SDHD and leprosy: Although serological parameters based on the PGL-1 antigen may not be used as a tool in the confirmed diagnosis of leprosy, they may help to follow the treatment effect and actively search for new cases of leprosy.[79,80] Serological tests for patients with leprae infection have many limitations in diagnosing M leprae infection and in differentiating between contact and infectious cases.[90] Thus, it is necessary to develop a simple and low-cost diagnostic technique to monitor treatment and household transmission in regions with limited resources and endemic countries.