02533nas a2200193   4500000000100000008004100001653001300042653001700055653001200072653001400084100001400098700001300112700001600125700001500141700001500156245011000171520204400281022001402325       2016                            d10aSerology10aMycobacteria10aleprosy10adiagnosis1 aBalagon M1 aDuthie M1 aMaghanoy AA1 aOrcullo FM1 aAbbelana J00aComparative evaluation of antibody detection tests to facilitate the diagnosis of multibacillary leprosy.3 a<p>Despite control efforts, leprosy persists as a significant health concern in many regions. Diagnosis is achieved by a combination of clinical, histopathological, and bacteriological examinations, each of which presents a barrier to expeditious diagnosis, particularly by non-experts. Immunological investigations in research laboratories have clearly indicated that antibody detection tests could aid the diagnosis of leprosy. In this study, we detected circulating antibodies with two rapid diagnostic tests (RDT) involving immunochromatographic lateral flow platforms and one rapid ELISA system. Leprosy patients were identified with a high degree of sensitivity in each assay (over 80&nbsp;% in all; over 90&nbsp;% among cases with bacterial indices &gt;1+), although critical differences were observed in specificity. While the specificity of CTK OnSite Leprosy Ab Rapid Test and InBios Leprosy Detect™ fast ELISA were high (96.4 and 93.7&nbsp;% in the general population, respectively), there was a marked reduction in OrangeLife NDO-LID® RDT (only 25.0&nbsp;%). As anticipated, seropositivity rates were marginally higher in contacts of leprosy patients than in endemic controls. Although we observed a slight drop in test band intensity when blood, rather than serum, was used to develop OnSite Leprosy Ab Rapid Tests, the sensitivity and specificity of these tests was unaffected. When we contrasted test performance with clinical and bacteriological information, we found that RDT and ELISA results positively correlated with the bacteriological index. These data indicate that these assays could be a ready replacement of invasive, insensitive, and time consuming skin slit smear procedures that additionally require expert microscopic examinations. We propose that, due to their speed and point of care applicability, the RDT could be used as an initial entry point to the diagnostic protocols, with confirmation of results attained in a highly quantitative manner following serum transfer to a reference laboratory.</p>
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