Development of a LAMP method with lateral flow DNA chromatography to diagnose toxoplasmosis in immunocompromised patients

• Published in: Tropical Medicine and Health
• Main Authors: Kei Mikita, Takehiko Mori, Tamayo Komine, Seiki Kobayashi, Satoshi Iwata, Koichi Suzuki, Naoki Hasegawa
• Format: Article in Journal/Newspaper
• Language: English
• Published: BMC 2024
• Subjects: Loop-mediated isothermal amplification; DNA chromatography; Toxoplasmosis; Toxoplasma encephalitis; Toxoplasma gondii; Arctic medicine. Tropical medicine; RC955-962; Arctic
• Online Access: https://doi.org/10.1186/s41182-024-00613-4; https://doaj.org/article/b9271896b1604071806f8c5a1c1efdb9

Abstract Background Rapid and accurate diagnosis of toxoplasmosis is critical, particularly for immunocompromised patients. Several molecular methods could have value for toxoplasmosis diagnosis, but often require sophisticated and expensive equipment, and as such are impractical for use in resource-limited countries. Our study aimed to develop a new rapid diagnostic test for toxoplasmosis that can be used in developed countries as well as low- or middle-income countries. Methods Common primers for conventional loop-mediated isothermal amplification (LAMP) and the new LAMP DNA chromatography method were designed based on a 529-bp repeat present in Toxoplasma gondii genomic DNA. A total of 91 clinical samples from 44 patients suspected of having toxoplasmosis who were treated at several hospitals across Japan were tested using the new LAMP DNA chromatography method, conventional LAMP, and nested PCR and the sensitivity and specificity of the methods was compared. Results The LAMP DNA chromatography method showed better sensitivity and specificity (68.2% and 100%, respectively) compared with the nested PCR (45.4% and 100%, respectively) and conventional LAMP (63.6% and 100%, respectively) methods for diagnosis of toxoplasmosis in immunocompromised patients. LAMP DNA chromatography also has better sensitivity and specificity (75% and 100%, respectively) than nested PCR (50.0% and 93.5%, respectively) and conventional LAMP (62.5% and 100%, respectively) to diagnose toxoplasma encephalitis using CSF samples. Conclusion We developed a LAMP DNA chromatography method to detect T. gondii DNA in clinical samples. This method also successfully detected T. gondii DNA in CSF from patients with toxoplasma encephalitis. This newly developed method can be a valuable rapid diagnostic test for toxoplasmosis in a range of settings, including resource-limited areas like those in low- or middle-income countries.