Do Patients adherent on PrEP exposed to HIV
have seroconversion symptoms & falsely
reactive HIV tests?
Mark Roche1, Elaney Youssef1, Yvonne Gilleece¹, Daniel Richardson¹,Amanda Clarke¹, Nicky Perry¹, Martin Fisher¹, Yolanda
Collaco Moraes², Laura Else³, Sheena McCormack²
1.Brighton & Sussex University Hospitals Trust
2.MRC Clinical Trials Unit @ University College London
3.University of Liverpool
Sensitivity & Specificity rates of Point of
Care Tests
Background
Name
Truvada is licensed for use as pre-exposure prophylaxis
(PrEP) for the reduction of HIV in the US. In the UK,
PrEP is only widely available via enrolment to the
PROUD study for men who have sex with men (MSM).
Participants are randomised to immediate daily Truvada
for two years or deferred Truvada for the last year only.
Ag / Ab Sensitivity (95% Specificity (95%
CI)
CI)
Determine
Ag / Ab 100% (Ag/Ab)
HIV - 1/2
(CI 99.7% Ag/Ab Combo
100%)
99.6% (Ag) (CI
98.5 - 99.9%)
99.2% (Ab) (CI
95.7% - 99.8%)
Case
Clearview
COMPLETE
HIV-1/2
1. Patient M presented to his local GUM clinic reporting
a significant increase in unprotected passive anal
intercourse in the previous 6 months.
2. He was enrolled in the PROUD study and was
randomised to the immediate Truvada arm. At
baseline he had a HIV negative POCT and serum
test.
3. At his 3 month PROUD visit he was unwell
complaining of flu like symptoms and malaise for 5
weeks; rectal pain, bleeding and constipation for 2
weeks, and 8kg weight loss. He reported passive anal
intercourse 8 weeks previously with several known
HIV positive partners.
4. An HIV POCT test was performed which was p24
Antigen and Antibody reactive (Determine HIV-1/2
Ag/Ab Combo). He also had rectal gonorrhoea. At this
stage Patient M was advised to discontinue taking his
Truvada immediately.
5. The following day, a serum HIV test collected on the
same day as POCT (Abbott Architect framework and
confirmed by Biomerieux Vider) was negative. An HIV
RNA (Abbott PCR) was <40 copies/ml. Samples taken
on the same day as the reactive HIV POCT were
analysed for Tenofovir and emtricitabine levels and
although there were variations between plasma and
serum levels, they were consistent with the patient’s
report of 100% adherence.
Ab
OraQuick
Ab
Advance HIV1/2
99.7% (98.9% - 99.9% (CI 99.6%
100%)
- 100%)
99.6% (98.5 99.9%)
100% (CI 99.7% 100%)
Tenofovir & Emtrcitabine Levels
Drug
TDF (ng/ml)
FTC (ng/ml)
Plasma Level
188.80
1602.78
Serum Level
116.64
1043.20
Title
Conclusion
1. Patient M may have been sufficiently exposed to HIV to have a positive DETERMINE but by being on PrEP prevented an established
infection.
2. The reactive DETERMINE was both Antigen and Antibody falsely reactive.
3. Sensitivity of POCTs in HIV positive MSM is 96% compared to 98% for a 4th generation test (Delaney et al, 2011)
4. Confirmatory HIV testing in MSM on PrEP is needed to inform decisions about continuing or discontinuing treatment
Acknowledgments
Many thanks to Patient M who gave his informed consent for this abstract.
References:
Clinical and Laboratory Standards Institute. Procedures and Devices for the Collection of Diagnostic Capillary Blood Specimens; Approved Standard-5th H4-A5
Vol.24 No.21
Delaney, P et al, (2011) Evaluation of the Performance Characteristics of 6 Rapid HIV Antibody tests; Journal of Clinical Infectious Diseases 52 (2): 257-263.
http://www.proud.mrc.ac.uk
email: PROUD@ctu.mrc.ac.uk