Murine Leukemia Virus (MLV) Related Human Retroviruses and Blood Safety

BPAC meeting, December 14, 2010

Indira Hewlett, Ph. D

Chief, Laboratory of Molecular Virology

DETTD/CBER/FDA

Issue

FDA is seeking the advice of the BPAC on 1) donor deferral based on a history or

diagnosis of Chronic Fatigue Syndrome (CFS) or Prostate Cancer (PC) and,

2) testing for the newly identified MLV related retroviruses in humans recognizing that disease causation has not been established.

Identification of MLV related retroviruses in humans

3

Prostate Cancer Tissue

DNA Virochip

Urisman A, et al. PLoS Pathogen 2006; 2(3): e25Silverman R, et al. Nat. Rev. Urol 2010;Schlaberg R, et al. PNAS 2009; 106(38):16351-6Lo S, et al. PNAS 2010; 107(36):15874-9

polytropicMLV

xenotropicMLV

MLV/XMRV and Blood Safety

In 2009, a US study reported XMRV detection in blood of 67% (68/101) of CFS patients and 3.7% (8/218) of healthy controls using PCR.

XMRV and MLV-related human retroviruses have since been detected in the blood of 0-14% of healthy controls.

However, several studies have shown lack of MLV/XMRV detection in CFS, PC and blood donors.

Although disease association has been reported, causation has not yet been established.

July 2010 BPAC Informational Session

Topics discussed: Identification and detection (or lack of) in CFS, PC

blood donors. Assay validation study plans and assay development

efforts. AABB recommendation for use of donor education

materials on CFS and indefinite deferral for donors who voluntarily disclose their CFS diagnosis.

Health Canada’s policy of indefinite deferral for PC and recent introduction of deferral for those who voluntarily disclose their CFS diagnosis.

Update on MLV/XMRVDisease Association – CFS

Lo et al, PNAS, Aug. 2010 32/37 (86.5%) of CFS patients positive for polytropic MLV-related

sequences by PCR on PBMC DNA 3/44 (6.8%) of US healthy volunteer blood donors positive by PCR on

PBMC DNA. Hanson et al, 1st Intl. Workshop on XMRV, Sept. 2010 MLV related sequences detected in PBMC DNA of 8/10 severe CFS,

3/10 recovered CFS cases and 1/10 healthy controls. Virus isolated from plasma of 6 individuals including 5 CFS patients.

Mikovits et al, 1st Intl. workshop on XMRV, Sept. 2010 50 CFS patients in UK, PCR, culture and serology; > 60% positive for

XMRV by culture and serology.

Lack of Disease Association – CFSAuthor Country No. of Samples Detection Methods Reference

Switzer B, et al USA 51 CFS cases53 healthy controls 41 U.S. blood donors

Nested PCR, WB, ELISA, IFA (Done in three labs)

Retrovirology 2010; 7:57

Henrich TJ, et al USA 32 CFS261 controls

PBMC DNA; nested PCR J Infect. Dis 2010; 202:1478-81

Van Kuppeveld FJM, et al

Netherlands 32 CFS pts43 controls

Nested PCR of gag gene.Real time PCR of integrase

BMJ. 2010; 340: c1018.

Groom HC, et al UK 170 CFS patients395 controls

PCR or real time PCRViral neutralization assay for XMRV and MLV.

Retrovirology. 2010; 7:10

Hong P, et al. China 65 CFS patients85 blood donors

RT PCRPBMCs and plasma

Virology Journal. 2010; 7:224.

Hohn O, et al Germany 36 CFS50 MS with fatigue 30 controls

Gag & env ELISAsNested PCR

1st International Worskshop XMRV. 2010.

Blomberg J Sweden 40 CFS plasma50 CFS PBMCs200 controls

RT qPCRIntegrase, Gag & env PCR Serology, virus culture

1st International Worskshop XMRV. 2010

Petros et al, 1st Intl. Workshop on XMRV, Sept. 2010

3 PC tissues from 3 separate PC patients tested and found to be positive for XMRV/MLV sequences by PCR.

Fischer et al, 1st Intl. Workshop on XMRV, Sept. 2010

355 PC tissue, 40 PBMC from PC patients and 70 healthy controls from Northern Europe tested by PCR;

2/355 (0.56%) tissues positive for XMRV, 1 wild type and 1 heterozygous for R462Q.

PBMC from 2 XMRV positive PC patients negative by PCR. All healthy controls negative for XMRV sequences.

Danielson et al, JID, epub Oct. 2010 Prostatic tissue of 144 PC patients from southern US by PCR for the env

gene; 32/144 (22%) positive for XMRV sequences. Both normal and tumor tissue for 57 cases tested; 21/57 (36.8%) normal

and 25/57 (43.9%) tumor tissue samples positive for XMRV.

Disease association - PC

Lack of Disease Association – PC

Author Country No. of Samples Detection Methods Reference

Aloia, et al USA 161 tumor derived samples (PCR);596 tumor tissue samples (IHC) 452 benign prostatic tissue samples (IHC)

Nested RT-PCRIHC

Cancer Research 2010; Oct 21. [Epub ahead of print]

D’Arcy F, et al Ireland 139 PC nested PCR European Urology 2008; 7(suppl):271

Hohn O, et al Germany 589 PC tissue samples146 PC serum samples

Gag & env ELISAsNested PCR

Retrovirology 2009;6:92

Blomberg etal Sweden 400 PC patients RT-qPCR, gag, env PCR, serology, virus culture

1st International Worskshop XMRV. 2010.

Evaluation of Transfusion Risk

Transfusion transmission of MLV/XMRV theoretically possible due to presence in blood cells, evidence of cell-free virus (Lombardi et al, 2009).

Low but detectable transient viremia in rhesus macaques 4-14 days and seroconversion 11-14 days post intravenous inoculation (Qiu et al, 2010).

Sero-prevalence of 1.7% (5/300) in Japanese blood donors; 0.1% (3/2861) in US blood donors (Qiu et al, 2010) and 6.8% (3/44) positive by PCR on PBMC DNA (Lo et al, 2010).

However, no evidence of XMRV in 1) US study of 121 blood donors by PCR and serology (Switzer et al, 2010) and 2) different US study of 1435 HIV-ve and 44 HIV-1 +ve blood donors by TMA ( Gao et al, 2010).

No XMRV sequences in 105 plasma and 19 PBMC from Cameroon blood donors, 94 HIV-1 infected individuals from Uganda (Tang et al, 2010).

Potential Sources of Discrepancies

Study populations and geographic differences in prevalence

Case definition criteria and stage of illness Specimen processing, sensitivity and specificity of

test methods Potential genetic variation of the virus Other unknown factors

Need for assay standardization and validation to evaluate blood safety and disease association.

Assay validation for blood donor studies

NHLBI Scientific Research Working Group comprised of scientists from govt., academia and blood organizations established to validate assays for transfusion transmission studies.

BSRI’s analytical and clinical reference panels evaluated by multiple labs including CDC, NIH, WPI, BSRI and 2 labs at FDA for testing of blood donors in future studies.

FDA currently developing NAT and serology panels for future lot release, if needed.

NIH sponsored Proposed Study on XMRV and Related Viruses in Chronic Fatigue Syndrome

Laboratory sitesCDC, NCI, WPI, othersSample preparation TBDtime to extraction

Clinical collection sites TBDaccess, expertise, geographyAssaysmolecular, cultivation/co-cultivation

Organizational Meeting, 4-5 October 2010Labs: Harvey Alter (NIH), Bill Switzer (CDC), Judy Mikovits (WPI)

Consultants: John Coffin (NCI), Simone Glynn (NHLBI), Suzanne Vernon (CFIDS), Nancy Klimas (U of Miami)

Columbia Faculty: Bruce Levin, Mady Hornig, W. Ian Lipkin

NIH sponsored Proposed Study on XMRV and Related Viruses in Chronic Fatigue Syndrome

Laboratory sites

CDC, NCI, WPI, others

Sample preparation TBD

time to extraction

MLV/XMRV and Blood Donation

No direct evidence for transfusion transmission or association with a transfusion transmitted disease, therefore, FDA has not established donor policy specific to MLV/XMRV.

FDA regulations require donors to be in good health at time of donation; medical directors exercise judgment on whether CFS patients meet criteria.

In regard to PC, large survey in Sweden and Denmark (SCANDAT) showed no increase in disease cases in 888,843 blood transfusion recipients without a prior cancer diagnosis at the index transfusion.

Indefinite deferral of donors who voluntarily disclose CFS diagnosis in Australia, New Zealand, UK and parts of Canada.

In the US, AABB issued bulletin (No. 10-03) recommending use of donor education materials on CFS and indefinite deferral for donors who voluntarily disclose their CFS diagnosis.

Questions for the Committee

1. Do the scientific data support asking donors about a medical history and/or diagnosis of CFS as a basis for indefinite deferral?

2. Please discuss whether the scientific data support asking donors about a medical history and/or diagnosis of prostate cancer as a basis for indefinite deferral.

Questions for the committee – con’t

3. Please comment on the scientific evidence that would be needed to justify a policy of donor testing for infection with MLV-related human retroviruses. In particular, should donor testing be considered in the absence of confirmed disease causation ?

4.Assuming that testing is warranted, please comment on the potential utility of NAT and /or serologic testing of blood donations to ensure safety of the blood supply from transmission of MLV-related human retroviruses.

BPAC presentations

The BPAC session today will include the following presentations on MLV/XMRV:

Review of current data on MLV/XMRV including highlights of the Ist International Workshop.

Research updates and current data on association of MLV/XMRV with CFS.

Data from animal infectivity studies. Update from the Blood Scientific Research Working group on

assay validation using MLV/XMRV panels. Prospective and retrospective donor prevalence studies. Assay development efforts on MLV-related retroviruses.