Doug Joshua

International Myeloma Working Group guidelines for serum-free light chain analysis in multiple myeloma and related disorders

The serum immunoglobulin-free light chain (FLC) assay measures levels of free κ and λ immunoglobulin light chains. There are three major indications for the FLC assay in the evaluation and management of multiple myeloma and related plasma cell disorders (PCD). In the context of screening, the serum FLC assay in combination with serum protein electrophoresis (PEL) and immunofixation yields high sensitivity, and negates the need for 24-h urine studies for diagnoses other than light chain amyloidosis (AL). Second, the baseline FLC measurement is of major prognostic value in virtually every PCD. Third, the FLC assay allows for quantitative monitoring of patients with oligosecretory PCD, including AL, oligosecretory myeloma and nearly two-thirds of patients who had previously been deemed to have non-secretory myeloma. In AL patients, serial FLC measurements outperform PEL and immunofixation. In oligosecretory myeloma patients, although not formally validated, serial FLC measurements reduce the need for frequent bone marrow biopsies. In contrast, there are no data to support using FLC assay in place of 24-h urine PEL for monitoring or for serial measurements in PCD with measurable disease by serum or urine PEL. This paper provides consensus guidelines for the use of this important assay, in the diagnosis and management of clonal PCD.

International Myeloma Working Group guidelines for the management of multiple myeloma patients ineligible for standard high-dose chemotherapy with autologous stem cell transplantation

In 2005, the first guidelines were published on the management of patients with multiple myeloma (MM). An expert panel reviewed the currently available literature as the basis for a set of revised and updated consensus guidelines for the diagnosis and management of patients with MM who are not eligible for autologous stem cell transplantation. Here we present recommendations on the diagnosis, treatment of newly diagnosed non-transplant-eligible patients and the management of complications occurring during induction therapy among these patients. These guidelines will aid the physician in daily clinical practice and will ensure optimal care for patients with MM.

Management of relapsed multiple myeloma: Recommendations of the international myeloma working group

The prognosis for patients multiple myeloma (MM) has improved substantially over the past decade with the development of new, more effective chemotherapeutic agents and regimens that possess a high level of anti-tumor activity. In spite of this important progress, however, nearly all MM patients ultimately relapse, even those who experience a complete response to initial therapy. Management of relapsed MM thus represents a vital aspect of the overall care for patients with MM and a critical area of ongoing scientific and clinical research. This comprehensive manuscript from the International Myeloma Working Group provides detailed recommendations on management of relapsed disease, with sections dedicated to diagnostic evaluation, determinants of therapy, and general approach to patients with specific disease characteristics. In addition, the manuscript provides a summary of evidence from clinical trials that have significantly impacted the field, including those evaluating conventional dose therapies, as well as both autologous and allogeneic stem cell transplantation. Specific recommendations are offered for management of first and second relapse, relapsed and refractory disease, and both autologous and allogeneic transplant. Finally, perspective is provided regarding new agents and promising directions in management of relapsed MM.

The labelling index of primitive plasma cells determines the clinical behaviour of patients with myelomatosis

For patients with multiple myeloma the most important laboratory correlate of prognosis and disease activity is the bromodeoxyuridine (BrdUrd) plasma cell labelling index (LI). However, the traditional immunofluorescent microscope LI technique, like other manual enumeration assays, can suffer from poor precision and accuracy. In this study the LI of different subpopulations of plasma cells (CD38++) as determined by flow cytometry was correlated with disease state. The mean LI of the total CD38++ population was significantly higher (2.7±0.4%) than the LI determined by the traditional slide technique (0.6±0.1%) for 65 samples tested. Primitive plasma cells (CD38++, CD45++) had a higher labelling index than mature plasma cells (CD38++, CD45−) (7.0±1.3% v 1.8%±0.3%) and in one patient the LI of the primitive plasma cells was 46%. In addition, the LI of the mature plasma cells was lower than the total plasma cell population. As expected, there was a significant difference between the LI of patients in plateau phase and progressive disease but this difference was greatest when the LI of the primitive plasma cells was studied (9.2±2.9% v 2.2±0.7%; z=19.9, P<0.001). This study has raised some concerns about the sensitivity and accuracy of the traditional labelling index and has shown that the increased LI associated with progressive disease is almost entirely attributable to an increase in the LI of the primitive plasma cell subpopulation and that the LI of primitive plasma cells provides a more clinically significant correlation with disease status than the traditional assay.

Either interleukin-12 or interferon-γ can correct the dendritic cell defect induced by transforming growth factor β1 in patients with myeloma

The poor response to immunotherapy in patients with multiple myeloma (MM) indicates that a better understanding of any defects in the immune response in these patients is required before effective therapeutic strategies can be developed. Recently we reported that high potency (CMRF44+) dendritic cells (DC) in the peripheral blood of patients with MM failed to significantly up‐regulate the expression of the B7 co‐stimulatory molecules, CD80 and CD86, in response to an appropriate signal from soluble trimeric human CD40 ligand. This defect was caused by transforming growth factor β1 (TGFβ1) and interleukin (IL)‐10, produced by malignant plasma cells, and the defect was neutralized in vitro with anti‐TGFβ1. As this defect could impact on immunotherapeutic strategies and may be a major cause of the failure of recent trials, it was important to identify a more clinically useful agent that could correct the defect in vivo. In this study of 59 MM patients, the relative and absolute numbers of blood DC were only significantly decreased in patients with stage III disease and CD80 up‐regulation was reduced in both stage I and stage III. It was demonstrated that both IL‐12 and interferon‐γ neutralized the failure to stimulate CD80 up‐regulation by huCD40LT in vitro. IL‐12 did not cause a change in the distribution of DC subsets that were predominantly myeloid (CD11c+ and CDw123−) suggesting that there would be a predominantly T‐helper cell type response. The addition of IL‐12 or interferon‐γ to future immunotherapy trials involving these patients should be considered.

Osteonecrosis of the jaw complicating bisphosphonate treatment for bone disease in multiple myeloma: an overview with recommendations for prevention and treatment

Osteonecrosis of the Jaw (ONJ) is a recently recognised and potentially highly morbid complication of bisphosphonate therapy in the setting of metastatic malignancy, including myeloma. Members of the Medical and Scientific Advisory Group of the Myeloma Foundation of Australia formulated guidelines for the management of bisphosphonates around the issue of ONJ, based on the best available evidence in June 2008. Prior to commencement of therapy, patients should have an oral health assessment and be educated about the risks of ONJ. Dental assessment should occur 6 monthly during therapy. If tooth extraction is required, sufficient time should be allowed for complete healing to occur prior to commencement of bisphosphonate. As the risk of ONJ increases with duration of bisphosphonate therapy, we recommend annual assessment of dose with modification to 3 monthly i.v. therapy or to oral therapy with clodronate for those with all but the highest risk of skeletal‐related event. Established ONJ should be managed conservatively; a bisphosphonate “drug holiday” is usually indicated and invasive surgery should generally be avoided. These recommendations will assist with clinical decision making for myeloma patients who are at risk of bisphosphonate‐associated ONJ.

The Oncoprotein Phenotype of Plasma Cells from Patients with Multiple Myeloma

The expression of 6 different oncoproteins and 2 tumour suppressor gene products in the plasma cells of 63 bone marrow samples was used to determine a profile of the oncogenic phenotype of patients with multiple myeloma. Dual label flow cytometry after periodatelysine paraformaldehyde fixation was used to detect cell surface phenotype and intracellular protein expression simultaneously. The normal range for both the incidence and intensity of expression was determined for each protein by analysing plasma cells (high CD38 intensity) in 22 normal bone marrow samples. The percentage of myeloma patients with a greater than normal incidence of plasma cells expressing these proteins was 53% for c-myc, 28% for Rb, 28% for bcl-2, 27% for c-fos, 24% for p53 wild, 22% for p53 mutant, 13% for c-neu and 13% for pan-ras. When a panel of 8 antibodies was used, 82% of the samples (n = 28) had an increased incidence of expression by at least one oncoprotein or tumour suppressor gene product. The 5 patients with a normal incidence of expression of all 8 proteins were in plateau stage and 4 had not received chemotherapy for more than 12 months. The number of patients with an increased incidence of expression by 2 or more oncoproteins was significantly greater (X2 = 9.0; p < 0.005) in progressive disease (55%) than in stable disease (14%) but there was no specific phenotype pattern associated with progressive disease. All 6 oncoproteins and both tumour suppressor gene products had a greater incidence and intensity of expression in progressive than in stable disease. The expression of c-myc oncoprotein correlated with c-myc mRNA expression in the same samples (n = 10) but c-myc did not correlate with either the plasma cell labelling index (r = -0.15) nor serum thymidine kinase (r = 0.10). Our results suggest that there is a heterogeneous, non-systematic but almost universal presence of activated oncogenes and tumour suppressor genes in the plasma cells of patients with multiple myeloma and that disease progression is associated with the accumulation of a variety of secondary genetic changes which confer increased malignant behaviour.

The bone marrow plasma cell labeling index by flow cytometry.

The bone marrow plasma cell labeling index is the most important prognostic indicator for patients with multiple myeloma. Traditionally, this test has been performed as a two color immunofluorescent microscope technique which is time consuming and requires a degree of subjectivity in its interpretation. We have assessed various adaptations of this method to flow cytometry. A bromodeoxyuridine method has been compared with a propidium iodide DNA method to detect cells in S phase and CD38-FITC has been compared with CD38-FITC + CD138-FITC and CD38-biotin + streptavidin FITC to identify plasma cells. The mean channel fluorescent intensity of the plasma cell peaks for each of these markers was 12. 7, 17.4 and 35.3 respectively demonstrating the superiority of CD38-biotin + streptavidin FITC. Analysis after propidium iodide staining provided a good correlation with the slide technique (r = 0. 71; P < 0.0001) but the bromodeoxyuridine method did not correlate with the slide method (r = 0.09; P = NS). The labeling index values obtained from either of the flow methods were greater than the microscopic method. Thus a labeling index of >4% will replace the traditional >1% threshold for identifying patients with a significantly increased labeling index. The advantages of the new method are that it takes less time to perform, is more objective and provides additional data on ploidy and cell cycle status.

Erratum: International uniform response criteria for multiple myeloma (Leukemia (2006) vol. 20 (1467-1473) 10.1038/sj.leu.2404284)

Correction to: Leukemia (2006) 20, 1467–1473. doi:10.1038/sj.leu.2404284 It has been identified by the authors that there was an error in the author list. The following author was omitted in error. M Cavo, Institute of Hematology and Medical Oncology ‘Seràgnoli’, University of Bologna, Italy. The corrected list is mentioned here.

Idiotypic oligonucleotide probes to detect myeloma cells by mRNA in situ hybridization

An mRNA in situ hybridization (ISH) method which used non‐radioactive idiotypic oligonucleotide probes has been used to detect malignant cells in the bone marrow and peripheral blood of patients with multiple myeloma. For each of two patients with multiple myeloma a pair of biotinylated antisense oligonucleotide probes (18–22mer) was prepared from non‐germline sequences of the rearranged immunoglobulin heavy chain (IgH) gene. These oligonucleotide sequences were not homologous with any previously published sequence. The probes from each patient were specific as shown by a failure to hybridize to any cells from six other myeloma patients and four normal individuals. Specific staining of IgH gene mRNA occurred only when the myeloma cells and the sequence of the probe used were from the same patient. Using simultaneous fluorescent immunocytochemistry it was shown that more than 95% of the ISH‐positive cells expressed the malignant light chain in their cytoplasm. ISH positive cells were found in 1–4% of the peripheral blood mononuclear fraction of these two patients. These studies show that idiotypic oligonucleotide IgH gene probes can be used to identify individual cells belonging to the malignant clone and offer the possibility of developing innovative tumour‐specific therapeutic procedures using antisense technology for patients with myeloma.