title: Is Chlamydia pneumoniae infection associated with stroke in children with sickle cell disease?
abstract: BACKGROUND
  Stroke is often a devastating complication of sickle cell disease (SCD). Most children with SCD-related stroke have stenotic and occlusive disease of cerebral blood vessels due to intimal hyperplasia. This hyperplasia is hypothesized to result from an inflammatory response similar to that in atherosclerosis and has been attributed to infection by Chlamydia pneumoniae.
  
  
  OBJECTIVE
  To determine whether C pneumoniae infection is associated with stroke and cerebrovascular disease, including transient ischemic attacks and abnormal transcranial Doppler examinations, in children with SCD.
  
  
  METHODS
  Children with SCD on chronic transfusion due to a history of stroke, transient ischemic attack, or abnormal transcranial Doppler; children with SCD without stroke; healthy controls; and children being transfused for other reasons were enrolled. Peripheral blood and nasopharyngeal (NP) swab specimens were collected from all patients. In patients on transfusion, pretransfusion specimens and samples from the unit of packed red blood cells being transfused were obtained. Peripheral blood monocytic cells (PBMCs) and NP swab specimens were cultured for C pneumoniae in HEp-2 cells. C pneumoniae polymerase chain reaction was performed on PBMCs with a nested touch-down method with primers from the omp-1gene (in duplicate) and a second real-time polymerase chain reaction by using 16S ribosomal RNA primers.
  
  
  RESULTS
  C pneumoniae DNA was detected in the PBMCs of 1 of 14 (7.1%) children with SCD on chronic transfusion, 1 of 10 (10%) sickle cell controls, 1 of 10 (10%) healthy controls, and none of the 5 children receiving chronic transfusion for other reasons. It was not detected in specimens from transfusion units. One child with SCD and stroke, 1 sickle cell control, and 1 transfusion control had positive NP cultures for C pneumoniae. C pneumoniae DNA was not detected in their PBMCs, and all 3 children were asymptomatic. C pneumoniae was not detected by culture of PBMCs from any of the patients after 7 passages.
  
  
  CONCLUSIONS
  Stroke in children with SCD does not seem to be associated with C pneumoniae infection in our population.
authors.affiliation: Division of Hematology-Oncology, Department of Pediatrics, State University of New York, Downstate Medical Center, Brooklyn, New York 11203-2098, USA.
authors.forename: Meenakshi
authors.initials: M
authors.lastname: Goyal
authors.forename: Scott T
authors.initials: ST
authors.lastname: Miller
authors.forename: Margaret R
authors.initials: MR
authors.lastname: Hammerschlag
authors.forename: Maureen
authors.initials: M
authors.lastname: Gelling
authors.forename: Charlotte A
authors.initials: CA
authors.lastname: Gaydos
authors.forename: Justin
authors.initials: J
authors.lastname: Hardick
authors.forename: Billie Jo
authors.initials: BJ
authors.lastname: Wood
authors.forename: Tamara
authors.initials: T
authors.lastname: Reznik
authors.forename: S P
authors.initials: SP
authors.lastname: Rao
mesh_terms: D000293:Adolescent; D000328:Adult; D000755:Anemia, Sickle Cell / Q000150:complications*; D002648:Child; D023521:Chlamydophila Infections / Q000150:complications*; D016993:Chlamydophila pneumoniae / Q000235:genetics / Q000302:isolation & purification; D004269:DNA, Bacterial / Q000097:blood; D005260:Female; D006801:Humans; D007963:Leukocytes, Mononuclear / Q000821:virology; D008297:Male; D009305:Nasopharynx / Q000821:virology; D020521:Stroke / Q000209:etiology*
chemical_list: D004269:DNA, Bacterial