Biology of multiple myeloma--host-tumour interactions and immune regulation of disease activity

Cytokine profiles in patients with newly diagnosed multiple myeloma: Survival is associated with IL-6 and IL-17A levels

BACKGROUND

Identifying specific risk factors associated with multiple myeloma (MM) remains a significant issue. Different cytokines take part in the pathogenesis, progression, and prognosis of MM. Therefore, this study aimed to investigate the correlations between serum cytokine levels and clinical characteristics and determine their effects on disease progression and survival of MM patients.

METHODS

We retrospectively analyzed the serum levels of 7 cytokines in 105 patients with newly diagnosed MM and in 20 healthy subjects. Interleukin (IL)-2, IL-4, IL-6, IL-10, and IL-17A, tumor necrosis factor (TNF)-α, and interferon (IFN)-γ were quantitatively determined by cytometric bead assay techniques. The concentrations of each cytokine were compared between the MM patients and healthy subjects using the Mann-Whitney U test. The Kaplan-Meier method was used to analyze progression-free survival (PFS) and overall survival (OS).

RESULTS

Serum IL-2, IL-4, IL-6, IL-10, IL-17A, TNF-α, and IFN-γ levels were higher in patients with newly diagnosed MM than in healthy controls. Positively significant correlations were found between IL-6, IL-10, IL-17A, and β2-microglobulin. Significant correlations were also observed between IL-6 and IL-10, and lactate dehydrogenase. The overall response rate of low-IL-6 and IL-17A patients was significantly higher than that of high-IL-10 and IL-17A patients (P < 0.01). Univariate and multivariate analyses revealed that serum IL-6 levels were >3 pg/mL, serum IL-17A levels were >4 pg/mL, and treatment regimens were independent prognostic factors for PFS and OS.

CONCLUSIONS

Cytokine deregulation, especially that of IL-6 and IL-17A, may be a powerful predictor of clinical prognosis for MM patients.

Bone marrow histology and serum beta 2 microglobulin in multiple myeloma--a new prognostic strategy

Bone marrow biopsies of 720 patients with multiple myeloma (MM) were investigated from 1968-1989. Histologic variables were correlated with clinical parameters and survivals to determine prognostic factors. In 207 of these patients initial levels of serum beta 2 microglobulin (SB2M) were also measured for prognostic evaluation. Four tumour growth patterns were distinguished: interstitial (56%), interstitial/sheets (13%), nodular (15%) and packed marrow (16%) with median survivals of 46, 31, 22 and 16 months. When grouped according to the tumour cell mass in the biopsy, four histologic stages were recognized. Cellular characteristics were used to classify MM into 6 histologic types which were subsequently combined into 3 grades of malignancy: low, intermediate and high, analogous to the malignant lymphomas. With respect to tumour products, only SB2M proved to be a valuable prognostic indicator for staging and follow-up. Complications of MM such as anaemia, azotaemia, osteolytic lesions, hypercalcaemia and hypoalbuminaemia all predicted a poor prognosis, highly significant in the test statistics. We propose a new prognostic approach in MM, comprising 1) parameters defining the tumour itself, 2) the tumour products (SB2M) and 3) the tumour complications. This prognostic strategy combines information both on stage and malignancy of MM and enables definition of smouldering and of aggressive variants of MM at an early stage.

Lymphocyte recovery and clinical response in multiple myeloma patients receiving interferon alpha 2 beta after intensive therapy

The recovery of immunoregulatory cells in the peripheral blood of patients with multiple myeloma receiving maintenance therapy with interferon alpha 2 beta (IFN-alpha 2 beta) after intensive therapy with high-dose melphalan and autologous bone marrow or peripheral blood stem cell rescue was studied. IFN-alpha 2 beta significantly inhibited the recovery of CD3+, CD4+, CD8+, CD56+/CD3- and CD16+/CD3- lymphocytes compared with numbers found in patients who had no further post-transplant treatment, but had no effect on the recovery of CD19+ cells. Among patients who did not receive IFN-alpha 2 beta, the number of CD8+, CD56+/CD3- and CD16+CD3- lymphocytes recovered to values similar to normal volunteers with increasing time after intensive therapy, however the number of CD4+ cells remained significantly below levels found in normal volunteers. Although CD16+/CD3- and CD56+/CD3- cell numbers were reduced in patients receiving IFN-alpha 2 beta, natural killer (NK) activity was not affected. The levels of soluble interleukin 2 receptor (sIL-2R) were similar in all patients and IL-2 was not detected in any patient. At the time of writing, of the total of 69 patients, seven have relapsed, of whom three were receiving IFN-alpha 2 beta, however there was no correlation between the absolute numbers of any lymphocyte subset with imminent relapse. The data suggest that the recovery of a specific lymphocyte subset(s) in peripheral blood is unlikely to be associated with the maintenance of response after intensive therapy.

Circulating Ki67 positive lymphocytes in multiple myeloma and benign monoclonal gammopathy

AIMS

To estimate the proportion and nature of the proliferating (Ki67+) circulating lymphocytes in a series of patients with multiple myeloma and monoclonal gammopathy of unknown significance (MGUS) and to correlate this with other clinical and laboratory parameters, using blood from healthy adults as a control. To investigate the extent to which the B and T lymphoid components are involved in progression and/or control of disease.

METHODS

Blood lymphocytes from 15 patients with multiple myeloma, 10 patients with MGUS and 10 healthy adults were analysed using a sequential double immunoenzymatic staining technique. Antibodies directed against Ki67 were used to detect cells in cycle, CD3, CD4, and CD8 to identify T cells, HLA-Dr as a marker for B cells and activated T cells, and CD11b as a marker for natural killer cells. Polyclonal antibodies directed against the kappa and lambda immunoglobulin light chains were also used to detect B cells.

RESULTS

The proportion of proliferating (Ki67+) lymphocytes was significantly higher in patients with multiple myeloma (6.8 +/- 2.6) and MGUS (3.5 +/- 1.1) compared with the normal controls (1.69 +/- 0.3); this was also true when multiple myeloma and MGUS cases were compared. In multiple myeloma and MGUS over 50% of the Ki67+ cells were activated T lymphocytes (CD3+/HLA-Dr+); a minority (11%) were non-clonal B lymphocytes. In contrast to controls (6.7 +/- 1.9), in patients with multiple myeloma and MGUS the proportion of proliferating T cells expressing CD8 (23.6 +/- 12.5 and 15.3 +/- 7.7, respectively) and CD11b (13 +/- 8.7 and 11.6 +/- 3.9, respectively) was higher. In multiple myeloma there was a positive correlation between the proportion of Ki67+ lymphocytes, beta-2-microglobulin concentrations and disease stage.

CONCLUSIONS

Although the number of patients investigated is small, this study suggests that Ki67 expression in blood lymphocytes from patients with multiple myeloma may be a good prognostic indicator for aggressive disease and may help to distinguish multiple myeloma from MGUS. The activated proliferating T cells in these diseases may represent an immunological reaction against the tumour.

Peripheral blood lymphocyte surface antigen expression and prognosis in myeloma: Australian Leukaemia Study Group Study

The Australian Leukaemia Study Group myeloma study (MM1) aimed to determine the prognostic significance of clinical and immunophenotypic markers in patients with multiple myeloma. All patients were treated with standard dose melphalan and prednisone. Seventy-four patients were entered and the median survival was 27 months. Serum beta 2-microglobulin (beta 2M) and albumin levels were the only significant clinical factors influencing survival (p = 0.007 and p = 0.008, respectively). Patients with raised levels of CD38+ lymphocytes at presentation had a significantly shorter survival than patients with normal levels (p = 0.01, logrank test, median 19 months vs 33 months). CD38 antigen expression was independent of beta 2M but patients with raised levels of CD38 had significantly lower levels of albumin than patients with normal levels (p = 0.001) which may explain their poorer survival. Salmon and Durie stage was not associated with antigen expression. No other B-cell antigens (CD10, CD19, CD20, CD21, CD22, CD23, FMC1 or FMC7) or plasma cell antigens tested (PCA-1) were found to be associated with prognosis. Patients who achieved plateau phase had a better prognosis than those who did not (p = 0.04 in a landmark analysis). Patients who achieved plateau phase following an objective response appeared to have a better prognosis than those who were in plateau phase at presentation (p = 0.09 in a landmark analysis). Light chain isotype suppression (LCIS) was not associated with a significant survival advantage and did not correlate with any known prognostic indicator.(ABSTRACT TRUNCATED AT 250 WORDS)

Measurement of free kappa and lambda chains in serum and the significance of their ratio in patients with multiple myeloma

An inhibition enzyme-linked immunoassay technique using commercially available antibodies has been developed for the quantitation of both kappa and lambda light chains in the serum of patients with B-cell malignancies. Assay conditions were selected to enable measurement of free light chains in the concentration range between 0.1 and 20 mg/l. The normal range for free lambda chains in serum was found to be 0.4-4.2 mg/l and for free kappa chains it was 1.6-15.2 mg/l. At diagnosis the serum of most patients with multiple myeloma contained increased levels of the malignant free light chain and in some cases there was also elevation of the non-malignant light chain. The absolute level of the malignant light chain at diagnosis did not correlate with survival nor with laboratory parameters such as IgM or creatinine. A correlation with beta 2 M and serum paraprotein levels was evident only in cases of IgA myeloma. Although the absolute level of free serum light chain had no value as a prognostic indicator, the ratio of kappa:lambda chains closely followed the clinical assessment of disease status, being near the normal range (1.2-9.1) in plateau phase or stable disease. During periods of progressive disease this ratio ranged from 19 to 460 (n = 14) in patients with kappa myeloma, and 0.0013-0.14 (n = 9) in patients with lambda myeloma. Determination of the ratio of free light chains in the serum may allow effective monitoring and earlier warning of disease progression in patients with multiple myeloma.

Increased expression of natural-killer-associated and activation antigens in multiple myeloma

The expression of both natural-killer (NK)-associated and activation antigens was studied by flow cytometry in the peripheral blood of 47 untreated multiple myeloma (MM) patients. A significant increase in both absolute and relative numbers of CD57 positive cells as well as in the proportion of CD16 and CD11b cells was observed in patients with MM, specially in those in early stages of the disease (clinical stages I and II), suggesting a possible surveillance mechanism in response to an emerging malignant clone. Additional double stainings showed that strong CD16+ NK cells coexpress the CD56, CD11b, and CD2 antigens, while they lacked CD3, CD5, and WT31 antigens. Moreover, the previously reported increase in CD8 cells present in MM would be mainly due to a subset of CD8 cells that coexpress the CD57 Ags. The expression of activation antigens, especially CD38, was increased in peripheral blood lymphocytes of MM patients, the differences reaching statistical significance both in absolute and relative numbers in those cases with high numbers of CD16 NK cells and thus suggesting that these cells are functionally activated. These results reveal the existence of an increase in NK and activated cells in the peripheral blood of myeloma patients that may reflect a host's immunological mechanism in an attempt to modulate tumor cell growth.

Histologic, biochemical, and clinical parameters for monitoring multiple myeloma

In a retrospective and prospective follow-up study from 1968 to 1989, bone marrow biopsy specimens, serum beta-2-microglobulin (SB2M) levels, and the clinical features of 251 patients with multiple myeloma (MM) and 28 patients with monoclonal gammopathy of undetermined significance (MGUS) were investigated. The main histologic variables (tumor cell type, tumor growth, tumor load, and fibrosis), SB2M level, serum thymidine kinase (STK) level, and various clinical parameters were analyzed to determine factors of value in monitoring the clinical phases of activity in MM. Our recently proposed prognostic strategy combining bone marrow histologic type, SB2M level, and signs of organ failure was tested for its ability to (1) diagnose the early and smoldering variants; (2) facilitate decisions on the time of initiation, the type and duration of initial induction therapy in the pretreatment phases (active and rapidly progressive phases); and (3) characterize variations in tumor regression and tumor-host interactions during chemotherapy (early treatment, plateau, relapse, transition, and refractory phases). The results indicate that this clinicopathologic monitoring combines information both on stage and aggressivity of MM and thus facilitates therapeutic decisions in the various clinical phases of MM.

Cytogenetic studies in patients with multiple myeloma

Fourteen patients diagnosed as having multiple myeloma were studied cytogenetically. In eight patients a sufficient number of metaphases was obtained and four of them showed abnormal karyotypes of bone marrow cells. Hypodiploidy was a consistent finding, as was the involvement of chromosome 9.

Colony stimulating activity in the serum of patients with multiple myeloma is enhanced by interleukin 3: a possible role for interleukin 3 after high dose melphalan and autologous bone marrow transplantation for multiple myeloma

Sera from 36/37 multiple myeloma patients and 19/21 sera from patients with other solid or liquid tumours had granulocyte-macrophage colony stimulating activity (CSA) towards normal human donor bone marrow whereas 1/16 sera from normal donors had this activity. Unlike human rhGM-CSF and GM-CSF from 5637 (human bladder cell line) conditioned medium which is heat stable, CSA from serum is heat labile (56 degrees C/30 min). In multiple myeloma patients, CSA was detectable more than 2 years after treatment with 'high dose melphalan. Although multiple myeloma patients, at relapse, have sufficient CSA in their serum to produce maximal stimulation of GM-CFUc from normal donor bone marrow in vitro, their own GM population responds poorly. The results suggest that the failure of patients own bone marrow to respond to endogenous CSA may be due to damage to the stem cells of the marrow or the failure of precursor cells to respond to CSA. Addition of rhIL-3 to myelomatous serum increased the number of GM-CFUc from both normal and myelomatous bone marrow but did not stimulate the growth of MY-CFUc significantly. The results suggest that rhIL-3 may assist bone marrow recovery in multiple myeloma patients after intensive chemotherapy.

Monoclonal gammopathies: new approaches to clinical problems in diagnosis and prognosis

When a patient presents with monoclonal gammopathy, a wide variety of clinical conditions must be considered. The importance of distinguishing accurately between patients with stable monoclonal gammopathies and those with overt multiple myeloma cannot be over-emphasised. The bone marrow examination with plasma cell labeling index, and newer techniques such as magnetic resonance imaging and computed tomography can improve diagnostic discrimination. In difficult cases, the detection of small numbers of circulating myeloma cells, the peripheral blood B-cell labeling index, and light chain isotype suppression may bring better diagnostic resolution. These tests may also be used to help assess disease activity. If the diagnosis is multiple myeloma, prediction of outcome assumes clinical importance. There are widely disparate survivals among patients with different clinical presentations. Standard clinical assays or a combination of these as in clinical staging do not provide sufficient prediction of outcome but are routinely available and therefore widely used. Independent predictive tests such as the plasma cell labeling index and beta 2-microglobulin improve prognostic accuracy. Ploidy analysis and immunophenotyping are additional variables that may assume more importance as the results of ongoing studies appear. Other promising approaches include detection of oncogene and multiple drug resistance gene expression. All such techniques will become more relevant as we apply more intensive treatment earlier in the disease course, particularly for the younger myeloma patients in whom the prognosis is poor.

Serum thymidine kinase as a marker of disease activity in patients with multiple myeloma

Serum thymidine kinase (STK) levels have recently been used to detect tumour regression and progression in a number of hematological malignancies. In this study, patients with myeloma were monitored longitudinally for STK and several other potentially useful tumour markers to determine which laboratory parameters are the most useful for differentiating between stable and progressive disease. STK was determined by radioenzyme assay, lymphocyte surface markers were analysed by flowcytometry, plasma cell labelling index (LI) by immunofluorescence with anti BU-1, serum B2-microglobulin (SB2M) by radioimmunoassay and M proteins by radial immunodiffusion. Detailed multiparameter longitudinal investigations of 5 patients and ongoing studies of 70 other patients suggest that STK is a more reliable marker of progressive disease than either SB2M, LI, M-protein or CD10 positive lymphocytes. A rise in STK during the emergence of progressive disease at least paralleled and usually preceded any change in the other parameters which often did not change at all. All samples from patients with progressive disease (n = 29) had a STK above the normal range (0-5U/l) whereas 76% of patients in clear stable disease had a STK within the normal range. All samples (n = 34) from patients with light chain isotype suppression (LCIS) had STK values of less than 12 U/L and 82% of samples (n = 33) from patients without LCIS had a STK above the normal range (0-5U/L). The correlation between STK and LI was r = 0.65; p less than 0.001 (n = 21). The radioenzyme assay for STK is simple, reproducible and a valuable tool for monitoring patients with myeloma and when used in conjunction with other clinical and laboratory investigations, aids in the separation of patients with stable myeloma from patients whose disease is progressive.