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Memórias do Instituto Oswaldo Cruz
Fundação Oswaldo Cruz, Fiocruz
ISSN: 1678-8060 EISSN: 1678-8060
Vol. 90, Num. 4, 1995, pp. 513
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Mem Inst Oswaldo Cruz, Rio de Janeiro, Vol.
90(4): 513 Jul/Aug. 1995
Detection of Anti-Schistosoma Antibodies in Oral
Fluids
Maria Monica de Aguiar Garcia+, Marcia Nogueira Amorim,
Luciana de GouvEa Viana, Teresa Cristina de Melo Garcia,
Naftale Katz, Ana Lucia Teles Rabello
Laboratorio de Esquistossomose, Centro de Pesquisas Rene
Rachou-FIOCRUZ, Av. Augusto de Lima 1715, 30190-002 Belo
Horizonte, MG, Brasil
Code Number: OC95101
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Key words: Schistosoma mansoni - oral fluids -
antibodies
The use of saliva and oral transudate samples has been
suggested as a non-invasive alternative for detection of
antibodies to a variety of viral agents including hepatitis A,
B and C virus, rubella virus, HIV antigens (JV Parry et
al. 1987 Lancet 2: 72-75, T Thieme et al. 1992 J
Clin Microbiol 30: 1076-1079, H Tamashiro, NT Constantine 1994
Bull WHO 72: 135-143).
In this preliminary study, saliva and oral transudate from 14
patients with chronic schistosomiasis and 6 negative
individuals were simultaneously tested for the presence of IgG
and IgA antibodies against soluble S. mansoni egg
antigen (SEA) by ELISA (MN Lunde et al. 1979 Am J Trop
Med Hyg 28: 87-91). Serum from these groups was tested for the
presence of IgG antibodies against SEA by ELISA.
Eggs of S. mansoni in feces were detected by Kato/Katz
method with one stool examination (N Katz et al. 1972
Rev Inst Med Trop S Paulo 14: 297-340). Fourteen patients (age
range 13-19 years, geometric mean number of S. mansoni
eggs = 488.14, range 12-2232) were studied. Six individuals
(age range 27-62 years) who have never lived in an endemic
area and who had had three negative stool examination, formed
the control group.
Saliva from both groups was obtained with SDS Omni-Sal, Saliva
Diagnostics Systems, Vancouver, WA, USA. The fluid content of
the pad is expelled by using a separator. The supernatant,
which represents a 1:2 dilution, is then used directly for
testing.
For the collection of the oral transudate from both groups,
the collect device Ora Sure®, Epitope Inc., Beaverton, OR, USA
was used. The fluid content of the pad is expelled by
refrigerated centrifugation and tested without further
dilution.
Blood samples were taken by venopuncture. The serum, saliva
and oral transudate obtained were stored at -20 C until
use.
ELISA - Polystyrene plates (Nunc Immunoplate Maxshorp® - Nunc
Denmark) were coated with SEA and blocked according to ALT
Rabello et al. (1992 Mem Inst Oswaldo Cruz 87:
187-190). Sera were tested at 1:100 dilution and reaction was
considered positive when the optical density was higher than
the mean plus two standard deviations of six negative control
sera.
Presence of IgG and IgA antibodies to SEA in saliva and oral
transudate were tested. Reaction was considered positive when
the optical density was higher than the mean plus two standard
deviations of six negative control saliva or oral
transudate.
For statistic analysis the SAS software and guides (SAS
version 6, SAS Institute Inc., North Caroline, USA) were used.
All variables were individually tested by the W test of
normality (SS Shapiro, MB Wilk 1965 Biometrika 52: 591-611).
The coefficient of correlation of Pearson was used.
Sensitivity obtained for IgG detection using saliva, oral
transudate and serum was 100%. For IgA detection, sensitivity
was 28.6 and 42.0%, in saliva and oral transudate,
respectively. Specificity was 100% for IgG and IgA detection
using all specimens.
The coefficient of correlation of Pearson of specific anti-S.
mansoni antibodies IgG between serum and oral transudate was r
= 0.73 (p = 0.0002) and between serum and saliva was r = 0.44
(p = 0.05).
Demonstration of anti-S. mansoni antibodies in saliva
and oral transudate seems to be a promising test for diagnosis
of S. mansoni infection. A comprehensive investigation of a
larger number of positive and negative endidual patients is in
progress.
Acknowledgements: to SDS Omni-Sal, Saliva Diagnostics Systems,
Ora Sure, Epitope for the collection devices and Dr Andrew
Simpson for critical review of the manuscript.
Copyright 1995 Fundacao Oswaldo Cruz
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