title: Identifying Leprosy and Those at Risk of Developing Leprosy by Detection of Antibodies against LID-1 and LID-NDO.
abstract: Leprosy is caused by Mycobacterium leprae infection and remains a major public health problem in many areas of the world. Challenges to its timely diagnosis result in delay in treatment, which is usually associated with severe disability. Although phenolic glycolipid (PGL)-I has been reported as auxiliary diagnostic tool, currently there is no serological assay routinely used in leprosy diagnosis. The aim of this study was to evaluate the effectiveness of two related reagents, LID-1 and LID-NDO, for the detection of M. leprae infection. Sera from 98 leprosy patients, 365 household contacts (HHC) and 98 endemic controls from Rio Grande do Norte, Brazil, were evaluated. A subgroup of the HHC living in a hyperendemic area was followed for 7-10 years. Antigen-specific antibody responses were highest in multibacillary (MB) at the lepromatous pole (LL/BL) and lowest in paucibacillary (PB) at the tuberculoid pole (TT/BT). A positive correlation for both anti-LID-1 and anti-LID-NDO antibodies was found with bacterial burden (LID-1, r = 0.84, p<0.001; LID-NDO, r = 0.82, p<0.001), with higher sensitivity than bacilloscopy. According to Receiver Operating Curve, LID-1 and LID-NDO performed similarly. The sensitivity for MB cases was 89% for LID-1 and 95% for LID-NDO; the specificity was 96% for LID-1 and 88% for LID-NDO. Of the 332 HHC that were followed, 12 (3.6%) were diagnosed with leprosy in a median time of 31 (3-79) months after recruitment. A linear generalized model using LID-1 or LID-NDO as a predictor estimated that 8.3% and 10.4% of the HHC would become a leprosy case, respectively. Together, our findings support a role for the LID-1 and LID-NDO antigens in diagnosing MB leprosy and identifying people at greater risk of developing clinical disease. These assays have the potential to improve the diagnostic capacity at local health centers and aid development of strategies for the eventual control and elimination of leprosy from endemic areas.
authors.affiliation: Department of Biochemistry, Bioscience Center, and Institute of Tropical Medicine of Rio Grande do Norte, Universidade Federal do Rio Grande do Norte, Natal, Rio Grande do Norte, Brazil.
authors.forename: Francianne M
authors.initials: FM
authors.lastname: Amorim
authors.affiliation: Department of Biochemistry, Bioscience Center, and Institute of Tropical Medicine of Rio Grande do Norte, Universidade Federal do Rio Grande do Norte, Natal, Rio Grande do Norte, Brazil.|Post-graduate Program in Tropical Medicine, Instituto Oswaldo Cruz, Fiocruz, Rio de Janeiro, Brazil.|Hospital Giselda Trigueiro, Rio Grande do Norte Health Secretariat, Natal, Rio Grande do Norte, Brazil.
authors.forename: Maurício L
authors.initials: ML
authors.lastname: Nobre
authors.affiliation: Department of Biochemistry, Bioscience Center, and Institute of Tropical Medicine of Rio Grande do Norte, Universidade Federal do Rio Grande do Norte, Natal, Rio Grande do Norte, Brazil.
authors.forename: Leonardo C
authors.initials: LC
authors.lastname: Ferreira
authors.affiliation: Department of Biochemistry, Bioscience Center, and Institute of Tropical Medicine of Rio Grande do Norte, Universidade Federal do Rio Grande do Norte, Natal, Rio Grande do Norte, Brazil.
authors.forename: Larissa S
authors.initials: LS
authors.lastname: Nascimento
authors.affiliation: Department of Biochemistry, Bioscience Center, and Institute of Tropical Medicine of Rio Grande do Norte, Universidade Federal do Rio Grande do Norte, Natal, Rio Grande do Norte, Brazil.
authors.forename: Alesson M
authors.initials: AM
authors.lastname: Miranda
authors.affiliation: Department of Biochemistry, Bioscience Center, and Institute of Tropical Medicine of Rio Grande do Norte, Universidade Federal do Rio Grande do Norte, Natal, Rio Grande do Norte, Brazil.
authors.forename: Glória R G
authors.initials: GR
authors.lastname: Monteiro
authors.affiliation: Center for Global Health, Weill Cornell Medical College, New York, New York, United States of America.
authors.forename: Kathryn M
authors.initials: KM
authors.lastname: Dupnik
authors.affiliation: Infectious Disease Research Institute, Seattle, Washington, United States of America.
authors.forename: Malcolm S
authors.initials: MS
authors.lastname: Duthie
authors.affiliation: Infectious Disease Research Institute, Seattle, Washington, United States of America.
authors.forename: Steven G
authors.initials: SG
authors.lastname: Reed
authors.affiliation: Department of Biochemistry, Bioscience Center, and Institute of Tropical Medicine of Rio Grande do Norte, Universidade Federal do Rio Grande do Norte, Natal, Rio Grande do Norte, Brazil.|Instituto Nacional de Ciência e Tecnologia de Doenças Tropicais (INCT-DT), Salvador, Bahia, Brazil.
authors.forename: Selma M B
authors.initials: SM
authors.lastname: Jeronimo