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Serological diagnosis of paracoccidioidomycosis: high rate of inter-laboratorial variability among medical mycology reference centers.

Authors :
Vidal MS
Del Negro GM
Vicentini AP
Svidzinski TI
Mendes-Giannini MJ
Almeida AM
Martinez R
de Camargo ZP
Taborda CP
Benard G
Source :
PLoS neglected tropical diseases [PLoS Negl Trop Dis] 2014 Sep 11; Vol. 8 (9), pp. e3174. Date of Electronic Publication: 2014 Sep 11 (Print Publication: 2014).
Publication Year :
2014

Abstract

Background: Serological tests have long been established as rapid, simple and inexpensive tools for the diagnosis and follow-up of PCM. However, different protocols and antigen preparations are used and the few attempts to standardize the routine serological methods have not succeeded.<br />Methodology/principal Findings: We compared the performance of six Brazilian reference centers for serological diagnosis of PCM. Each center provided 30 sera of PCM patients, with positive high, intermediate and low titers, which were defined as the "reference" titers. Each center then applied its own antigen preparation and serological routine test, either semiquantitative double immunodifusion or counterimmmunoelectrophoresis, in the 150 sera from the other five centers blindly as regard to the "reference" titers. Titers were transformed into scores: 0 (negative), 1 (healing titers), 2 (active disease, low titers) and 3 (active disease, high titers) according to each center's criteria. Major discordances were considered between scores indicating active disease and scores indicating negative or healing titers; such discordance when associated with proper clinical and other laboratorial data, may correspond to different approaches to the patient's treatment. Surprisingly, all centers exhibited a high rate of "major" discordances with a mean of 31 (20%) discordant scores. Alternatively, when the scores given by one center to their own sera were compared with the scores given to their sera by the remaining five other centers, a high rate of major discordances was also found, with a mean number of 14.8 sera in 30 presenting a discordance with at least one other center. The data also suggest that centers that used CIE and pool of isolates for antigen preparation performed better.<br />Conclusion: There are inconsistencies among the laboratories that are strong enough to result in conflicting information regarding the patients' treatment. Renewed efforts should be promoted to improve standardization of the serological diagnosis of PCM.

Details

Language :
English
ISSN :
1935-2735
Volume :
8
Issue :
9
Database :
MEDLINE
Journal :
PLoS neglected tropical diseases
Publication Type :
Academic Journal
Accession number :
25211336
Full Text :
https://doi.org/10.1371/journal.pntd.0003174