Clinical value of anti-live Leishmania (Viannia) braziliensis immunoglobulin G subclasses, detected by flow cytometry, for diagnosing active localized cutaneous leishmaniasis
To evaluate the clinical value of flow cytometry anti-live promastigate antibody (FC-ALPA), for diagnosing active cutaneous leishmaniasis. method
Serum samples from 145 individuals living in endemic areas for localized cutaneous leishmaniasis (population 1) were classified as having the disease or not and then tested for their IgG reactivity by indirect immunofluorescence assay and FC-ALPA-IgG. The results of FC-ALPA-IgG were expressed as percentage of positive fluorescent parasite. Both tests were also evaluated in serum samples of people with visceral leishmaniasis and Chagas disease (population 1A). results
In population 1, FC-ALPA-IgG performed better than the immunofluorescence assay regarding sensitivity, specificity and predictive values. Analysis of the results according to the likelihood ratios indicated that a percentage of positive fluorescent parasite ≤60 practically excludes the diagnosis of localized cutaneous leishmaniasis (likelihood ratio = 0.07), whereas at >60% it reinforces diagnosis of the disease (likelihood ratio = 7.0). Immunofluorescent assay is of little value (likelihood ratio = 2.04). In population 1A, both tests performed worse, but FC-ALPA-IgG achieved better statistical indexes than immunofluorescent assay. conclusion
The FC-ALPA-IgG is a valuable method for serological diagnosis of localized cutaneous leishmaniasis. FC-ALPA-IgG1/ALPA-IgG2 combined analysis is an additional serological tool for discriminating localized visceral leishmaniasis, Chagas disease and visceral leishmaniasis in areas where these infections co-exist.
Document Type: Research Article
Affiliations: 1: Laboratório de Doença de Chagas, CPqRR-FIOCRUZ/BH, Belo Horizonte, Brazil 2: Laboratório de Leishmanioses, CPqRR-FIOCRUZ/BH, Belo Horizonte, Brazil 3: Laboratório de Imunologia Celular e Molecular, CPqRR-FIOCRUZ/BH, Belo Horizonte, Brazil 4: Faculdade de Medicina, Universidade Federal de Minas Gerais/UFMG, Belo Horizonte, Brazil 5: Laboratório de Imunologia, Universidade Federal de Juiz de Fora/UFRJ, Juiz de Fora, Brazil 6: Departamento de Parasitologia, ICB/UFMG, Belo Horizonte, Brazil
Publication date: February 1, 2006