Evaluation of Novel Tools to Facilitate the Detection and Characterization of Leprosy Patients in China

Abstract

Leprosy is the disabling outcome of chronic infection with Mycobacterium leprae. The disease often evades early detection, particularly now that fewer clinicians are able to confidently diagnose the disease following the integration of leprosy control measures within general health services in many countries. Although leprosy is officially eliminated in China, endemic regions remain in some difficult-to-reach, underdeveloped areas in Southwest China. In order to better understand the extent of M. leprae infection and identify new leprosy cases in a timely manner, simple tools that can detect infection and the early disease are required. In this report we evaluated the performance of antigen-specific ELISA, the NDO-LID rapid diagnostic test, and antigen-specific whole blood assays (WBA) as potential diagnostic tools. Our data support the use of antibody detection tests and WBA to facilitate the diagnosis of multibacillary and paucibacillary leprosy, respectively. These tools could be invaluable for increased, but simplified, monitoring of individuals in order to provide referrals for clinical exam and early leprosy diagnosis.

Specific antigen serologic tests in leprosy: implications for epidemiological surveillance of leprosy cases and household contacts

“…Only the differences in the proportions of NDOHSA versus LID-1 seropositivity and NDOLID versus LID-1 seropositivity among household contacts were significant. Similar results were observed in a study developed in China, in which the proportion of seropositivity to natural disaccharide linked to bovine serum albumin via octyl (NDOBSA) among contacts was higher than the proportion reported for NDOLID ( Wen et al 2014 ). However, the percentage of reactivity observed for NDOLID did not reflect the expected reactivity to NDOHSA and LID-1 ( Duthie et al 2014a ).…”

“…In the group of PB cases, the proportion of seropositivity for NDOHSA (18.5%) was higher than those observed in studies with native or synthetic PGL-I ( Araújo et al 2012 , Hungria et al 2012 , Freitas et al 2015 ). However, these proportions were lower than those observed in other studies with native or synthetic PGL-I ( Duthie et al 2007 , Lobato et al 2011 , Wen et al 2014 , Fabri et al 2015 , Freitas et al 2015 ) The anti-LID-1 (3.7%) and anti-NDOLID (14.8%) seropositivity rates were also lower than described in the literature for LID-1 ( Duthie et al 2007 , Wen et al 2014 , Fabri et al 2015 , Freitas et al 2015 ) and NDOLID ( Wen et al 2014 , Fabri et al 2015 ).…”

“…The proportions of seropositivity observed for the three antigens in the group of MB cases (59.1% for NDOHSA; 58.2% for LID-1 and 60.0% for NDOLID) were lower than have been described in other studies for native or synthetic PGL-I ( Duthie et al 2007 , Lobato et al 2011 , Araújo et al 2012 , Hungria et al 2012 , Wen et al 2014 , Fabri et al 2015 , Freitas et al 2015 ), LID-1 ( Duthie et al 2007 , Wen et al 2014 , Fabri et al 2015 , Freitas et al 2015 ) and NDOLID ( Wen et al 2014 , Fabri et al 2015 ).…”

Evaluation of antigen-specific immune responses for leprosy diagnosis in a hyperendemic area in China

“…Antigen-specific antibody detection by NDO-LID was performed as previously described[ 15 ]. Serum antibodies were measured by the NDO-LID rapid diagnostic test (RDT; procured from Orange Life, Rio de Janeiro, Brazil).…”

“…Optical density (OD) values were determined with an ELISA plate reader (Asys Expert Plus-Microplate Reader UK) at 450 nm. The cut off for ELISA positivity was calculated from an OD value of 0.2, as described previously[ 15 ].…”