Paola Russo

The combination of high-sensitivity cardiac troponin T (hs-cTnT) at presentation and changes in N-terminal natriuretic peptide type B (NT-proBNP) after chemotherapy best predicts survival in AL amyloidosis

In light-chain (AL) amyloidosis, prognosis is dictated by cardiac dysfunction. N-terminal natriuretic peptide type B (NT-proBNP) and cardiac troponins (cTn) are used to assess the severity of cardiac damage. We evaluated the prognostic relevance of a high-sensitivity (hs) cTnT assay, NT-proBNP, and cardiac troponin I in 171 consecutive patients with AL amyloidosis at presentation and 6 months after treatment. Response and progression of NT-proBNP were defined as more than 30% and more than 300 ng/L changes. All 3 markers predicted survival, but the best multivariable model included hs-cTnT. The hs-cTnT prognostic cutoff was 77 ng/L (median survival 10.6 months for patients with hs-cTnT above the cutoff). After treatment, response and progression of NT-proBNP and a more than 75% increase of hs-cTnT were independent prognostic determinant. In AL amyloidosis, hs-cTnT is the best baseline prognostic marker. Therapy should be aimed at preventing progression of cardiac biomarkers, whereas NT-proBNP response confers an additional survival benefit.

Identification of Amyloidogenic Light Chains Requires the Combination of Serum-Free Light Chain Assay with Immunofixation of Serum and Urine

BACKGROUNDnThe diagnosis of systemic immunoglobulin light-chain (AL) amyloidosis requires demonstration of amyloid deposits in a tissue biopsy and amyloidogenic monoclonal light chains. The optimal strategy to identify the amyloidogenic clone has not been established. We prospectively assessed the diagnostic sensitivity of the serum free light chain (FLC) kappa/lambda ratio, a commercial serum and urine agarose gel electrophoresis immunofixation (IFE), and the high-resolution agarose gel electrophoresis immunofixation (HR-IFE) developed at our referral center in patients with AL amyloidosis, in whom the amyloidogenic light chain was unequivocally identified in the amyloid deposits.nnnMETHODSnThe amyloidogenic light chain was identified in 121 consecutive patients with AL amyloidosis by immunoelectron microscopy analysis of abdominal fat aspirates and/or organ biopsies. We characterized the monoclonal light chain by using IFE and HR-IFE in serum and urine and the FLC kappa/lambda ratio in serum. We then compared the diagnostic sensitivities of the 3 assays.nnnRESULTSnThe HR-IFE of serum and urine identified the amyloidogenic light chain in all 115 patients with a monoclonal gammopathy. Six patients with a biclonal gammopathy were omitted from the statistical analysis. The diagnostic sensitivity of commercial serum and urine IFE was greater than that of the FLC kappa/lambda ratio (96% vs 76%). The combination of serum IFE and the FLC assay detected the amyloidogenic light chain in 96% of patients. The combination of IFE of both serum and urine with the FLC kappa/lambda ratio had a 100% sensitivity.nnnCONCLUSIONSnThe identification of amyloidogenic light chains cannot rely on a single test and requires the combination of a commercially available FLC assay with immunofixation of both serum and urine.

Salvage therapy with lenalidomide and dexamethasone in patients with advanced AL amyloidosis refractory to melphalan, bortezomib, and thalidomide

The increasing number of effective agents allows rescue therapy of patients with light-chain (AL) amyloidosis refractory to ≥2 previous treatments. Lenalidomide is effective in this disease and its toxicity profile encourages its use in salvage regimens. All the patients with AL amyloidosis refractory to both melphalan and bortezomib referred to our center between July 2007 and July 2009 were treated with the combination of lenalidomide and dexamethasone. Twenty-four consecutive patients were enrolled. Seventy-nine percent were also refractory to thalidomide. Two patients died before evaluation of response, and 50% experienced severe adverse events. Survival was significantly shorter in subjects with troponin I >0.1xa0ng/mL and in patients diagnosed <18xa0months before treatment initiation. Hematologic response was observed in 41% of patients and prolonged survival (median 10xa0months vs. not reached, Pu2009=u20090.005) independently from troponin I concentration and from pre-treatment disease duration. Salvage therapy beyond second line of treatment can improve survival in AL amyloidosis and lenalidomide plus dexamethasone is a valuable option in this setting.

Treatment of patients with advanced cardiac AL amyloidosis with oral melphalan, dexamethasone, and thalidomide

Patients with primary (AL) amyloidosis and heart failure have a very poor prognosis and cannot tolerate aggressive therapy, such as autologous stem cell transplantation and high-dose dexamethasone-based regimens. We prospectively treated 22 patients with advanced cardiac amyloidosis combining oral melphalan, thalidomide, and reduced intensity dexamethasone (MTD). Six patients died due to cardiac amyloidosis before completing cyclexa03. Early death was associated with reduced ejection fraction. Eight patients achieved a hematological response and four achieved a durable improvement of cardiac dysfunction. Treatment with MTD is feasible in patients with advanced cardiac AL amyloidosis and effective in subjects with preserved systolic function.

Best use of cardiac biomarkers in patients with AL amyloidosis and renal failure.

In AL amyloidosis prognosis depends on the severity of heart dysfunction which is best assessed by natriuretic peptides (BNP and NT‐proBNP). However, their clearance relies on glomerular filtration rate (GFR) and their concentration increases with renal failure. We evaluated the diagnostic and prognostic performance of NT‐proBNP and BNP in 248 patients with AL amyloidosis with different degrees of renal failure. Patients were grouped according to GFR. Group 1 comprised 109 patients with GFR ≥60 mL/min/1.73 m2, Group 2, 77 subjects with GFR <60 and ≥15 mL/min/1.73 m2, and Group 3, 62 patients with GFR <15 mL/min/1.73 m2. The ability of natriuretic peptides to detect heart involvement and to predict survival in the three groups was assessed. Decreasing eGFR required higher cutoffs of both NT‐proBNP and BNP for detecting heart involvement and predicting survival. Both natriuretic peptides were independent prognostic markers in Groups 1 and 2, whereas in Group 3 only BNP independently predicted survival. Natriuretic peptides are powerful and useful markers of cardiac dysfunction and prognosis, provided that eGFR is considered in interpreting their clinical meaning. BNP should be preferred in patients with end‐stage renal failure. Am. J. Hematol. 87:465–471, 2012.

The workings of the amyloid diseases

The amyloidoses constitute a large group of diseases caused by an alteration in the conformation and metabolism of several globular proteins which, under particular conditions, deposit in tissues as insoluble fibrillar aggregates. To date, at least 24 different proteins have been recognized as causative agents of amyloid diseases. Despite a high heterogeneity in amino acid sequence, three‐dimensional structure, and biological function, all amyloidogenic proteins share a reduced folding stability, a strong propensity to acquire more than one conformation, and the capacity to form almost indistinguishable amyloid fibrils. In some cases, the generation of an aggregation‐prone state can be triggered or enhanced by the occurrence of mutations, a proteolytic cleavage, or a seeding process. The interaction between the amyloidogenic precursor, some common components of amyloid deposits, and the extra‐cellular environment also plays a role in fibrillogenesis and in particular in the organ tropism of amyloid deposition. The process of amyloid fibril formation exerts a cytotoxic effect, resulting in tissue damage and organ dysfunction. Prefibrillar aggregates are thought to have an active part in this process. Due to the pathogenic complexity of amyloid diseases, the integration of several therapeutic interventions involving different critical levels of the amyloidogenic cascade is envisaged.

A phase II trial of cyclophosphamide, lenalidomide and dexamethasone in previously treated patients with AL amyloidosis

Immune-modulatory drugs are active in immunoglobulin light-chain amyloidosis and the addition of alkylating agents can potentiate their action. In this phase II prospective trial we used cyclophosphamide, lenalidomide and dexamethasone in the treatment of 21 patients who were refractory (n=13, 62%) or relapsed (n=8, 38%) after prior treatment including melphalan in all cases, bortezomib in 4 and thalidomide in 6. Median number of cycles administered was 4 (range 2–9 cycles). Severe adverse events were observed in 57% of patients, most common being neutropenia (29%). The hematologic response rate was 62%, with one complete response and 5 very good partial responses. Overall median survival was three years. The achievement of CR/VGPR was associated with a significant survival advantage. The combination of cyclophosphamide, lenalidomide and dexamethasone is an effective treatment for relapsed/refractory AL amyloidosis, and good quality hematologic response should be the aim of treatment in this setting. (clinicaltrials.gov identifier: NCT00607581)

The role of minor salivary gland biopsy in the diagnosis of systemic amyloidosis: results of a prospective study in 62 patients.

Histological demonstration of amyloid deposits is required for the diagnosis of amyloidosis. Less invasive approaches than the biopsy of the organs involved, such as abdominal fat and salivary gland biopsy are feasible. In AL amyloidosis, abdominal fat sensitivity is approximately 80%. We report the results of salivary gland biopsy in 62 consecutive patients with suspected systemic amyloidosis and negative abdominal fat aspirates. Amyloid deposits were detected in 7 of the 12 patients in whom amyloidosis was eventually diagnosed. The deposits were characterized as AL l in 4 cases (57%), AL k in 2 (29%), and AA in 1 (14%). In the remaining five patients, amyloidosis was diagnosed by organ biopsy and characterized as AL l in three subjects and AL k in two. Overall, the diagnostic sensitivity of the salivary gland biopsy in patients with negative fat aspirate was 58%, specificity 100% and negative predictive value 91%. A sequential diagnostic approach based on second-step salivary gland biopsy can spare organ biopsy to more than half the patients with systemic amyloidosis. Introduction: Histological demonstration and accurate characterization of amyloid deposit is pivotal in the diagnosis of amyloidosis [1,2]. When amyloidosis is suspected, biopsy of the involved organ could be performed. Although recent patient series do not confirm the previously reported increased risk of bleeding associated with organ biopsy in systemic amyloidoses [3,4], the ready availability of alternative, less invasive, biopsy sites, such as abdominal fat and minor salivary gland, represent appealing alternatives to organ biopsy. In a large series of patients referred for suspected systemic amyloidosis, we recently reported that the sensitivity of abdominal fat is 87% [5]. Thus, approximately 15% of patients with systemic amyloidosis are not diagnosed by abdominal fat aspirate alone. Minor salivary gland biopsy is a simple and safe technique that has been shown to be highly sensitive for the diagnosis of immunoglobulin light chain (AL) amyloidosis [6–9], as well as of familial amyloid polyneuropathy Portuguese type [10]. In this study, we report the results of a sequential approach in patients with suspected systemic amyloidosis and negative abdominal fat aspirate, in whom minor salivary gland biopsy was employed as second step. Methods: Sixty-two consecutive patients referred to the Pavia Amyloidosis Research and Treatment Center between 2002 and 2007 for suspected systemic amyloidosis, in whom amyloid deposit were not detected in the abdominal fat aspirates underwent minor salivary gland biopsy. The patients gave written informed consent according to the Institutional Review Board guidelines. In all subjects, evidence of a plasma cell clone was searched by serum and urine high resolution immunofixation electrophoresis and by the free light chain assay [11]. Mutations related to hereditary systemic amyloidosis were searched by DNA analysis. The salivary gland biopsies were performed in the Department of Rheumatology of the Fondazione IRCCS Policlinico San Matteo, Pavia as previously described [9]. Briefly, after evaluation of the coagulation parameters, minor salivary glands were located by visual inspection and the area disinfected and anesthetized. A small incision was made with a scalpel, and the salivary gland was removed with a biopsy forceps. The sample collected were fixed in formalin and stained with hematoxylin and eosin and Congo red. Congo red stain was performed according to Westermark et al. [12]. Samples deemed positive were analyzed by immuno-electron microscopy [13]. Ultrathin sections were stained with uranyl acetate 5% and lead and scanned with a Philips CM12 electron microscope. To characterize the constitutive protein monoclonal or polyclonal antibodies were employed. In Figure 1, the results of the staining of the salivary biopsy are shown. The diagnosis of amyloidosis was eventually excluded in the remaining patients who were followed for at least 2 years after the salivary gland biopsy or until the cause underlying their clinical syndrome was identified. Results and conclusions: Sixty-two patients were included in the study. Their median age was 62 years (range, 29–79 years) and 68% were males. In 39 patients (63%), a monoclonal component was detected. The monoclonal protein was k in 15 (24%) subjects, l in 21 (34%), and 3 patients (5%) had a biclonal gammopathy. The clinical features leading to suspect systemic amyloidosis in this patient population was nephrotic syndrome in 39 subjects (63%), 18 patients (29%) had an elevated mean left ventricular wall thickness (mLVW), carpal tunnel syndrome and peripheral neuropathy were 80

AL Amyloidosis Associated with IgM Monoclonal Protein: A Distinct Clinical Entity

IgM-associated AL amyloidosis is rare and may represent a distinct entity. Sixty (7%) of 868 consecutive AL patients referred to our center had an IgM monoclonal protein. They were significantly older than non-IgM patients (median, 67 years vs. 62 years), had a higher frequency of lymph-node involvement (25% vs. 2%) and significantly lower median proteinuria (1.2 g/24h vs. 3.4 g/24h), N-terminal pro-natriuretic peptide type-B (1177 ng/L vs. 2135 ng/L) and troponin I (0.02 ng/mL vs. 0.05 ng/mL). In IgM patients, kappa light-chains were more frequent (42% vs. 23%) and the involved free light-chain concentration was lower (median 63 mg/L vs. 182 mg/L). Serum albumin and NT-proBNP were independent prognostic determinants. Response to treatment improved survival. The 14 patients who received melphalan/dexamethasone showed a 64% hematologic (complete remissions, 29%) and a 43% organ response rate. IgM-associated AL amyloidosis is a distinct entity, with less advanced organ dysfunction. Treatment with melphalan/ dexamethasone might be effective in these patients.

Nutritional status independently affects quality of life of patients with systemic immunoglobulin light-chain (AL) amyloidosis

Nutritional status is an independent prognostic factor in immunoglobulin light-chain amyloidosis (AL), but its influence on quality of life (QoL) is unknown. The aim of this cross-sectional study was to investigate the association between nutritional status and QoL in AL patients at diagnosis. One hundred and fifty consecutive patients with biopsy-proven AL were assessed for nutritional status by anthropometry [body mass index, unintentional weight loss (WL) in the previous 6xa0months and mid-arm muscle circumference (MAMC)], biochemistry (serum prealbumin), and semiquantitative food intake at referral. QoL was assessed by the Medical Outcomes Study 36-item Short Form General Health Survey. The composite physical component summary (PCS) and the mental component summary (MCS) for AL outpatients were 36.2u2009±u200910.1 and 44.9u2009±u200911.3, respectively (pu2009<u20090.001 for both vs the population norms of 50). In multivariate linear regression models adjusted for gender, age, Eastern Cooperative Oncology Group performance status, the number of organs involved, the severity of cardiac damage, C-reactive protein, energy intake, and WL, PCS was significantly lower for serum prealbumin <200xa0mg/L and MAMC <10th percentile (adjusted difference 3.8, 95% CI 0.18–7.5, pu2009=u20090.040 and 5.3, 95% CI 2.0–8.7, pu2009=u20090.002, respectively). MCS was decreased by 0.47 (95% CI 0.18–0.75, pu2009=u20090.002) for each kilogram of body weight lost in the previous 6xa0months. Nutritional status independently affects QoL in AL patients since diagnosis. Nutritional evaluation should be integral part of the clinical assessment of AL patients. Nutritional support intervention trials are warranted in such patients population.