title: [Early pneumonia after allogenic stem cell transplantation].
abstract: BACKGROUND
  Pneumonia is one of the main causes of mortality following allogenic stem cell transplantation, especially in the first months after the transplant has been performed.
  
  
  BACKGROUND
  Pneumonia is the most common infection occurring after transplant and the infection with the highest mortality. Following the classical, myeloablative approach to transplant, two thirds of the pneumonias that occur are of infectious origin. Their causes roughly follow the timing of the immune reconstitution, and may depend on the type of transplant, the match between donor and recipient, and, overall, the occurrence of graft-versus-host disease. Most bacterial pneumonias occur during the initial neutropenic phase. The 2nd and 3rd month post transplant are mainly complicated by viral pneumonia, especially respiratory virus and adenovirus pneumonia in deeply immunosuppressed patients. Preemptive and prophylactic strategies have considerably reduced the incidence of cytomegalovirus pneumonia. Pneumonia due to encapsulated bacteria, such as Haemophilus influenzae and Streptococcus pneumoniae, usually considered to be late infections, may actually be observed from the second month post-transplant.
  
  
  CONCLUSIONS
  The increasing use of reduced-intensity conditioning regimens has modified the time course of the main adverse events following transplantation, including the timing of the infectious pneumonias. The pneumonias that are specifically related to allogenic transplant are idiopathic interstitial pneumonia, bronchiolitis obliterans, and bronchiolitis obliterans organizing pneumonia, which are all considered to be pulmonary manifestations of graft-versus-host disease, and treated as such. Prophylaxis for many of these infectious pneumonias (i.e., P jiroveci, S pneumoniae, toxoplasmosis) are well standardized.
  
  
  CONCLUSIONS
  Much remains to be done to decrease the incidence of pneumonia in these patients and to understand their mechanisms.
authors.affiliation: Service d'Hématologie Clinique, CHU Henri Mondor, Assistance Publique-Hôpitaux de Paris et Université Paris 12, France. carlcord@club-internet.fr
authors.forename: C
authors.initials: C
authors.lastname: Cordonnier
authors.forename: C
authors.initials: C
authors.lastname: Pautas
authors.forename: M
authors.initials: M
authors.lastname: Kuentz
authors.forename: B
authors.initials: B
authors.lastname: Maitre
authors.forename: S
authors.initials: S
authors.lastname: Maury
mesh_terms: D006801:Humans; D011014:Pneumonia / Q000175:diagnosis / Q000209:etiology* / Q000517:prevention & control; D033581:Stem Cell Transplantation / Q000009:adverse effects*; D019172:Transplantation Conditioning; D014184:Transplantation, Homologous