Enzywell Recombinant Enzyme Immunoassay for the Serological Diagnosis of Syphilis

Abstract

The aim of this study was to evaluate Enzywell TP, a new rapid enzyme immunoassay (EIA) that uses 2 recombinant Treponema pallidum antigens for the serological diagnosis of syphilis. Specificity was evaluated by screening 1055 unselected bloods requesting serological tests for syphilis in parallel with Enzywell TP and the Syphilis ICE EIA which is our standard screening test for syphilis. Sensitivity was evaluated using a panel of 159 known treponemal sera representing various stages of syphilis and 5 treponemal sera detected on screening. The specificity of Enzywell TP on initial and repeat testing (99.6% and 99.7% respectively) was similar to that of the Syphilis ICE test (99.8% and 99.9% respectively). The sensitivity of Enzywell TP (100%) was similar to that of Syphilis ICE (99.4%): both tests were significantly more sensitive (P=0.01) than the fluorescent antibody absorbed test (94.5%) but not the T. pallidum particle agglutination (TPPA) assay (99.4%). Both Enzywell TP and Syphilis ICE were positive with sera from 16 known HIV-infected patients who had been treated for syphilis many years previously (mean 9.4 years) confirming the value of these tests in excluding previous syphilis in HIV-infected individuals. We conclude that the Enzywell recombinant EIA is simple, rapid, highly sensitive and specific, and is a welcome addition to the range of currently available diagnostic tests for syphilis.

Lessons from the syphilis outbreak in homosexual men in east London

“…11 The lack of sensitivity of the screening syphilis serology in PS emphasises the need for DGM and serosurveillance for up to 3 months in undiagnosed GUD. [11][12][13][14] Almost equal numbers opt for parenteral or oral treatment; the popularity of the latter is based on convenience; encouragingly, all who opted for daily procaine penicillin injections completed their course. The long term efficacy of oral treatment is unknown and requires clinical and serological follow up, particularly in HIV cases, as clinical relapse is a real possibility in this group.…”

Serodiagnosis of Syphilis: Antibodies to Recombinant Tp0453, Tp92, and Gpd Proteins Are Sensitive and Specific Indicators of Infection byTreponema pallidum

“…A variety of T. pallidum proteins have been tested including TpN44.5 (TmpA, Tp0768), TpN15 (Tp0171), TpN17 (Tp0435), and TpN47 (Tp0574) (20,29,30,32). These antigens FIG.…”

“…From screening many hundreds of serum samples, it has been determined that the sensitivity and specificity of tests employing some of these antigens can be as high as 99.7% (7,20,29,30,32). However, not all those with early syphilis are detected with the use of these antigens (27), and more sensitive and specific recombinant T. pallidum proteins would be useful for syphilis seroscreening.…”

Laboratorial Diagnosis of Syphilis

“…The reacting human IgG treponemal antibodies are detected by antihuman IgG monoclonal antibodies labeled with biotin and horse radish peroxidase (HRP) labeled streptavidin and revealed by tetramethylbenzidine (TMB) substrate. The sensitivity has ranged from 92.4% to 100% and specificity from 98.2% to 99.3% (Halling et al, 1999;Silletti, 1995;Young et al, 1989;Young et al, 1998). The newer Captia select Syph-G EIA (Trinity Biotech) using anti-human IgG monoclonal antibodies labeled with HRP as a conjugate instead of biotin-streptavidin system had sensitivity and specificity of 99.0% and 98.0%, respectively (Woznicova & Valisova, 2007).…”

“…The intensity of the enzyme substrate TMB color is proportional to the concentration of antibodies reacting with recombinant T.pallidum antigens. The range of sensitivity and specificity for the ICE Syphilis assay were 98.2% to 100% and 99.2% to 100%, respectively (Cole www.intechopen.com et al, 2007;Lam et al, 2010;Viriyataveekul et al, 2006;Young et al, 1998). Other studies for evaluation of ICE Syphilis (Murex) as a screening test for syphilis, the sensitivity in primary syphilis were 84% (48/50) (Manavi & McMillan, 2007) and 77.2% (61/79) (Young et al, 2009).…”