Risk factors for infection in multiple myeloma

At EHA 2026, Prof Cecilia Hveding Blimark, hematologist at the Sahlgrenska University Hospital in Gothenburg, presented findings from a population-based study investigating risk factors for infections in patients with multiple myeloma (MM). The analysis included patients recorded in the Swedish Myeloma Registry who were diagnosed between 2008 and 2021, together with approximately 34,000 matched controls. Building on previous work demonstrating that patients with multiple myeloma have a fivefold higher risk of infections than matched controls, the current study aimed to identify clinical characteristics associated with an increased risk of infection during myeloma treatment.

Patient characteristics were obtained from the Swedish Myeloma Registry, while comorbidity data were collected from the Swedish Patient Registry, examining diagnoses recorded during the five years preceding myeloma diagnosis. Multivariable Cox regression analyses, adjusted for age and sex, were performed to identify independent risk factors for infections. Patients with a higher tumour burden at diagnosis, including those with elevated LDH levels, del(17p), higher ISS stage, and higher R-ISS stage, were found to have the greatest risk of developing infections.

The analysis also identified three major comorbidity groups associated with an increased infection risk: pre-existing renal disease, lung disease, and heart failure. In contrast, the Charlson Comorbidity Index at diagnosis did not predict infection risk in this dataset. 

Prof Hveding Blimark concluded that patients with a high tumour burden and these specific comorbidities should be considered at elevated risk of infections when initiating treatment in patients with MM.