Laboratory Results IHC Results 1 RPR test
nonreactive Positive FTA-ABS test reactive Tpallidum qualitative real-time PCR positive HIV test positive 2 RPR test
reactive Positive FTA-ABS test reactive HIV test unknown 3 RPR test
reactive Positive TP-PA test reactive HIV test unknown 4 RPR test
reactive Positive Syphilis treponemal antibody positive HIV test positive Abbreviations: FTA-ABS, fluorescent treponemal antibody absorption; HIV, human immunodeficiency virus;IHC, immunohistochemistry; MSM, men who have sex with men; PCR, polymerase chain reaction; RPR, rapid plasma reagin; TP-PA, Treponema pallidum particle agglutination.
The RPR test
had an unacceptably low sensitivity as a syphilis screening procedure, indicating a low syphilis prevalence of only 1% (the TPHA test indicated a prevalence of 11.7%).
Nontreponemal tests, such as the RPR test
and venereal disease research laboratory (VDRL) test, detect antibodies to cardiolipin and are not specific for treponemal infection.
As with the RPR test
, patients whose ulcerations were only MPCRTP positive had a higher FTA-ABS seropositivity rate than those with other aetiologies recorded (96.2% v.
Among the many serologic tests available, the RPR test
and FTA-ABS test are the most widely employed.
While non-treponemal tests (NTTs), VDRL test and RPR tests
are used for screening, follow-up and treatment, treponemal tests are used to verify the diagnosis (7).
ESPLINE TP and RPR tests
have been validated for use in OWPs (11).
Results in every sample were confirmed in Lisbon, using RPR tests
Some data were also available on 13 patients with equivocal (2) or positive (11) EIA results, positive FTA assays and negative RPR tests
. Of these three had a past history of syphilis and two of AID while eight had a history of neither.