False-negative result of serum cryptococcal antigen lateral flow assay in an HIV-infected patient with culture-proven cryptococcaemia

Moara Alves Santa Bárbara Borges; João Alves de Araújo Filho; Renata de Bastos Ascenço Soares; José Ernesto Vidal; Marília Dalva Turchi

doi:10.1016/j.mmcr.2019.10.009

False-negative result of serum cryptococcal antigen lateral flow assay in an HIV-infected patient with culture-proven cryptococcaemia

Med Mycol Case Rep. 2019 Nov 1:26:64-66. doi: 10.1016/j.mmcr.2019.10.009. eCollection 2019 Dec.

Authors

Moara Alves Santa Bárbara Borges¹, João Alves de Araújo Filho^{1

2

3}, Renata de Bastos Ascenço Soares^{2

3}, José Ernesto Vidal^{4

5}, Marília Dalva Turchi^{1

3}

Affiliations

¹ Instituto de Patologia Tropical e Saúde Pública da Universidade Federal de Goiás - R. 235, S/n - Setor Leste Universitário, CEP 74605-450, Goiânia, Goiás, Brazil.
² Pontifícia Universidade Católica de Goiás - R. 235, 15 - Setor Leste Universitário, CEP 74605-050, Goiânia, Goiás, Brazil.
³ Hospital Estadual de Doenças Tropicais Dr. AnuarAuad, Alameda do Contorno, 3556 - Jardim Bela Vista, CEP 74850-400, Goiânia, Goiás, Brazil.
⁴ Instituto de Infectologia Emilio Ribas, Av. Doutor Arnaldo, 165, Pacaembu, CEP 01246-900, São Paulo, São Paulo, Brazil.
⁵ Hospital das Clinicas, Faculdade de Medicina, Universidade de São Paulo, Av. Dr. Enéas de Carvalho Aguiar, 255, Cerqueira César, CEP 05403-000, São Paulo, Brazil.

Abstract

The detection of cryptococcal capsular antigen (CrAg) is very sensitive and specific, however false-negative results have been reported, mostly in cerebrospinal fluid. We report the case of an HIV-infected patient with CD4 = 42 cells/mL, asthenic, negative serum CrAg lateral flow assay (LFA) and culture-proven cryptococcaemia. Despite the high accuracy of LFA, false-negative result is possible. Careful clinical evaluation and close follow-up are relevant.

Keywords: AIDS; Cryptococcosis; False negative reaction; Fungal antigens; Prozone effect.

Publication types

Case Reports