biopsy positive for amyloid deposition (Congo red histology and immunofluorescence study) led to the diagnosis of AL amyloidosis. Considering that the patient did not fulfill diagnostic criteria for lymphoproliferative diaseases (myeloma, lymphoma or Waldenstr?m's macroglubulinemia), nor for secondary malignant paraproteinemia, a diagnosis of idiopathic AL amyloidosis with biclonal gammopathy was made. Very few cases of idiopathic AL amyloidosis with double component are reported in the literature. Our review suggests that idiopathic AL amyloidosis with biclonal gammopathy is similar to idiopathic AL amyloidosis with monoclonal paraproteinemia in terms of clinical features, response to therapy and prognosis. Further studies, however, are necessary to clarify the true incidence and the clinical features of idopathic AL amyloidosis associated with biclonal gammopathy.     

Chromosomal abnormalities in systemic amyloidosis

Primary systemic amyloidosis (AL) is a plasma cell disorder characterized by deposition of monoclonal light chains in different organ systems. Although multiple and complex numerical chromosomal abnormalities have been described in patients with multiple myeloma, it is currently unknown whether such changes occur in systemic amyloidosis.
Bone marrow samples from 21 patients with AL were studied by standard cytogenetics and interphase fluorescence in situ hybridization (FISH) for the presence of numerical chromosomal abnormalities. We tested for six chromosomes (7, 11, 9, 15, 18 and X) using centromere-specific probes. The monoclonal plasma cells were identified by simultaneous fluorescent staining of the monotypic cytoplasmic immunoglobulin. We compared these results with those obtained from 19 patients with monoclonal gammopathy of undetermined significance (MGUS) and normal controls.
Multiple numerical chromosomal abnormalities were detected in AL by interphase FISH, including trisomy of chromosomes 7 (42%), 9 (52%), 11 (47%), 15 (39%), 18 (33%) and X (13% in women and 54% in men). Monosomy of chromosome 18 was seen in 72% of cases. Previous exposure to alkylator therapy did not appear to correlate with these abnormalities. No significant difference was observed in the prevalence of these abnormalities between AL and MGUS.
Multiple chromosomal numerical abnormalities were detected by interphase FISH analysis in patients with AL, especially monosomy of chromosome 18. Aneuploidy in the monotypic plasma supports a neoplastic nature for the disorder.     

Nodular lung disease with five year survival and unilateral pleural effusion in AL amyloidosis

A 67-year-old female patient with biopsy proven AL systemic amyloidosis developed rapidly progressive dyspnea. Chest roentgenogram and CT scan revealed a large right pleural effusion in addition to nodular lesions with bilateral hilar lymphadenopathy. The patient's serum showed IgG λ type monoclonal gammopathy and she also had Bence Jones proteinuria. The pleural effusion was an exudate that contained many mononuclear cells and a high concentration of protein. Cardiac function was not seriously disturbed Except for amyloidosis, no other causes for the severe pleural effusion were found. This patient was treated with chemical pleurodesis using Picibanil and a low dose of prednisolone. Eighteen months after this treatment, her right pleural effusion did not recur. Bronchopulrnonary tissues are known to be frequently involved by AL systemic amyloidosis, but a nodular pattern of pulmonary amyloid deposition and a unilateral large pleural effusion are rare clinical manifestations in this disease.     

Nodular lung disease with five year survival and unilateral pleural effusion in AL amyloidosis.

A 67-year-old female patient with biopsy proven AL systemic amyloidosis developed rapidly progressive dyspnea. Chest roentgenogram and CT scan revealed a large right pleural effusion in addition to nodular lesions with bilateral hilar lymphadenopathy. The patient's serum showed IgG lambda type monoclonal gammopathy and she also had Bence Jones proteinuria. The pleural effusion was an exudate that contained many mononuclear cells and a high concentration of protein. Cardiac function was not seriously disturbed. Except for amyloidosis, no other causes for the severe pleural effusion were found. This patient was treated with chemical pleurodesis using Picibanil and a low dose of prednisolone. Eighteen months after this treatment, her right pleural effusion did not recur. Bronchopulmonary tissues are known to be frequently involved by AL systemic amyloidosis, but a nodular pattern of pulmonary amyloid deposition and a unilateral large pleural effusion are rare clinical manifestations in this disease.     

Successful heart transplantation following melphalan plus dexamethasone therapy in systemic AL amyloidosis

Recurrence in the allograft and progression in other organs increase mortality after cardiac transplantation in AL amyloidosis. Survival may be improved after suppression of monoclonal light chain (LC) production following high dose melphalan and autologous stem cell transplantation (HDM/ASCT). However, because of high treatment related mortality, this tandem approach is restricted to few patients without significant extra-cardiac involvement. A diagnosis of systemic AL amyloidosis was established in a 45-year old patient with congestive heart failure related to restrictive cardiomyopathy, nephrotic syndrome, peripheral neuropathy, postural hypotension, macroglossia, and lambda LC monoclonal gammopathy. After melphalan and dexamethasone (M-Dex) therapy, which resulted in 80% reduction of serum free lambda LC, he underwent orthotopic cardiac transplantation. Two years later, he remains in a sustained hematologic remission, with no evidence of allograft or extra-cardiac amyloid accumulation. M-Dex should be considered as an alternative therapy in AL amyloid heart transplant recipients ineligible for HDM/ASCT.     

Primary systemic amyloidosis presenting as polymyalgia rheumatica and giant cell arteritis

Primary systemic amyloidosis or AL-amyloidosis is an uncommon disease characterized by the accumulation in vital organs of a fibrillar protein consisting of monoclonal light chains. It is a plasma-cell dyscrasia related to multiple myeloma where clonal plasma cells in the bone marrow produce immunoglobulins that are amyloidogenic. A monoclonal component is present in the serum or urine of 90% of patients. The presentation of most patients with AL amyloidosis is usually related to congestive heart failure, nephrotic syndrome o peripheral neuropathy, but there are unusual features suggesting giant cell arteritis (GCA) and polymyalgia rheumatic (PMR). Although in the majority of AL cases the plasma cells clone is small, the assumption is that the outcome of the disease is uniformly fatal (median survival 12-15 months) and treatment is analogous to those used in malignant proliferative disease. We describe a patient with AL amyloidosis who presented with manifestations of GCA and PMR, and we review the main characteristics of primary amyloidosis.     

Senile systemic amyloidosis presenting with heart failure: a comparison with light chain-associated amyloidosis

BACKGROUND: Small deposits of amyloid are often found in the hearts of elderly patients. However, extensive deposition of transthyretin-derived amyloid fibrils in the heart (senile systemic amyloidosis [SSA]) can cause heart failure. The clinical features of SSA that involve the heart are ill defined, and the condition may be overlooked as a cause of heart failure. We sought to better define the clinical, echocardiographic, and electrocardiographic features of cardiac involvement in SSA and to compare them with the findings in patients with light chain-associated (AL) amyloidosis that affects the heart. METHODS: Eighteen consecutive patients with SSA and heart failure evaluated at a tertiary referral center for the diagnosis and treatment of amyloidosis were compared with 18 randomly selected patients with AL amyloidosis that involved the heart. All patients underwent a complete clinical and biochemical evaluation. Echocardiograms and electrocardiograms were interpreted by blinded investigators. RESULTS: Patients with SSA were older than those with AL amyloidosis and were all male. Proteinuria (protein output of >1 g per 24 hours) was common in AL amyloidosis but was not present in SSA. Left ventricular wall thickness was greater in patients with SSA than those with AL amyloidosis, but despite thicker walls and older age, the severity of heart failure was less in the SSA group and the median survival was much longer (75 vs 11 months; P = .003). CONCLUSIONS: Senile systemic amyloidosis is a disorder of elderly men and is characterized by amyloidosis clinically limited to the heart. In contrast to the rapid progression of heart failure in AL amyloidosis, SSA results in slowly progressive heart failure. The difference in survival, despite evidence of more myocardial disease in the senile group, suggests that heart failure in AL amyloidosis may have a toxic component, possibly related to the circulating monoclonal light chain.     

Systemic lupus erythematosus and multiple myeloma: an uncommon association. Two cases and literature review

The association of systemic lupus erythematosus and multiple myeloma is uncommon. We report two cases of systemic lupus erythematosus associated to multiple myeloma. The cases are discussed in the light of a review of the literature. The clinical, laboratory and radiographic findings of the patients, as well as the subsequent therapeutic approach are discussed. A systematic review of all the other cases of this association is performed. We report two female patients of 50 and 35 years old who developed a multiple myeloma seven and three years respectively after the diagnosis of systemic lupus erythematosus. In the second case, systemic lupus erythematosus was associated to monoclonal gammopathy. One patient died after three months and one patient is still in remission after three years of the diagnosis of multiple myeloma. The coexistence of systemic lupus erythematosus and multiple myeloma is very rare and the possible pathogenetic mechanisms underlying this association remain unclear.     

The evolving use of serum free light chain assays in haematology

Over the last few years new immunoassays have emerged that allow the measurement of free immunoglobulin light chains (FLCs) in serum to a level of 2-4 mg/l and provide a much greater sensitivity than older methods, such as immunofixation, which is able to detect FLCs at a minimum concentration of 100-150 mg/l. The new FLC assay has enabled the detection of monoclonal protein in some patients with non-secretory myeloma and amyloidosis that were previously undetectable. FLC measurements are quantitative, correlating with disease activity, and are an advance in monitoring light chain only multiple myeloma, AL amyloidosis, non-secretory and oligo-secretory multiple myeloma. Serum FLC concentrations also reflect the disease course in the majority of myeloma patients producing intact monoclonal immunoglobulin proteins and have been incorporated into the new response criteria. The rapid half life of lambda and kappa free light chains means that FLC assays may provide a more rapid indication of the response to treatment but their clinical utility in this setting needs further study. An abnormal FLC ratio has been shown to be a risk factor for progression of monoclonal gammopathy of undetermined significance, smouldering myeloma and solitary plasmacytoma of bone and is prognostic in multiple myeloma.     

Lenalidomide and dexamethasone in the treatment of AL amyloidosis: results of a phase 2 trial

In immunoglobulin light chain (AL) amyloidosis, amyloid fibril deposits derived from immunoglobulin light chains produced by a clonal plasma cell dyscrasia accumulate in tissues and damage vital organs. Treatment regimens used in multiple myeloma can be effective in AL amyloidosis; however, patients with this disease often tolerate these regimens poorly because of multisystem organ dysfunction. Thalidomide and lenalidomide have both been shown to be effective in myeloma. In this report, we describe results of a phase 2 trial of the use of lenalidomide, as a single agent and in combination with dexamethasone, for the treatment of AL amyloidosis. Thirty-four patients with AL amyloidosis, most with prior therapies, were enrolled in the trial. The initial dose of lenalidomide used (25 mg/d) was poorly tolerated; however, a reduced dose of 15 mg/d was generally well tolerated. Of 24 evaluable patients, 7 (29%) achieved a hematologic complete response and 9 (38%) achieved a partial hematologic response, for an overall hematologic response rate of 67%. Hematologic responses were also associated with clinical responses. Fatigue and myelosuppression were the most common treatment-related adverse events (35%), while thromboembolic complications (9%) were the most serious. Findings from this trial indicate that lenalidomide can be effective in treating AL amyloidosis.     

Clinical characteristics and outcomes in biclonal gammopathies

A single monoclonal protein typically characterizes monoclonal gammopathies, but a small proportion may have more than one M protein identifiable. In the setting of symptomatic multiple myeloma (MM), the development of a new monoclonal protein following therapy is associated with better outcomes. As for the precursor conditions, monoclonal gammopathy undetermined significance (MGUS) and smoldering multiple myeloma (SMM), there is limited information on the impact of a second monoclonal protein on the disease course, including progression and response to treatment. The outcomes of patients with MGUS and SMM with more than one monoclonal protein, after identifying 539 patients with biclonal proteins on electrophoresis and/or immunofixation, were reported. About 22 of 393 patients with MGUS/biclonal gammopathy of undetermined significance (BGUS) progressed to SMM (6), MM (11), AL (3), or WM (2), and 5 of 16 patients with biclonal SMM progressed to MM. The rate of progression for BGUS was approximately 1% per year, which is similar to MGUS with one monoclonal protein. The median estimated time of progression of biclonal SMM was 2.6 years; similar to monoclonal SMM. For patients with biclonal MM, both M spikes responded to treatment and, upon relapse, the original dominant M protein remained dominant as the disease progressed. In conclusion, the presence of a second monoclonal protein does not appear to affect the progression of precursor states and suggests multiple monoclonal proteins do not clinically impact one another in the course of the disease. Am. J. Hematol. 91:473–475, 2016. © 2016 Wiley Periodicals, Inc.