title: Serum sCD30: A promising biomarker for predicting the risk of bacterial infection after kidney transplantation.
abstract: BACKGROUND
  The transmembrane glycoprotein CD30 contributes to regulate the balance between Th1and Th2responses. Previous studies have reported conflicting results on the utility of its soluble form (sCD30) to predict post-transplant infection.
  
  
  METHODS
  Serum sCD30 was measured by a commercial ELISA assay at baseline and post-transplant months 1, 3, and 6 in 100 kidney transplant (KT) recipients (279 monitoring points). The impact of sCD30 levels on the incidence of overall, bacterial and opportunistic infection during the first 12 months after transplantation was assessed by Cox regression.
  
  
  RESULTS
  There were no differences in serum sCD30 according to the occurrence of overall or opportunistic infection. However, sCD30 levels were higher in patients with bacterial infection compared to those without at baseline (P=.038) and months 1 (P<.0001), 3 (P=.043), and 6 after transplantation (P=.006). Patients with baseline sCD30 levels ≥13.5 ng/mL had lower 12-month bacterial infection-free survival (35.0% vs 80.0%; P<.0001). After adjusting for potential confounders, baseline sCD30 levels ≥13.5 ng/mL remained as an independent risk factor for bacterial infection (adjusted hazard ratio [aHR]: 4.65; 95% confidence interval [CI]: 2.05-10.53; <.001). Analogously, sCD30 levels ≥6.0 ng/mL at month 1 acted as a risk factor for subsequent bacterial infection (aHR: 5.29; 95% CI: 1.11-25.14; P=.036).
  
  
  CONCLUSIONS
  Higher serum sCD30 levels were associated with an increased risk of bacterial infection after KT. We hypothesize that this biomarker reflects a Th2-polarized T-cell response, which exerts a detrimental effect on the immunity against bacterial pathogens.
authors.affiliation: Unit of Infectious Diseases, Hospital Universitario "12 de Octubre", Instituto de Investigación Hospital "12 de Octubre" (i+12), School of Medicine, Universidad Complutense, Madrid, Spain.
authors.forename: Mario
authors.initials: M
authors.lastname: Fernández-Ruiz
authors.affiliation: Unit of Infectious Diseases, Hospital Universitario "12 de Octubre", Instituto de Investigación Hospital "12 de Octubre" (i+12), School of Medicine, Universidad Complutense, Madrid, Spain.
authors.forename: Patricia
authors.initials: P
authors.lastname: Parra
authors.affiliation: Unit of Infectious Diseases, Hospital Universitario "12 de Octubre", Instituto de Investigación Hospital "12 de Octubre" (i+12), School of Medicine, Universidad Complutense, Madrid, Spain.
authors.forename: Francisco
authors.identifier: http://orcid.org/0000-0001-5333-7529
authors.initials: F
authors.lastname: López-Medrano
authors.affiliation: Unit of Infectious Diseases, Hospital Universitario "12 de Octubre", Instituto de Investigación Hospital "12 de Octubre" (i+12), School of Medicine, Universidad Complutense, Madrid, Spain.
authors.forename: Tamara
authors.initials: T
authors.lastname: Ruiz-Merlo
authors.affiliation: Unit of Infectious Diseases, Hospital Universitario "12 de Octubre", Instituto de Investigación Hospital "12 de Octubre" (i+12), School of Medicine, Universidad Complutense, Madrid, Spain.
authors.forename: Esther
authors.initials: E
authors.lastname: González
authors.affiliation: Department of Nephrology, Hospital Universitario "12 de Octubre", Instituto de Investigación Hospital "12 de Octubre" (i+12), School of Medicine, Universidad Complutense, Madrid, Spain.
authors.forename: Natalia
authors.initials: N
authors.lastname: Polanco
authors.affiliation: Unit of Infectious Diseases, Hospital Universitario "12 de Octubre", Instituto de Investigación Hospital "12 de Octubre" (i+12), School of Medicine, Universidad Complutense, Madrid, Spain.
authors.forename: Julia
authors.initials: J
authors.lastname: Origüen
authors.affiliation: Unit of Infectious Diseases, Hospital Universitario "12 de Octubre", Instituto de Investigación Hospital "12 de Octubre" (i+12), School of Medicine, Universidad Complutense, Madrid, Spain.
authors.forename: Rafael
authors.initials: R
authors.lastname: San Juan
authors.affiliation: Department of Nephrology, Hospital Universitario "12 de Octubre", Instituto de Investigación Hospital "12 de Octubre" (i+12), School of Medicine, Universidad Complutense, Madrid, Spain.
authors.forename: Amado
authors.initials: A
authors.lastname: Andrés
authors.affiliation: Unit of Infectious Diseases, Hospital Universitario "12 de Octubre", Instituto de Investigación Hospital "12 de Octubre" (i+12), School of Medicine, Universidad Complutense, Madrid, Spain.
authors.forename: José María
authors.initials: JM
authors.lastname: Aguado
mesh_terms: D000328:Adult; D000368:Aged; D001424:Bacterial Infections / Q000175:diagnosis* / Q000453:epidemiology; D015415:Biomarkers / Q000097:blood; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005500:Follow-Up Studies; D006084:Graft Rejection / Q000517:prevention & control; D006801:Humans; D007165:Immunosuppression Therapy / Q000009:adverse effects*; D015994:Incidence; D017730:Ki-1 Antigen / Q000097:blood*; D016030:Kidney Transplantation / Q000009:adverse effects* / Q000401:mortality; D008297:Male; D008875:Middle Aged; D009894:Opportunistic Infections / Q000175:diagnosis* / Q000453:epidemiology; D011446:Prospective Studies; D012044:Regression Analysis; D012307:Risk Factors; D015996:Survival Rate
chemical_list: D015415:Biomarkers; D017730:Ki-1 Antigen
keywords: immunological monitoring; kidney transplantation; post-transplant infection; prediction; soluble CD30