Guidance for Industry 
 
 
 
 
 
Adequate and Appropriate Donor 
Screening Tests for Hepatitis B; 
Hepatitis B Surface Antigen (HBsAg) 
Assays Used to Test Donors of Whole 
Blood and Blood Components, 
Including Source Plasma and Source 
Leukocytes 
 
 
 
Additional copies of this guidance document are available from the Office of Communication, 
Training and Manufacturers Assistance (HFM-40), 1401 Rockville Pike, Rockville, MD 20852-
1448, or by calling 1-800-835-4709 or 301-827-1800, or from the Internet at 
http:www.fda.gov/cber/guidelines.htm. 
 
For questions on the content of this guidance, contact the Division of Emerging and Transfusion 
Transmitted Diseases at 301-827-3008.  
 
 
 
 
U.S. Department of Health and Human Services 
Food and Drug Administration 
Center for Biologics Evaluation and Research 
November 2007 
 
This guidance updates the July 2007 guidance of the same title to extend the 
implementation date.  Contains Nonbinding Recommendations 
Table of Contents 
 
 
I.  INTRODUCTION.................................................................................................................1 
II.  BACKGROUND...................................................................................................................2 
III.  RECOMMENDATIONS......................................................................................................3 
IV.  IMPLEMENTATION..........................................................................................................4 
V.  REFERENCES......................................................................................................................4 
 
 
 
 
 
 
i  Contains Nonbinding Recommendations 
Guidance for Industry 
 
Adequate and Appropriate Donor Screening Tests for Hepatitis B; 
Hepatitis B Surface Antigen (HBsAg) Assays Used to Test Donors of 
Whole Blood and Blood Components, Including Source Plasma and 
Source Leukocytes 
 
 
This guidance represents the Food and Drug Administrations (FDAs) current thinking on this 
topic. It does not create or confer any rights for or on any person and does not operate to bind 
FDA or the public.  You can use an alternative approach if the approach satisfies the 
requirements of the applicable statutes and regulations.  If you want to discuss an alternative 
approach, contact the appropriate FDA staff.  If you cannot identify the appropriate FDA staff, 
call the appropriate number listed on the title page of this guidance. 
 
 
I.  INTRODUCTION 
 
Blood establishments are required under 21 CFR 610.40(a)(3) and (b) to test donations of human 
blood and blood components for hepatitis B virus using approved screening tests that are 
adequate and appropriate for this purpose.  One test used to detect the presence of hepatitis B 
infection is the hepatitis B surface antigen (HBsAg) test.  This document provides 
recommendations to manufacturers of HBsAg assays that are intended to be used to test donors 
of Whole Blood and blood components, including Source Plasma and Source Leukocytes, and to 
establishments using an HBsAg assay.  This guidance represents the Food and Drug 
Administrations (FDAs) current thinking on minimum sensitivity standards for such HBsAg 
assays, as they relate to testing to reduce adequately and appropriately the risk of transmission 
of communicable disease under 21 CFR 610.40(b) (see Section III).  Under 21 CFR 610.44, 
manufacturers of test kits used to test donations for hepatitis B virus must use a reference panel 
from FDA or an FDA-designated source when such panel is available and appropriate to verify 
acceptable sensitivity and specificity of such kits (see Ref. 1).  This guidance document finalizes 
the draft guidance document entitled Guidance for Industry:  A Modified Lot-Release 
Specification for Hepatitis B Surface Antigen (HBsAg) Assays Used to Test Blood, Blood 
Components, and Source Plasma Donations dated April 2002. 
 
FDAs guidance documents, including this guidance, do not establish legally enforceable 
responsibilities.  Instead, guidances describe the FDAs current thinking on a topic and should be 
viewed only as recommendations, unless specific regulatory or statutory requirements are cited.  
The use of the word should in FDAs guidances means that something is suggested or 
recommended, but not required. 
1  Contains Nonbinding Recommendations 
II.  BACKGROUND  
 
Since 1975, we, FDA, have distributed Reference Hepatitis B Surface Antigen panels to 
manufacturers of HBsAg detection assays used to test donors of Whole Blood and blood 
components, including Source Plasma and Source Leukocyte donations.  Manufacturers use 
these panels, suitable for testing HBsAg assays of so-called third generation sensitivity (mostly 
radioimmunoassays and enzyme immunoassays), to test manufactured kit lots of HBsAg 
detection assays for screening Whole Blood and blood components, including Source Plasma 
and Source Leukocytes, to ensure a minimum sensitivity for those kit lots.  FDA also distributes 
the panels to unlicensed manufacturers who are developing such HBsAg assays.  The panels are 
used to test the sensitivity of HBsAg assay lots, pre- and post-licensure, under our lot-release and 
surveillance programs. 
 
The current Center for Biologics Evaluation and Researchs (CBERs) panel, distributed since 
1996, contains 10 plasma samples:  eight reactive and two nonreactive for HBsAg.  The eight 
reactive samples are estimated to contain about 0.02, 0.04, 0.5, 0.9, 1.0, 2.5 to 3.0, 5.0 to 6.0 and 
7.0 to 8.0ng HBsAg/mL (see footnote to the table on page 3, under Section III.).  The current 
lower limit of detection specification for HBsAg assays used to test blood donations corresponds 
to 1.0ng HBsAg/mL.  The CBER panel sample estimated to contain about 1.0ng HBsAg/mL is 
detected by all HBsAg test kit lots used to test Whole Blood and blood components, including 
Source Plasma and Source Leukocyte donations. 
 
Since this 1.0ng HBsAg/mL sensitivity specification for HBsAg assays was implemented, we 
acquired information that the different HBsAg detection assays, both licensed and investigational 
assays that are developed for eventual licensure, varied widely in relative sensitivity below this 
limit.  Furthermore, we learned that some of these assays might have detection capabilities well 
below 1.0ng HBsAg/mL. 
 
Therefore, we initiated a study comparing three (at that time) investigational and four licensed 
HBsAg detection assays and procedures, to evaluate whether newer HBsAg assays were more 
sensitive than the then-used licensed methods.  The rationale for performing such a study was to 
ascertain whether newer assays might increase the capability of detecting donations that are 
potentially infectious for hepatitis B virus.  Since that time, FDA has licensed all three 
previously investigational assays. 
 
At a Blood Products Advisory Committee (BPAC) meeting held on March 15, 2001 (Ref. 2), 
preliminary data generated by FDA and industry were presented which indicated that the 
sensitivity of HBsAg licensed and investigational assays varies significantly.  In particular, the 
lower limit of detection ranged from 0.07 to 0.13ng HBsAg/mL for the three investigational 
assays (all of which are now licensed) and for one licensed assay tested.  On the other hand, a 
detection limit range from 0.27 to 0.62ng HBsAg/mL was observed for three licensed assays 
tested.  Based on these observations, we asked BPAC whether the HBsAg donor screening 
assays should be capable of a lower limit of detection.  BPAC voted in favor of a lower limit of 
detection, with 14 yes votes, 0 no votes and 0 abstentions. 
 
2  Contains Nonbinding Recommendations 
Taking BPACs recommendation into consideration, we are recommending that assays used 
under 21 CFR 610.40(b) to test Whole Blood and blood components, including Source Plasma 
and Source Leukocyte donations have a capability of detecting at least 0.5ng HBsAg/mL.  
HBsAg assays that do not have this capability should not be used to test Whole Blood and blood 
components, including Source Plasma and Source Leukocyte donations, because FDA believes 
that tests that are incapable of identifying HBsAg at these limits are not adequate to reduce the 
risk of communicable disease transmission.  If more HBsAg assays demonstrate greater 
capability to detect HBsAg at even lower levels, we will reconsider this recommendation. 
 
 
III.  RECOMMENDATIONS 
 
We recommend that establishments using HBsAg detection assays to test Whole Blood and 
blood components, including Source Plasma and Source Leukocyte donations, use assays that 
have a lower limit of detection capability of 0.5ng HBsAg/mL or less in order to reduce 
adequately and appropriately the risk of transmission of communicable disease.  HBsAg assays 
that do not have this capability should not be used to test Whole Blood and blood components, 
including Source Plasma and Source Leukocyte donations, because FDA believes that they are 
not adequate or appropriate for this purpose.  FDA recommends that test kits that are used to test 
Whole Blood and blood components, including Source Plasma and Source Leukocyte donations, 
employ the following performance standard when testing the CBER HBsAg Lot-Release Panel 
#12: 
 
 
Panel Sample    Estimated Concentration    Expected Reactivity* 
      of HBsAg (ng/mL) 
1201        1.0          +  
 
1202        5.0 to 6.0        + 
 
1203        0           
 
1204        0.04a         + 
 
1205        0.5          + 
 
1206        0           
 
1207        2.5 to 3.0        + 
 
1208        7.0 to 8.0        + 
 
1209        0.02a         +  
 
1210        0.9          + 
 
3  Contains Nonbinding Recommendations 
* +  =  reactive;  +  =  reactive or non-reactive;    =  non- reactive 
a  <0.1 ng/mL; imputed value shown is based on dilutions 
 
 
IV.  IMPLEMENTATION 
 
We recommend implementation of these recommendations on July 31, 2008. 
 
 
V.  REFERENCES 
 
1.  Requirements for Testing Human Blood Donors for Evidence or Infection Due to    
      Communicable Disease Agents; Final Rule, June 11, 2001 (66 FR 31146).  
 
- 21 CFR 610.40. 
- 21 CFR 610.44. 
 
2.   Blood Products Advisory Committee Transcript, March 15, 2001.
  (http://www.fda.gov/ohrms/dockets/ac/01docsbc.htm). 
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