Efforts in blood safety: Integrated approach for serological diagnosis of syphilis

Abstract

Recent efforts in transfusion medicine are focused on improving blood safety as well as establishing effective and efficient diagnostic algorithms for donor screening. To date, syphilis is a transfusion-transmitted infection re-emerged in many countries as a public health threat especially among populations at specific risk. This task requires new diagnostic tools and hemovigilance programs. The current diagnostic methodologies are debated, since presenting limitations and unresolved issues with special regard to the clinical interpretation of serological patterns, especially in asymptomatic patients and in blood donors. Furthermore, the switch from the traditional to alternative diagnostic algorithms underlines the lack of a gold standard, which has not been supported by shared guidelines. Besides, a lot of ongoing clinical trials on the performance of diagnostic assays, on the serological response associated with different pharmacological treatments, as well as on the prevention programs are currently under investigation. Here, we review the recent literature about the diagnosis of syphilis especially for low-risk populations proposing the adoption of an algorithm for blood donor screening that should satisfy the need of increasing safety for transfusion-transmitted infections in the modern blood transfusion centers.

The evaluation of the reverse algorithm for syphilis screening in blood donors

“…The blood samples of the three individuals were retested one month after the first evaluation, and the TPHA titers were observed to double, but the VDRL test was still negative ( Table 3). The three blood donors with repeated samples and test results were referred to the infectious diseas- (1,(3)(4)(5)(6). Nontreponemal VDRL and RPR tests produce false negative results in 30% to 50% syphilis cases in the primary stage (1,(3)(4)(5).…”

“…The three blood donors with repeated samples and test results were referred to the infectious diseas- (1,(3)(4)(5)(6). Nontreponemal VDRL and RPR tests produce false negative results in 30% to 50% syphilis cases in the primary stage (1,(3)(4)(5). Studies have shown that the reverse algorithm is highly specific in screening low-risk populations, such as blood donors (1,4).…”

“…Nontreponemal VDRL and RPR tests produce false negative results in 30% to 50% syphilis cases in the primary stage (1,(3)(4)(5). Studies have shown that the reverse algorithm is highly specific in screening low-risk populations, such as blood donors (1,4). Beginning the screening process with a treponemal test can help detect infection at the same time as or slightly earlier than nonspecific antibody tests (1)(2)(3)(4).…”

“…For the screening of syphilis (Treponema pallidum), methods that can detect the presence of nonspecific antibodies or specific treponemal antibodies are used. The techniques commonly used for syphilis screening include the Venereal Disease Research Laboratory (VDRL) test that employs a nonspecific antigen containing lecithin and cardiolipin; the highly sensitive and specific T. pallidum hemagglutination (TPHA) test involving the use of rapid plasma reagin (RPR) and/or treponemal antibodies; the T. pallidum particle agglutination test (TPPA); and the enzyme immunoassay (EIA) test (1,(3)(4)(5)(6). Recent studies on transfusion medicine focused on the creation of effective diagnostic algorithms for the screening of blood donors (1,4,5).…”

“…The techniques commonly used for syphilis screening include the Venereal Disease Research Laboratory (VDRL) test that employs a nonspecific antigen containing lecithin and cardiolipin; the highly sensitive and specific T. pallidum hemagglutination (TPHA) test involving the use of rapid plasma reagin (RPR) and/or treponemal antibodies; the T. pallidum particle agglutination test (TPPA); and the enzyme immunoassay (EIA) test (1,(3)(4)(5)(6). Recent studies on transfusion medicine focused on the creation of effective diagnostic algorithms for the screening of blood donors (1,4,5). This study was conducted to evaluate the results of the chemiluminescence immunoassay (CLIA) method based on a reverse algorithm, which is more sensitive and specific than currently used traditional algorithm and VDRL test for syphilis screening.…”