Open AccessIn situ indirect fluorescent antibody: A new specific test to detect ongoing chagasic infections
Author(s) -
de Apparecida Levy Antonio Marcos,
Boainain Elias,
Kloetzel Judith Kardos
Publication year - 1996
Publication title -
journal of clinical laboratory analysis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.536
H-Index - 50
eISSN - 1098-2825
pISSN - 0887-8013
DOI - 10.1002/(sici)1098-2825(1996)10:2<98::aid-jcla7>3.0.co;2-h
Subject(s) - immunofluorescence , titer , direct fluorescent antibody , in situ , indirect immunofluorescence , glutaraldehyde , antibody , leishmaniasis , antibody titer , antigen , immunology , medicine , virology , pathology , chemistry , organic chemistry
In situ immunofluorescence assay (ISIFA) was developed for the selection for treatment of chronically infected chagasic patients and their follow‐up. Trypomastigotes flash fixed in situ on microscopic slides with 0.025% glutaraldehyde were used as antigen. ISIFA results were compared with complement‐mediated lysis (CoML), membrane immunofluorescence (MbIFA), immunofluorescence assay (IFA) with epimastigotes, and xenodiagnosis (XENO). ISIFA was able to distinguish nontreated chagasic patients (geometric mean liter [GMT] = 180) and treatment failures (GMT = 160) from those considered successfully treated (GMT = 25). ISIFA revealed a high sensitivity and titers of 80 or higher detected 98.6% of patients with active infections, even in those with negative XENO, CoML, or MbIFA. Specificity evaluated in 63 sera from other infections, including leishmaniasis and autoimmune diseases, was 98%. IFA used in routine diagnostic procedures exhibited similar results in all groups, irrespective of therapy. © 1996 Wiley‐Liss, Inc.