title: Microbiologically documented infections in patients undergoing high-dose melphalan and autologous stem cell transplantation for the treatment of light chain amyloidosis.
abstract: BACKGROUND
  Immunoglobulin light chain (AL) amyloidosis can be treated with high-dose melphalan and autologous stem cell transplantation (HDM/SCT). Risk factors for infections may include hyposplenism, hypogammaglobulinemia, treatment-related neutropenia, melphalan-induced mucositis, and nosocomial exposures.
  
  
  METHODS
  A review of 493 patients with AL amyloidosis undergoing treatment with HDM/SCT from August 1994 to August 2009 was performed. The objectives were to determine the rate and types of infections following HDM/SCT, to identify factors associated with microbiologically documented infections, and to assess the contribution of infections to all-cause treatment-related mortality (TRM; defined as deaths within 100 days of SCT).
  
  
  RESULTS
  Microbiologically documented infections after HDM/SCT occurred in 24% (n = 119) of patients. TRM was 10% (n = 48) overall, and 21% (n = 25) in patients who had a documented infection. Thus, the relative risk of TRM in a patient with a documented infection was 3.42 (95% confidence interval [CI] 2.02-5.79). Infections were caused by gram-positive bacteria in 51%, anaerobic bacteria in 16%, gram-negative bacteria in 13%, and fungi in 9% of cases. Serum creatinine >2 mg/dL was associated with increased risk of post-SCT infection (38% vs. 21%, P = 0.0007) with an odds ratio of 2.27 (95% CI 1.40-3.68). No significant association for infection was found for age, gender, cardiac involvement, prior steroid therapy, dose of melphalan, multiorgan involvement, days to neutrophil engraftment, or dose of CD34 +  cells infused.
  
  
  CONCLUSIONS
  Serum creatinine >2 mg/dL is a risk factor for infections in patients with AL amyloidosis undergoing HDM/SCT. The relative risk of TRM in a patient with a documented infection was increased >3-fold. A broad spectrum of infections, similar to that in other SCT patients, is seen in this population in the early post-SCT period.
authors.affiliation: Section of Infectious Diseases, Boston Medical Center, Boston University School of Medicine, Boston, Massachusetts, USA.
authors.forename: S
authors.initials: S
authors.lastname: Taimur
authors.forename: C
authors.initials: C
authors.lastname: Nader
authors.forename: C
authors.initials: C
authors.lastname: Lloyd-Travaglini
authors.forename: D C
authors.initials: DC
authors.lastname: Seldin
authors.forename: V
authors.initials: V
authors.lastname: Sanchorawala
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000686:Amyloidosis / Q000628:therapy*; D001424:Bacterial Infections / Q000175:diagnosis / Q000209:etiology* / Q000401:mortality; D003131:Combined Modality Therapy; D003428:Cross Infection / Q000209:etiology; D004305:Dose-Response Relationship, Drug; D005260:Female; D006801:Humans; D007147:Immunoglobulin Light Chains; D008297:Male; D008558:Melphalan / Q000008:administration & dosage*; D008875:Middle Aged; D009181:Mycoses / Q000175:diagnosis / Q000209:etiology* / Q000401:mortality; D019653:Myeloablative Agonists / Q000008:administration & dosage*; D011183:Postoperative Complications; D012307:Risk Factors; D033581:Stem Cell Transplantation / Q000009:adverse effects*; D014182:Transplantation, Autologous
chemical_list: D007147:Immunoglobulin Light Chains; D019653:Myeloablative Agonists; D008558:Melphalan