[Is it necessary to investigate anti-hepatitis A virus (HAV) IgM antibodies when the hepatic enzymogram is normal?]

Is it necessary to investigate anti-hepatitis A virus (HAV) IgM antibodies when the hepatic enzymogram is normal? Type A viral Hepatitis (HAV) is the most frequent viral hepatitis around the world, especially in low income countries. In order to confirm this disease, a lot of laboratory tests are annually carried out where HAV is endemic. Our objective was to establish the utility of investigating anti-hepatitis A virus (HAV) IgM antibodies for HAV diagnosis in patients with normal levels of serum aspartate and alanine aminotransferases (AST/ALT). All patients (n = 158) received in the laboratory requesting a hepatic enzymograme and anti-HAV IgM were evaluated in a prospective study between October 2005 and March 2006. Anti-HAV IgM assays were carried out by microparticle enzyme immunoassay (MEIA). The quantification of hepatic enzymes was made in a multianalyzer. The most frequent clinical data were: presumption of hepatitis and jaundice (27.5 and 12.7%). Eighty four of the 158 patients (53%) showed elevated values of ALT and AST, whereas 69 patients in this group (82%) were anti-Hav IgM reactive. The remaining 74 patients (47%) showed normal levels of AST/ALT and none of them were anti-HAV IgM reactive, except 7, who were on control of a confirmed HAV infection. Of the anti-HAV IgM reactive group of patientss, 49% were children under 10 years of age. Laboratory HAV confirmatory tests would have to be made in sequential form, the determination of anti-HAV IgM antibodies being unnecessary when normal values of serum aminotransferases are observed.