Leung, Nelson

Abstract Smoldering multiple myeloma (SMM) bridges the gap between monoclonal gammopathy of undetermined significance (a mostly premalignant disorder) and active multiple myeloma (MM). Until recently, no interventional study in patients with SMM showed improved overall survival (OS) with therapy as compared with observation. A report from the PETHEMA-GEM (Programa Español de Tratamientos en Hematologica) group described both fewer myeloma-related events and better OS among patients with high-risk SMM who were treated with lenalidomide and dexamethasone. This unique study prompted us to review current knowledge about SMM and address the following questions: (1) Are there patients currently defined as SMM who should be treated routinely? (2) Should the definitions of SMM and MM be reconsidered? (3) Has the time come when not treating is more dangerous than treating? (4) Could unintended medical harm result from overzealous intervention? Our conclusion is that those patients with the highest-risk SMM (extreme bone marrow plasmacytosis, extremely abnormal serum immunoglobulin free light chain ratio, and multiple bone lesions detected only by modern imaging) should be reclassified as active MM so that they can receive MM-appropriate therapy and the paradigm of careful observation for patients with SMM can be preserved.

Abstract Recently, the term monoclonal gammopathy of renal significance (MGRS) was introduced to distinguish monoclonal gammopathies that result in the development of kidney disease from those that are benign. By definition, patients with MGRS have B-cell clones that do not meet the definition of multiple myeloma or lymphoma. Nevertheless, these clones produce monoclonal proteins that are capable of injuring the kidney resulting in permanent damage. Except for immunoglobulin light chain amyloidosis with heart involvement in which death can be rapid, treatment of MGRS is often indicated more to preserve kidney function and prevent recurrence after kidney transplantation rather than the prolongation of life. Clinical trials are rare for MGRS-related kidney diseases, except in immunoglobulin light chain amyloidosis. Treatment recommendations are therefore based on the clinical data obtained from treatment of the clonal disorder in its malignant state. The establishment of these treatment recommendations is important until data can be obtained by clinical trials of MGRS-related kidney diseases.

Key PointsRadiation is appropriate primary therapy in approximately 25% of cases. Radiation provides long-term remissions in more than 50% of patients.

To clarify the presentation and course of patients with chronic lymphocytic leukemia (CLL) and amyloidosis. Mayo databases were interrogated for patients who carried a diagnosis of amyloidosis and CLL evaluated at Mayo Clinic, Rochester from January 1974 to October 2012. Charts were abstracted and data analyzed. Of the 33 patients identified, 20 (61%) were diagnosed with AL and 13 (39%) with non‐AL. Only four patients had immunoglobulin light chain amyloidosis (AL) that could be solely attributed to the CLL clone; another six had both a plasma cell clone and a CLL clone that shared the same light chain. Median overall survival was 15.6 months for patients with AL and 58.1 months for patients with non‐AL. For patients with AL management involved chemotherapy targeted toward monoclonal plasma cells, lymphocytes or both, and for patients with non‐AL no specific amyloid treatment was administered. AL is a rare complication of CLL, but in this elderly population of patients non‐AL is nearly as common. Distinguishing between these two groups is essential since patients with non‐AL amyloidosis have better outcomes and they do not require cytotoxic chemotherapy to treat their amyloidosis. Am. J. Hematol. 88:375–378, 2013. © 2013 Wiley Periodicals, Inc.

AbstractMultiple myeloma is the most frequent monoclonal gammopathy to involve the kidney; however, a growing number of kidney diseases associated with other monoclonal gammopathies are being recognized. Although many histopathologic patterns exist, they are all distinguished by the monoclonal immunoglobulin (or component) deposits. The hematologic disorder in these patients is more consistent with monoclonal gammopathy of undetermined significance (MGUS) than with multiple myeloma. Unfortunately, due to the limitations of the current diagnostic schema, they are frequently diagnosed as MGUS. Because treatment is not recommended for MGUS, appropriate therapy is commonly withheld. In addition to end-stage renal disease, the persistence of the monoclonal gammopathy is associated with high rates of recurrence after kidney transplantation. Preservation and restoration of kidney function are possible with successful treatment targeting the responsible clone. Achievement of hematologic complete response has been shown to prevent recurrence after kidney transplantation. There is a need for a term that properly conveys the pathologic nature of these diseases. We think the term monoclonal gammopathy of renal significance is most helpful to indicate a causal relationship between the monoclonal gammopathy and the renal damage and because the significance of the monoclonal gammopathy is no longer undetermined.

ABSTRACT The vancomycin dose necessary for the achievement of target serum trough concentrations during continuous venovenous hemofiltration (CVVH) remains to be elucidated. This was a retrospective cohort study of critically ill adults at a tertiary medical center on concurrent CVVH and vancomycin between 2006 and 2010 with a steady-state vancomycin trough concentration. The 87 included patients were grouped according to low (≤30 ml/kg/h; n = 10) or high (>30 ml/kg/h; n = 77) CVVH hemofiltration rate (HFR) for analysis. Vancomycin goal trough achievement occurred in only 32 (37%) patients. The primary endpoint of trough attainment significantly differed between HFR subgroups: 90% versus 30% in low- and high-HFR individuals, respectively ( P < 0.001). Patients with subtherapeutic trough concentrations had a median (interquartile range) HFR of 40 ml/kg/h (range, 37 to 47 ml/kg/h) compared to 36 ml/kg/h (range, 30 to 39 ml/kg/h) in those who achieved the trough goal. Irrespective of goal trough, an inverse correlation existed between HFR and serum vancomycin concentration ( r = −0.423; P < 0.001). In the subgroup of 14 methicillin-resistant Staphylococcus aureus (MRSA) patients, trough achievement was similar to the aggregate cohort (36%). Mortality at 28 days was unrelated to trough achievement in both the overall sample ( P = 0.516) and in culture-positive MRSA patients ( P = 0.396). Critically ill patients undergoing CVVH therapy may experience clinically significant reductions in goal vancomycin troughs. The results of the present study justify prospective evaluations in this population to determine the optimal vancomycin dosing strategy for attainment of goal trough concentrations.

AbstractAmyloidosis is a rare group of diseases characterized by deposition of amyloid fibrils in soft tissues. More than 28 types of amyloid have been identified. They all share common ultrastructural and chemical characteristics. Treatments are available for many types but are type specific. Therefore, confirmation and typing of amyloid are essential before initiating treatment. Monoclonal protein studies should be performed on suspected cases, but the diagnosis requires a tissue biopsy. Congo red stain and electron microscopy are helpful to discriminate between amyloid and other pathologic fibrils. Once amyloid is confirmed, typing should be performed. Immunofluorescence and immunohistochemistry are frequently used and are helpful, but this approach has limitations, such as availability, specificity and sensitivity of commercial antibodies. Genetic mutational analysis is vital for ruling in and out hereditary amyloidoses but is unhelpful in nonmutated forms. The most advanced technique of amyloid typing is laser microdissection followed by mass spectrometry. Using proteomics, laser microdissection followed by mass spectrometry can directly identify proteins with or without mutations. Finally, imaging studies, such as cardiac MRI with gadolinium and 123I-labeled SAP scintigraphy not only assist in evaluation of patients with known amyloidosis but cardiac MRI has detected amyloid in patients previously unsuspected of the disease.

Purpose Cardiac involvement predicts poor prognosis in light chain (AL) amyloidosis, and the current prognostic classification is based on cardiac biomarkers troponin-T (cTnT) and N-terminal pro–B-type natriuretic peptide (NT-ProBNP). However, long-term outcome is dependent on the underlying plasma cell clone, and incorporation of clonal characteristics may allow for better risk stratification. Patients and Methods We developed a prognostic model based on 810 patients with newly diagnosed AL amyloidosis, which was further examined in two other datasets: 303 patients undergoing stem-cell transplantation, and 103 patients enrolled onto different clinical trials. Results We examined the prognostic value of plasma cell–related characteristics (ie, difference between involved and uninvolved light chain [FLC-diff], marrow plasma cell percentage, circulating plasma cells, plasma cell labeling index, and β 2 microglobulin). In a multivariate model that included these characteristics as well as cTnT and NT-ProBNP, only FLC-diff, cTnT, and NT-ProBNP were independently prognostic for overall survival (OS). Patients were assigned a score of 1 for each of FLC-diff ≥ 18 mg/dL, cTnT ≥ 0.025 ng/mL, and NT-ProBNP ≥ 1,800 pg/mL, creating stages I to IV with scores of 0 to 3 points, respectively. The proportions of patients with stages I, II, III and IV disease were 189 (25%), 206 (27%), 186 (25%) and 177 (23%), and their median OS from diagnosis was 94.1, 40.3, 14, and 5.8 months, respectively (P < .001). This classification system was validated in the other datasets. Conclusion Incorporation of serum FLC-diff into the current staging system improves risk stratification for patients with AL amyloidosis and will help develop risk-adapted therapies for AL amyloidosis.

Abstract High-dose melphalan (HDM) plus stem cell transplantation is an effective treatment for light-chain amyloidosis (AL), but is associated with high treatment-related mortality in patients with cardiac involvement. We studied 187 patients with cardiac involvement with AL who underwent HDM between 1996 and 2008. The median age was 57 years and the median time from diagnosis to HDM was 3.6 months. Half of the patients received reduced-dose melphalan (100-160 mg/m2). The median overall survival (OS) was 66 months, 54 months from diagnosis and HDM, respectively, and 91 patients (49%) were alive at the last follow-up 52 months (median) from HDM. Thirty patients (16%) died within 100 days of transplantation; only low serum albumin predicted early deaths. Overall, hematologic response (HR) and cardiac responses were seen in 66% and 41% of patients, respectively. The median OS for patients with and without HR was not reached and 22 months, respectively (P < .01); and for those with any decrease and no decrease in N-terminal-pro-brain natriuretic peptide was not reached and 26 months, respectively (P < .01). In multivariate analysis of baseline factors, only reduced-dose melphalan predicted shorter OS. HDM is feasible in patients with cardiac amyloidosis, and achievement of HR and organ response is associated with improved survival.

Abstract IgD monoclonal gammopathies are uncommon. They are seen rarely as a monoclonal gammopathy of undetermined significance and are present in 1%-2% of patients with multiple myeloma. In light-chain amyloidosis, IgD monoclonal proteins are found in ap-proximately 1% of patients. When an IgD monoclonal protein is found, amyloidosis is often omitted from the differential diagnosis. In the present study, we reviewed the natural history of IgD-associated amyloidosis among 53 patients seen over 41 years. The distribution of clinical syndromes suggests that these patients have a lower frequency of renal and cardiac involvement. The overall survival of these patients does not appear to be different from that of patients who have light-chain amyloidosis associated with another monoclonal protein.