Elevated monoclonal and polyclonal serum immunoglobulin free light chain as prognostic factors in B- and T-cell non-Hodgkin lymphoma

Serum Paraprotein Is Associated with Adverse Prognostic Factors and Outcome, across Different Subtypes of Mature B-Cell Malignancies-A Systematic Review

The presence of a serum paraprotein (PP) is usually associated with plasma-cell dyscrasias, Waldenstrom Macroglobulinemia/lymphoplasmacytic lymphoma, and cryoglobulinemia. However, PP is also often reported in other high- and low-grade B-cell malignancies. As these reports are sparse and heterogeneous, an overall view on this topic is lacking, Therefore, we carried out a complete literature review to detail the characteristics, and highlight differences and similarities among lymphoma entities associated with PP. In these settings, IgM and IgG are the prevalent PP subtypes, and their serum concentration is often low or even undetectable without immunofixation. The relevance of paraproteinemia and its prevalence, as well as the impact of IgG vs. IgM PP, seems to differ within B-NHL subtypes and CLL. Nonetheless, paraproteinemia is almost always associated with advanced disease, as well as with immunophenotypic, genetic, and clinical features, impacting prognosis. In fact, PP is reported as an independent prognostic marker of poor outcome. All the above call for implementing clinical practice, with the assessment of paraproteinemia, in patients' work-up. Indeed, more studies are needed to shed light on the biological mechanism causing more aggressive disease. Furthermore, the significance of paraproteinemia, in the era of targeted therapies, should be assessed in prospective trials.

Serum Free Light Chain Assay as a Prognostic Marker in Patients with Aggressive B-Cell Non-Hodgkin's Lymphoma: Impact on Survival Outcome

T.M. AnoopBackground  The role of serum free light chain (FLC) as a prognostic biomarker in lymphoproliferative diseases is being increasingly studied. In this study we present the 5-year survival outcome for patients with aggressive B-cell non-Hodgkin's lymphoma (NHL) and their relation to FLC and other known prognostic markers. Materials and Methods  This is a prospective study conducted in patients diagnosed with aggressive B-cell NHL. Serum FLC level and ratio were estimated prior to initiation of treatment. Results  A total of 100 patients were included in the study from December 2013 to December 2015 with a median age of 53 years. Thirty-eight patients (38%) had elevated FLC level of which 26% were polyclonal and 12% were monoclonal elevations. Abnormal FLC ratio was noted in 12% patients. Median follow-up duration of the study was 75 months. Five-year relapse-free survival (RFS) for the study population was 54.4%. Five-year RFS was 64.1% for early stage and 48.2% for advanced stage diseases ( p  = 0.05). The RFS was significantly better in age less than 60 years (59.5% vs 43.8%, p  < 0.001). Five-year overall survival (OS) was 61.3%. OS was significantly better in younger patients (73.6% vs 33.4%, p  < 0.001), with International Prognosis Index score of 0 to 2 (87.4% vs 26.7%, p  < 0.001). Patients with elevated FLC had inferior RFS (50% vs 71.4%, p  = 0.04). Abnormal FLC ratio also strongly corresponded to inferior RFS (54.5% vs 66.2%, p  = 0.001). OS was also significantly inferior in patients with abnormal FLC ratio (72.6% vs 63.6%, p  = 0.001). Conclusion  In patients with newly diagnosed aggressive B-cell NHL, elevated FLC levels and abnormal FLC ratio were significantly associated with inferior survival.

Non-invasive monitoring associated with B lymphoma cells in post-transplant lymphoproliferative disorder (PTLD) patients: Systematic review

BACKGROUND

One of the most severe side effects of solid-organ transplantation is posttransplant lymphoproliferative disease (PTLD). People with human immunodeficiency virus infection (HIV), an immunosuppressive disease comparable to HIV, have a higher chance of developing lymphoma when their peripheral blood contains elevated levels of the immunoglobulins kappa and lambda free light chains (FLCs).

METHODS

This systematic review's objective was to monitor associated B lymphoma cells in PTLD patients. In order to find relevant studies published between 1/1/2000 and 1/9/2022, two independent researchers conducted searches (MT, AJ). A literature search of English language publications was conducted using MEDLINE through PubMed, EMBASETM through Ovid, the Cochrane Library, and Trip. In addition to Magiran and SID, we searched KoreaMed and LILACS for literature published in other languages. sFLC or PTLD, transplant, or Electrophoresis are terms used in the search strategy.

RESULTS

A total of 174 studies were selected. After analyzing their correspondence with the required criteria, a final review of five studies was conducted. The manuscript presents current findings on the potential benefits of the clinical applicability of sFLCs in PTLD. While the preliminary results appear promising, the only consistent result is that early-onset PTLD is predicted within the first two years after transplant, a biomarker that could be used to diagnose the condition.

CONCLUSIONS

Therefore, PTLD has been predicted by using the sFLCs. There have been contradictory results to date. Future research could include assessing the quantity of sFLCs and their quality in transplant recipients. In addition to PTLD and complications after transplantation, sFLCs may provide insight into other diseases. To confirm the validity of sFLCs, more studies are needed.

Serum and Urine Protein Electrophoresis and Serum-Free Light Chain Assays in the Diagnosis and Monitoring of Monoclonal Gammopathies

BACKGROUND

Laboratory methods for diagnosis and monitoring of monoclonal gammopathies have evolved to include serum and urine protein electrophoresis, immunofixation electrophoresis, capillary zone electrophoresis, and immunosubtraction, serum-free light chain assay, mass spectrometry, and newly described QUIET.

CONTENT

This review presents a critical appraisal of the test methods and reporting practices for the findings generated by the tests for monoclonal gammopathies. Recommendations for desirable practices to optimize test selection and provide value-added reports are presented. The shortcomings of the serum-free light chain assay are highlighted, and new assays for measuring monoclonal serum free light chains are addressed.

SUMMARY

The various assays for screening, diagnosis, and monitoring of monoclonal gammopathies should be used in an algorithmic approach to avoid unnecessary testing. Reporting of the test results should be tailored to the clinical context of each individual patient to add value. Caution is urged in the interpretation of results of serum-free light chain assay, kappa/lambda ratio, and myeloma defining conditions. The distortions in serum-free light chain assay and development of oligoclonal bands in patients' status post hematopoietic stem cell transplants is emphasized and the need to note the location of original monoclonal Ig is stressed. The need for developing criteria that consider the differences in the biology of kappa and lambda light chain associated lesions is stressed. A new method of measuring monoclonal serum-free light chains is introduced. Reference is also made to a newly defined entity of light chain predominant intact immunoglobulin monoclonal gammopathy. The utility of urine testing in the diagnosis and monitoring of light chain only lesions is emphasized.

Association of elevated serumfree light chains with chronic lymphocytic leukemia and monoclonal B-cell lymphocytosis

Chronic lymphocytic leukemia (CLL) and its precursor, monoclonal B-cell lymphocytosis (MBL), are heritable. Serumfree light-chain (sFLC) measures are a prognostic factor for CLL, but their role in susceptibility to CLL is not clear. We investigated differences between sFLC measurements in pre-treatment serum from five groups to inform the association of sFLC with familial and sporadic CLL: (1) familial CLL (n = 154), (2) sporadic CLL (n = 302), (3) familial MBL (n = 87), (4) unaffected first-degree relatives from CLL/MBL families (n = 263), and (5) reference population (n = 15,396). The percent of individuals having elevated monoclonal and polyclonal sFLCs was compared using age-stratified and age- and sex-adjusted logistic regression models. In age groups >50 years, monoclonal sFLC elevations were increased in sporadic and familial CLL cases compared to the reference population (p's < 0.05). However, there were no statistically significant differences in sFLC monoclonal or polyclonal elevations between familial and sporadic CLL cases (p's > 0.05). Unaffected relatives and MBL cases from CLL/MBL families, ages >60 years, showed elevated monoclonal sFLC, compared to the reference population (p's < 0.05). This is the first study to demonstrate monoclonal sFLC elevations in CLL cases compared to controls. Monoclonal sFLC levels may provide additional risk information in relatives of CLL probands.

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.

Light chain monoclonal gammopathy of undetermined significance is characterized by a high disappearance rate and low risk of progression on longitudinal analysis

We determined the 10-year progression rate of light chain monoclonal gammopathy of undetermined significance (LCMGUS) and investigated potential associations with cancer utilizing the German population-based Heinz Nixdorf Recall Study. The Heinz Nixdorf Recall Study comprises 4814 men and women aged 45-75 years. Serum samples from baseline (2000-2003) and five-year (2006-2008) and 10-year (2011-2015) follow-up examinations were screened for monoclonal free light chains (FLC). LCMGUS was defined as abnormal FLC ratio, increase of involved FLC with complete loss of immunoglobulin heavy chain, and absence of a history of lymphoproliferative disease (LPD). Seventy-five individuals with LCMGUS were identified across all three evaluation time points (median age 64 years; 43 (57%) male; FLCR > 1.65 65 (87%); FLCR ≤ 0.65 10 (13%)). After a median observation time of 11.5 years, none of the LCMGUS cases had progressed to overt LPD; in particular, we did not observe incident light chain multiple myeloma. On serial analysis 17/31 (55%), LCMGUS could not be confirmed and disappearance of the monoclonal protein was associated with low concentrations of the involved FLC. Individuals with LCMGUS had a 1.5-fold increased risk of cancer but did not show differences in overall survival or renal function as compared to individuals with normal FLC. In conclusion, LCMGUS represents a relatively benign condition with a high disappearance rate of the monoclonal protein on longitudinal analysis and normal overall survival at least in the population-based setting.

Mantle cell lymphoma in the era of precision medicine-diagnosis, biomarkers and therapeutic agents

Despite advances in the development of clinical agents for treating Mantle Cell Lymphoma (MCL), treatment of MCL remains a challenge due to complexity and frequent relapse associated with MCL. The incorporation of conventional and novel diagnostic approaches such as genomic sequencing have helped improve understanding of the pathogenesis of MCL, and have led to development of specific agents targeting signaling pathways that have recently been shown to be involved in MCL. In this review, we first provide a general overview of MCL and then discuss about the role of biomarkers in the pathogenesis, diagnosis, prognosis, and treatment for MCL. We attempt to discuss major biomarkers for MCL and highlight published and ongoing clinical trials in an effort to evaluate the dominant signaling pathways as drugable targets for treating MCL so as to determine the potential combination of drugs for both untreated and relapse/refractory cases. Our analysis indicates that incorporation of biomarkers is crucial for patient stratification and improve diagnosis and predictability of disease outcome thus help us in designing future precision therapies. The evidence indicates that a combination of conventional chemotherapeutic agents and novel drugs designed to target specific dysregulated signaling pathways can provide the effective therapeutic options for both untreated and relapse/refractory MCL.

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.

Serum-free light chains in HIV-associated lymphoma: no correlation with histology or prognosis

OBJECTIVES

Serum-free light chains (sFLCs) are a biomarker of B-cell proliferation. Two case-control studies found elevated levels of polyclonal sFLCs predict the development of HIV-associated lymphomas (HALs) in people living with HIV. This effect appears greater for non-Hodgkin's lymphomas than Hodgkin's lymphoma. In this study, we measured sFLCs at diagnosis of HALs, and correlated levels with histology and survival.

METHODS

The clinic database of the National Centre for HIV Malignancy was used to identify HAL patients, in the antiretroviral treatment era. Levels of sFLCs were measured using stored sera (cases from 1996 to 2008) and prospectively from 2008 to 2014. Serum immunoglobulins were available for 201 patients. We assessed correlations between sFLCs, serum immunoglobulins, and histological subtypes and overall survival.

RESULTS

Two hundred and sixty-four patients were identified and 70% had polyclonal sFLC, 8% monoclonal sFLC (90% kappa sFLC), and 22% normal sFLC levels. No significant difference in sFLCs was observed between the three major histological subtypes of HAL (Hodgkin's lymphoma, diffuse large B-cell lymphoma, and Burkitt lymphoma). Elevated sFLCs did not influence overall survival in HAL or for the three subtypes individually.

DISCUSSION

Whilst these data confirm the finding of elevated sFLC in HAL, there was no significant difference in sFLC measurements between histological subtypes despite differences in pathogenesis. sFLC did not predict survival in HAL overall or by histological subtype. Elevated sFLCs may predict HAL, but measurement of sFLCs has limited utility in the classification and prognostication of these cases.