(PA-374) MGUS Prevalence from a Large-Scale Community Study from Rural India (IMAGe-002B Study)

Considerable variation has been observed in the prevalence of monoclonal gammopathies across the globe. Although the prevalence of monoclonal gammopathy of undetermined significance (MGUS) has been evaluated in two hospital-based studies in India, no data exists on its prevalence in community-based settings amongst the rural Indian population. We aimed to determine the prevalence of MGUS in a rural Indian population in a community-based setting.

Methods:

A cross-sectional study was conducted across 92 villages spreading over 2976 square miles (sq-mi), as part of SIMPLe (Screening Intervention for Myeloma and Prevention of Lifestyle diseases) study. For the complete study population, demographic details, medical history, and blood samples were collected after a thorough medical examination. SPEP was performed in all individuals using on-site capillary zone electrophoresis. SIFE and biochemistry (liver and renal function tests) were performed for those with abnormal SPEP graphs (those with M spike and those with abnormal bulges in alpha, beta-2 or gamma region suspicious of M Spikes). Patients with monoclonal protein on SPEP or SIFE were further assessed for any smoldering/ multiple myeloma features as per IMWG guidelines. Amongst those patients with doubtful reports or isolated light chain disease, they were further subjected to mass spectrometry for evaluation. The data was analyzed using JMP ver. 17.2.0.

Results:

A total of 18,716 individuals were screened and data was analyzed for 16283 (8527 Tribal + 7756 non-tribal) individuals. The prevalence of MGUS in the study population was 111 (0.68%) across age group (12-99y) and was 1.04% above the age of 45y (109 of 10447). Only two patients among our study were younger than 45 (14y and 36y respectively) and neither of them had family history of plasma cell dyscrasia or positivity on family screening. The prevalence was 1.8% above 55y (109 of 6034), and 2.43% above 65y (84 of 3447). The median age of individuals with MGUS was 65y (IQR 57-72) with male preponderance. None of the patients with M protein in this community study satisfied the criteria for SMM/ MM using IMWG criteria. Among those with MGUS, the distribution of heavy and light chains was IgG - 83.78% (n-93), IgA - 16.22% (n-18), with none having IgM paraprotein, Lambda – 69.36% (n-77) and Kappa – 30.63% (n-34). Seven individuals who were initially labeled as light chain MGUS had IgG disease detected on mass spectrometry. Follow up of the 62 patients with MGUS at one year after diagnosis revealed none of the patients had progression to SMM or MM at one year.

Conclusions: The prevalence of MGUS in the India is low at 1.04% above the age of 45y rising to 2.43% in individuals over 65 years, predominantly affecting older males, with IgG lambda MGUS being the most common type. The background prevalence appears to be lower compared to the Western (both USA ~3% and European~5%) population.