title: Optimal time for repeating the IgM anti-hepatitis A virus antibody test in acute hepatitis A patients with a negative initial test.
abstract: OBJECTIVE
  The nonspecific clinical presentation of acute hepatitis A (AHA) mandates the detection of anti-hepatitis A virus IgM antibodies (IgM anti-HAV) in the serum for obtaining a definitive diagnosis. However, IgM anti-HAV might not be present during the early phase of the disease. The aim of this study was to determine the optimal time for repeating the IgM anti-HAV test (HAV test) in AHA patients with a negative initial test.
  
  
  METHODS
  In total, 261 patients hospitalized with AHA were enrolled for this retrospective study. AHA was diagnosed when the test for IgM anti-HAV was positive and the serum alanine aminotransferase (ALT) level was ≥400 IU/L. Repeat HAV test was conducted after 1-2 weeks if the initial HAV test was negative but AHA was still clinically suspected.
  
  
  RESULTS
  The results of the initial HAV test were negative in 28 (10.7%) patients. The intervals from symptom onset to the initial-HAV-test day and from the peak-ALT day to the initial-HAV-test day were significantly shorter in the negative-initial-HAV-test group, but on multivariate analysis only the latter was significantly associated with negative results for the initial HAV test (β=-0.978; odds ratio [95% confidence interval]=0.376 [0.189-0.747]; P=0.005). The HAV test was positive in all patients when it was performed at least 2 days after the peak-ALT day.
  
  
  CONCLUSIONS
  The results of HAV tests were significantly associated with the interval from the peak-ALT day to the HAV-test day. The optimal time for repeating the HAV test in clinically suspicious AHA patients with a negative initial HAV test appears to be at least 2 days after the peak-ALT day.
authors.affiliation: Department of Internal Medicine, Korea University College of Medicine, Seoul, Korea.
authors.forename: Jong Jin
authors.initials: JJ
authors.lastname: Hyun
authors.forename: Yeon Seok
authors.initials: YS
authors.lastname: Seo
authors.forename: Hyonggin
authors.initials: H
authors.lastname: An
authors.forename: Sun Young
authors.initials: SY
authors.lastname: Yim
authors.forename: Min Ho
authors.initials: MH
authors.lastname: Seo
authors.forename: Hye Sook
authors.initials: HS
authors.lastname: Kim
authors.forename: Chang Ha
authors.initials: CH
authors.lastname: Kim
authors.forename: Ji Hoon
authors.initials: JH
authors.lastname: Kim
authors.forename: Bora
authors.initials: B
authors.lastname: Keum
authors.forename: Yong Sik
authors.initials: YS
authors.lastname: Kim
authors.forename: Hyung Joon
authors.initials: HJ
authors.lastname: Yim
authors.forename: Hong Sik
authors.initials: HS
authors.lastname: Lee
authors.forename: Soon Ho
authors.initials: SH
authors.lastname: Um
authors.forename: Chang Duck
authors.initials: CD
authors.lastname: Kim
authors.forename: Ho Sang
authors.initials: HS
authors.lastname: Ryu
mesh_terms: D000208:Acute Disease; D000328:Adult; D000410:Alanine Transaminase / Q000097:blood; D005260:Female; D006506:Hepatitis A / Q000175:diagnosis*; D035922:Hepatitis A Antibodies / Q000097:blood*; D030041:Hepatitis A virus / Q000276:immunology*; D006801:Humans; D007075:Immunoglobulin M / Q000097:blood*; D008297:Male; D016017:Odds Ratio; D012189:Retrospective Studies; D013997:Time Factors
chemical_list: D035922:Hepatitis A Antibodies; D007075:Immunoglobulin M; D000410:Alanine Transaminase