International Myeloma Working Group guidelines for serum-free light chain analysis in multiple myeloma and related disorders. Leukemia. 2009;23:215-224. [PMID: 19020545 DOI: 10.1038/leu.2008.307]

Importance of achieving a complete response in multiple myeloma, and the impact of novel agents

The goal of treatment for multiple myeloma (MM) is to improve patients' long-term outcomes. One important factor that has been associated with prolonged progression-free and overall survival is the quality of response to treatment, particularly achievement of a complete response (CR). There is extensive evidence from clinical studies in the transplant setting in first-line MM demonstrating that CR or maximal response post-transplant is significantly associated with prolonged progression-free and overall survival, with some studies demonstrating a similar association with postinduction response. Supportive evidence is also available from studies in the nontransplant and relapsed settings. With the introduction of bortezomib, thalidomide, and lenalidomide, higher rates of CR are being achieved in both first-line and relapsed MM compared with previous chemotherapeutic approaches, thereby potentially improving long-term outcomes. While standard CR by established response criteria has been shown to have differential prognostic impact compared with lesser responses, increasingly sensitive analytic techniques are now being explored to define more stringent degrees of CR or elimination of minimal residual disease (MRD), including multiparameter flow cytometry and polymerase chain reaction. Demonstrating eradication of MRD by these techniques has already been shown to predict for improved outcomes. Here, we review the prognostic significance of achieving CR in MM and highlight the importance of CR as an increasingly realizable goal at all stages of treatment. We discuss clinical management issues and provide recommendations relevant to practicing oncologists, such as the routine use of sensitive techniques for assessment of disease status to inform evidence-based decisions on optimal patient management.

High-dose therapy and autologous stem-cell transplantation in Waldenstrom macroglobulinemia: the Lymphoma Working Party of the European Group for Blood and Marrow Transplantation

PURPOSE

The role of autologous stem-cell transplantation (ASCT) in Waldenström macroglobulinemia (WM) is not defined. The aim of this study was to analyze the results of ASCT in patients with WM and to determine the prognostic factors that have a significant impact on outcome.

PATIENTS AND METHODS

We analyzed 158 adult patients with WM reported to the European Group for Blood and Marrow Transplantation (EBMT) between January 1991 and December 2005. Median time from diagnosis to ASCT was 1.7 years (range, 0.3 to 20.3 years), 32% of the patients experienced treatment failure with at least three lines of therapy, and 93% had sensitive disease at the time of ASCT. Conditioning regimen was total-body irradiation-based in 45 patients. Median follow-up for surviving patients was 4.2 years (range, 0.5 to 14.8 years).

RESULTS

Nonrelapse mortality was 3.8% at 1 year. Ten patients developed a secondary malignancy, with a cumulative incidence of 8.4% at 5 years. Relapse rate was 52.1% at 5 years. Progression-free survival (PFS) and overall survival were 39.7% and 68.5%, respectively, at 5 years and were significantly influenced by number of lines of therapy and chemorefractoriness at ASCT. The achievement of a negative immunofixation after ASCT had a positive impact on PFS after ASCT. When used as consolidation at first response, ASCT provided a PFS of 44% at 5 years.

CONCLUSION

ASCT is a feasible procedure in young patients with advanced WM. ASCT should not be offered to patients with chemoresistant disease and to those who received more than three lines of therapy.

Multiple myeloma treatment response assessment with whole-body dynamic contrast-enhanced MR imaging

PURPOSE

To compare posttreatment bone marrow changes at whole-body dynamic contrast material-enhanced magnetic resonance (MR) imaging with clinical response in patients with multiple myeloma (MM) and to determine if this technique can be used to assess treatment response in patients with MM.

MATERIALS AND METHODS

This study was approved by an institutional review board; all patients gave informed written consent. Thirty patients (21 men, nine women; mean age, 58 years +/- 10 [standard deviation]) underwent whole-body dynamic contrast-enhanced MR imaging before treatment, after induction chemotherapy (n = 30), and after autologous stem cell transplantation (ASCT) (n = 20). Maximal percentages of bone marrow (BME(max)) and focal lesion (FLE(max)) enhancement were assessed at each MR imaging examination. Clinical responses were determined on the basis of international uniform response criteria. Posttreatment changes in BME(max)and FLE(max)were compared with clinical response to therapy by using the Mann-Whitney U test. Receiver operating characteristic (ROC) analysis of posttreatment BME(max)was used to identify poor responders.

RESULTS

Eleven of 30 patients were good responders to induction chemotherapy; 16 of 20 patients were good responders to ASCT. After induction chemotherapy, mean BME(max)differed between good and poor responders (94.3% vs 138.4%, respectively; P = .02). With the exclusion of results from six examinations with focal lesions in which a poor clinical response was classified but BME(max)had normalized, a posttreatment BME(max)of more than 96.8% had 100% sensitivity for the identification of poor responders (specificity, 76.9%; area under the ROC curve, 0.90; P = .0001). Mean FLE(max)after induction chemotherapy did not differ between good and poor responders. Mean timing (ie, the number of postcontrast dynamic acquisitions where FLE(max)was observed) was significantly delayed in good responders compared with poor responders (4.7 vs 2.9, P < .0001). Post-ASCT MR imaging results correctly depicted all four clinically good responders whose disease subsequently progressed.

CONCLUSION

With quantitative analysis of BME(max)and the timing of FLE(max), whole-body dynamic contrast-enhanced MR imaging can be used to assess treatment response in patients with MM.

Systemic light-chain amyloidosis: advances in diagnosis, prognosis, and therapy

Systemic light-chain amyloidosis (AL) is caused by misfolded immunoglobulin light-chain proteins that aggregate and deposit as unique fibrils, ultimately leading to organ failure and death. Recent developments that have significantly aided the management of patients with AL include diagnostic techniques for definitive typing of amyloid deposits by use of laser microdissection with mass spectrometry and customized protein bioinformatics, and validated staging and response-scoring systems that improve clinical trial design. The widespread use of cardiac biomarker staging and serum-free light-chain levels to evaluate response to therapy has also improved care. Standard therapies such as oral melphalan and dexamethasone or autologous stem cell transplant continue to be important options, while thalidomide and its analogs, lenalidomide and pomalidomide, and the proteasome-inhibitor bortezomib have activity in AL and have expanded our armamentarium. Continued improvement in outcomes, however, will require the commitment and cooperation of pharmaceutical companies, regulatory agencies, academic investigators, and cooperative groups/consortia. This effort will involve the conduct of well-designed clinical trials of new agents and combinations within a modern framework that categorizes the study populations of patients with AL, defines the end points appropriate to those populations and to the different phases of clinical trials, employs the newly available staging and response criteria, and standardizes adverse event reporting.

How I treat multiple myeloma in younger patients

Therapeutic options for multiple myeloma (MM) patients have changed quickly in recent years and uncertainty has arisen about optimal approaches to therapy. A reasonable goal of MM treatment in younger “transplant eligible” patients is to initiate therapy with a target goal of durable complete remission, and the anticipated consequence of long-term disease control. To achieve this goal we recommend induction therapy with multi-agent combination chemotherapies (usually selected from bortezomib, lenalidomide, thalidomide, cyclophosphamide, and corticosteriods) which when employed together elicit frequent, rapid, and deep responses. We recommend consolidation with high-dose melphalan and autologous stem cell transplantation in the majority of patients willing and able to undergo this procedure and subsequent maintenance therapy, especially in those failing to achieve a complete response or at high risk for early relapse based on prognostic, genetically defined risk factors. Defining genetic risk for early relapse is therefore an important aspect of early diagnostic testing and attention to minimizing expected toxicities once therapy begins is critical in ensuring the efficacy of modern combination therapy approaches. When access to newer drugs is restricted participation in clinical trials should be pursued.

Evidence of serum immunoglobulin abnormalities up to 9.8 years before diagnosis of chronic lymphocytic leukemia: a prospective study

Immune-related deficiencies are well-known complications of chronic lymphocytic leukemia (CLL). Although recent data indicate that almost all CLL patients are preceded by a monoclonal B-cell lymphocytosis precursor state, patterns of immune defects preceding CLL diagnosis are unclear. We identified 109 persons who developed CLL from the prospective and nationwide Prostate, Lung, Colorectal and Ovarian Cancer Screening Trial with 77 469 participants, with serially collected prediagnostic serum samples. We assayed monoclonal (M)-proteins, kappa/lambda free light chains (FLCs) in prediagnostic obtained up to 9.8 years before CLL diagnosis. The prevalence of an abnormal FLC ratio, M-protein, and hypogamma-globulinemia before CLL diagnosis was 38% (95% confidence interval, 29%-47%), 13% (7%-21%), and 3% (1%-8%), respectively. M-proteins and abnormal FLC ratios were detected up to 9.8 years before CLL diagnosis in a total of 48 persons (44%). Hypogammaglobulinemia was not present until 3 years before the diagnosis of CLL. Among 37 patients with information on tumor cell immunophenotype, an association between immunophenotype and involved FLC (P = .024, Fisher exact test) was observed. Among 61 persons with a normal FLC ratio and without an M-protein, 17 had elevated kappa and/or lambda FLC levels, indicating polyclonal B-cell activation in 17 of 109 (16%) patients. These findings support a role for chronic immune stimulation in CLL genesis.

The role of complete response in multiple myeloma

In multiple myeloma (MM), the impact of complete response (CR) could be shown only after introduction of high-dose therapy plus autologous stem cell transplantation (ASCT). In the context of ASCT, achieving CR (negative immunofixation and normal bone marrow) or at least very good partial response is associated with longer progression-free survival and in most studies longer survival. With novel agents, high CR rates are achieved and this prognostic impact of CR is being shown as well, both in relapsed and in newly diagnosed MM. However the benefit of CR achievement depends on the type of treatment and is not identical for all patients. In elderly patients, treatments inducing more CR may be more toxic. Although CR achievement is necessary in patients with poor-risk disease, it might not be as critical for long survival in more indolent MM. CR achievement is not the only objective of treatment because it is possible to further improve the depth of response and the outcome by continuing treatment after CR achievement. Finally, there are several levels of CR and in the future it will be necessary to confirm the prognostic impact of immunophenotypic or molecular CR or of CR defined by imaging procedures.

Abnormal serum free light chain ratio in patients with multiple myeloma in complete remission has strong association with the presence of oligoclonal bands: implications for stringent complete remission definition

The prevalence of an abnormal serum free light chain (FLC) ratio in 34 patients with multiple myeloma in complete response (CR) after hematopoietic stem cell transplantation was studied. Fourteen of 34 patients (41.2%) showed an abnormal FLC ratio. The frequency of abnormal FLC ratio in patients with or without oligoclonal bands was 72.7% versus 26%, respectively (P = .023). The median value of FLC ratio was 2.55 (95% confidence interval, 1.89-3.20) in patients with oligoclonal bands versus 0.87 (95% confidence interval, 0.70-1.04) for those with no oligoclonal bands (P = .011). This is the first report showing that the presence of oligoclonal bands in patients with multiple myeloma in CR frequently results in an abnormal FLC ratio. Because an oligoclonal immune response is associated with a good outcome, our results question the current definition of stringent CR and support that the prognostic impact of oligoclonal bands should be also assessed on multivariate analysis.

How I treat amyloidosis

Amyloidosis is an uncommon disorder in which proteins change conformation, aggregate, and form fibrils that infiltrate tissues, leading to organ failure and death. The most frequent types are light-chain (AL) derived from monoclonal B-cell disorders producing amyloidogenic immunoglobulin light chains, and the hereditary and "senile systemic" (ATTR) variants from mutant and wild-type transthyretin (TTR). Diagnosis requires tissue biopsy. AL is more frequent and causes more organ disease than ATTR. Although both can cause cardiomyopathy and heart failure, AL progresses more quickly, so survival depends on timely diagnosis. Typing is usually based on clinical and laboratory findings with monoclonal gammopathy evaluation and, if indicated, TTR gene testing. Direct tissue typing is required when one patient has 2 potential amyloid-forming proteins. In coming years, widespread use of definitive proteomics will improve typing. New therapies are in testing for ATTR, whereas those for AL have followed multiple myeloma, leading to improved survival. Challenges of diagnosing and caring for patients with amyloidosis include determination of type, counseling, and delivery of prompt therapy often while managing multisystem disease. Recent advances grew from clinical research and advocacy in many countries, and global husbandry of such efforts will reap future benefits for families and patients with amyloidosis.

Assessment of monoclonal gammopathies by nephelometric measurement of individual immunoglobulin kappa/lambda ratios

BACKGROUND

Currently, monoclonal immunoglobulins are identified and quantified from bands on electrophoretic gels. As an alternative, clonality might be determined by measuring the separate light chain types of each Ig class to allow numerical assessment of Ig'kappa/Ig'lambda ratios, analogous to free light chain kappa/lambda ratios.

METHODS

Using immunization, tolerization, and adsorption procedures, we prepared sheep antibodies against each of the 6 separate molecules, IgGkappa, IgGlambda, IgAkappa, IgAlambda, IgMkappa, and IgMlambda. Antibody targets comprised the junctional epitopes between the heavy chain and light chain domains. After purification, we assessed the antisera on a Siemens Dade-Behring BN II nephelometer for analytical quality and clinical utility.

RESULTS

High-avidity, specific antibodies allowed the production of automated nephelometric immunoassays for each Ig light chain type. Laboratory comparison with serum protein electrophoresis, using dilution experiments, showed lower analytical sensitivity for monoclonal IgG detection but similar or greater sensitivity for IgA and IgM, particularly when the monoclonal bands overlaid transferrin. Results obtained from typing of monoclonal proteins into IgG, A, or M types were comparable with results obtained by immunofixation-electrophoresis methods. Initial clinical studies, in multiple myeloma patients, indicated that Ig'kappa/Ig'lambda ratios were sometimes more sensitive than immunofixation electrophoresis, provided numerical results, and correlated with changes in disease.

CONCLUSIONS

Immunoassays for intact Ig kappa/lambda pairs are possible and should assist in the management of patients with monoclonal gammopathies.

Staging systems and prognostic factors as a guide to therapeutic decisions in multiple myeloma

Multiple myeloma (MM) patients have a highly variable disease course and survival varies from a few months to more than 10 years. Numerous prognostic factors have been identified, including age, performance status (PS), serum albumin, beta2-microglobulin (beta2M), lactate dehydrogenase (LDH), renal function, genetic factors, and serum free light chains (sFLCs) or their ratio (sFLCR). Several models have been built to separate patients into various risk groups with different outcomes. Staging systems need to be simple, accurate, and readily available in order to effectively guide treatment decisions now that effective treatments exist that prolong survival. The International Staging System (ISS) is currently in use; it is highly prognostic but presents some limitations. We suggest that the ISS prognostic potential could be improved with the addition of sFLCR and eventually LDH.

Screening panels for detection of monoclonal gammopathies

BACKGROUND

The repertoire of serologic tests for identifying a monoclonal gammopathy includes serum and urine protein electrophoresis (PEL), serum and urine immunofixation electrophoresis (IFE), and quantitative serum free light chain (FLC). Although there are several reports on the relative diagnostic contribution of these assays, none has looked at the tests singly and in combination for the various plasma cell proliferative disorders (PCPDs).

METHODS

Patients with a PCPD and all 5 assays performed within 30 days of diagnosis were included (n = 1877). The diagnoses were multiple myeloma (MM) (n = 467), smoldering multiple myeloma (SMM) (n = 191), monoclonal gammopathy of undetermined significance (MGUS) (n = 524), plasmacytoma (n = 29), extramedullary plasmacytoma (n = 10), Waldenström macroglobulinemia (WM) (n = 26), primary amyloidosis (AL) (n = 581), light chain deposition disease (LCDD) (n = 18), and POEMS syndrome (n = 31).

RESULTS

Of the 1877 patients, 26 were negative in all assays. Omitting urine from the panel lost an additional 23 patients (15 MGUS, 6 AL, 1 plasmacytoma, 1 LCDD), whereas the omission of FLC lost 30 patients (6 MM, 23 AL, and 1 LCDD). The omission of serum IFE as well as urine lost an additional 58 patients (44 MGUS, 7 POEMS, 5 AL, 1 SMM, and 1 plasmacytoma).

CONCLUSIONS

The major impact of using a simplified screening panel of serum PEL plus FLC rather than PEL, IFE, and FLC is an 8% reduction in sensitivity for MGUS, 23% for POEMS (7 patients), 4% for plasmacytoma (1 patient), 1% for AL, and 0.5% for SMM. There is no diminution in sensitivity for detecting MM, macroglobulinemia, and LCDD.

Nonsecretory multiple myeloma

Multiple myeloma is characterized by clonal proliferation of plasma cells usually of the B cell type. The skeletal manifestations are usually osteolytic lesions whose differential diagnosis includes primary and secondary bone tumor. This tumor is characterized by the presence of abnormal paraprotein 8 in blood and urine. However, one to five per cent of the cases do not have any protein. Hence they are termed nonsecretory. It often poses a diagnostic dilemma when it is presented to orthopedic surgeons with no clear features of the disease. Our case report exemplifies such a diagnostic dilemma. A high index of suspicion must be borne in mind when excluding multiple myeloma as a cause of pain, pathological fracture or lytic lesion.