Validity of a new immunochromatographic test in detection of Toxoplasma gondii in cancer patients

Abstract

Screening of toxoplasmosis in cancer patients is mandatory especially before starting treatment to guard against life-threatening disseminated disease. Diagnosis of toxoplasmosis rely mainly on serology. The most widely used method for detection of anti-Toxoplasma gondii (T. gondii) antibodies is the enzyme linked immunosorbent assay (ELISA), being available and reliable. Immunochromatographic tests (ICT) attracted a lot of attention recently being one of the high quality, rapid and easy to perform tests. Available data comparing the performance of ICT versus ELISA techniques have yielded inconsistent results and none compared their performance among the immunocompromised cancer patients. Therefore, we designed this study to compare the performance of a new ICT (the OnSite Toxo IgG/IgM Combo Rapid test) and ELISA techniques for the detection of anti-T. gondii antibody as a tool for screening for toxoplasmosis among cancer patients in Cairo-Egypt. Among 180 cancer patients, a total of 110 patients (61.1%) were positive for anti-T. gondii antibodies by one or both methods. Agreement between both methods was found in 78.8% of the samples. By using ELISA technique as a gold standard test for the detection of anti-T. gondii antibodies, our results showed 87.5% specificity and 74% sensitivity of ICT technique. Moreover, our results proved that ICT is more sensitive in detecting lower level of antibodies than ELISA, that makes it preferable as a screening test for the immunocompromised patients.

Comparison of Elisa and Rapid Immunochromatographic Tests in Diagnosis of Toxoplasmosis in Port Harcourt, Nigeria

“…Kappas test showed that the diagnostic methods significantly detect IgG. Similar ascertains were made in a similar study carried out by other scholars [3,18].…”

“…The sensitivity and specificity of Rapid ICT in the study was 46.7% and 81.7% respectively. This result is slightly at variance with findings from similar studies where sensitivity and specificity were found to be 62.2% and 96.3% [22], 97.2% and 100% [3], 61.5% and 80% [9], 87.5% and 74% [18] respectively in comparing the rapid ICT with ELISA. These studies all ascertained that rapid ICT test demonstrated optimal analytical sensitivity and specificity for Toxoplasma-IgG testing and can be used in detecting T. gondii antibodies especially chronic infections [3,18,22] The low sensitivity value reported in this study may be due to false positive results.…”

Review on the Current Trends of Toxoplasmosis Serodiagnosis in Humans

“…Its ease of application and rapidity of test results with no special equipment required makes the ICT suitable for field application. In toxoplasmosis, this technology has been used to diagnose human (Lévêque et al, 2019;Taha et al, 2019;Wassef and Abdel-Malek, 2019) and animal cases (Khan and Noordin, 2019). ICT has been shown to have a high agreement with ELISA in terms of sensitivity and specificity (Terkawi et al, 2013;Ybañez, Kyan and Nishikawa, 2020).…”

Ocular toxoplasmosis: a review of the current diagnostic and therapeutic approaches

“…Several serological procedures have been extensively used, including Sabin-Feldman dye test (DT), indirect fluorescent antibody test (IFA), direct agglutination test (DAT), differential agglutination test (HS/AC test), latex agglutination and indirect agglutination tests (LAT), immunosorbent agglutination assay (ISAGA), immunochromatographic tests (ICT), enzyme-linked immunosorbent assay (ELISA), IgG avidity test, and Western blot (WB) analysis [ 77 , 91 , 92 ] (Table 2 ). However, they are not all routinely performed by most hospital-based clinical laboratories, because of excessive cost, lack of experienced personnel and sensitivity, specificity, and interpretation deficiencies.…”