Epidemiology and Risk Factors for the Development of Infectious Complications in Newly Diagnosed Multiple Myeloma: A Multicenter Prospective Cohort Study in Latin America.

Purpose: Infections are a significant cause of morbidity and mortality in patients with multiple myeloma (MM). In Latin America, data on infectious complications in this patient population are lacking.

Methods: We conducted a prospective cohort study of patients with newly diagnosed MM (NDMM) in seven Latin American countries between June 2019 and May 2020. Patients with active disease, on active therapy, and with a follow-up of 6 months from the time of diagnosis were included. Our primary end point was the number of infectious events that required hospitalization for ≥ 24 hours.

Results: Of 248 patients with NDMM, 89 (35.9%) had infectious complications (113 infectious events), the majority (67.3%) within the first 3 months from diagnosis. The most common sites of infection were respiratory (38%) and urinary tract (31%). The microbial agent was identified in 57.5% of patients with gram-negative bacteria (73.5%) as the most common pathogen. Viral infections were infrequent, and no patients with fungal infection were reported. In the multivariable analysis, diabetes mellitus (odds ratio [OR], 2.71; 95% CI, 1.23 to 6.00; = .014), creatinine ≥ 2 mg/dL (OR, 4.87; 95% CI, 2.29 to 10.35; < .001), no use of trimethoprim-sulfamethoxazole prophylaxis (OR, 6.66; 95% CI, 3.43 to 12.92; < .001), and treatment with immunomodulatory drugs (OR, 3.02; 95% CI, 1.24 to 6.29; = .003) were independent factors associated with bacterial infections. At 6 months, 21 patients (8.5%) had died, 47.6% related to infectious complications.

Conclusion: Bacterial infections are a substantial cause of hospital admissions and early death in patients with NDMM. Antibiotic prophylaxis should be considered to reduce infectious complications in patients with MM.