MGUS in Black individuals in Soweto, South Africa screened by mass spectrometry: results of the PROMISE South Africa study

Summary: Background: Only few studies have screened for monoclonal gammopathy of undetermined significance (MGUS) among Black Africans in sub-Saharan Africa, with mixed results.

Methods

In this cross-sectional study, we enrolled 2004 Black Africans aged 40–75 years from Soweto, South Africa, from January 2021 to August 2023. Participants completed an interview-guided exposure survey, underwent height and weight measurements, and provided blood samples that were screened for MGUS by matrix-assisted laser desorption ionisation-time of flight mass spectrometry. The primary outcome was the prevalence of MGUS, assessed from blood samples collected at the participants’ single study visit. Prevalence was compared to those of high-risk United States (US)-based cohorts screened by the same method. Multivariable logistic regression models evaluated associations between exposures and MGUS.