Overview of monoclonal gammopathies of undetermined significance

Monoclonal gammopathies regardless of subtypes are associated with poor prognosis of diffuse large B-cell lymphoma: A STROBE-compliant article

Monoclonal gammopathy (MG), a positive result of serum immunofixation electrophoresis (SIFE), has been reported in cases of diffuse large B-cell lymphoma (DLBCL). We performed this study to further investigate the prognostic value of MG in DLBCL.We retrospectively reviewed patients diagnosed with DLBCL between January 2007 and December 2014, and identified 37 patients with MG. The clinical characteristics of these patients were then reviewed. A 1:2 case-control analysis was conducted on 74 matched controls, who were patients with DLBCL and without MG. Both cases and controls were age-matched and were diagnosed within the same year.Among 37 DLBCL patients with MG, the monoclonal component of IgM was the most frequent compared to the other subtypes. Laboratory tests showed that the presence of MG was correlated with a decreased platelet-to-lymphocyte ratio (PLR). Survival analysis showed that MG-secreting DLBCL patients had an inferior overall survival (OS) and progression-free survival (PFS), compared with MG-nonsecreting patients, regardless of MG subtype. However, treatment response analysis showed that MG was not a good indicator for tumor relapse. When patients with DLBCL were grouped by immunophenotype, we found that MG was associated with poor prognosis in the non-germinal center B-cell-like (GCB) type, rather than GCB type in OS analysis. Meanwhile, there was no statistical significance upon PFS analysis in both immunophenotypes. Furthermore, our study found that the appearance of MG during treatment did make prognostic sense compared to nonsecretors.Overall, MG can serve as a prognostic factor for DLBCL. We hypothesize that its presence in DLBCL may reflect the immune microenvironment in tumor progression and warrants further study to unveil the underlying molecular pathogenesis.

Penile ulcer as a specific clinical manifestation of Waldenstrom's macroglobulinemia

Waldenstrom's macroglobulinemia is considered a lymphoma by the World Health Organization. Cutaneous lesions, particularly of a specific type, are rare occurring in 5% of patients. What draws attention in this case is the unusual cutaneous clinical manifestation and its location on the genitals, which has not been described in researched literature, therefore imposing differential diagnosis with other etiologies of genital ulcers.

Prevalence, clinical aspects, and natural history of IgM MGUS

BACKGROUND

Waldenström macroglobulinemia (WM) and chronic lymphocytic leukemia (CLL) are related B-cell cancers that share several clinical and biological features. Both WM and CLL have associated precursor conditions: monoclonal gammopathy of undetermined significance (MGUS) of immunoglobulin M (IgM) type and monoclonal B-cell lymphocytosis (MBL), respectively. Recently, a case of MBL with an IgM MGUS was reported, suggesting a close biological relationship between these entities. While much is known about MGUS overall, investigations of IgM MGUS specifically have been fragmentary.

METHODS

In this article, we review data on the prevalence, clinical aspects and natural history of IgM MGUS, and focus on identifying gaps in our understanding of the complex relationships among B-cell malignancies and their precursors.

RESULTS

There appears to be marked heterogeneity in the prevalence of IgM MGUS across populations. However, studies have varied in definition, design, laboratory methods, and endpoints. IgM MGUS differs from non-IgM MGUS in certain respects, including prevalence across racial groups, rate of progression, and pattern of malignant outcomes. There are limited data regarding the coincident occurrence of IgM MGUS and MBL.

CONCLUSIONS

Future studies incorporating both protein electrophoresis and flow cytometry are needed to define the underlying spectrum and causes of precursor development, risk factors for progression, and markers that distinguish low- and high-risk precursor patients.

Prevalence of monoclonal gammopathy of undetermined significance: a systematic review

Monoclonal gammopathy of undetermined significance (MGUS) is a premalignant plasma cell disorder that is associated with a lifelong risk of multiple myeloma. We conducted a systematic review of all studies investigating the prevalence and incidence of MGUS in the online database PubMed. The review was conducted from January 6, 2009, through January 15, 2010. The following MeSH search headings were used: monoclonal gammopathy, benign and prevalence; monoclonal gammopathy, benign and incidence; paraproteinemia and prevalence; and paraproteinemia and incidence. Articles were limited to those written in English and published by January 2009. Fourteen studies that met prespecified criteria were included and systematically assessed to identify the most accurate prevalence estimates of MGUS based on age, sex, and race. On the basis of our systematic review, we estimate that the crude prevalence of MGUS in those older than 50 years is 3.2% in a predominantly white population. Studies in white and Japanese populations demonstrate a clear increase in prevalence with age. The prevalence is also affected by sex: 3.7% and 2.9% in white men and women, respectively; and 2.8% and 1.6% in Japanese men and women, respectively. Additionally, MGUS is significantly more prevalent in black people (5.9%-8.4%) than in white people (3.0%-3.6%). We conclude that MGUS is a common premalignant plasma cell disorder in the general population of those older than 50 years. The prevalence increases with age and is affected by race, sex, family history, immunosuppression, and pesticide exposure. These results are important for counseling, clinical care, and the design of clinical studies in high-risk populations.

Multiple myeloma, chronic lymphocytic leukaemia and associated precursor diseases

Multiple myeloma and chronic lymphocytic leukaemia share common biological and clinical features including the presence of defined precursor conditions (monoclonal gammopathy of undetermined significance and monoclonal B-cell lymphocytosis respectively). Here, we discuss evidence from the literature on the potential aetiological roles for genetic and chronic immune stimulatory factors on the pathway from precursor to malignancy. Also, we speculate on the relationship between precursor and malignancy and talk about future directions and gaps in the literature.

B cells behaving badly

The pathogenesis of B-cell lymphoproliferative disorders in general and B-cell chronic lymphocytic leukaemia in particular appears to involve dysfunctional regulation of humoral and cellular immunity with the subsequent development of genetic aberrations in B cells. In theory, either component may arise de novo or may be influenced by environmental exposures including infectious agents, antigens, genotoxic chemicals, or radiation. As an intermediary within the exposure-disease continuum, monoclonal B-cell lymphocytosis may be a helpful biomarker for teasing out these various contributions to risk. This article introduces a series of papers that resulted from an International Workshop held in May 2007 entitled 'Monoclonal B-cell Lymphocytosis and Chronic Lymphocytic Leukemia: Environmental and Genetic Risk Factors'. Research efforts, such as those described in this issue, should lead to improved interventions, more predictive biomarkers, more effective treatments, and a greater appreciation of how the immune system functions over the entire human lifespan.