Evaluating CD1a Immunohistochemistry for Tegumentary Leishmaniasis
Diagnosis in the New World: A Focus on Colombia.
Abstract
Introduction: Leishmaniasis, a chronic vector-borne disease
caused by parasites of the genus Leishmania, presents diagnostic
challenges. Conventional diagnostic methods struggle with accurate
visualization of these parasites. Immunostaining with CD1a has
demonstrated effectiveness in visualizing Leishmania parasites,
particularly in the Old World. However, the application of CD1a
immunostaining in Colombian leishmaniasis remains unexplored.
Objective: To determine the utility of CD1a as an immunomarker
in detecting chronic forms of tegumentary leishmaniasis.
Materials and methods: This proof-of-concept study involved 48
paraffin-embedded samples categorized into three groups:
moderate-to-high parasite load (n=15), low load (n=15), and chronic
granulomatous inflammation (n=13); five samples diagnosed with cutaneous
histoplasmosis. These samples were stained with the immunomarker CD1a
clone EP3622 for comparative analysis. Additionally, CD1a
immunohistochemistry was compared with 18S rDNA qPCR and
hematoxylin-eosin staining to evaluate its performance in relation to
these established methods. Results: CD1a Immunohistochemistry
was positive in 46.51% of the samples evaluated. This immunomarker
showed lower sensitivity and negative predictive value than 18S rDNA
qPCR and hematoxylin-eosin staining; specificity and negative predictive
value were consistent. ROC indicated inferior discrimination for
leishmaniasis compared to 18s rDNA qPCR and hematoxylin-eosin staining.
Conclusions: Immunohistochemistry for CD1a could be a
diagnostic support in the detection of chronic forms of tegumentary
leishmaniasis.