[Current methods for serological diagnosis of syphilis].

The paper gives information on novel diagnostic tests based on immunoblotting and immunochromatographic methods used to detect antibodies against Treponema pallidum. Whether these tests should be incorporated into an algorithm of the current serological diagnosis of syphilis is discussed.

Evaluation of ID-PaGIA syphilis antibody test.

BACKGROUND: Laboratory diagnosis of syphilis is usually accomplished by serology. There are currently a large number of different commercial treponemal tests available that vary in format, sensitivity and specificity. AIM: To evaluate the ID-PaGIA Syphilis Antibody Test as an alternative to other specific treponemal tests for primary screening or confirmation of diagnosis. METHODS: Serum samples from healthy adults (n = 100) were used for detection of specificity of ID-PaGIA. To evaluate sensitivity of ID-PaGIA serum samples (n = 101) from patients with confirmed or suspected syphilis were tested for syphilis antibodies with FTA-Abs IgM, ID-PaGIA, ELISA IgM and TPHA tests. RESULTS: No false-positive results were found with ID-PaGIA. Sensitivity of various treponemal tests was the following: FTA-Abs IgM: 95.5%, ID-PaGIA and ELISA IgM: 94%, and TPHA 75%. The positive and negative predictive values of ID-PaGIA were 100 and 89.5%, respectively. CONCLUSIONS: Compared with other treponemal tests ID-PaGIA has excellent sensitivity and specificity.

[The centenary of Wassermann reaction--the future of serological diagnosis of syphilis, up-to-date studies]. / Stulecie odczynu Wassermanna--przyszlosc serologicznej diagnostyki kily w swietle najnowszych badan.

One hundred years after the discovery of the infectious agent of syphilis and implementation of the first serological test for the diagnosis of syphilis, important progress in the evaluation of host immune response against Treponema (T.) pallidum infection has been made. The paper focuses on the new modifications of non-treponemal tests (the use of synthetic cardiolipin and lecithin in Venereal Disease Research Laboratory--VDRL test and the application of the VDRL antigen to immunoenzymatic assays) as well as of treponemal tests. Original treponemal antigens are replaced by recombinant and synthetic antigens (TpN44,5- TmpA, TpN15, TpN17 and TpN47) and by antigens obtained after sequencing of the complete T. pallidum genome (Tp0453, Tp0257 and Tp92) in modifications of immunoenzymatic assays. The new diagnostic strategy, namely the examination of the number of cells producing T. pallidum specific antibodies is also presented. Despite the progress achieved in studies on humoral response in syphilis during last years, the practical application of new tests in diagnosis of the infection requires further studies.

Valoración de un Nuevo Método de Serodiagnóstico para Sífilis (ELISA. IgG)

Se realizó un estudio descriptivo prospectivo en el que se valoró la técnica de ELISA (Captia Syphilis G, Mercia Diagnostic, Guilford, England) para detectar anticuerpos anti-Treponema pallidum de la clase inmunoglobulina G. El antígeno utilizado fue extracto protéico de T. pallidum perteneciente a la cepa Nichols. Para comparar la ELISA Captia Syphilis G se utilizó la técnica de inmunofluorescencia indirecta FTA-Abs. Se evaluaron 100 sueros de pacientes cuya distribución fue: 60 sueros de pacientes enfermos de sifilis, 20 sueros de paciente sanos sin enfermedades de trasmisión sexual conocida, 15 sueros de pacientes con enfermedades del colágeno y 5 sueros de pacientes con tuberculosis. La sensibilidad de ELISA Captia Syphilis G fue del 98.4 por ciento mientras que FTA-Abs fue del 100 por ciento. La especificidad de ELISA Captia Syphilis fue del 100 por ciento y del FTA-Abs del 97.3 por ciento. Esta técnica podría ser incluida en Colombia como prueba confirmatoria para el diagnóstico de sífilis por su alta sensibilidad y especificidad, sumado a la facilidad de su realización, sencillez del procedimiento y economía, que ofrece resultados objetivos y confiables

[Recent progress in syphilis serology]. / Neue Fortschritte der Syphilisserologie.

Serological investigations for the diagnosis of syphilis have been performed in a special subunit at the Department of Dermatology to Lainz Hospital, Vienna, since 70 years. At present 80,000 to 100,000 sera are tested annually. The classical test systems VDRL, TPHA, AMHA-TP and FTA-ABS demonstrate, in particular, the presence of IgG antibodies and are, thus, suitable for the diagnosis of the disease, but do not permit conclusions on the activity of the disease and the actual need for antisyphilitic treatment. The newly developed IgM diagnosis of syphilis with the IgM-SPHA- and the 19S-IgM-FTA-ABS test solve these problems and can be performed even under routine conditions using the methods of solid phase haemadsorption and computerized high pressure liquid chromatography. In addition, the serological diagnosis of neurosyphilis has been worked out by the determination of the TPHA-index and the detection of antitreponemal IgM-antibodies in the cerebrospinal fluid. The relative frequency of latent syphilis infections has increased over the past years and serodiagnosis of syphilis, thus, become more and more important. The availability of five independent test systems has enabled the elaboration of a test profile which keeps the margin of error to below 0.1%. A further method, the ELISA technique is at present under investigation and renders promising results by the use of recently developed reagents.

[Recent developments in the field of syphilis serology (author's transl)]. / Neuere Entwicklungen auf dem Gebiet der Syphilisserologie.

All lipoid antigen tests are outdated except for the VDRL and RPR or RPRC and even these methods will be superseded in the near future. The TPI (Nelson-Mayer) test has been replaced by more reliable assays. The micro-haemagglutination assay with Tr. pallidum antigen (MHA-TP) or its automated version (AMPHA-TP) serve for screening. Reactive results in the AMPHA-TP have to be checked by the FTA-ABS. Reactivity to both tests indicates an infection with Tr. pallidum. The margin of error of this method is as low as 0.04 to 0.45%. The VDRL titre indicates, as yet, the activity of a syphilitic infection and the limit appears to be around 1 : 8. A decrease in the VDRL titre after adequate treatment suggests a successful therapeutic outcome. More reliable methods for assessing the necessity of treatment, as well as the results of therapy and the distinction between relapse and reinfection are provided by the identification of 19S-IgM-antibodies to Tr. pallidum by means of the 19S-IgM-FTA-ABS or the SPHA (SPIT) test. These assays will soon be available as routine procedures and their application will terminate the traditional era of lipoid antigen serology which has lasted for more than 70 years.

Serología de la sífilis adquirida y congénita: su desarrollo histórico y tendencia actual / Serology of acquired and congenital syphilis: is historical development and current trend

Todos los clínicos se muestran interesados en el desarrollo del serodiagnóstico de la sifilis adquirida y congénita, ya que esta enfermedad se encuentra actualmente en un proceso de recrudescencia en la mayoria de las naciones, de acuerdo a los reportes hechos por los Departamentos de Salud Pública de la OMS.Se estudia todo el desarrollo serológico de la sífilis desde el descubrimiento de la reacción de Wassermann (1906), hasta la apararición de las pruebas treponémicas (1949), abarcando las principales reacciones de floculación con antígenos lipoídicos y de cardiolipina (1941). Se orienta que estas pruebas de laboratorio deben ser realizadas por un personal adiestrado técnicamente y con gran capacidad, ya que son más complejas que las realizadas para la determinación de albúmina en la orina. Las pruebas treponémicas son costosas y dificiles técnicamente, por lo que solo se realizan en "Laboratorios de Salud Pública especializados". Son muy útiles para distinguir las reacciones de sífilis, de las llamadas biológicamente falsas positivas. Las reacciones que determinan el anticuerpo reagina (antígenos crudos o cardiolipina) serán las usadas en la práctica diaria, ya que son muy fáciles y se hacen positivas con más rapidez(AU)