title: Evaluation of a rapid serological test for leprosy classification using human serum albumin as the antigen carrier.
abstract: The presence of anti-BSA antibodies may interfere in serological tests, as ELISA or immunochromatographic assays. BSA is frequently used as a blocking agent or as "inert" carrier of antigens, such as the NT-P-BSA, the semi-synthetic trisaccharide analogue of the PGL-I (phenolic glycolipid-I) antigen from the cell wall of the Mycobacterium leprae. PGL-I was prepared and linked to human serum albumin based in the hypothesis that replacing BSA by a human protein carrier would enhance the performance of leprosy serological tests. A total of 1162 serum samples were tested by ELISA and by the ML Flow rapid test using NT-P-BSA or NT-P-HSA antigens. When grouping leprosy patients as paucibacillary (PB) or multibacillary (MB) according to the Ridley & Jopling classification, ML Flow BSA and ML Flow HSA tests correctly allocated 70.9% and 68.6% of patients in the PB group, and 87% and 81% of patients in the MB group, respectively. Concordant results were found in 82.0% (953/1162) (kappa value=0.637; sd=0.023) of samples between ML Flow tests and 85.7% (996/1162) (kappa value=0.703; sd=0.021) between ELISA tests. ML Flow results were statistically similar and the same was true for ELISA tests using HSA or BSA. However, we noticed a tendency to decreased capacity to detect MB patients and an increased positivity among PB patients, HHC, TB patients and healthy controls by the HSA carrier in both ML Flow and ELISA. The PGL-I serology performed by the ML Flow test with BSA or HSA as antigen carriers can be a useful, friendly auxiliary tool to identify patients with higher bacterial load.
authors.affiliation: Instituto de Patologia Tropical e Saúde Pública, Universidade Federal de Goiás, Goiânia, GO, Brazil.
authors.forename: Rodrigo Scaliante
authors.initials: RS
authors.lastname: Moura
authors.affiliation: Núcleo de Medicina Tropical, Universidade de Brasília, Brasília, DF, Brazil.
authors.forename: Gerson Oliveira
authors.initials: GO
authors.lastname: Penna
authors.affiliation: Institute for Natural Science Nara University, Nara, Japan.
authors.forename: Tsuyoshi
authors.initials: T
authors.lastname: Fujiwara
authors.affiliation: Centro de Dermatologia Dona Libânia, Fortaleza CE, Brazil.
authors.forename: Maria Araci de Andrade
authors.initials: MA
authors.lastname: Pontes
authors.affiliation: Fundação de Dermatologia Tropical e Venereologia Alfredo da Matta, Manaus, AM, Brazil.
authors.forename: Rossilene
authors.initials: R
authors.lastname: Cruz
authors.affiliation: Centro de Dermatologia Dona Libânia, Fortaleza CE, Brazil.
authors.forename: Heitor de Sá
authors.initials: Hde S
authors.lastname: Gonçalves
authors.affiliation: Departamento de Epidemiologia e Bioestatística, Universidade Federal Fluminense, Rio de Janeiro, RJ, Brazil.
authors.forename: Maria Lúcia Fernandes
authors.initials: ML
authors.lastname: Penna
authors.affiliation: Instituto de Patologia Tropical e Saúde Pública, Universidade Federal de Goiás, Goiânia, GO, Brazil.
authors.forename: Ludimila Paula Vaz
authors.initials: LP
authors.lastname: Cardoso
authors.affiliation: Instituto de Patologia Tropical e Saúde Pública, Universidade Federal de Goiás, Goiânia, GO, Brazil.
authors.forename: Mariane Martins de Araújo
authors.initials: MM
authors.lastname: Stefani
authors.affiliation: Instituto de Patologia Tropical e Saúde Pública, Universidade Federal de Goiás, Goiânia, GO, Brazil. Electronic address: samira.buhrer@gmail.com.
authors.forename: Samira
authors.initials: S
authors.lastname: Bührer-Sékula
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000818:Animals; D000907:Antibodies, Bacterial / Q000097:blood; D000942:Antigens, Bacterial / Q000378:metabolism*; D058491:Bacterial Load; D002417:Cattle; D002648:Child; D002846:Chromatography, Affinity; D004797:Enzyme-Linked Immunosorbent Assay; D005189:False Positive Reactions; D005260:Female; D006017:Glycolipids / Q000138:chemical synthesis / Q000378:metabolism*; D006801:Humans; D007075:Immunoglobulin M / Q000378:metabolism; D007918:Leprosy / Q000145:classification* / Q000175:diagnosis*; D008297:Male; D008875:Middle Aged; D009166:Mycobacterium leprae / Q000276:immunology / Q000378:metabolism*; D012698:Serologic Tests / Q000379:methods*; D012709:Serum Albumin / Q000138:chemical synthesis / Q000378:metabolism; D012710:Serum Albumin, Bovine / Q000138:chemical synthesis / Q000378:metabolism; D055815:Young Adult
chemical_list: D000907:Antibodies, Bacterial; D000942:Antigens, Bacterial; D006017:Glycolipids; D007075:Immunoglobulin M; D012709:Serum Albumin; C045169:phenolic glycolipid I, Mycobacterium leprae; D012710:Serum Albumin, Bovine
keywords: BSA; Leprosy; Serology