1 - 2 days
Turnaround time is defined as the usual number of days from the date of pickup of a specimen for testing to when the result is released to the ordering provider. In some cases, additional time should be allowed for additional confirmatory or additional reflex tests. Testing schedules may vary.
Serum or plasma
0.5 mL
0.3 mL (Note: This volume does not allow for repeat testing.)
Red-top tube, gel-barrier tube, or lavender-top (EDTA) tube
If tube other than a gel-barrier tube is used, transfer separated serum or plasma to a plastic transport tube.
Room temperature
Temperature
Period
14 days
Refrigerated
Frozen
Freeze/thaw cycles
Stable x3
Cadaver specimens; heat-inactivated specimens; body fluids other than serum or plasma
Presence of antibody to hepatitis B surface antigen (anti-HBs) is used to determine immune status to HBV or disease progression in individuals infected with HBV. Anti-HBs levels can be measured to determine if vaccination is needed, or following a vaccination regimen, to determine if protective immunity has been achieved.
Presence of anti-HBs is not an absolute indicator of resolved hepatitis infection, nor of protection from future infection. Since there are different serologic subtypes of hepatitis B virus, it is possible (and has been reported) for a patient to have antibody to one surface antigen type and to be acutely infected with virus of a different subtype. Thus, a patient may have coexisting HBsAg and anti-HBs. Transfused individuals or hemophiliacs receiving plasma components may give false-positive tests for antibody to hepatitis B surface antigen.
Immunochemiluminometric assay (ICMA)
• Nonreactive: Inconsistent with immunity
• Reactive: Consistent with immunity
Anti-HBs usually can be detected several weeks to several months after HBsAg is no longer found, and it may persist for many years or for life after acute infection has been resolved. It may disappear in some patients, with only antibody to core remaining. Patients with this antibody are not overtly infectious. Presence of the antibody without the presence of the antigen is evidence for immunity from reinfection, with virus of the same subtype.
