Serological Tests for HTLV Viruses by Blood and Blood Components

Human T-lymphotropic viruses type I (HTLV-I) and type II (HTLV-II), also collectively referred to as HTLV-I/II, are retroviruses that can cause severe hematological and neurological diseases in infected individuals.

For this reason, FDA recommends that blood establishments use serological tests to reduce the risk of transmission by blood or blood components. These recommendations apply to the collection of Whole Blood and blood components - except for Source Plasma, which do not have to be tested by the donor facility under the current 21 CFR requirements.

In the past, the FDA has issued a number of documents to support or regulate the HTLV-I/II challenge in blood establishments: 

• HTLV-I Antibody Testing, Memorandum, November 29, 1988 (November 1988 memorandum). 
• HTLV-I Antibody Testing, Memorandum, July 6, 1989 (July 1989 memorandum). oRecommendations for the Quarantine and Disposition of Units from Prior Collections from Donors with Repeatedly Reactive Screening Tests for Hepatitis B Virus (HBV), Hepatitis C Virus (HCV) and Human T- Lymphotropic Virus Type I (HTLV-I), Memorandum, July 19, 1996 (July 1996 memorandum). 
• Guidance for Industry:   Donor Screening for Antibodies to HTLV-II; August 1997 (August 1997 guidance).
• Recommendations for Requalification of Blood Donors Deferred Because of Reactive Test Results for Antibodies to Human T-Lymphotropic Virus Types I and II (anti-HTLV-I/II); Draft Guidance for Industry, September 2018 (September 2018 draft guidance).

The new document now consolidates FDA's current recommendations on HTLV-I/II as follows:

• It finalizes the September 2018 draft guidance. 
• It supersedes the recommendations specific to HTLV-I contained in the July 1996 memorandum.
• and supersedes the November 1988 and July 1989 memoranda, and the August 1997 guidance.

The truly new recommendations contained in this guidance document are those relating to donor requalification, which are found in Section III.B. All other suggestions reflect current regulations and the availability of a licensed supplemental test for antibodies to HTLV-I/II (anti-HTLV-I/II) and are otherwise consistent with FDA's previously published recommendations.

Further details can be found in the original document entitled "Use of Serological Tests to Reduce the Risk of Transfusion-Transmitted Human T-Lymphotropic Virus Types I and II (HTLV-I/II)".