Multiple myeloma and polyclonal hypogammaglobulinaemia

Clinical Considerations for Immunoparesis in Multiple Myeloma

Simple Summary

Immunoparesis in multiple myeloma is defined as the suppression of one or more of the uninvolved immunoglobulins, AKA, polyclonal immunoglobulin. The extent of immunoparesis is an independent prognostic factor in patients with newly diagnosed multiple myeloma. Myeloma patients with suppressed uninvolved immunoglobulins at diagnosis have shorter median overall survival (OS) and progression-free survival (PFS). This review article summarizes immunoparesis in myeloma patients, contributing factors, its impact on myeloma progression, general outcomes, and infectious complications.

Abstract

Multiple myeloma is a relatively common clonal plasma cell disorder, comprising 17% of hematologic malignancies. One of the hallmark features of this disease is immunoparesis, which is characterized by the suppression of immunoglobulin polyclonality. Though not entirely elucidated, the mechanism behind this process can be attributed to the changes in the tumor microenvironment. All treating clinicians must consider potential complications related to immunoparesis in the management of multiple myeloma. Though not explicitly described in large data series, the increased risk of infection in multiple myeloma is likely, at least in part, due to immunoglobulin suppression. Additionally, the presence of immunoparesis serves as a prognostic factor, conveying poorer survival and a higher risk of relapse. Even in the era of novel agents, these findings are preserved, and immunoglobulin recovery also serves as a sign of improved outcome following autologous HSCT. Though not within the diagnostic criteria for multiple myeloma, the presence and degree of immunoparesis should be at diagnosis for prognostication, and immunoglobulin recovery should be tracked following myeloablative therapy and autologous HSCT.

Anti-bacterial antibodies in multiple myeloma patients at disease presentation, in response to therapy and in remission: implications for patient management

Multiple myeloma (MM) is associated with increased risk of infection, but little is known regarding antibody levels against specific bacteria. We assessed levels of polyclonal immunoglobulin and antibacterial antibodies in patients recruited to the TEAMM trial, a randomised trial of antibiotic prophylaxis at the start of anti-myeloma treatment. Polyclonal IgG, IgA and IgM levels were below the reference range in 71%, 83% and 90% of 838 MM patients at diagnosis. Anti-vaccine targeted tetanus toxoid antibodies were protective in 95% of 193 healthy controls but only 41% of myeloma patients. In healthy controls, protective antibodies against 6/12 pneumococcal serotypes, haemophilus and meningococcus A were present in 67%, 41% and 56% compared to just 15%, 21% and 17% of myeloma patients. By 1 year, myeloma patients IgG levels had recovered for 57% of patients whilst the proportion with protective levels of IgG against thymus-dependent protein antigen tetanus toxoid had changed little. In contrast the proportions of patients with protective levels against thymus independent polysaccharide antigens pneumococcus, haemophilus and meningococcus had fallen from 15 to 7%, 21 to 0% and 17 to 11%. Findings highlight the need for strategies to protect patients against bacterial infections during therapy and vaccination programmes during remission.

Characterisation and prognostic impact of immunoparesis in relapsed multiple myeloma

Characterisation and prognostic impact of immunoparesis in relapsed multiple myeloma (MM) is lacking in the current literature. We evaluated 258 patients with relapsed MM, diagnosed from 2008 to 2015, to investigate the prognostic impact of deep immunoparesis on post-relapse survival. On qualitative immunoparesis assessment, no, partial and full immunoparesis was present in 9%, 30% and 61% of patients, respectively. Quantitative immunoparesis was assessed by computing the average relative difference (ARD) between polyclonal immunoglobulin(s) and corresponding lower normal limit(s), with greater negative values indicating deeper immunoparesis. The median ARD was -39%, with an optimal cut-off of -50% for overall survival (OS) by recursive partitioning analysis. Deep immunoparesis (ARD ≤-50%) was associated with a higher tumour burden at first relapse compared to none/shallow [ARD >-50%] immunoparesis. The OS (P = 0·007) and progression-free survival (PFS; P < 0·001) differed significantly between the deep and none/shallow immunoparesis groups. Kaplan-Meier estimates for 3-year OS were 36% and 46%, and for 2-year PFS were 17% and 27%, respectively. On multivariable analysis (MVA) for PFS, both qualitative and quantitative immunoparesis retained negative prognostic impact independently. However, only quantitative immunoparesis was independently prognostic for OS on MVA. Depth of immunoparesis in relapsed MM is an important prognostic factor for post-relapse survival in the era of novel agents and continuous therapy.

Characterisation of immunoparesis in newly diagnosed myeloma and its impact on progression-free and overall survival in both old and recent myeloma trials

We measured immunosuppression at myeloma diagnosis and assessed the impact on survival in 5826 UK myeloma trial patients. Polyclonal immunoglobulin levels were below normal in 85% of patients and above normal in only 0.4% of cases for IgA, 0.2% for IgM and no cases for IgG. Immunoparesis had a greater impact in recent trials: median overall survival (OS) was up to 3 years longer for patients without immunoparesis compared to the old trials, less than 1 year longer. Median progression-free survival (PFS) was 39%, 36% and 57% longer for patients with normal IgG, IgA and IgM levels, respectively. The depth of IgM suppression, but not the depth of IgG or IgA suppression, was prognostic for survival: the most severely suppressed IgM tertile of patients OS was 0.9 years shorter than those in the top tertile, and 2.6 years shorter than OS of those with normal IgM levels (p = .007). The degree of suppression of polyclonal IgM levels below normal was associated with worse PFS (p = .0002). Infection does not appear to be the main mechanism through which immunoparesis affects survival. We hypothesise that IgM immunoparesis impacts through a combination of being associated with more aggressive disease and reduced immune surveillance against relapse.

Active multiple myeloma suppresses and typically eliminates coexisting MGUS

Background:

Myeloma is consistently preceded by premalignant monoclonal gammopathy of undetermined significance (MGUS). In >5% of MGUS patients there is a second MGUS clone (biclonal gammopathy of undetermined significance; BGUS), yet, at myeloma diagnosis, presentation of biclonal gammopathy myeloma (BGMy) is considered less frequent, implying that myeloma eradicates coexisting MGUS.

Methods:

In the largest study of its kind, we assessed BGMy frequency amongst 6399 newly diagnosed myeloma patients enrolled in recent UK clinical trials.

Results:

Compared to expected prevalence (i.e., >5% of MGUS have BGUS), only 58 of 6399 (0.91%) newly diagnosed myeloma patients had BGMy, indicating myeloma typically eliminates coexistent MGUS. In these 58 BGMy cases, the MGUS plasma cell clone was greatly suppressed in size compared to typical levels observed in conventional MGUS; contrarily, the MGUS clone did not inhibit the myeloma plasma cell clone in BGMy.

Conclusion:

Myeloma eliminates the majority of competing MGUS, and when it does not, the MGUS clone is substantially reduced in size.

CD8+/CD57 cells and apoptosis suppress T-cell functions in multiple myeloma

The aim of this study was to evaluate the role of CD8+/CD57+ lymphocytes in the immune dysregulation of multiple myeloma (MM). Cytofluorimetry of peripheral blood lymphocytes (PBL) purified from 39 MM patients showed an inverse relationship between the percentage of CD8+/CD57+ cells and CD4/CD8 ratio. Analysis of their activation antigens revealed that they were prevalently HLA-DR+ and Fas+. Removal of CD8+/CD57+ cells from MM PBL significantly improved cell proliferation and pokeweed mitogen (PWM)-induced polyclonal Ig production in vitro, whereas the addition of supernatants from patients' CD8+/CD57+ cell cultures to normal PBL suppressed both the PWM-driven Ig synthesis and the proliferative rate of stimulated PBL, supporting the contention that CD8+/CD57+ cells release in vitro an inhibitory factor that is directly involved in T-cell regulatory function. However, since the proliferative recovery of PWM- and phytohaemagglutinin (PHA)-stimulated MM PBL in the absence of CD8+/CD57+ lymphocytes was only partial, a dysregulated activation-induced apoptosis was anticipated. In fact, patients' PBL displayed an increased susceptibility to apoptosis and this was significantly enhanced after PWM and, even more, after PHA stimulation. Analysis of CD57 antigen expression on apoptotic or viable cells demonstrated a substantial defect of apoptosis in the CD8+/CD57+ population. Our results indicate that both the immunosuppressive effect of CD8+/CD57+ cells and the enhanced susceptibility to apoptosis of PBL could be involved in the pathogenesis of the immunodeficiency observed in this disease.

Biological and NMR markers for cancer

The search for a universal tumor marker continues. Present markers range from tumor products (polyamines, glycoproteins, peptides, hormones or carbohydrate-linked markers) to reaction products produced by the host tissues during tumor invasion. Techniques used to identify them include the classical methods of histology and cytochemistry as well as the more recent radioimmunoassay and metabolic probes. The in vivo techniques of increasing use for patient monitoring are MRS (magnetic resonance spectroscopy) and MRI (magnetic resonance imaging). The efficiency of some markers and statistical methods used in analyzing data are discussed, as are the ethical problems surrounding the use of new testing methods. Recent developments in MRI and MRS, marker elucidation, and evidence for a new autocrine differentiation-inhibiting factor (ADIF) are reviewed. Future needs and approaches focus on greater utilization of indicators of the preneoplastic state and of risk to cancer, as well as more careful attention to statistical analysis.