Multiple Factors Contribute to Positive Results for Hepatitis A Virus Immunoglobulin M Antibody

From the Department of Pathology, University of Texas Southwestern Medical Center, Dallas.
Archives of pathology & laboratory medicine (Impact Factor: 2.84). 01/2013; 137(1):90-5. DOI: 10.5858/arpa.2011-0693-OA
Source: PubMed


Context.-In the United States, a successful vaccination program for hepatitis A virus (HAV) infection has decreased both its incidence and the true positive rate for diagnostic immunoglobulin M (IgM) antibody to HAV in acute hepatitis. Objective.-To survey positive results of HAV IgM tests and determine the effect of changing ordering options. Design.-We reviewed all positive results for IgM antibody to HAV between January 2007 and December 2010. Patient demographics, clinical history, and laboratory data were recorded and the encounter, order, and reason for test reviewed. Each result was categorized as indicating acute, recent, resolved, or indeterminate HAV infection. Results.-A total of 10 735 tests were performed; 35 patients had 49 positive results. Most positive test results were associated with outpatient visits and were ordered in the assessment of patients with liver disease, but not clinical acute hepatitis. In the final analysis, 4 patients had acute hepatitis A and 20 individual patients had recent and/or resolved hepatitis. All but 1 of the remaining 11 patients had another established cause of liver disease with a positive IgM HAV antibody test result; data to determine causality were insufficient. The total number of tests requested annually decreased more than 35% with the introduction of computerized physician order entry. Conclusions.-Current assays for IgM HAV antibodies are overused in the absence of clinical acute hepatitis; future clinical decision support may improve patterns of order entry. Most patients have findings consistent with HAV exposure but not acute hepatitis; dormant viral infection may be a continuing source of antigen.

Download full-text


Available from: Jennifer A Cuthbert, Mar 19, 2015
  • Source
    • "A positive test is considered false positive in a patient without clinical criteria, which can be varied from mild prodromal symptoms to fulminant hepatitis with or without extrahepatic manifestations [25]. False positive IgM tests have been reported with concomitant viral illnesses or a positive rheumatoid factor [26]. It may indicate hepatitis A virus exposure or dormant viral infection [25]. "
    [Show abstract] [Hide abstract]
    ABSTRACT: Hepatitis A has a variety of associated extrahepatic manifestations that clinicians should be aware of for early diagnosis and treatment. We report a unique case of hepatitis A presenting with multiple extrahepatic manifestations not previously described in a single patient. A 34-year-old male presented with sudden onset of left sided facial pain, swelling, and skin rash, with diffuse body pains and muscle weakness, and was found to be positive for hepatitis A immunoglobulin M (IgM). He was initially started on antibiotics for concerns of bacterial parotitis but did not show any improvement. A punch biopsy of his mandibular rash and swelling was done which showed lymphohistiocytic infiltration with a few eosinophils. A trial of prednisone resulted in improvement of his symptoms. Clinicians should be aware to look for hepatitis A infection in a patient with atypical clinical picture causing a widespread systemic inflammatory response. Treatment with prednisone may result in resolution.
    Full-text · Article · Sep 2014
  • [Show abstract] [Hide abstract]
    ABSTRACT: Since hepatitis A virus (HAV) infection during childhood is mostly asymptomatic, only seroprevalence studies can provide reliable information on incidence of HAV infection in children. The prevalence of anti-HAV antibodies was determined in sera taken in 2008 to 2010 from 1,645 children aged 0-17 years and in sera taken in 2010-2011 from 400 adult blood donors in Germany. For examination of trend over time, 715 sera collected between 1999 and 2006 from children at the age of 0-17 years within the federal state Thuringia were included. Antibody testing was carried out using the test kits ETI-AB-HAVK PLUS and ETI-HA-IGMK PLUS from DiaSorin. In children, the overall prevalence of antibodies was 10.8 %. After the seroprevalence declined from 8.8 % among the 0-2 year-olds to 2.4 % among the 3-4 year-olds, there was a significant increase to 20.5 % in the group of the 15-17 year-olds. Boys had with 12.7 % a significantly higher seroprevalence of anti-HAV antibodies compared to 8.8 % among girls. In adult blood donors, there was a HAV seroprevalence of 19.3 %. The likelihood of past infection or immunization within the age groups of children from 0 to 12 years differed significantly from that of adults. In conclusion, in Germany, only a small number of HAV infections occur in children, especially up to the age of 12 years. The proportion of susceptible children is greater than the proportion of susceptible adults. Thus, during outbreaks, the rate of infection among children would usually be higher than the rate among adults.
    No preview · Article · Jun 2013 · Medical Microbiology and Immunology
  • [Show abstract] [Hide abstract]
    ABSTRACT: Test utilization is an essential strategy in the clinical laboratory, especially with increasing numbers of tests and health care costs. We designed a triage system for molecular microbiology tests ordered from 2007 through 2010 to assess their appropriateness before they were sent out to a reference laboratory for testing. The number of tests ordered and approved and the number with positive results were calculated during the study period. Cost avoidance was subsequently calculated. A total of 13,839 tests were ordered, averaging 3,335 tests/year. The overall approval rate was 76%, ranging from 72% in 2007 to 81% in 2010. With the exception of cytomegalovirus (CMV) and BK virus PCR, the numbers of all tests decreased in 2010 compared to 2007. The total savings over 4 years was $374,791, with an average cost avoidance of $93,698/year. Pathologists and microbiologists should design a utilization system for laboratory testing to avoid unnecessary cost and improve patient care.
    No preview · Article · Dec 2014 · Clinical Microbiology Newsletter