False-negative fluorescent treponemal tests and confirmation of syphilis infection

Using the Line Blot Syphilis test system for diagnosingsyphilis by the linear immunoblotting method

ZAO ECOlab (Russia) developed Line Blot Syphilis, a new test system on the basis of the linear immunoblotting method using Treponema рallidum recombinant antigens. The article assessed the diagnostic value of the Line Blot Syphilis test system in the form of a confirmatory test. As a part of the conducted study, the test system demonstrated its absolute sensitivity and specificity to serum-positive (n = 237) and serum-negative (n = 114) samples, in which the presence or absence of Т.pallidum antibodies was confirmed by two treponemal tests. As a result of examining 14 samples attributed to doubtful analytes based on two test results (passive hemagglutination test and immunofluorescence test with absorption), the data compliance between the Line Blot Syphilis test system and data from INNO-LIA Syphilis Score amounted to 100% (14/14) or 93% (13/14) for the immune-enzyme assay and 57% (8/14) for the immunofluorescence test with absorption. It is recommended to use the Line Blot Syphilis test system (ZAO ECOlab) as a confirmatory syphilis test.

Syphilis and HIV Infection: an Update

Although once on decline in the United States and Europe, the incidence of syphilis has been on the rise since 2000. This increase is noteworthy because there is a high coinfection rate with HIV, especially among men who have sex with men. In light of high coinfection rates, all HIV-infected patients should be tested for syphilis and vice versa. HIV can alter the clinical manifestations of syphilis and, in turn, syphilis has the potential to change the course and transmission of HIV. This article addresses variations in clinical presentation, diagnosis, and management of individuals coinfected with HIV and syphilis.

Comparison of a recombinant-antigen enzyme immunoassay with Treponema pallidum hemagglutination test for serological confirmation of syphilis

A recombinant-antigen enzyme immunoassay (EIA), BioSCREEN anti-Treponema pallidum, was compared favorably with the T. pallidum hemagglutination test, in the detection of specific antibodies in different groups of sera from patients with primary (n = 38), secondary (n = 10), early latent (n = 28) and congenital syphilis (n = 2), patients with leptospirosis ( n= 8), infectious mononucleosis (n = 7), hepatitis (n = 9), diabetes mellitus (n = 11), rheumatoid arthritis (n = 13), leprosy (n = 11), tuberculosis (n = 9), HIV/Aids ( n= 12), systemic lupus erythematosus (n = 4), rheumatic fever (n = 3), old-persons (n = 9), pregnant women (n = 29) and blood donors (n = 164). The coincidence between them was 95.1%. The sensitivity and specificity of the EIA were 93.3% and 95.5%, respectively. Fifteen serum specimens belonging to old-persons, pregnant women, blood donors, and patients with human leptospirosis, hepatitis, diabetes mellitus, tuberculosis and rheumatic fever gave false-positive results by Venereal Disease Research Laboratory and/or Rapid Plasma Reagin. The EIA can be used as alternative method for the serological confirmation of syphilis.

The Interaction Between HIV and the Classic Sexually Transmitted Diseases

Because HIV is sexually transmitted, HIV infection is common in populations with high prevalences of other sexually transmitted diseases (STDs). This epidemiologic coprevalence provides an opportunity for bidirectional influences. The presence of some other STDs increases the transmissibility of HIV and may, in some circumstances, actually affect the course of HIV disease through the stimulation of susceptible cell types. The presence of HIV increases susceptibility to some STDs and modifies the presentation, course, rate of complications, and response to therapy of some of these classic infections. Recent studies and reviews have further defined these interactions but have provided no startlingly new approaches.

Validation of the INNO-LIA syphilis kit as a confirmatory assay for Treponema pallidum antibodies

The commercially available diagnostic tests for syphilis are mostly based on the use of extracted antigens of Treponema pallidum. Pronounced cross-reactivities with other spirochete antigens are often reported. The aim of this study was to validate a novel multiparametric assay (the assay performed with the kit) INNO-LIA Syphilis for the confirmation of syphilis antibodies in a set of 840 documented human serum samples. All serum samples were previously tested at the French World Health Organization reference center for venereal diseases (Institute Alfred Fournier, Paris, France), with a consensus result provided for each sample. The study was conducted in two phases, with each phase involving a validation set (500 well-documented serum samples) and an exploratory set (340 serum samples) of serum samples, respectively. By measuring the sensitivity and specificity, we compared the result of the new assay with the consensus result on the basis of the results of a variable number of classical serological methods and clinical information when available. A sensitivity of 99.6% (95% confidence internal [CI], 98.5 to 99.9%) and a specificity of 99.5% (95% CI, 98.1 to 99.9%) were found for the new line immunoassay. Six of seven samples with indeterminate results by classical serology tested positive with the INNO-LIA Syphilis kit. This single multiparametric assay provides reliable confirmatory diagnostic information that must currently be obtained by the performance and interpretation of results of a combination of serological assays.