title: Decreased levels of serum complement C3 and natural killer cells add to the predictive value of total immunoglobulin G for severe infection in heart transplant recipients.
abstract: BACKGROUND
  Infection remains a source of mortality in heart recipients. We previously reported that post-transplant immunoglobulin G (IgG) quantification can help identify the risk for infection. We assessed whether other standardized parameters of humoral and cellular immunity could prove useful when identifying patients at risk of infection.
  
  
  METHODS
  We prospectively studied 133 heart recipients over a 12-month period. Forty-eight patients had at least one episode of severe infection. An event was defined as an infection requiring intravenous antimicrobial therapy.
  
  
  RESULTS
  Cox regression analysis revealed an association between the risk of developing infection and the following: lower IgG2 subclass levels (day 7: relative hazard [RH] 1.71; day 30: RH 1.76), lower IgA levels (day 7: RH 1.61; day 30: RH 1.91), lower complement C3 values (day 7: RH 1.25), lower CD3 absolute counts (day 30: RH 1.10), lower absolute natural killer [NK] cell count (day 7: RH 1.24), and lower IgG concentrations (day 7: RH 1.31; day 30: RH 1.36). Cox regression bivariate analysis revealed that lower day 7 C3 levels, IgG2 concentration, and absolute NK cell count remained significant after adjustment for total IgG levels.
  
  
  CONCLUSIONS
  Data suggest that early immune monitoring including C3, IgG2, and NK cell testing in addition to IgG concentrations is useful when attempting to identify the risk of infection in heart transplant recipients.
authors.affiliation: Clinical Immunology Department, University Hospital Gregorio Marañón, Madrid, Spain.
authors.forename: E
authors.initials: E
authors.lastname: Sarmiento
authors.forename: N
authors.initials: N
authors.lastname: del Pozo
authors.forename: A
authors.initials: A
authors.lastname: Gallego
authors.forename: J
authors.initials: J
authors.lastname: Fernández-Yañez
authors.forename: J
authors.initials: J
authors.lastname: Palomo
authors.forename: A
authors.initials: A
authors.lastname: Villa
authors.forename: M
authors.initials: M
authors.lastname: Ruiz
authors.forename: P
authors.initials: P
authors.lastname: Muñoz
authors.forename: C
authors.initials: C
authors.lastname: Rodríguez
authors.forename: J
authors.initials: J
authors.lastname: Rodríguez-Molina
authors.forename: J
authors.initials: J
authors.lastname: Navarro
authors.forename: K
authors.initials: K
authors.lastname: Kotsch
authors.forename: E
authors.initials: E
authors.lastname: Fernandez-Cruz
authors.forename: J
authors.initials: J
authors.lastname: Carbone
mesh_terms: D000328:Adult; D003176:Complement C3 / Q000378:metabolism*; D005260:Female; D016027:Heart Transplantation / Q000009:adverse effects*; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood*; D007239:Infections / Q000175:diagnosis / Q000453:epidemiology / Q000209:etiology / Q000276:immunology*; D053208:Kaplan-Meier Estimate; D007694:Killer Cells, Natural / Q000276:immunology*; D008297:Male; D008875:Middle Aged; D015166:Monitoring, Immunologic / Q000379:methods*; D011237:Predictive Value of Tests; D012720:Severity of Illness Index
chemical_list: D003176:Complement C3; D007074:Immunoglobulin G