Risk and Severity of COVID-19 Infection in Monoclonal Gammopathy of Undetermined Significance: A 3-Year Propensity Matched Cohort Study.

INTRODUCTION: Monoclonal gammopathy of undetermined significance (MGUS) is a premalignant disorder causing monoclonal plasma cell proliferation in bone marrow. This population is at risk of developing multiple myeloma (MM) and severe viral infections; risk factors of severe COVID-19 infection. Using TriNetX, a global platform providing data of 120 million patients, we aimed to quantify the risk and severity of COVID-19 in MGUS patients. PATIENTS AND METHODS: A retrospective cohort analysis was performed using the TriNetX Global Collaborative Network. From January 20, 2020, to January 20, 2023, we identified a cohort of 58,859 MGUS patients and compared to non-MGUS patients, determined by relevant diagnosis/LOINC test codes. After 1:1 propensity score-matching, we identified COVID-19 cases to quantify risk and identify patients who had been hospitalized, ventilated/intubated, and deceased to quantify severity. Measures of association and Kaplan-Meier analysis were conducted. RESULTS: After propensity-score matching, there were 58,668 patients in both cohorts. MGUS patients were found to be at a reduced risk of contracting COVID-19 (RR 0.88, 95% CI 0.85-0.91). MGUS patients with COVID-19 showed higher mortality risk and decreased survival time compared to the general population (HR 1.14, 95% CI 1.01-1.27). MGUS patients with COVID-19 who were hospitalized exhibited significantly decreased survival time (log-rank test, P = 0.04). CONCLUSION: As COVID-19 remains a looming health concern, especially amongst vulnerable populations, our analysis emphasizes the need for adequate vaccination and treatment regimens as well as an understanding of the severity of infection in MGUS patients and justification for precautionary measures.