Suppression of uninvolved immunoglobulins defined by heavy/light chain pair suppression is a risk factor for progression of MGUS

Osteonecrosis of the Jaw Associated with Bisphosphonates Infusion for Treatment of Plasma Cell Myeloma-A Retrospective Observational Study of Northern Portuguese Population

Objectives: To verify medication-related osteonecrosis of the jaw (MRONJ) frequency among patients with plasma cell myeloma (PCM) that had been treated with bisphosphonates, to identify predisposing factors that could influence the development of osteonecrosis. Methods: This observational retrospective study was performed at the Department of Hematology of Hospital Center of Porto (CHUP), Portugal. Results: The study population (n = 112) had a 15.2% (n = 17) prevalence of osteonecrosis. Clinically, bone exposure was the most frequently observed sign, present in 100% (n = 17) of the patients, followed by inflammation in 82.4% (n = 14), orofacial pain in 70.6% (n = 12), suppuration in 47.1% (n = 8), and intra or extra-oral fistula in 17.6% (n = 3) of the cases. The most frequent triggering local factor was dental extraction (82.4%). There was a dependence between the presence of extractions and the development of MRONJ (p < 0.001) but not with the time elapsed from the initiation of infusions with BPs and dental extractions (p = 0.499). In the sample of patients with multiple myeloma (MM), 13.8% were found to be more likely to develop MRONJ after an extraction. Conclusions: The most common local predisposing factor was dental extraction. No dependence was observed between the development of osteonecrosis and the time elapsed from the beginning of treatment with bisphosphonates infusions to surgical procedures.

Investigation and management of the monoclonal gammopathy of undetermined significance: A British Society for Haematology Good Practice Paper

This Good Practice Paper provides recommendations for the diagnosis, risk stratification and management of the monoclonal gammopathy of undetermined significance (MGUS). It describes the recently recognised entity of the monoclonal gammopathy of clinical significance (MGCS), and recommends how it should be managed. The potential for targeted population screening for MGUS is also discussed.

Laboratory and Clinical Settings of Heavy/Light Chain (HLC) Assays in the Management of Monoclonal Gammopathies and Multiple Myeloma

The antibody-related immune response is mediated by immunoglobulins (Igs), soluble circulating glycoproteins produced by activated B cells that, upon the recognition of specific epitopes on pathogen surfaces, activate, proliferate, and differentiate into antibody-secreting plasma cells. Although the antibodies are effectors of the humoral immune adaptive response, their overproduction in response to a dysregulated proliferation of clonal plasma cell production in tumoral conditions (i.e., multiple myeloma), enriches the serum and urinary matrices, assuming the crucial role of biomarkers. Multiple myeloma (MM) is a plasma cell dyscrasia characterized by the expansion and accumulation of clonally activated plasma cells in bone marrow, determining the release of high amounts of monoclonal component (MC) that can be detected as intact immunoglobulin (Ig), immunoglobulin fragments, or free light chains (FLCs). The importance of detecting biomarkers for the diagnosis, monitoring, and prognosis of diseases is highlighted by the international guidelines that recommend specific assays for the analysis of intact Igs and FLC. Moreover, a developed assay called Hevylite^® allows for the quantification of immunoglobulins that are both involved (iHLC) and not involved (uHLC) in the tumor process; this is a fundamental aspect of following up the patient's workup and evaluating the progression of disease, together with the treatments response. We here summarize the major points of the complex scenario involving monoclonal gammopathies and MM clinical management in view of advantages derived for the use of Hevylite^®.

Monoclonal Gammopathies of Clinical Significance: A Critical Appraisal

Simple Summary

Monoclonal gammopathy of clinical significance (MGCS) refers to a recently coined term describing a complex and heterogeneous group of nonmalignant monoclonal gammopathies. These patients are characterized by the presence of a commonly small clone and the occurrence of symptoms that may be associated with the clone or with the monoclonal protein through diverse mechanisms. This is an evolving, challenging, and rapidly changing field. Patients are classified according to the key organ or system involved, with kidneys, skin, nerves, and eyes being the most frequently affected. However, multiorgan involvement may be the most relevant clinical feature at the presentation or during the course. This review delves into the definition, history, differential diagnosis, classification, prognosis, and treatment of this group of entities by analyzing the evidence accumulated to date from a critical perspective.

Abstract

Monoclonal gammopathies of clinical significance (MGCSs) represent a group of diseases featuring the association of a nonmalignant B cells or plasma cells clone, the production of an M-protein, and singularly, the existence of organ damage. They present a current framework that is difficult to approach from a practical clinical perspective. Several points should be addressed in order to move further toward a better understanding. Overall, these entities are only partially included in the international classifications of diseases. Its definition and classification remain ambiguous. Remarkably, its real incidence is unknown, provided that a diagnostic biopsy is mandatory in most cases. In fact, amyloidosis AL is the final diagnosis in a large percentage of patients with renal significance. On the other hand, many of these young entities are syndromes that are based on a dynamic set of diagnostic criteria, challenging a timely diagnosis. Moreover, a specific risk score for progression is lacking. Despite the key role of the clinical laboratory in the diagnosis and prognosis of these patients, information about laboratory biomarkers is limited. Besides, the evidence accumulated for many of these entities is scarce. Hence, national and international registries are stimulated. In particular, IgM MGCS deserves special attention. Until now, therapy is far from being standardized, and it should be planned on a risk and patient-adapted basis. Finally, a comprehensive and coordinated multidisciplinary approach is needed, and specific clinical trials are encouraged.

Recovery of polyclonal immunoglobulins during treatment in patients ineligible for autologous stem-cell transplantation is a prognostic marker of longer progression-free survival and overall survival

Immunoparesis is the suppression of normal polyclonal immunoglobulins and is present in most patients with newly diagnosed multiple myeloma (MM). The association of immunoparesis at diagnosis, and particularly its recovery along with treatment, with survival in patients ineligible for autologous stem-cell transplantation (ASCT) has not been well established. This retrospective study evaluated the impact of immunoparesis in 431 patients diagnosed with MM, ineligible for ASCT, with a median overall survival of 36 months [95% confidence interval (CI): 31-40]. Immunoparesis was present in 81.2% of patients at diagnosis and was associated with a trend to a worse overall response rate (ORR: 84.8% vs. 74.9%; OR 1.88 (95% CI: 0.97-3.63), shorter progression-free survival (PFS) [22.0 vs. 18.2 months; hazard ratio (HR) 0.775; 95%CI: 0.590-1.018; p = 0.066], and overall survival (OS) (45.9 vs. 34.2 months; HR 0.746; 95% CI: 0.551-1.010; p = 0.057). Twenty-four per cent of patients who had immunoparesis at diagnosis recovered polyclonal immunoglobulins in the follow-up period. Interestingly, these patients had a better ORR (96.3% vs. 68.2%; OR 12.29 (95% CI: 3.77-40.06), PFS (HR 0.703; 95CI%: 0.526-0.941; p = 0.018) and OS (HR 0.678; 95 CI%: 0.503-0.913; p = 0.011) than patients who did not recover it. In summary, restoring a healthy immune system along with first-line treatment in patients with MM, not receiving ASCT, is associated with better outcomes.

The Current Role of the Heavy/Light Chain Assay in the Diagnosis, Prognosis and Monitoring of Multiple Myeloma: An Evidence-Based Approach

Despite tremendous progress being made in recent years, multiple myeloma (MM) remains a challenging disease. The laboratory plays a critical role in the overall management of patients. The diagnosis, prognosis, clinical monitoring and evaluation of the response are key moments in the clinical care process. Conventional laboratory methods have been and continue to be the basis of laboratory testing in monoclonal gammopathies, along with the serum free light chain test. However, more accurate methods are needed to achieve new and more stringent clinical goals. The heavy/light chain assay is a relatively new test which can overcome some of the limitations of the conventional methods for the evaluation of intact immunoglobulin MM patients. Here, we report an update of the evidence accumulated in recent years on this method regarding its use in MM.

[Monoclonal gammopathy of undetermined significance and evolution to myeloma: Experience in 153 patients]

INTRODUCTION

Based on risk factors, the Mayo Clinic Multiple Myeloma Group (MCMMG) established a model of progression from monoclonal gammopathy of undetermined significance (MGUS) to multiple myeloma (MM) at 20 years. It is also described that MGUS with a progressive increase of monoclonal protein (M-protein) and/or immunoparesis (IMP) may be more predisposed to progress to myeloma. Our objective was to make a review of MGUS, to see how those who presented IMP and/or progression of their M-protein, contrasting them with MGUS that presented intermediate/high and high risk according to MCMMG.

METHODOLOGY AND MATERIALS

A review of the MGUS objectified during the realization of a serum proteinogram (SPEP) was carried out during 2010-2014, in our area. Serum immunoglobulins, serum immunofixation (IFs), and serum free light chain ratio (FLCr) were determined for all MGUS.

RESULTS

Of the 153 MGUS that are followed up for 4 years, 6 progress to MM. Of these 6 MM, 5 progress from MGUS with intermediate/high risk taking into account the MCMMG. Of these 5, 3 have IMP or progression of their M-protein. 2 present IMP plus progression of their M-protein. The sixth MM evolves from a MGUS without any risk factor, but with progression of its M-protein plus IMP.

CONCLUSIONS

IMP and/or M-protein progression are important risk factors to be taken into account in the MGUS, in the first years after diagnosis, due to their possible evolution to MM.

Immunoparesis defined by heavy/light chain pair suppression in smoldering multiple myeloma shows initial isotype specificity and involves other isotypes in advanced disease

Smoldering multiple myeloma (SMM) is an asymptomatic and biologically heterogeneous plasma cell disorder, with a highly variable clinical course. Immunoparesis, defined by total immunoglobulin measurements, has been shown to be an independent risk factor for progression to symptomatic disease. The heavy/light chain (HLC) assay allows precise measurement of the polyclonal immunoglobulin of the same isotype, enabling the evaluation of isotype-matched immunoparesis (IMI). In this study, we prospectively characterized immunoparesis, as determined by HLC measurements, in 53 SMM patients. Severe IMI was present in 51% of patients, while severe IP of uninvolved isotypes (HLC IP) was present in 39%. Most of the patients with severe HLC IP presented with severe IMI, but not the other way around. Isotype specificity of immune suppression was suggested by lower relative values of isotype-matched HLC pairs, both for IgG and IgA SMM. Severe IMI was associated with other risk factors for progression while patients with severe IMI and severe HLC IP showed an even higher risk profile. Both severe IMI and severe IgM HLC IP showed a significantly shorter time to progression. Finally, gene expression analysis demonstrated differences in the bone marrow microenvironment between patients with IMI and IMI plus HLC IP, with an increased expression of genes associated with cytolytic cells. In conclusion, our data supports isotype specificity of early immunoglobulin suppression mechanisms. While suppression of both involved and uninvolved isotypes is associated with risk of progression, the later appears to develop with more advanced disease and could be mediated by different mechanisms.

Serum Hevylite® assay in the differential diagnosis of patients with high suspicion of AL Amyloidosis

INTRODUCTION

AL amyloidosis (AL) is a malignant form of plasma cell dyscrasia (PCD). It is insidious, and its end-organ damage can mimic that of common diseases. At diagnosis, routine tests for monoclonal protein are insufficient for the differential diagnosis. We hypothesized that Hevylite^® (HLC) isotype patterns may help discriminate between AL and benign PCD states.

METHODS

Serum samples of patients with a high clinical suspicion of AL were prospectively tested for IgGκ, IgGλ, IgAκ, IgAλ, IgMκ, and IgMλ concentrations and ratios using Hevylite^® assays in a blinded manner. The results were correlated with the final diagnosis.

RESULTS

Of the 99 samples analyzed, 46 were newly diagnosed AL, and the majority, 38 (82.6%), presented with suppression of at least one HLC isotype. Of the 53 benign PCD patients, 36 (67.9%) presented with elevation of at least one HLC isotype. By multivariate analysis, Hevylite^® was the best independent test predictor of AL amyloidosis. HLC suppression had an odds ratio (OR) of 14.591, and elevation an OR of 10.149, and thus were significant variables in the diagnosis and exclusion of AL. Furthermore, patients with both HLC suppression, together with no elevation, had an OR of 316.69 to be diagnosed with AL rather than a benign PCD.

CONCLUSIONS

Hevylite^® HLC analysis for Ig isotypes patterns offers an effective non-invasive tool in the evaluation of patients with high suspicion of AL and may assist further explorative decisions for diagnosis.

Biomarkers of minimal residual disease in rituximab-treated patients with mixed cryoglobulinemia

Hepatitis C virus (HCV) represents the major risk factor for mixed cryoglobulinemia (MC), a small-vessel vasculitis that may evolve into an overt B-cell non-Hodgkin's lymphoma. Here, we aimed to identify a biomarker signature for the early diagnosis of minimal residual disease (MRD). We assessed free light chains (FLCs), IgM k,and IgM λ heavy/light chain (HLC) pairs, and vascular endothelial growth factor (VEGF) in sera from 34 patients with MC vasculitis (32 HCV- and 2 HBV-related), treated with low-dose rituximab (RTX). FLCs and IgM HLCs were measured by turbidimetric assay; VEGF by an enzyme-linked immunosorbent assay. After RTX, the positive (complete + partial) clinical and laboratory responses were of 85.29% and 50%, respectively; in contrast, the mean levels of FLCs, IgM HLCs, and VEGF were substantially unaffected in most patients and still above the normal range. In those achieving a reduction of FLCs and IgM k and λ chains values within the range of normality, we found that post-treatment free λ chains and IgM k values correlated with clinical and laboratory response. Our results suggest that high levels of FLCs, IgM HLCs, and VEGF could represent the signature of "dormant" B cell clones' activity that could be very useful to identify MRD indicative of possible relapse or worsening outcome.

A new risk model to predict time to first treatment in chronic lymphocytic leukemia based on heavy chain immunoparesis and summated free light chain

BACKGROUND

Chronic lymphocytic leukemia (CLL) is frequently accompanied by immune dysregulation.

AIMS

In this multicenter prospective study, we investigated whether heavy + light chains (HLC: IgGκ, IgGλ, IgAκ, IgAκ, IgMκ, IgMλ) and IgG subclasses (IgG1, IgG2, IgG3, and IgG4) could be used as novel prognostic markers of immunoparesis in 105 treatment-naïve patients with CLL.

RESULTS

Heavy + light chains immunoparesis of ≥1, ≥2, and ≥3 isotypes was evident in 74 (70%), 58 (55%), and 36 (34%) patients, respectively. Severe HLC immunoparesis was identified in 40 (38%) patients. Of the IgG subclasses, IgG1 and IgG2 were most frequently suppressed, affecting 46 (44%) and 36 (34%) patients, respectively; 63 (60%) patients had low levels of at least one IgG subclass. In multivariate analysis, severe HLC immunoparesis (hazard ratio [HR]: 36.5; P = .010) and ΣFLC ≥ 70 mg/L (HR: 13.2; P = .004) were the only factors independently associated with time to first treatment (TTFT). A risk model including these variables identified patients with 0, 1, and 2 risk factors and significantly different TTFT (P < .001). Patients with two factors represented an ultra-high-risk group with a median TTFT of only 1.3 months.

CONCLUSION

The above findings demonstrate the potential for the use of HLC immunoparesis, together with sFLC measurements, as future prognostic biomarkers in CLL.

Elevated IgM and abnormal free light chain ratio are increased in relatives from high-risk chronic lymphocytic leukemia pedigrees

Abnormal serum immunoglobulin (Ig) free light chains (FLC) are established biomarkers of early disease in multiple B-cell lymphoid malignancies, including chronic lymphocytic leukemia (CLL). Heavy chains have also been shown to be biomarkers in plasma cell disorders. An unanswered question is whether these Ig biomarkers are heritable, i.e., influenced by germline factors. CLL is heritable but highly heterogeneous. Heritable biomarkers could elucidate steps of disease pathogenesis that are affected by germline factors, and may help partition heterogeneity and identify genetic pleiotropies across malignancies. Relatives in CLL pedigrees present an opportunity to identify heritable biomarkers. We compared FLCs and heavy chains between relatives in 23 high-risk CLL pedigrees and population controls. Elevated IgM (eIgM) and abnormal FLC (aFLC) ratio was significantly increased in relatives, suggesting that these Ig biomarkers are heritable and could offer risk stratification in pedigree relatives. Within high-risk CLL pedigrees, B-cell lymphoid malignancies were five times more prevalent in close relatives of individuals with eIgM, prostate cancer was three times more prevalent in relatives of individuals with aFLC, and monoclonal B-cell lymphocytosis increased surrounding individuals with normal Ig levels. These different clustering patterns suggest Ig biomarkers have the potential to partition genetic heterogeneity in CLL and provide insight into distinct heritable pleiotropies associated with CLL.

[The value of serum heavy/light chain immunoassay to assess therapeutic response in patients with multiple myeloma]

Objective: To assess the value of immunoglobulin heavy/light chain (HLC) immunoassay on therapeutic response in patients with multiple myeloma(MM). Methods: A total of 45 newly diagnosed MM patients were retrospectively enrolled in Peking Union Medical College Hospital from 2013 to 2016, whose 115 serum samples were consecutively collected. HLC was tested to evaluate response and compare with other methods for M protein detection. Results: ①There were 30 males and 15 females in total of whom the monoclonal immunoglobulin was IgG in 27 (IgGκ∶IgGλ 12∶15) and IgA (IgAκ∶IgAλ 9∶9) in 18. The arerage age of the studied population was 59 (range 43-80) . ② In 34 patients with serum sample at diagnosis, 32 (94.1%) had abnormal HLC ratio (rHLC) while 2 patients with IgG had normal rHLC. The percentages of abnormal rHLC was 81.8% (18/22) at partial response、50.0%(9/18) at very good complete response and 16.0%(4/25) at complete response. ③In 25 patients reaching CR, there were 13 with IgG and 12 with IgA. 4 patients equally split of IgG and IgA had abnormal rHLC at complete response. ④By monitoring the rHLC of some patients consecutively, we found that the remission of rHLC was to some extent behind the remission of SPE and IEF, or even rFLC. Conclusion: Immunoglobulin HLC detection is one feasible method for minimal residual disease detection.

Prognostic utility of serum free light chain ratios and heavy-light chain ratios in multiple myeloma in three PETHEMA/GEM phase III clinical trials

We investigated the prognostic impact and clinical utility of serum free light chains (sFLC) and serum heavy-light chains (sHLC) in patients with multiple myeloma treated according to the GEM2005MENOS65, GEM2005MAS65, and GEM2010MAS65 PETHEMA/GEM phase III clinical trials. Serum samples collected at diagnosis were retrospectively analyzed for sFLC (n = 623) and sHLC (n = 183). After induction or autologous transplantation, 309 and 89 samples respectively were available for sFLC and sHLC assays. At diagnosis, a highly abnormal (HA) sFLC ratio (sFLCr) (<0.03 or >32) was not associated with higher risk of progression. After therapy, persistence of involved-sFLC levels >100 mg/L implied worse survival (overall survival [OS], P = 0.03; progression-free survival [PFS], P = 0.007). Among patients that achieved a complete response, sFLCr normalization did not necessarily indicate a higher quality response. We conducted sHLC investigations for IgG and IgA MM. Absolute sHLC values were correlated with monoclonal protein levels measured with serum protein electrophoresis. At diagnosis, HA-sHLCrs (<0.29 or >73) showed a higher risk of progression (P = 0.006). Additionally, involved-sHLC levels >5 g/L after treatment were associated with shorter survival (OS, P = 0.001; PFS, P = 0.018). The HA-sHLCr could have prognostic value at diagnosis; absolute values of involved-sFLC >100 mg/L and involved-sHLC >5 g/L could have prognostic value after treatment.

Analytical validation of the Hevylite assays for M-protein quantification

Background:

The heavy/light chain (HLC) immunoassay quantifies the different heavy chain/light chain combinations of each immunoglobulin (Ig) class. This makes the HLC assay suited to quantify monoclonal immunoglobulins (M-protein) and for monitoring of patients with monoclonal gammopathies. This method is particularly advantageous for those samples in which electrophoretic quantification of the M-protein is not possible.

Methods:

In this study we tested the analytical performance of the HLC assay in 166 routine clinical samples and in 27 samples derived from the Dutch external quality assessment (EQA) for M-protein diagnostics (74 participating laboratories). Analytical accuracy was assessed by verification that the sum of the HLC-pairs equaled total Ig concentration. Sensitivity of the HLC assay was determined in a direct method comparison with immunofixation electrophoresis (IFE).

Results:

Comparison of HLC data with routine Ig diagnostics in 27 EQA samples showed very good correlation for both the quantification of polyclonal and monoclonal IgG, IgA and IgM (Pearson correlations [r] were 0.94, 0.99 and 0.99, respectively; slopes were 0.94, 1.07 and 0.98, respectively). The overall concordance between IFE and the HLC ratio was high (93%) with a Cohen κ coefficient of 0.84. Discrepancies between both assays were mainly caused by the higher sensitivity of IFE to detect monoclonality.

Conclusions:

We conclude that the HLC assay is an accurate method to quantify M-proteins that can improve monitoring of M-proteins in the beta fraction that cannot be quantified using electrophoretic techniques.

Severe Isotype-Matched Immunosuppression (IMI) as a Potential Risk Factor for Progression of MGUS Patients

Background

Monoclonal gammopathy of undetermined significance (MGUS) precedes multiple myeloma in virtually every case. However, only a small percentage will progress and at very different rates. In addition, recent data have suggested that MGUS is associated with other comorbidities including infections, suggesting impaired immune function in some MGUS patients. Therefore, we aimed at assessing the value of isotype-matched immunosuppression (IMI; e.g., suppression of an IgAκ in an IgAλ patient), a type of immunosuppression more specific than classical immunoparesis (IP; e.g., IgG and/or IgM suppression in an IgA patient), as a prognostic marker for MGUS progression.

Methods

The Hevylite assay was used to assess IMI and immunoglobulin ratios in 307 serum samples from a cohort of 248 MGUS patients. Follow-up clinical records were available for 154 individuals.

Results

A greater incidence of IMI (51%) over classical IP (37%) was observed, although both show a progressive increase with higher risk groups. Survival analysis of 154 patients showed that severe IMI (&gt;50% suppression) differentiates 2 groups with significantly different time to progression (P = 0.024) while severe IP does not (P = 0.48). Also, a combination of severe IMI and involved monoclonal immunoglobulin &gt;1.5g/dL by Hevylite (both variables found to be independent prognostic markers in multivariate analysis) identified a group of patients with a median time to progression 6-fold shorter than the remaining group (P &lt; 0.0001).

Conclusions

These findings indicate a possible role for IMI in the malignant transformation of MGUS patients and a potential utility as a new risk factor.

Prognostic Biomarkers in the Progression From MGUS to Multiple Myeloma: A Systematic Review

Multiple myeloma (MM), characterized by malignant plasma cells in the bone marrow, is consistently preceded by asymptomatic premalignant stage monoclonal gammopathy of undetermined significance (MGUS). These MGUS patients have an annual risk of 1% to progress to MM. Clinical, imaging, and genomic (genetic and epigenetic) factors were identified, whose presence increased the risk of progression from MGUS to MM. In this systematic review we summarize the currently identified clinical, imaging, and genomic biomarkers suggested to increase the progression risk or shown to be differentially expressed/present between both cohorts of patients. Despite the wide range of proposed markers, there are still no reliable biomarkers to individually predict which MGUS patient will progress to MM and which will not. Research on biomarkers in the progression from MGUS to MM will give more insight in the unknown pathogenesis of this hematological malignancy. This would improve research by elucidating new pathways and potential therapeutic targets as well as clinical management by closer follow-up and earlier treatment of high-risk MGUS patients.

Flow cytometric aberrancies in plasma cell myeloma and MGUS - correlation with laboratory parameters

BACKGROUND

Multiparametric flow cytometry is a useful tool for diagnosis of plasma cell (PC) dyscrasias and assessment of minimal residual disease in plasma cell myeloma (PCM). However, the immunophenotypic differences between the clonal PCs of PCM and those of monoclonal gammopathy of undetermined significance (MGUS) as well as the correlation of these flow cytometric markers with pertinent laboratory parameters have not been evaluated.

METHODS

We retrospectively identified all newly diagnosed treatment-naive PCM and MGUS patients between 09/2014 and 06/2015 who underwent 10-color flow-cytometric evaluation: CD45, CD38, CD138, cKappa, cLambda, CD19, CD27, CD28, CD56, CD117. FACSDiva analysis was used to identify antigenic aberrancies and associations with pertinent laboratory parameters were evaluated.

RESULTS

All cases demonstrated at least two aberrancies. There was a trend toward a greater number of aberrancies in PCM, with 68% showing >/= 4 aberrancies compared with 44% in MGUS (P = 0.11). The only marker more frequently aberrant in one disease class was CD19, aberrant in 68% of PCM and 25% of MGUS (P < 0.01). In PCM, significant associations were found for CD56 non-aberrancy (P = 0.05) and the presence of amyloid and CD27 aberrancy and normal serum albumin (P = 0.05). In MGUS, CD117 expression was associated with normal hemoglobin (P = 0.03).

CONCLUSIONS

The PCs of PCM show a trend toward more antigenic aberrancy than those of MGUS. There is significant association between the antigenic profiles of PCM/MGUS and clinical parameters including amyloidosis, albumin level, and hemoglobin. © 2018 International Clinical Cytometry Society.

Long-Term Follow-up of Monoclonal Gammopathy of Undetermined Significance

BACKGROUND

Monoclonal gammopathy of undetermined significance (MGUS) occurs in approximately 3% of persons 50 years of age or older.

METHODS

We studied 1384 patients who were residing in southeastern Minnesota and in whom MGUS was diagnosed at the Mayo Clinic in the period from 1960 through 1994; the median follow-up was 34.1 years (range, 0.0 to 43.6). The primary end point was progression to multiple myeloma or another plasma-cell or lymphoid disorder.

RESULTS

During 14,130 person-years of follow-up, MGUS progressed in 147 patients (11%), a rate that was 6.5 times (95% confidence interval [CI], 5.5 to 7.7) as high as the rate in the control population. The risk of progression without accounting for death due to competing causes was 10% at 10 years, 18% at 20 years, 28% at 30 years, 36% at 35 years, and 36% at 40 years. Among patients with IgM MGUS, the presence of two adverse risk factors - namely, an abnormal serum free light-chain ratio (ratio of kappa to lambda free light chains) and a high serum monoclonal protein (M protein) level (≥1.5 g per deciliter) - was associated with a risk of progression at 20 years of 55%, as compared with 41% among patients who had one adverse risk factor and 19% among patients who had neither risk factor. Among patients with non-IgM MGUS, the risk of progression at 20 years was 30% among those who had the two risk factors, 20% among those who had one risk factor, and 7% among those who had neither risk factor. Patients with MGUS had shorter survival than was expected in the control population of Minnesota residents of matched age and sex (median, 8.1 vs. 12.4 years; P<0.001).

CONCLUSIONS

Significant differences were noted in the risk of progression between patients with IgM MGUS and those with non-IgM MGUS. Overall survival was shorter among patients with MGUS than was expected in a matched control population. (Funded by the National Cancer Institute.).

The clinical utility of serum free light chain and heavy/light chain assays in monitoring disease activity in patients with IgG myeloma after achieving a deep response

Heavy/light chain (HLC) assay will enable us to evaluate the changes in the concentrations of iHLC and uHLC separately and to better identify whether the change observed is clonal or reactive. It would therefore aid in decision making for earlier implementation or discontinuation of treatment for patients with intact immunoglobulin multiple myeloma (MM).

Immunoparesis in newly diagnosed Multiple Myeloma patients: Effects on overall survival and progression free survival in the Danish population

Immunoparesis (hypogammaglobulinemia) is associated to an unfavorable prognosis in newly diagnosed Multiple myeloma (MM) patients. However, this finding has not been validated in an unselected population-based cohort. We analyzed 2558 newly diagnosed MM patients in the Danish Multiple Myeloma Registry representing the entire MM population in Denmark from 2005–2013. Two-thousand two hundred and fifty three patients (90%) presented with reduction below lower normal levels of at least one uninvolved immunoglobulin. Using multivariable Cox regression we found that high age, high ISS score, high LDH and IgA MM were associated to both shorter overall survival and progression free survival. Furthermore, bone marrow plasma cell % was associated to short progression free survival. Immunoparesis had no independent significant effect on OS (HR 0.9 (95%CI: 0.7;1.0; p = 0.12)). Likewise, the number of suppressed immunoglobulins or the relative degree of suppressed uninvolved immunoglobulins from lower normal level (quantitative immunoparesis) was not associated to OS in the multivariable analysis. However, quantitative immunoparesis with at least 25% reduction (from lower normal level) of uninvolved immunoglobulins was associated to shorter PFS for the entire population. The impact of quantitative immunoparesis on PFS was present irrespective of calendar periods 2005–2008 and 2009–2013. Our population-based study does not confirm that immunoparesis at diagnosis is an independent prognostic factor regarding OS. However, quantitative immunoparesis is associated to a shorter PFS.

Immunoparesis defined by heavy+light chain suppression is a novel marker of long-term outcomes in cardiac AL amyloidosis

Cardiac involvement and presenting dFLC (difference between involved and uninvolved free light chains) are independent predictors of outcome in systemic AL amyloidosis. These markers have limited prognostic utility in patients surviving the initial months following diagnosis. Here we assessed immunoparesis, as determined by novel heavy+light chain (HLC) immunoassays, as a prognostic marker for survival in AL amyloidosis. HLC measurements identified immunoparesis of at least one immunoglobulin (Ig) isotype in 145 (85%) patients; and severe immunoparesis (≥2 Ig isotypes suppressed by >50% below normal levels) in 29 (17%) patients. Median overall survival (OS) on intention to treat (ITT) analysis was 26·2 months. In the ITT cohort, dFLC >180 mg/l was associated with shorter OS (P = 0·05); whereas HLC immunoparesis was not prognostic. On a landmark analysis of 127 patients alive at 6 months, presenting dFLC was not prognostic for OS (P = 0·33) and severe HLC immunoparesis trended towards poorer survival (20·2 vs. 42·8 months; P = 0·09). In the subset of patients with cardiac involvement, severe HLC immunoparesis conferred very poor outcome (median OS 8·8 vs. 29·9 months, P = 0·007). In conclusion, severe HLC immunoparesis is an independent marker of long-term poor prognosis in AL patients with cardiac involvement. The pathophysiological significance of this observation needs further study.

The serum heavy/light chain immunoassay: A valuable tool for sensitive paraprotein assessment, risk, and disease monitoring in monoclonal gammopathies

OBJECTIVE

The heavy/light chain (HLC)-immunoassay quantifies light chain types of each immunoglobulin class in patients with monoclonal gammopathies.

METHODS

We assessed 147 consecutive patients with different forms and stages of plasma cell dyscrasias (PCD) who received standard tests (serum and urine protein electrophoresis [SPEP, UPEP], immunofixation [IFE], serum-free light chain [SFLC]), and HLC-immunoassay. Patients with multiple myeloma (MM, n = 102), smoldering MM (SMM, n = 5), monoclonal gammopathy of undetermined significance (MGUS, n = 28), and Waldenström's macroglobulinemia (WM, n = 12) were included.

RESULTS

We verified a significant correlation between HLC- and standard monoclonal protein (mp)-parameters, and HLC-increases with higher disease stage and unfavorable remission status. In patients with difficult to quantify mp, more abnormal HLC- than SPEP-, immunoglobulin-, or SFLC-results were found. In WM, a pathological HLC κ/λ-ratio and M-component were observed in 95% and 58%, respectively. In 21/28 MGUS and 5/5 SMM patients, HLC κ/λ-ratios were abnormal. Testing different HLC cutoffs, patients with extreme HLC values showed impaired progression-free survival (PFS).

CONCLUSIONS

Despite the fact that different PCD patients were included, the assessment of the HLC-immunoassay in MGUS, SMM, MM, and WM, our comparison with standard mp-assays, and relevant PFS differences may excite future applications, which should be confirmed in prospective multicenter trials.

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.

Evolutionary biology of high-risk multiple myeloma

The outcomes for the majority of patients with myeloma have improved over recent decades, driven by treatment advances. However, there is a subset of patients considered to have high-risk disease who have not benefited. Understanding how high-risk disease evolves from more therapeutically tractable stages is crucial if we are to improve outcomes. This can be accomplished by identifying the genetic mechanisms and mutations driving the transition of a normal plasma cell to one with the features of the following disease stages: monoclonal gammopathy of undetermined significance, smouldering myeloma, myeloma and plasma cell leukaemia. Although myeloma initiating events are clonal, subsequent driver lesions often occur in a subclone of cells, facilitating progression by Darwinian selection processes. Understanding the co-evolution of the clones within their microenvironment will be crucial for therapeutically manipulating the process. The end stage of progression is the generation of a state associated with treatment resistance, increased proliferation, evasion of apoptosis and an ability to grow independently of the bone marrow microenvironment. In this Review, we discuss these end-stage high-risk disease states and how new information is improving our understanding of their evolutionary trajectories, how they may be diagnosed and the biological behaviour that must be addressed if they are to be treated effectively.

Novel Immunotherapies for Multiple Myeloma

PURPOSE OF REVIEW

The treatment landscape of multiple myeloma is rapidly changing; however, despite improvement in patients' survival, it still remains a largely incurable disease. One hallmark of myeloma is substantial immune dysfunction leading to an increased infection rate and the inability of immune surveillance to detect neoplastic cells. Here, we critically analyze clinical approaches to harness the immune system to overcome this defect with a focus on antibody based and adoptive cellular therapies.

RECENT FINDINGS

Clinical trials exploring these immunotherapies to treat myeloma are now well underway and show promising results. In relapsed myeloma, monoclonal antibodies directed against plasma cell antigens and immune checkpoints have already shown substantial efficacy. In parallel, trials of adoptive cellular therapy have exciting promise in myeloma, having induced dramatic responses in a handful of early study participants. Taken together, immunotherapeutic approaches hold enormous potential in the field of multiple myeloma and in the near future can be combined with or even replace the current standard of care.

Free light chains and heavy/light chains in monitoring POEMS patients

BACKGROUND

POEMS syndrome is defined by Polyneuropathy, Organomegaly, Endocrinopathy, Monoclonal gammopathy and Skin changes. The vascular endothelial growth factor (VEGF) appears to play a key role in the pathogenesis of the syndrome, and its concentrations are deemed to correlate to disease activity. The aim of the present study was to verify whether other biochemical markers including serum free light chains (FLC) and heavy/light chains (HLC) would be of value in monitoring POEMS patients.

METHODS

Fifty-three serum samples were collected from seven POEMS patients at diagnosis and during a follow-up period (range 14-56 months). VEGF was measured using an ELISA method, while FLC and HLC concentrations were measured using Binding Site reagents on a BNII (Siemens) nephelometer.

RESULTS

At diagnosis all patients presented high VEGF concentrations, while the κ/λFLC ratio (FLCr) was within the reference range. Four patients had abnormal HLC, HLCκ/HLCλ (HLCr) and FLC values. The relationship between the trend of VEGF and both HLC and FLC during the follow-up was analysed by means of Cohen's κ coefficient. VEGF and HLC values displayed a significant κ-Cohen (0.537, p=0.002) in all chemotherapy-responder patients while in non-responders it did not. Conversely, in both responders and non-responders, VEGF and FLC values did not attain a significance on κ-Cohen analysis. In three out of four responders HLCr values increased, thus reflecting an improved clinical condition.

CONCLUSIONS

The findings made in the present study indicate that HLC, either as intact immunoglobulin or as HLCr, may provide useful information, particularly in identifying responders and confirm that the role of FLC is unreliable in monitoring patients with POEMS syndrome.

Changes in uninvolved immunoglobulins during induction therapy for newly diagnosed multiple myeloma

Little is known about the impact of multiple myeloma (MM) treatment on uninvolved immunoglobulins (Ig). We identified 448 patients who received high-dose dexamethasone (HD-DEX), lenalidomide and dexamethasone (RD), bortezomib and dexamethasone (VD), bortezomib, cyclophosphamide and dexamethasone (VCD) or bortezomib, lenalidomide and dexamethasone (VRD) for newly diagnosed MM at our institution between 2000 and 2013, and who had available data on absolute lymphocyte count (ALC) and quantitative uninvolved Ig at baseline and at the end of four cycles of therapy. Changes in ALC and uninvolved Ig were significantly different across treatments, with VCD and HD-DEX producing reductions in uninvolved Ig, and RD, VD and VRD leading to increases in uninvolved Ig. In addition, treatment with RD, VD and VRD was independently associated with higher odds of achieving a ⩾25% increase in or normalization of the primary uninvolved Ig on multivariate analysis. Although achievement of a humoral response in the primary uninvolved Ig was associated with a higher odds of achieving VGPR or better after four cycles of therapy, it was not associated with improved overall survival. These data highlight the different mechanisms of action of MM drugs and point toward a possible role for the use of VCD in treating antibody-mediated autoimmune disease.

Performance Evaluation of Serum Free Light Chain Analysis: Nephelometry vs Turbidimetry, Monoclonal vs Polyclonal Reagents

OBJECTIVES

Free light chain (FLC) measurement gained a lot of interest for diagnostic workup of monoclonal gammopathy.

METHODS

We evaluated the performance of turbidimetric polyclonal Freelite (The Binding Site, Birmingham, UK) assays on Cobas 6000 (Roche Diagnostics, Rotkreuz, Switzerland) and nephelometric monoclonal N Latex (Siemens Healthcare Diagnostics, Marburg, Germany) assays on BN ProSpec (Dade Behring, Deerfield, IL) vs established nephelometric Freelite assays on BN ProSpec.

RESULTS

Analytical performance was acceptable. Method comparison (n = 118) showed significant proportional FLC differences for N Latex assays. However, good correlation and clinical concordance were shown. Recovery study in the low concentration range demonstrated consistent over- and underrecovery for Freelite reagents, hampering future research on prognostic value of suppressed noninvolved FLC. Antigen excess detection was successful for κ FLC in three-fourths of cases with Freelite reagents and in all cases with N Latex reagents. However, the latter resulted in underestimated κ FLC concentrations.

CONCLUSIONS

FLC analysis requires continuous awareness of analytical limitations. Monitoring of disease response requires FLC analysis on the same platform using the same reagents.

Analytical Criticalities Associated to Different Immunological Methods for Serum Free Light Chain Detection in Plasma Cell Dyscrasias: A Description of Particular Clinical Cases

Current criteria for differential diagnosis of multiple myeloma (MM), Monoclonal gammopathy of undetermined significance (MGUS), and smoldering multiple myeloma (SMM) are included in the 2003 guidelines by the International Myeloma Working Group (IMWG). An updated version was then published in 2014, highlighting the importance of serum free light chain (sFLC) detection, as well as the κ/λ ratio as excellent indicators of clonality. At present, two commercial assays for sFLC quantification are available: the Freelite™ assay and the N-Latex assay. The first was developed by The Binding Site based on a mixture of polyclonal antibodies directed against a variety of FLC epitopes. It may be run on a wide range of nephelometers, as well as on turbidimeters. The second method was developed by Siemens and runs exclusively on Siemens instruments. It employs a probe mixture of mouse monoclonal antibodies. The aim of our study was to evaluate sFLC measurement and calculated κ/λ ratio in 85 patients with monoclonal gammopathies (MGs) in order to compare methods. We demonstrated that there is only a moderate concordance between the two FLC assays. In particular, in one case, we observed no qualitative alterations of the serum protein pattern, and in the absence of a Freelite™ assay, sFLC measurement would not have been possible to highlight the increase of λ FLC.

Multiple myeloma patients in long-term complete response after autologous stem cell transplantation express a particular immune signature with potential prognostic implication

The proportion of multiple myeloma patients in long-term complete response (LTCR-MM) for more than 6 years after autologous stem cell transplantation (ASCT) is small. To evaluate whether this LTCR is associated with a particular immune signature, peripheral blood samples from 13 LTCR-MM after ASCT and healthy blood donors (HBD) were analysed. Subpopulations of T-cells (naïve, effector, central memory and regulatory), B-cells (naïve, marginal zone-like, class-switched memory, transitional and plasmablasts) and NK-cells expressing inhibitory and activating receptors were quantified by multiparametric flow cytometry (MFC). Heavy/light chains (HLC) were quantified by nephelometry. The percentage of CD4⁺ T-cells was lower in patients, whereas an increment in the percentage of CD4⁺ and CD8⁺ effector memory T-cells was associated with the LTCR. Regulatory T-cells and NK-cells were similar in both groups but a particular redistribution of inhibitory and activating receptors in NK-cells were found in patients. Regarding B-cells, an increase in naïve cells and a corresponding reduction in marginal zone-like and class-switched memory B-cells was observed. The HLC values were normal. Our results suggest that LTCR-MM patients express a particular immune signature, which probably reflects a 'high quality' immune reconstitution that could exert a competent anti-tumor immunological surveillance along with a recovery of the humoral immunity.

Abnormal heavy/light chain ratio after treatment is associated with shorter survival in patients with IgA myeloma

Immunoglobulin (Ig) heavy/light chain (HLC) assays enable the separate quantification of the different light chain types of each Ig class. We retrospectively analyzed the correlation of heavy/light chain ratio (HLCR) with clinical status and its impact on outcome in 120 patients with multiple myeloma (MM). Abnormal HLCR was seen more frequently in patients with poorer myeloma response, and it appeared to be more sensitive for detecting clonality in IgA myeloma compared to IgG myeloma after treatment. Among the 85 patients who achieved ≥VGPR, the patients remained HLCR abnormal were showed significantly shorter overall survival (OS) compared to those achieving a normal HLCR (not reached vs 55.5 months, P = 0.032). This correlation was seen in IgA myeloma patients (not reached vs 30.1 months, P = 0.014), but not in IgG myeloma patients when patients were analyzed separately. Univariate and multivariate analysis of factors that may affect survival identified abnormal HLCR at the best response as the only independent risk factor (hazard ratio, 4.7; 95% confidence interval, 1.4 – 15.26; P = 0.012) for shorter OS in this subset of patients. This study highlighted the HLC assay as a prognostic predictor in patients with IgA myeloma.

Immunoparesis in IgM gammopathies as a useful biomarker to predict disease progression

Background:

The management of IgM monoclonal gammopathies undetermined significance (IgM-MGUS) and Waldenstrom’s macroglobulinemia (WM) may be challenging. Modern immunoassays that quantify specific monoclonal heavy and light chain immunoglobulins are promising for their use in these applications.

Methods:

Ninety consecutive patients (39 IgM-MGUS, 32 indolent WM [iWM], and 19 WM) seen between January 2007 and March 2014 were analyzed. Heavy/light chain (HLC) and serum free light chains assays (FLC) were determined at diagnosis to study their utility as biomarkers in IgM monoclonal gammopathies.

Results:

The HLC involved to uninvolved IgM ratios (iHLC/uHLC) showed a progressive increase when going from IgM-MGUS, to iWM and to WM (p=0.002). Furthermore, an iHLC/uHLC>62 identified a group of iWM patients with a shorter time-to-progression (TTP) (108 vs. 133 months, p=0.033). Separate analysis of the involved and uninvolved components showed that only the suppression of the uninvolvedimmunoglobulin was predictive of shorter TTP (HR=3.04, p=0.03) suggesting that it could be the majorcontributor to the prognostic value of the Hevylite assay. Additionally, a multivariate analysis showed that immunosuppression (either classical immunoparesis or Hevylite immunosuppression) was an independent prognostic factor (p=0.016) reinforcing its relevance in the disease mechanism. Finally, monoclonal sFLC levels were highest in WM patients, with 83% presenting values>60 mg/L.

Conclusions:

The results suggest that the levels of immunosuppression and/or the iHLC/uHLC ratio of IgM immunoglobulins measured by Hevylite are associated with greater disease activity which significantly impacts in the outcome of WM patients and may also help in the differentiation of IgMMGUS from iWM.

Serum Free Light Chain Assay and κ/λ Ratio: Performance in Patients With Monoclonal Gammopathy-High False Negative Rate for κ/λ Ratio

Background

Serum free light chain assay (SFLCA) and κ/λ ratio, and protein electrophoretic methods are used in the diagnosis and monitoring of monoclonal gammopathies.

Methods

Results for serum free light chains, serum and urine protein electrophoreses and immunofixation electrophoreses in 468 patients with a diagnosis of monoclonal gammopathy were compared. The results of the two methods were graded as concordant, non-concordant or discordant with the established diagnoses to assess the relative performance of the methods. Results of κ/λ ratio in samples with monoclonal protein detectable by electrophoretic methods were also analyzed.

Results

Protein electrophoreses results were concordant with the established diagnoses significantly more often than κ/λ ratio. The false negative rate for κ/λ ratio was higher than that for electrophoretic methods. κ/λ ratio was falsely negative in about 27% of the 1,860 samples with detectable monoclonal immunoglobulin. The false negative rate was higher in lesions with lambda chains (32%) than those with kappa chains (24%). The false negative rate for κ/λ ratio was over 55% in samples with monoclonal gammopathy of undetermined significance. Even at first encounter, the false negative rates for κ/λ ratios for monoclonal gammopathy of undetermined significance, smoldering myeloma and multiple myeloma were 66.98%, 23.08%, and 30.15%, respectively, with false negative rate for lambda chain lesions being higher.

Conclusions

Electrophoretic studies of serum and urine are superior to SFLCA and κ/λ ratio. Abnormal κ/λ ratio, per se, is not diagnostic of monoclonal gammopathy. A normal κ/λ ratio does not exclude monoclonal gammopathy. False negative rates for lesions with lambda chain are higher than those for lesions with kappa chains. Electrophoretic studies of urine are underutilized. Clinical usefulness and medical necessity of SFLCA and κ/λ ratio is of questionable value in routine clinical testing.

The Effect of Suppressed Levels of Uninvolved Immunoglobulins on the Prognosis of Symptomatic Multiple Myeloma

Objective:

The majority of multiple myeloma (MM) patients have high levels of monoclonal immunoglobulin in the serum and/or urine and suppressed levels of the uninvolved immunoglobulins. The prognostic significance of this phenomenon has not been assessed sufficiently. In this study, our aim is to evaluate the prognostic significance of uninvolved immunoglobulin suppression measured by nephelometry in patients with new symptomatic MM and the association with other features of the disease.

Materials and Methods:

Between August 2003 and February 2015, 137 patients who were referred for the treatment of newly diagnosed symptomatic myeloma to the Hematology Department polyclinics of the İstanbul University İstanbul Faculty of Medicine were prospectively included and had available pretreatment immunoglobulin levels measured by nephelometry.

Results:

Suppression of at least one uninvolved immunoglobulin was observed in 87% of patients and this situation was slightly more common in patients with immunoglobulin A myeloma but had no statistical significance (p>0.05). Uninvolved immunoglobulin suppression was also more common among patients who had bone marrow plasma cell infiltration of ≥40% and presented with anemia and hypercalcemia (p<0.05). The overall survival time was shorter in patients with positive calcium-renal-anemia-bone criteria and International Staging System stage 3 compared with others (p<0.05). Factors that were independently associated with inferior survival in the multivariate analysis included patients with estimated glomerular filtration rate of <60 mL/min, age of >65 years, lactate dehydrogenase of >300 IU/L, bone marrow plasma cells of ≥40%, and β2-microglobulin of >3.5 mg/dL (p<0.05).

Conclusion:

In this study, 13.1% of MM patients had preserved levels of uninvolved immunoglobulins. We observed that patients who had preserved uninvolved immunoglobulin levels had better treatment responses and better pathologic signs, but statistical significance could not be shown. Conversely, patients with suppression of even one of the uninvolved immunoglobulins had a shorter survival, but similarly, statistical significance could not be shown.

Serum Free Light Chain Assay and κ/λ Ratio Performance in Patients Without Monoclonal Gammopathies: High False-Positive Rate

OBJECTIVES

Serum free light chain assay is a recommended screening test for monoclonal gammopathies. Anecdotal observations indicated a high rate of false-positive abnormal κ/λ ratios. This study was undertaken to ascertain the magnitude of the false-positive rate and factors contributing to the error rate.

METHODS

Results of serum protein electrophoresis, serum free light chains, and related tests, usually done for investigation of suspected monoclonal gammopathy, were reviewed retrospectively for 270 patients and 297 observations.

RESULTS

Using the conventional κ/λ ratio, 36.4% of the ratios were abnormal, in the absence of monoclonal gammopathy. When the renal κ/λ ratio was used, the rate of abnormal κ/λ ratios was 30.1%. In patients with a γ-globulin concentration of 1.6 g/dL or more, the usual κ/λ ratio was abnormal in 54.8% of the patients. Urine protein electrophoresis was used in 53 (19.6%) instances, whereas bone marrow examination was done in 65 (24.1%) cases.

CONCLUSIONS

Usual κ/λ ratio was abnormal in 36.4% of the observations in patients without evidence of monoclonal gammopathy, and an abnormal κ/λ ratio should not be used as the sole indicator for diagnosis of neoplastic proliferation of the lympho-plasmacytic system. Hypergammaglobulinemia is associated with a higher rate of false-positive abnormal κ/λ ratios. Examination of urine for monoclonal immunoglobulins may be underused, and recommendations by some to use serum free light chain assay in place of, rather than as an adjunct to, urine electrophoresis are not warranted.

Comparison of Fully Automated and Semiautomated Systems for Protein Immunofixation Electrophoresis

BACKGROUND

In order to establish a diagnosis of monoclonal gammopathy, it is necessary to detect and identify monoclonal components. To confirm the immunological nature of the proteins, the next step is to define their composition in heavy and light chains using immunofixation. The purpose of this study was to compare two different instruments, one semiautomated and the other fully automated for serum and urine immunofixation.

METHODS

We selected 150 sera and 100 urines from patients admitted for routine analysis, which were analyzed by immunofixation to characterize monoclonal components.

RESULTS AND CONCLUSION

Comparison study showed a difference in the identification of small monoclonal components and hypogammaglobulinemia, in serum and urine, between the two analyzers. We also observed a difference in the length of the electrophoretic pattern that is of considerable importance as it leads to a better resolution of the gamma region, allowing to identify even the smallest monoclonal component that can be easily hide in an oligoclonal pattern. For this reason, there is need to ameliorate commercial immunofixation assays. It is essential to improve data harmonization and standardize measurement procedures in order to guarantee a correct diagnosis for the right patient care.

Vaccination in Multiple Myeloma: Review of Current Literature

Multiple myeloma is a cancer of the immune system. Infection is a major cause of morbidity and mortality in patients with multiple myeloma. Some of these infections are preventable by vaccines available to the general population. However, little is known about the clinical effectiveness of these vaccines in patients with multiple myeloma, and the cellular and humoral immune response to vaccination has not been well characterized, especially in conjunction with modern myeloma therapies. The present report reviews the basics of multiple myeloma and the immune system, the available evidence on the immunologic response of patients with multiple myeloma after vaccination, and current practice recommendations regarding specific vaccines. Understanding the immune response to vaccines could help us understand how immuno-oncology-based therapies work in multiple myeloma and provide future directions for research.

Assessment and monitoring of patients receiving chemotherapy for multiple myeloma: strategies to improve outcomes

Improved understanding as to the biology of multiple myeloma (MM) and the bone marrow microenvironment has led to the development of new drugs to treat MM. This explosion of new and highly effective drugs has led to dramatic advances in the management of MM and underscores the need for supportive care. Impressive and deep response rates to chemotherapy, monoclonal antibodies, and small molecule drugs provide hope of a cure or prolonged remission for the majority of individuals. For most patients, long-term, continuous therapy is often required to suppress the malignant plasma cell clone, thus requiring clinicians to become more astute in assessment, monitoring, and intervention of side effects as well as monitoring response to therapy. Appropriate diagnosis and monitoring strategies are essential to ensure that patients receive the appropriate chemotherapy and supportive therapy at relapse, and that side effects are appropriately managed to allow for continued therapy and adherence to the regimen. Multiple drugs with complex regimens are currently available with varying side effect profiles. Knowledge of the drugs used to treat MM and the common adverse events will allow for preventative strategies to mitigate adverse events and prompt intervention. The purpose of this paper is to review updates in the diagnosis and management of MM, and to provide strategies for assessment and monitoring of patients receiving chemotherapy for MM.