Prevalence of monoclonal gammopathy of undetermined significance (MGUS) among farmers involved in open field farming and/or cattle breading in France

Prevalence of monoclonal gammopathy of undetermined significance in Shenzhen, China

BACKGROUND

Data on the prevalence of monoclonal gammopathy of undetermined significance (MGUS) in China are very limited. Our aim was to determine the prevalence and clinical characteristics of MGUS in a large Chinese population.

METHODS

This study included 49,220 healthy people who received serum immunofixation electrophoresis (sIFE) and serum protein electrophoresis (SPE) tests. Serum free light chain ratio, immunoglobulin quantification, and other clinically correlates of MGUS were performed for all patients with M-protein.

RESULTS

A total of 576 MGUS patients were identified by sIFE, with a median age of 58 years and an overall prevalence of 1.17% (95% CI, 1.08-1.27). Among those aged 50 years and older, the prevalence of MGUS was 2.26% (95% CI, 2.04-2.50). The prevalence of MGUS was significantly higher in males than in females (P < 0.05). The median concentration of M-protein was 3.1 g/L, ranging from 0.5 g/L to 25.1 g/L. The M-protein type was IgG in 55.4% of MGUS patients, followed by IgA (31.1%), IgM (9.5%), IgD (0.5%), biclonal (2.3%), and light chain (1.2%). Abnormalities in SPE, FLC ratios, and immunoglobulin levels were observed in 78.3%, 31.1%, and 38.4% of MGUS patients, respectively.

CONCLUSIONS

The prevalence of MGUS is substantially lower in southern China than in whites and blacks.

Monoclonal gammopathy in the setting of Pyoderma gangrenosum

Pyoderma gangrenosum (PG) is a neutrophilic dermatosis characterized by ulcerative painful lesions with violaceous undermined borders. Up to 75% of PG cases develop in association with an underlying systemic disease. Monoclonal gammopathy is reportedly a concomitant condition with PG, with studies indicating immunoglobulin (Ig) A gammopathy as the most common. Whether gammopathy is associated with PG or is an incidental finding has been debated. We sought to investigate the association and characteristics of gammopathy in patients with PG. We retrospectively identified PG patients at our institution from 2010 to 2022 who were screened for plasma cell dyscrasia. Of 106 patients identified, 29 (27%) had a gammopathy; subtypes included IgA (41%), IgG (28%), and biclonal (IgA and IgG) (14%). Mean age was similar between those with and without gammopathy (60.7 vs. 55.9 years; P = .26). In addition, hematologic or solid organ cancer developed in significantly more patients with vs. without gammopathy (8/29 [28%] vs. 5/77 [6%]; P = .003). Among the subtypes of gammopathy, IgG monoclonal gammopathy had the highest proportion of patients with subsequent cancer development (4 of 8 patients, 50%). Study limitations include a retrospective, single-institution design with a limited number of patients. Overall, our data show a high prevalence of gammopathy in patients with PG; those patients additionally had an increased incidence of cancer, especially hematologic cancer.

Monoclonal gammopathy of undetermined significance: evaluation, risk assessment, management, and beyond

Monoclonal gammopathy of undetermined significance (MGUS) is a premalignant state for a spectrum of lymphoplasmacytic malignancies. The risk of progression of MGUS to a symptomatic therapy requiring plasma cell dyscrasia is about 1% per year. Studies carried out over the previous 10 years have improved risk stratification of MGUS based on serologic and genomic evaluations, which has led to better management of patients. In this review, we address the epidemiology, diagnosis, and pathogenesis of MGUS and discuss risk-adapted best practice approaches to monitor patients.

Lifetime Pesticide Use and Monoclonal Gammopathy of Undetermined Significance in a Prospective Cohort of Male Farmers

BACKGROUND

Farmers have a higher incidence of multiple myeloma, and there is suggestive evidence of an elevated prevalence of its precursor, monoclonal gammopathy of undetermined significance (MGUS), relative to the general population. Pesticide exposures are suspected to play a role; however, the biologic plausibility for associations with multiple myeloma remains unclear.

OBJECTIVES

Our objectives were to examine the prevalence of MGUS and evaluate associations with a wide range of pesticides in a large sample of farmers.

METHODS

We obtained sera and assessed MGUS among 1,638 male farmers ≥ 50  years of age in the Agricultural Health Study (AHS), a prospective cohort in Iowa and North Carolina. Odds ratios (ORs) and 95% confidence intervals (CIs) were computed to estimate associations with MGUS for recent use (within the 12 months before phlebotomy) and cumulative intensity-weighted lifetime days of use of specific pesticides.

RESULTS

The age-standardized MGUS prevalence was significantly elevated among AHS farmers (7.7%) compared with demographically similar men in the National Health and Nutrition Examination Survey (2.8%) or Olmsted County, Minnesota (3.8%; p < 0.001 ). Recent use of permethrin was associated with MGUS [recent use vs. no recent use, OR = 1.82 (95% CI: 1.06, 3.13)], especially among those who had also used it in the past [recent and past use vs. never use, OR = 2.49 (95% CI: 1.32, 4.69)]. High intensity-weighted lifetime use of the organochlorine insecticides aldrin and dieldrin was associated with MGUS relative to those who never used either of these pesticides [OR = 2.42 (95% CI: 1.29, 4.54); p trend = 0.006 ]. We also observed a positive association with high lifetime use of petroleum oil/distillates as an herbicide, as well as an inverse association with fonofos use.

DISCUSSION

This is the largest investigation of MGUS in farmers and the first to identify an association with MGUS for permethrin, a pyrethroid insecticide previously associated with multiple myeloma. Given the continued widespread use of permethrin in various residential and commercial settings, our findings may have important implications for exposed individuals in the general population. https://doi.org/10.1289/EHP6960.

Prevalence of monoclonal gammopathy of uncertain significance in chronic myeloid leukemia: A case report

RATIONALE

The abnormal cell types in chronic myeloid leukemia (CML) and monoclonal gammopathy of uncertain (MGUS) are quite different, being myeloid and plasma cells, respectively. The coexistence of CML and MGUS is an uncommon event, which is seldom reported in literature.

PATIENT CONCERNS

A 52-year-old female was diagnosed with CML in April 2001. From November 2006, the patient started on imatinib mesylate and kept a complete hematologic and cytogenetic response for nearly 11 years. During her follow-up on July 7, 2017, thrombocytopenia (35*109/L) was found. Bone marrow aspiration revealed 6% plasma cell infiltration. Serum immunoelectrophoresis revealed 1.24 g/dL of serum monoclonal (M) protein of IgG-κ type.

DIAGNOSIS

MGUS was diagnosed because of absence of anemia, hypercalcemia, lytic bone lesions, or renal failure. Immune thrombocytopenia (ITP) was also diagnosed in this patient following the detection of antiplatelet autoantibodies. Complex karyotype and missense mutation in PRDM1 were identified.

INTERVENTIONS

Because of her obvious decrease of platelets, she started treatment with thalidomide and prednisone.

OUTCOMES

Three months later, bone marrow aspirate showed disappearance of plasma cells. There developed an abrupt decrease in IgG and the absence of M-spike in serum immunoelectrophoresis. The platelet count kept normal during 1 year follow-up.

LESSONS

Karyotypic event and gene mutation found in this case may be the initiation of disease transformation. Administration of thalidomide and prednisone proved effective in this patient.

Cancer incidence in the AGRICAN cohort study (2005-2011)

BACKGROUND

Numerous studies have been conducted among farmers, but very few of them have involved large prospective cohorts, and few have included a significant proportion of women and farm workers. Our aim was to compare cancer incidence in the cohort (overall, by sex, and by work on farm, occupational status and pesticide use) within the general population.

METHODS

More than 180,000 participants in the AGRICAN cohort were matched to cancer registries to identify cancer cases diagnosed from enrolment (2005-2007) to 31st December 2011. We calculated standardized incidence ratios (SIRs) and 95% confidence intervals (95%CIs).

RESULTS

Over the period, 11,067 incident cancer cases were identified (7304 men and 3763 women). Overall cancer incidence did not differ between the cohort and the general population. Moreover, SIRs were significantly higher for prostate cancer (SIR=1.07, 95%CI 1.03-1.11) and non-Hodgkin lymphoma (SIR=1.09, 95%CI 1.01-1.18) among men, skin melanoma among women (SIR=1.23, 95%CI 1.05-1.43) and multiple myeloma (men: SIR=1.38, 95%CI 1.18-1.62; women: SIR=1.26, 95%CI 1.02-1.54). In contrast, SIRs were lower for upper aerodigestive tract and respiratory cancers. Increase in risk was greater in male farm workers for prostate and lip cancer, in female farm workers for skin melanoma, and in male farm owners for multiple myeloma. Moreover, incidence of multiple myeloma and skin melanoma was higher among male and female pesticide users respectively.

CONCLUSION

We found a decreased incidence for tobacco-related cancers and an increased incidence of prostate cancers, skin melanoma and multiple myeloma. Specific subgroups had a higher cancer incidence related to occupational status and pesticide use.