title: Clinical significance of high anti-entamoeba histolytica antibody titer in asymptomatic HIV-1-infected individuals.
abstract: BACKGROUND
  Anti-Entamoeba histolytica antibody (anti- E. histolytica) is widely used in seroprevalence studies though its clinical significance has not been assessed previously.
  
  
  METHODS
  Anti-E. histolytica titer was measured at first visit to our clinic (baseline) in 1303 patients infected with human immunodeficiency virus type 1 (HIV-1). The time to diagnosis of invasive amebiasis was assessed by Kaplan-Meier method and risk factors for the development of invasive amebiasis were assessed by Cox proportional-hazards regression analysis. For patients who developed invasive amebiasis, anti-E. histolytica titers at onset were compared with those at baseline and after treatment.
  
  
  RESULTS
  The anti-E. histolytica seroprevalence in the study population was 21.3% (277/1303). Eighteen patients developed invasive amebiasis during the treatment-free period among 1207 patients who had no history of previous treatment with nitroimidazole. Patients with high anti-E. histolytica titer at baseline developed invasive amebiasis more frequently than those with low anti-E. histolytica titer. Most cases of invasive amebiasis who had high anti-E. histolytica titer at baseline developed within 1 year. High anti-E. histolytica titer was the only independent predictor of future invasive amebiasis. Anti-E. histolytica titer was elevated at the onset of invasive amebiasis in patients with low anti-E. histolytica titer at baseline.
  
  
  CONCLUSIONS
  Asymptomatic HIV-1-infected individuals with high anti-E. histolytica titer are at risk of invasive amebiasis probably due to exacerbation of subclinical amebiasis.
authors: AIDS Clinical Center, National Center for Global Health and Medicine, Tokyo, Japan.
authors: Koji
authors: K
authors: Watanabe
authors: Takahiro
authors: T
authors: Aoki
authors: Naoyoshi
authors: N
authors: Nagata
authors: Junko
authors: J
authors: Tanuma
authors: Yoshimi
authors: Y
authors: Kikuchi
authors: Shinichi
authors: S
authors: Oka
authors: Hiroyuki
authors: H
authors: Gatanaga
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000913:Antibodies, Protozoan / Q000097:blood*; D015331:Cohort Studies; D004748:Entamoeba histolytica / Q000276:immunology*; D005260:Female; D015658:HIV Infections / Q000150:complications* / Q000453:epidemiology / Q000469:parasitology; D015497:HIV-1; D006801:Humans; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D016036:Seroepidemiologic Studies; D055815:Young Adult
chemical_list: D000913:Antibodies, Protozoan
keywords: Entamoeba histolytica; HIV-1; amebiasis; anti-E. histolytica antibody; seroprevalence