NAT Yield from Real Time Testing of Organ Donors for HIV-1 RNA and HCV RNA

Safer Organs and No False Positive Results

Claudia Chinchilla-Reyes, MB(ASCP)1, Thomas D. Mone, MBA2, Monica Johnson3, Patricia Niles4 and Marek Nowicki, PhD1

1MNIT, Los Angeles, CA, 2OneLegacy, Los Angeles, CA, 3GSDS, Sacramento, CA, and 4NMDS, Albuquerque, NM.

No Disclosures

Background• Transplant professionals must be able to rely on

organ and tissue screening tests to accurately detect the presence of viruses and their antibodies.

• Recent data shows that there is higher likelihood of accepting organs from high-risk donors if Nucleic Acid Testing (NAT) had been performed. – (Kucirka, L. M. et al. Am. J.Transpl. 2009; 9(5): 1197-204).

Background

• Antibody tests may give false negative results due to the presence of HCV or HIV-1 infection during the “window” period.

• Nucleic Acid Testing (NAT) can reduce “window” donations during the antibody negative phase infection.

Aim

• To determine the prevalence of “NAT reactive only” aka “NAT yield” donors among organ donors in the Western United States.

Methods

• Assay: Procleix HIV-1/HCV TMA (Novartis/GenProbe, San Diego, CA)

• Region: California, Nevada, Oregon, Washington, New Mexico and Utah.

• Period: Sept 2004 - October 2011

• Donors: 8204 prospective organ donors for HIV-1 and HCV RNA.

Results

• We identified 3 (0.04%) cases of NAT reactive donors with no HIV-1 or HCV serological markers.

• All cases were terminated and no organs were recovered.

Case 1 (December 2004)

• 23 Year’s old male from Northern California

• Anti-HIV-1/2: NonReactive

• Anti-HCV: NonReactive

• HIV-1/HCV Procleix Assay: Repeatedly Reactive

• HIV-1 discriminatory Procleix Assay: NonReactive

• HCV discriminatory Procleix Assay: Presumed HCV reactive*

• Case terminated, no organs recovered.

• Risk factors: pending chart abstraction

*QNS (Quantity Not Sufficient)

Case 2(March 2008)

• 40 Year’s old male from Southern California

• Anti-HIV-1/2: NonReactive

• Anti-HCV: NonReactive

• HIV-1/HCV Procleix Assay: Repeatedly Reactive

• HIV-1 discriminatory Procleix Assay: Repeatedly Reactive

• HCV discriminatory Procleix Assay: NonReactive

• Case terminated, no organs recovered.

• Risk Factor: Donor had drug use and incarceration history.

Case 3(November 2008)

• 24 Year’s old Male from New Mexico

• Anti-HIV-1/2: NonReactive

• Anti-HCV: NonReactive

• HIV-1/HCV Procleix Assay: Repeatedly Reactive

• HIV-1 discriminatory Procleix Assay: NonReactive

• HCV discriminatory Procleix Assay: Repeatedly Reactive

• Case terminated, no organs recovered.

• Risk Factor: Donor institutionalized (Mental Institution)

NAT Reactive Cases

Case Date Age Gender Origin HIV & HCV

Serology

HIV-1/HCV NAT

HIV-1 disc HCV disc Risk Factor

1 Dec 2004

23 M N. Cal Non - Reactive

Repeatedly Reactive

Non - Reactive

HCV* Pending

2 Mar 2008

40 M S. Cal Non - Reactive

Repeatedly Reactive

Repeatedly Reactive

Non - Reactive

Drug use and incarceration

3 Nov 2008

24 M NM Non - Reactive

Repeatedly Reactive

Non - Reactive

Repeatedly Reactive

Institutionalized

*Presumed HCV reactive, Quantity Not Sufficient

Results (2)

• All other NAT reactive cases had serological markers for HIV-1 and HCV.

Serology Prevalence *

*Chinchilla-Reyes, et al. abstract #1066, ATC 2012

HCV HIV

2010 6.5% 0.2%

2011 5.7% 0.3%

......But what about false positives?

How did we avoid them?

False Positives v. Non-Repeatable

Definitions

• False NAT Positive: specimen that is consistently NAT reactive but in fact the virus is not present in the specimen and/or organ donor.

• Non-Repeatable: discordant specimens results that initially tested reactive, retested non-reactive.

Testing:

• Real-time, no batching • Neat (undiluted) • Diluted 1:5 with PBS (manufacturers

recommendation)• Discrimination step if reactive• if needed, retesting was performed from an

untouched, virgin reference vial of serum

MNIT NAT Algorithm

=

“NAT+ only” results compared with serology and donor risk factors and if necessary repeated from untouched vial

•Our data shows that the prevalence of “NAT only” reactive donors is approx. 0.04% in the Western United States.

•2 out of the 3 cases had high risk factors for HCV and HIV-1.

•NAT testing potentially prevented multiple transmissions of HCV and HIV-1.

Conclusions

Conclusion (2)

• Contrary to prevailing opinion that NAT produce many false positive results increasing loss of organs, these events are rare in a properly designed and QA lab with the properly chosen assay.

Based on our 7 year experience:

Don’t relay on single NAT result - develop proper algorithm, we don’t relay on single EIA test don’t we?!

Evaluate NAT and serology and if necessary repeat from untouched, virgin vial.

To date there have been NO organs defer simply because of false positive results from our lab.

Thank you!Acknowledgments

•MNIT for support & encouragement to perform the study

•MNIT lab staff collaboration

•OPO’s •OneLegacy •Golden State Donor Services•New Mexico Donor Services

•ATC for inviting us to present this data.