López Trujillo, EmilioGonzàlez Farré, MònicaPujol Vallverdú, Ramon MariaBellosillo Paricio, BeatrizFisa, RoserRiera Carro, CristinaAlcover, MagdalenaBarranco Sanz, Luis CarlosMartin-Ezquerra, Gemma2021-06-172021-06-172021Lopez-Trujillo E, Gonzàlez-Farré M, Pujol RM, Bellosillo B, Fisa R, Riera C, et al. Diagnostic usefulness of immunohistochemical evaluation of CD1a antigen and polyclonal anti-leishmania antibodies in cutaneous leishmaniasis. Histol Histopathol. 2021 May;36(5):567-76. DOI: 10.14670/HH-18-3240213-3911http://hdl.handle.net/10230/47913Background: Different immunohistochemical markers to detect amastigotes in cutaneous leishmaniasis have been proposed with variable diagnostic usefulness. Objectives: To evaluate the diagnostic usefulness of immunohistochemical amastigotes identification by specific polyclonal anti-Leishmania antibodies and CD1a expression (clone EP3622) in a series of PCR confirmed cutaneous leishmaniasis. Materials and methods: Thirty-three skin samples corresponding to PCR confirmed cutaneous leishmaniasis were included in the study. All samples were stained with Hematoxylin-eosin and Giemsa. Moreover, immunohistochemical studies with anti-CD1a and anti-Leishmania antibodies were performed. The patients clinical features and the observed histopathological features were also recorded. Results: From the selected 33 biopsies, Leishmania spp. amastigotes were detected in 48.4% of cases with conventional Hematoxylin-eosin stain and in 57.5% of cases by Giemsa staining. In 31/33 cases, anti-CD1a allowed us to identify parasitic structures, and in 33/33 cases amastigotes were detected with anti-Leishmania antibodies. Concordance between both techniques, anti-CD1a and anti-Leishmania, was 94% [CI 95%: (79,8%-99,3%)] ; p value <0.05. The sensitivity of anti-CD1a in comparison with the PCR was 94%, with a positive predictive value of 100%. Two cases of low parasitic index were negative for CD1a immunostaining. In cases with high parasitic index, anti-CD1a stained amastigotes in superficial and deep dermis. Only a few cases were originally diagnosed with the available histological techniques, needing PCR for Leishmania spp. Conclusions: Anti-CD1a antibody seems to be a useful technique to identify amastigotes when PCR and anti-Leishmania antibodies are not available. The sensitivity to detect amastigotes is increased when the CD1a immunostaining is added to the classical Haematoxylin - eosin and Giemsa staining.application/pdfeng© The Author(s) 2021. Open Access. This article is licensed under a Creative Commons CC-BY International License (https://creativecommons.org/licenses/by/4.0/).info:eu-repo/semantics/articlehttp://dx.doi.org/10.14670/HH-18-324info:eu-repo/semantics/openAccess