Open AccessSerum anti‐phenolic glycolipid—1 IgA correlates to IgM isotype in leprosy patients: a possible candidate for seroepidemiological surveys?
Author(s) -
Macedo Alexandre C.,
Guimarães Juliana A.,
Rodrigues Raphael O.,
Araújo Thiago D. V.,
Tavares Clodis M.,
Cabral Paula B.,
MoraesPinto Maria Isabel,
NagaoDias Aparecida T.
Publication year - 2018
Publication title -
journal of clinical laboratory analysis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.536
H-Index - 50
eISSN - 1098-2825
pISSN - 0887-8013
DOI - 10.1002/jcla.22276
Subject(s) - isotype , serology , immunology , leprosy , glycolipid , immunoglobulin m , medicine , antibody , nephelometry , confidence interval , gastroenterology , immunoglobulin g , monoclonal antibody
Objective The aim of this study was to compare serum anti‐phenolic glycolipid‐1 IgA, IgG, and IgM levels in leprosy patients and controls. Method Analysis of anti‐ PGL ‐1 IgA, IgG, or IgM in serum samples from multibacillary ( MB , n=32) and paucibacillary ( PB , n=22) leprosy patients, and in non‐endemic controls (n=17), using an indirect enzyme‐linked immunosorbent assay. Results A strong correlation between serum IgM and IgA isotypes was found ( r =.745, P <.0001) in MB patients. A moderate correlation was found in all analyses in PB patients. A moderate agreement was found between anti‐ PGL 1 IgA and IgM tests. Based on the ROC curves, the cut‐off values were selected and the parameters of validation were calculated. Considering the clinical forms altogether, the diagnostic sensitivities were 50.0% for IgA, 22.2% for IgG, and 74.1% for IgM. The positive ( VPP ) and negative ( VPN ) predictive values were estimated for each isotype. For IgA, the VPP and VPN were, respectively, 100.0% (87.0%‐100.0%; 95% confidence interval) and 38.7% (24.4%‐54.5%); for IgG, 100% (87.0%‐100.0%) and 28.8% (17.8%‐42.1%), respectively; and for IgM, 95.2% (83.8%‐99.4%) and 51.7% (32.5%‐70.6%), respectively. Conclusion Despite the limiting factors, anti‐ PGL 1 IgA correlates to IgM levels and it could be considered as a possible laboratorial tool to be also used, for instance, in serological follow‐up studies.