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Syphilis in Serum Now Detected by ELISA

Apr 6, 2014 5:31:36 PM / by Maria

Independent publication uses disease-characterized human serum supplied by HemaCare to evaluate a novel ELISA based highly sensitive method of syphilis detection

Syphilis is a bacterial infection of the human serum by a spirochete, Treponema pallidum. This infection is sexually transmitted and ultimately results in life-threatening cardiovascular and neurological disorders. Though initially believed to be less prevalent in industrialized nations, this venereal disease is frighteningly re-emerging in Europe and U.S.A causing a worldwide public health concern. Therefore, early diagnosis of infection in serum, followed by treatment is of paramount importance.

Syphilis is initially present in the human serum in a primary latent form. If untreated, the non-symptomatic primary form progresses to symptomatic secondary stage (characterized by rash or ulcers in the area of infection) and finally to the debilitating tertiary stage. Traditionally, syphilis in the serum has been diagnosed by detecting antibodies, which include both treponemal and non-treponemal tests. While non-treponemal tests have the disadvantage of low specificity, they offer the exclusive advantage of monitoring therapy, as treponemal tests last a lifetime in spite of treatment. Thus, both tests are required to achieve correct diagnosis followed by treatment. European and German medical guidelines recommend TPPA (Treponema pallidum particle agglutination), a treponema test for testing in serum. However, an EIA (enzyme immunoassay) is recommended for testing in pregnant women. Busse et al., have evaluated and validated the diagnostic performance of a novel ELISA (enzyme-linked immunosorbent assay) method of syphilis detection using disease-characterized serum supplied by HemaCare.

Syphilis in serum Syphilis spirochete in serum. Image credits: www.wales.nhs.uk

This assay known as Virotech Screen ELISA, offers specificity and avoids false positives caused due to pregnancy, infection and malignancy. Busse et al., compared the performance of their assay with Phoenix Trep-Sure, an FDA cleared device. They used 421 serum samples, which included sera of pregnant women, patients with suspected infection and also commercially available syphilis infected serum panels from HemaCare. Virotech screen utilizes three recombinant treponemal antigens, TpN15, TpN17 and TpN47, which increases the chances of early detection. Virotech showed a sensitivity of 100% and a higher specificity (98.3% in comparison to 93.9% by Phoenix). Further, the analytical sensitivity of Virotech screen with two WHO standard preparations was determined at 0.02 IU/ml and 0.03IU/ml, which was slightly superior to Phoenix assay. Thus, this novel assay offers a specific, sensitive and easy to use alternative to diagnose syphilis in serum.

We are excited to read how serum supplied by HemaCare has helped in evaluation of a novel ELISA based highly reliable method of syphilis detection with suitability for automation. Try HemaCare’s serum and other blood products: all donors have undergone rigorous screening tests with each donation, including serological testing for syphilis, adhering to IRB, FDA and AABB guidelines.

Reference:

1.  Clemens Busse, Mojdeh Heidary Navid, Andreas Strubel, Paul Schintzler. Evaluation of a new recombinant antigen-based Virotech Treponema pallidum screen ELISA for diagnosis of syphilis. Clin. Lab. 2013 59:1-7.

Topics: Assay Development, diagnostic, Independent validation, serum

Maria

Written by Maria

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