title: Severe acute kidney injury and multiple myeloma: evaluation of kidney and patient prognostic factors.
abstract: BACKGROUND
  Patients with multiple myeloma (MM) manifesting acute kidney injury (AKI) and who later recover renal function and independence from renal replacement therapy (RRT) are considered to have a better outcome. The aim of this work was to study the factors associated with renal function recovery (independence of hemodialysis) and longer survival in these patients.
  
  
  METHODS
  A retrospective single center study including patients with a diagnosis of MM and severe AKI, defined as stage 3 of the Kidney Disease: Improving Global Outcomes (KDIGO) criteria: 3.0 times baseline increase in serum creatinine (sCr) or increase in sCr to ≥4.0mg/dL or initiation of RRT, was conducted. Data was registry-based and collected between January 2000 and December 2011. We examined demographic and laboratorial data, presenting clinical features, precipitating factors, need for RRT and chemotherapy. Death was considered the primary endpoint.
  
  
  RESULTS
  Lower serum β2-microglobulin was the only independent factor associated with recovery of renal function and independence of RRT (OR 0.95, 95% CI: 0.91-0.99, P=0.02). The median survival after AKI was 10.7±12.1months. The factors associated with longer survival were independence of RRT (HR 2.21; 95% CI: 1.08-4.49; P=0.02), lower CRP (HR 1.07; 95% CI: 1.03-1.12; P=0.001) and younger age (HR 1.03; 95% CI: 1.01-1.06; P=0.005).
  
  
  CONCLUSIONS
  Our study suggests that MM patients with lower serum β2-microglobulin have a higher likelihood of recovering renal function after severe AKI. Independence of RRT, lower CRP and younger age are associated with longer survival.
authors.affiliation: Centro Hospitalar e Universitário de Coimbra, Praceta Prof. Mota Pinto, 3000-075 Coimbra, Portugal. Electronic address: luis.arodrigues@hotmail.com.
authors.forename: Luís
authors.initials: L
authors.lastname: Rodrigues
authors.affiliation: Centro Hospitalar e Universitário de Coimbra, Praceta Prof. Mota Pinto, 3000-075 Coimbra, Portugal. Electronic address: martaraq_neves@hotmail.com.
authors.forename: Marta
authors.initials: M
authors.lastname: Neves
authors.affiliation: Centro Hospitalar e Universitário de Coimbra, Praceta Prof. Mota Pinto, 3000-075 Coimbra, Portugal. Electronic address: helena.oliveirasa@sapo.pt.
authors.forename: Helena
authors.initials: H
authors.lastname: Sá
authors.affiliation: Centro Hospitalar e Universitário de Coimbra, Praceta Prof. Mota Pinto, 3000-075 Coimbra, Portugal. Electronic address: henriquevgomes@gmail.com.
authors.forename: Henrique
authors.initials: H
authors.lastname: Gomes
authors.affiliation: Centro Hospitalar e Universitário de Coimbra, Praceta Prof. Mota Pinto, 3000-075 Coimbra, Portugal. Electronic address: jpratas.sousa@gmail.com.
authors.forename: Jorge
authors.initials: J
authors.lastname: Pratas
authors.affiliation: Centro Hospitalar e Universitário de Coimbra, Praceta Prof. Mota Pinto, 3000-075 Coimbra, Portugal. Electronic address: mariocampos@huc.min-saude.pt.
authors.forename: Mário
authors.initials: M
authors.lastname: Campos
mesh_terms: D058186:Acute Kidney Injury / Q000175:diagnosis / Q000209:etiology* / Q000628:therapy; D000368:Aged; D003404:Creatinine / Q000097:blood; D005260:Female; D005500:Follow-Up Studies; D005919:Glomerular Filtration Rate / Q000502:physiology*; D006801:Humans; D007677:Kidney Function Tests; D008297:Male; D008875:Middle Aged; D009101:Multiple Myeloma / Q000150:complications* / Q000175:diagnosis / Q000401:mortality; D011174:Portugal / Q000453:epidemiology; D011379:Prognosis; D020127:Recovery of Function; D017582:Renal Replacement Therapy / Q000379:methods*; D012189:Retrospective Studies; D012720:Severity of Illness Index; D015996:Survival Rate / Q000639:trends
chemical_list: D003404:Creatinine
keywords: Acute kidney injury; Hemodialysis; Multiple myeloma; Prognosis