Risk factors and characteristics of blood stream infections in patients with newly diagnosed multiple myeloma

Background: Patients with multiple myeloma are generally immune-compromised either due to pronounced depression in primary antibody responses or because of anti-myeloma therapy. Infection is a major risk factor for early deaths among these patients. The impact of blood stream infections (BSI) on newly diagnosed myeloma patients has been less studied. We aimed to study the incidence and risk factors of BSI within 3 months after diagnosis of multiple myeloma in a tertiary referral center. Methods: Between November 2002 and December 2008, consecutive patients with multiple myeloma in Taipei Veterans General Hospital were retrospectively enrolled. Characteristics of patients with or without BSI were collected. Possible factors associated with development of BSI were analyzed by Cox regression. Results: There were a total of 222 patients. The incidence of BSI within 3 months after diagnosis is 11.7%. The patients with BSI had poorer survival outcomes than those without (mortality rate: 50% vs. 20.9%, p < 0.001). Moreover, advanced International Staging System stage (stage III vs. I/II: odds ratio [OR] 2.69, p = 0.049) and poor Eastern Cooperative Oncology Group (ECOG) performance status (ECOG > 2 vs. <= 2: OR 3.58, p = 0.005) were the independent risk factors of BSI, whereas immunoglobulin deficiency and low absolute lymphocyte count were not associated with risk of BSI development. Conclusions: Our study highlights the characteristic of myeloma patients with BSI and the importance of disease and host factors on risk of BSI. Myeloma patients with risks of BSI should be properly managed to reduce early mortality.