PREFERRED: Serum is the preferred specimen. Collect blood in a 4 ml Gold Serum Separator Tube-Clot Activator & Gel.
REMARK: Plasma is an acceptable alternative specimen. Blood can be collected in plastic tubes containing dipotassium EDTA with or without gel separator, lithium heparin with gel separator, and sodium heparin.
4 ml of blood
2 ml of blood
A total of 2-4 ml of blood (for every 2-3 Hepatitis and HIV tests ordered) should be collected.
For the CHOP enterprise, submit blood specimens as soon as possible at room temperature to Central Laboratory Services.
For outside clients, it is recommended that serum or plasma specimens be removed from the clot, red blood cells, or separator gel as soon as possible after collection and before shipping specimens. When shipping serum or plasma specimens, package and label specimens in compliance with applicable state, federal, and international regulations covering the transport of clinical specimens and infectious substances. Specimens may be shipped at 2-8C (wet ice) or frozen (dry ice). Do not exceed the storage time limitations listed under the heading of Stability.
Serum or plasma specimens should be stored for no longer than 3 days at room temperature or 7 days at 2-8C following specimen collection and separation from clot, red blood cells, or separator gel. If a storage period greater than 7 days is anticipated, serum or plasma should be stored frozen at -20C or colder. No more than 3 freeze-thaw cycles should be performed on any sample prior to testing, and specimens should not be stored in frost-free freezers.
Do not use serum or plasma specimens that are heat-inactivated, pooled, grossly hemolyzed, or contain obvious microbial contamination. Performance has not been established for the use of cadeveric specimens or the use of boody fluids other than human serum or plasma.
Unprocessed blood specimens should routinely be refrigerated at 4C upon arrival in the laboratory. One should remove the serum or plasma from clotted blood, red blood cells, or separator gel as soon as possible to avoid hemolysis. The best results are generally observed for serum or plasma specimens that are clear and nonhemolyzed. Lipemic, icteric, or hemolyzed specimens should be avoided when possible, and specimens with obvious microbial contamination should not be used. Specimens containing unremoved clots, red blood cells, or particulate matter may give inconsistent results and should be clarified by centrifugation before testing.
Monday thru Friday
Chemiluminescent microparticle immunoassay
This assay measures total antibody (IgG + IgM) responses to Hepatitis B virus (HBV) core antigen. The presence of HBc total antibody indicates acute or chronic infection. Total antibody to HBV core antigen (anti-HBc Total) develops within 1-4 weeks of the appearance of HBsAg, rapidly rises to high levels, and is detectable for the remainder of a patient's life. Following the loss of HBV core IgM antibody during acute HBV infection, the total anti-HBc response primarily consists of IgG anti-HBc. Isolated positive results for total anti-HBc with negative results for HBsAg and anti-HBs antibody may indicate (1) a false-positive reaction in the serologic assay for total anti-HBc, (2) passive transfer of total anti-HBc antibody, (3) chronic infection without detectable HBsAg as a result of the development of viral mutant and the subsequent production of undectable levels of antigen in serum, (4) suppression of HBsAg production following HDV superinfection, and (5) acute infection involving the core window" period between the decline of detectable HBsAg and the subsequent rise in anti-HBs antibody. Low levels of total anti-HBc antibody usually represent nonspecific reactions and account for a large number of the isolated total anti-HBc positive results.
The presence of HBV core total antibody is indicative of either a past or present infection with hepatitis B virus. If you suspect an acute HBV infection, please also order hepatitis B core IgM antibody and surface antigen tests. HBV core total antibody will be present in virtually all patients with chronic HBV infection. Negative test results are indicative of no evidence of recent, past or chronic infection with HBV. This does not exclude the possibility of exposure to or early acute infection with HBV. If clinically indicated, please wait 1-2 weeks and submit another specimen for additional HBV core total antibody (IgG & IgM) testing. A hepatitis B surface antigen test and HBV core IgM antibody test may also be ordered on the current and repeat specimens. Recipients of intravenous immunoglobulin, newborn infants possessing pasively acquired maternal antibody, or patients who have received recent blood transfusions may be positive for total antibody to HBV. For diagnostic purposes, anti-HBc total reactivity should be correlated with patient history and other hepatitis markers for diagnosis of past or present infection, or vaccination against HBV.
Negative or nonreactive for hepatitis B virus (HBV) core total antibody (IgG & IgM)
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