Epidemiology and risk factors for infections in myelodysplastic syndromes

Abstract We conducted a case–control study to describe the epidemiology and risk factors for infections requiring hospitalization in patients with myelodysplastic syndromes ( MDS ). Of 497 patients identified, 103 patients developed 201 episodes of infection. The probability of acquiring an infection 1 year from date of MDS diagnosis was 15% (95% confidence interval [ CI ] 12–18%). Patients developing infections had decreased survival compared to those who did not ( P = 0.007). Significant risk factors for infection were higher risk MDS (hazard ratio [ HR ] = 2.7, 95% CI = 1.7–4.1, P < 0.0001), nadir absolute neutrophil count <500/mL ( HR = 1.8, 95% CI = 1.2–2.7, P < 0.007), chronic obstructive pulmonary disease ( HR = 2.6, 95% CI = 1.4–4.9, P < 0.003), history of other malignancy ( HR 2.0, 95% CI = 1.3–3.1, P < 0.003), and autoimmune disease ( HR 2.9, 95% CI = 1.4–6.0, P < 0.005). Age, nadir platelet count <20,000/mL, diabetes mellitus, and MDS treatment were not significant risk factors. Pneumonia was the most common infection, and bacteria the predominant pathogens.