|
Memórias do Instituto Oswaldo Cruz
Fundação Oswaldo Cruz, Fiocruz
ISSN: 1678-8060 EISSN: 1678-8060
Vol. 91, Num. 5, 1996, pp. 593-599
|
Mem Inst Oswaldo Cruz, Rio de Janeiro, Vol. 91(5),
593-599, Sep/Oct 1996,
The Immunopathology of Human Schistosomiasis-III.
Immunoglobulin Isotype Profiles and Response to
Praziquantel
Romelia M Ramirez^+, Evelia Ceballos, Belkisyole Alarcon de
Noya*, Oscar Noya*, Nicolas Bianco
Instituto de Inmunologia y *Seccion de Biohelmintiasis,
Instituto de Medicina Tropical, Facultad de Medicina,
Universidad Central de Venezuela, Apartado Postal 50109,
Caracas 1051-A, Venezuela
^+Corresponding author. Fax: (582) 6720371
Received 25 April 1995
Accepted 27 May 1996
Code Number: OC96108
Size of Files:
Text: 38.2K
Graphics: No associated graphics files
[TABLES AND FIGURES AT END OF TEXT]
Immunoglobulin (Ig) isotype (IgG, IgG1, IgG2, IgG3, IgG4, IgM,
IgD and IgE) levels were investigated, both pre- and post-
treatment with praziquantel (PZQ), in 43 adults and children
chronically infected with Schistosoma mansoni, by means
of a two-site, isotype-specific immunoenzymometric assay. The
patients were classified as responders (R) or non-responders
(NR) on the basis of their circumoval precipitin test (COPT)
results 12 months after treatment.
In comparison with controls, pre-treatment R children showed
significantly higher levels of IgG, IgG1, IgG4 (p<0.001) and
IgE (p<0.01), and diminished IgG2 (p<0.05), while NR children
showed significantly elevated levels only of IgE (p<0.05).
Twelve months after therapy, R children maintained
significantly lower levels of IgG2, but showed significantly
decreased levels of IgG, IgG1, IgG4, and IgE, while the Ig
isotype profile of NR children was unaltered.
Adult R and NR showed similar isotype profiles before
chemotherapy, with the exception of significantly elevated
IgM levels in R. Twelve months after therapy, R adults showed
significantly decreased levels of IgG, IgG1, and IgG4, while
NR adults showed only diminshed IgG4 levels.
These results reveal different Ig isotype profiles in
untreated adults and children chronically infected with S.
mansoni. The results further show that the pre-treatment
Ig isotype profile may be significantly modified after an
effective R to chemotherapy, accounted for by down regulation
of the IgG1 isotype in association with negative
seroconversion of the COPT in R patients. The COPT reaction
has been associated with the highly specific egg glycoprotein
antigen w1, which shows a significant reduction in reactivity
six months after treatment. IgG1 may thus play a main role in
the response against the w1 antigen.
Key words: isotypes - immunoglobulin - Schistosoma
mansoni - praziquantel
The role of the cellular and humoral immune response against
Schistosoma mansoni infection has been well
characterized by several laboratories (Colley et al. 1977,
Butterworth 1987, Butterworth et al. 1987, Mendlovic et al.
1987, Aldrey et al. 1988, Benarroch et al. 1988, Butterworth
et al. 1988). Hypergammaglobu-linemia is a common feature of
this response, with consistently elevated total serum IgG
(mainly IgG1 and IgG4) and IgE concentrations in untreated,
chronically infected individuals (Iskander et al. 1981, Jassim
et al. 1987, Evengard et al. 1988, Boctor & Peter 1990).
Resistance to reinfection by S. mansoni after
chemotherapy was investigated in Kenyan school children, in
whom the existence of a specific acquired immunity was
postulated. When patients susceptible to reinfection were
compared with those who were able to eliminate the parasite,
it was found that mean antibody levels were higher in the
former group. After six months, the titre of specific
antibodies against surface antigens declined and remained
relatively constant over a period of 18 months in both groups.
It was not clear, however, whether this finding was associated
with, or independent of, reinfection (Butterworth et al.
1985).
It has also been demonstrated that IgM and certain IgG
isotypes can act as blocking antibodies, preventing the
expression of an efficacious protective immunity. These
antibodies appear to be elicited in response to egg
polysaccharide antigens, and cross-react with glycosylated
epitopes located on the schistosomulum surface (Butterworth,
1987).
Rihet et al. (1991) measured enhanced anti-parasite IgE levels
in subjects resistant to reinfection with S. mansoni,
and found that reinfection occurred when patients produced
high levels of antibodies which could compete with IgE. A
similar conclusion, suggesting a positive effect of IgG4 in
reinfection by S. haematobium, was proposed by Hagan et
al. (1991), while Demeure et al. (1983) showed that resistance
to reinfection after oxamniquine (OX) chemotherapy was
associated positively with IgE and negatively with IgG2 and
IgG4 anti-larval antibodies. These results suggest that IgE
and IgG4 may be antagonistic in protection against schistosoma
infection.
Massive chemotherapy with OX or PZQ (Cline et al. 1982,
Andrews et al. 1983, Cioli et al. 1993) has been one of the
most important measures in the control of schistosomiasis in
endemic areas. While resistance to OX is well docummented,
such has not been the case for PZQ. Nevertheless, there have
been reports of possible failures in the treatment of humans
infected with S. mansoni in Brazil (Tavares Neto &
Prata 1988, Katz et al. 1991) and Senegal (Anonymous 1992),
and of induction of resistance in mice (Fallon & Doenhoff
1994).
Although published reports suggest that PZQ alone is capable
of killing or damaging adult schistosoma in vitro (Xiao
et al. 1985), other evidence strongly indicates that anti-
schistosome antibodies potentiate the effect of PZQ in
vivo (Xiao et al. 1985, Brindley & Sher 1987, Mondha et
al. 1990). However, a clear relationship between response to
PZQ and the host Ig isotype profile has not yet been
established. Studies in mice infected with S. mansoni
have shown that the efficacy of PZQ against this parasite is
probably linked to the host immune response. In fact,
considerably less effective schistosomicide activity has been
observed by Sabah et al. (1985) in adult thymectomized mice
treated with anti-thymocyte sera, in comparison with intact
animals.
As part of an ongoing research protocol on the immunopathology
of S. mansoni (Aldrey et al. 1988, Benarroch et al.
1988, Alarcon de Noya et al. 1992, Noya et al. 1995a, b), we
present herein the results of an immunoglobulin isotype level
quantitation study undertaken in Venezuelan patients
chronically infected with S. mansoni. Our results
suggest a possible relationship between response to PZQ and a
given isotype profile.
Materials and methods
Patients
Forty-three subjects chronically infected with S.
mansoni were selected for the study, by means of a
clinical, parasitological, and immunological protocol
standardized by the Biohelminthiasis Section of the Institute
of Tropical Medicine (Caracas, Venezuela). The subjects,
including 22 children (aged 8-12 years) and 21 adults (aged
18-40 years), came from the town of Caraballeda, an isolated
focus of schistosomiasis on the northern shore of Venezuela.
The possibility of reinfection was avoided by subsequent
elimination of schistosomiasis transmission by implementation
of environmental sanitation and massive PZQ treatment
programs.
All patients received PZQ in a single oral dose of 40 mg/kg,
and were reevaluated 3, 6, 9, and 12 months after treatment
(Alarcon de Noya et al. 1992, Noya et al. 1995a, b). Of the 43
patients, 27 (14 children and 13 adults) responded to PZQ
(responders, R) while 16 patients (8 children and 8 adults)
remained infected one year after treatment with PZQ (non-
responders, NR), as assessed by the circumoval precipitin test
(COPT) (Oliver-Gonzalez 1954, Alarcon de Noya et al. 1992,
Noya et al. 1995a, b). Thirty-seven healthy individuals,
including 12 children (aged 8-12 years) and 25 adults (aged
16-42 years) free of schistosomal infections, were selected as
the control group after evaluation under the same protocol.
Parasitological and specific immunodiagnostic assessment
Stool examination was performed by a formol-ether assay
(Martin & Beaver 1968) and quantified by the Kato-Katz
technique (Katz et al. 1972). From each subject, two fecal
samples were collected on different days before, and two
after, treatment. Three conventional Kato tests were performed
on each fecal sample. Antibodies to S. mansoni were
detected in sera by both COPT (with a 10% cut-off level) and
ELISA assays using soluble S. mansoni egg and
adult worm antigens (Alarcon de Noya et al. 1992).
Immunoglobulin isotypes
The immunoglobulin isotypes were measured by a two-site
immunoenzymometric assay, specific for each Ig isotype, as
previously described by Black et al. (1988) and Reimer et al.
(1988). Briefly, patients Igs were captured by a human
isotype-specific mouse monoclonal antibody bound to the
plastic surface of Immulon II 96-well microtest plates
(Dynatech, Alexandria, VA). The presence of each isotype was
quantitated using a mixture of peroxidase-conjugated
monoclonal antibodies (kindly provided by the late Dr CB
Reimer of the Centers for Disease Control, Atlanta, GA) to the
kappa, lambda, and/or other appropriate Ig epitopes.
The World Health Organization (WHO) International Standard for
human IgG, IgA and IgM, 67/97 (Rowe et al. 1972), was used to
establish the numerical basis for the IgG, IgG1, IgG2, IgG3,
and IgG4 assays, using the mass units assigned by Klein et al.
(1985). For IgA and IgM, the mass units used were the
International Units estimated for these two analytes by Reimer
et al. (1982). IgD and IgE calibration was performed using the
British Research Standard, 67/37 (Rowe et al. 1970), and the
WHO International Reference Standard, 67/204 (Rowe et al.
1973), respectively. Duplicates of the quality control
preparation for each isotype were systematically included to
estimate inter- and intra-assay variability.
Data analysis
Standard curves for each analyte were constructed using a
public domain BASIC computer program, as described by Black et
al. (1988), allowing an accurate computer interpolation of
unknowns. Statistical analysis was performed by Student test
for paired and unpaired samples; a linear correlation test and
Wilcoxon range test were also used.
Results
Parasitological and COP test
Results of the parasitological and standard immunodiagnostic
evaluations of R and NR adults and children are presented in
Table I. The parasitic load of these patients was low: only 2
of 22 children and 1 of 21 adults eliminated more than 100
eggs/g of feces. Posttreatment stool examinations were
negative in both groups. The pretreatment COPT was positive in
all the patients, while posttreatment values were below 10% in
the R group and above 10% in the NR group.
Immunoglobulin isotype levels
a) Children vs. controls
In comparison with the control group, the pretreatment R
children showed significantly higher levels of IgG, IgG1,
IgG4, and IgE, and lower levels of IgG2, while the NR children
exhibited significantly elevated levels only of IgE (Table
II). When pretreatment sera from R and NR children were
compared, the former showed significantly higher levels of IgG
and IgG1 (p<0.05), and lower levels of IgG2 (p<0.05);
differences between other isotypes were not significant.
b) Adults vs. controls
In comparison with controls, baseline pretreatment isotype
levels in R and NR adults showed similarly high concentrations
of IgG, IgG1, IgG3, IgG4, and IgE. IgM was significantly
higher only in R patients. After treatment, the R patients
maintained high levels of IgG, IgG1, IgG3, and IgE, while only
IgG and IgE remained significantly elevated in NR patients
(Table III).
c) Baseline vs. post-treatment comparison
When the pretreatment baseline levels of isotypes were
compared with the values at 12 months after therapy, R
children showed significantly decreased levels, although still
significantly higher than controls, of IgG (p<0.0001), IgG1
(p<0.05), IgG4 (p<0.05), and IgE (p<0.01), with consistently
lower levels of IgG2 (p<0.05). In NR children, only IgG4
levels were decreased (p<0.05).
The adult R patients had decreased levels of IgG (p<0.001),
IgG1 (p<0.01), and IgG4 (p<0.001), while in NR adults, the
levels of IgG (p<0.001), IgG4 (p<0.001), and IgE (p<0.05) were
significantly decreased.
Correlations between immunoglobulin isotypes and
immunoparasitological parameters
Among R children, a significant positive correlation was
observed before treatment between COPT and both IgG4 (p<0.001)
and parasitic load (p<0.001), while NR children showed a
significant positive correlation before treatment between COPT
and the levels of IgM (p<0.01), IgD (p<0.025), and IgE
(p<0.025).
Among adults, a positive correlation before treatment was
found only in R patients, between parasitic load and IgG4
levels (p<0.05).
Discussion
To gain further insight into the possible relationship between
Ig isotype levels and response to PZQ therapy, we evaluated,
by means of a high performance, two-site immunoenzymometric
assay (Black et al. 1988, Reimer et al. 1988), the pre- and
post-PZQ treatment serum immunoglobulin isotypic profiles of a
group of 43 patients (both children and adults) chronically
infected with S. mansoni.
This investigation was conducted in an isolated focus of
schistosomiasis in northern Venezuela, where the patients
presented with prevailing chronic infections and low egg
counts. It was possible to halt the spread of S.
mansoni infection in this area by eradicating the
intermediate host of S. mansoni by both the application
of molluscicides and the introduction, into the river snails
of the Thiaridae family, of competitors capable of
reducing, and even eliminating, the population of B.
glabrata (Pointer & McCullough 1989). Over the course of
the study, B. glabrata was not detected in the river,
and no new infections were identified in individuals under
four years of age. We therefore assume that the subjects
included in our protocol were not affected by episodes of
reinfection during the post-treatment evaluation period. Thus,
effects on isotype levels were dependent on the natural
progression of the chronic infection by S. mansoni and
on the action of both the host immune response to the parasite
and the PZQ therapy.
In patients eliminating more than 100 eggs/g of feces, stool
examination has conventionally been considered the best
measure of the effectiveness of chemotherapy (WHO 1995). The
sensitivity of the parasitological methods diminishes,
however, when individuals excrete less than 100 eggs/g of
feces (Mott & Cline 1980, Alarcon de Noya et al. 1992). In
this situation, the immunodiagnostic tests seem to better
assess the presence of the parasite. Among this kind of test,
the COPT and methods based on the detection of circulating
antigens have been extensively used. However, the antigen-
detecting techniques are not yet of sufficiently high
sensitivity in cases of low parasitic burden (De Jonge et al.
1991). The COP test, however, is both highly specific and
sensitive, and has the additional advantage of demonstrating
negative seroconver-sion after successful treatment, as has
been shown in both mice (Cancio et al. 1967) and humans
(Rifaat et al. 1969, Alarcon de Noya et al. 1992).
We have previously demonstrated that patients over five years
of age and with an excretion rate lower than 100 egg/g of
feces were correctly identified by COPT, with sensitivities
higher than 90%. In children under five years of age, COPT
sensitivity was 86% (Alarcon de Noya et al. 1992). In the
current study, all of the patients were positive by COPT
before treatment, and on initial observation, we could not
establish any baseline differences among patients. Twelve
months after treatment, all of the patients were negative for
S. mansoni eggs. However, 48.4% of the patients dropped
below the COPT cut-off value of 10%, while 48.5% remained
positive. On this basis, we identified two main groups of
patients: "responders" (R), characterized by negative COPT
conversion, and "non-responders" (NR), who remained COPT-
positive.
Previous studies (Rihet et al. 1991, Hagan et al. 1991,
Demeure et al. 1993) of resistant and susceptible subjects
revealed that resistance to reinfection was associated with
enhanced IgG and IgE levels, and occurrence of reinfection,
with high levels of IgG4 and IgG2. It has also been postulated
that IgG4 and IgG2 may compete with effective isotypes, such
as IgE and IgG1, thereby blocking the host immune response
against the parasite.
Jassin et al. (1987) found that Sudanese children from an area
highly endemic for S. mansoni had elevated levels of
IgG and IgE in comparison with a normal European population.
Additionally, they reported that a significant part of the
overall IgG increase was accounted for by IgG1, IgG3, and
IgG4, associated with an increase of IgA and IgM. The IgG
isotype profile in response to PZQ was not evaluated.
Demeure et al. (1993) suggested that resistance to reinfection
is influenced by the balance between a protective effect of
IgE and a negative action of IgG4 and IgG2 antibodies to
carbohydrate determinants on schistosomula. Rihet et al.
(1992) demonstrated that certain antibodies present in the
sera of chronically infected subjects compete with IgE
antigen-binding, and that IgG4 accounts for most of this
blocking activity. They identified the immunoglobulin isotypes
IgE, IgG4, and IgG2 as having a significant role in the human
response to S. mansoni infection.
In the present study, evaluation of the immunoglobulin isotype
profile in both R and NR patients showed a particular pattern
of expression. At presentation, the NR children showed
significantly elevated levels of IgE (p<0.05) and IgG4
(p<0.01), suggesting a predominant TH-2 response. In the^ R
children, who presented with significantly increased levels of
IgG1 (p<0.001), IgG4 (p<0.01), and IgE (p<0.05), and a
decreased level of IgG2, there was no clear-cut predominance
of either a TH-1 or TH-2 response, suggesting a possibly major
difference between the two groups of children at presentation
(Gascan et al. 1991). Although IgE has been considered to be
protective against parasitic infections (Demeure et al. 1993),
our findings indicated that increased levels of IgE alone were
not sufficient for protection in NR children.
Moreover, in comparing the behavior of the isotype profile
after treatment in both groups of children, the diminishment
of the level of total IgG (p<0.001) in R patients was found to
be due primarily to decreases in IgG1 (p<0.001) and IgG4
(p<0.001), with IgG2 levels remaining low, while in NR
patients, diminishment of the total level of IgG was due
primarily to a reduction in IgG4 (p<0.001). These observations
may indicate a specific protective response in R patients,
dependent on the IgG1 and IgE isotypes, which competes with
the blocking effect of IgG4, and that the balance between IgG4
and IgG1 may downregulate the synthesis of IgG2, as suggested
by its diminished levels in R children.
The diminishment of most of the elevated isotype levels found
in R children is consistent with previous studies of the
specific response against S. mansoni egg antigens,
which showed weaker recognition, after cure, of most of the
electrophoretic bands. In fact, after successful treatment,
the majority of the patients did not recognize the Sm-25
molecule (Noya et al. 1995b).
Isotype expression among the group of adult patients did not
show differences before treatment between R and NR
individuals, with the exception of increased levels of IgM in
the R group (p<0.02). Twelve months after treatment, IgG
(p<0.001), IgG1 (p<0.001), and IgG4 (p<0.001) showed
significantly diminished levels, while the increased IgM
remained unaltered in the R group. In the NR group, only the
IgG4 level was downregulated (p<0.001). These findings may
also be indicative of the importance of IgG1, and IgG4 in the
efficacy of PZQ treatment.
The simultaneous downregulation of IgG1 and IgE levels and
negative seroconversion of the COPT in post-treatment R
children suggest that both parameters may have a common
antigen specificity. The COPT reaction has been associated
with a very specific egg glycoprotein antigen, designated w1,
which has been postulated as one of the most promising
antigens for diagnosis, because it also correlates with cure
(Dune et al. 1981, 1988, 1991, McLaren 1981). The w1 antigen
is one of the most important components of the S.
mansoni egg antigen, which showed, in immunological tests,
a significant reduction in reactivity six months after
treatment (Mott & Dixon 1982). The downregulation of IgG1 in
the groups of R patients is very suggestive that this isotype
could act synergistically with PZQ, contributing to an
effective therapy, as well as contributing to the negative
seroconversion of the COPT by participating in reactions with
antigens such as w1.
In conclusion, our results are in agreement with those of
previous studies (Jassin et al. 1987, Hagan et al. 1991, Rihet
et al. 1991, Demeure et al. 1993), in demonstrating the
participation of IgG, IgG1, IgG2, IgG4, and IgE in the
response to S. mansoni infection, and suggest that the
assessment of Ig isotype profile may help to understand the
regulatory mechanism of the anti-parasite response in humans
subjected to praziquantel treatment.
Acknowledgement
This work was supported by the GENIC Program and the National
Council of Investigations on Science and Technology
(CONICIT)
References
Anonymous 1992. Praziquantel shows unexpected failure in
recent schistosomiasis outbreak. TDR News 41: 1-
2.
Alarcon de Noya B, Spencer L, Noya O 1992. Pre- and Post-
treatment immunodiagnostic evaluation in human schistosomiasis
mansoni. Mem Inst Oswaldo Cruz 87 (Supp IV) 271-
276.
Aldrey O, Noya B, Machado I, Noya O, Bianco NE, Perez GE 1988.
Immunopathology of human schistosomiasis mansoni I.
Immunomodulatory influences on T cell function. Rev Inst
Med Trop S o Paulo 30: 393-399.
Andrews P, Thomas H, Pohlke R, Seubert J 1983. Praziquantel.
Med Res Rev 3: 147-200.
Benarroch LK, Noya O, Noya B, Bianco NE, Blanca I 1988.
Immunopathology of human schistosomiasis mansoni II. Rev
Inst Med Trop S o Paulo 30: 400-405.
Black CM, Plikaytis BD, Wells TM, Ramirez RM, Carlone GM,
Chilmonczyk BA, Reimer CB 1988. Two sites immunoenzymometric
assays for serum IgG subclass infant/maternal ratios at full
term. J Immunol Methods 106: 71-81.
Boctor FN, Peter JB 1990. IgG subclasses in human chronic
schistosomiasis: Overproduction of schistosome-specific and
non-specific IgG4. Clin Exp Immunol 82: 574-
578.
Brindley PJ, Scher A 1987. The chemotherapeutic effect of
praziquantel against Schistosoma mansoni is dependent
on host antibody response. J Immunol 139:
215 220.
Butterworth AE 1987. Immunity in human schistosomiasis.
Acta Tropica 44 (Suppl 12) 31-40.
Butterworth AE, Bebsted-Smith R, Capron A, Capron M, Dalton
PR, Dunne DW, Grzych JN, Kariuki HC, Khalife J, Koech D,
Mugambi M, Ouma JH, Arap Siongok TK, Sturrock RF 1987.
Immunity in human schistosomiasis mansoni: prevention by
blocking antibodies of the expression of immunity in young
children. Parasitology 94: 281-300.
Butterworth AE, Capron M, Cordingley JS, Dalton PR, Dunne DW,
Kariuki HC, Kimani G, Koech D, Mugambi M, Ouma JH, Prentice
MA, Richardson BA, Arap Siongok TK, Sturrock RF, Taylor DW
1985. Immunity after treatment of human schistosomiasis
mansoni II. Identification of resistant individuals, and
analysis of their immune response. Trans R Soc Trop Med
Hyg 79: 393-408.
Butterworth AE, Dunne D, Fulford A, Capron M, Khalife J,
Capron A, Koech D, Ouma J, Sturrock R 1988. Immunity in human
schistosomiasis mansoni: cross reactive IgM and IgG2 anti-
carbohydrate antibodies block the expression of immunity in
young children. Biochimie 70: 1053-1063.
Cancio M, Rivera de Sala A, Ramirez de Arellano G, Rodriguez-
Molina R 1967. Circumoval antibodies measurements during
treatment of experimental schistosomiasis. Am J Trop Med
Hyg 16: 729-734.
Cioli D, Pica-Maltoccia L, Archer S 1993. Drug resistance in
schistosomes. Parasitol Today 9: 162-166.
Cline BA, Almeida Machado P, Almoatz Billah M, Mao SP, Shao BR
1982. The control of schistosomiasis in Brazil, Egypt and
China. Am J Trop Med Hyg 31: 75-102.
Colley DG, Cook JA, Freeman GL, Bartholomew RK, Jordan P 1977.
Human response during human schistosomiasis mansoni I. In
vitro lymphocyte blastogenic responses to heterogeneous
antigenic preparation from schistosome eggs, worms and
cercariae. Int Arch Allergs Appl Immun 53: 420-
433.
De Jonge N, Rabello ALT, Krijger FW, Kremsher PG, Rocha Katz
N, Deelder AM 1991. Levels of the circulanting anodic and
cathodic antigens in serum of schistosomiasis patients from
Brazil. Trans R Soc Trop Med Hyg 85: 756-759.
Demeuere CE, Rihet P, Abel I, Ouattara M, Bourgois A, Dessein
AJ 1993. Resistance to Schistosoma mansoni in humans
influence of IgE/IgG4 balance and IgG2 in immunity to
reinfection after chemotherapy. J Inf Dis 168:
1000-1008.
Dunne DW, George V, Hillyger V, Vazquez G 1988. Schistosoma
mansoni cationic egg antigens (CEF): Immunoserology with
oxamniquine-treated patients and involvement of CEF6 in the
circumoval precipitin reaction. Am J Trop Med Hyg
38: 508-514.
Dunne DW, Jones FM, Doenhoff MJ, 1991. The purification,
characterization, serological activity and hepatotoxic
properties of two cationic glycoproteins ("1 and T1) from
Schistosoma mansoni eggs. Parasitology
103: 225-236.
Dunne DW, Lucas S, Bickle Q, Pearson S, Madgwick L, Bain J,
Doenhoff MJ 1981. Identification and partial purification of
an antigen (T^1) from Schistosoma mansoni eggs is
putatively hepatotoxic in T-cell deprived mice. Trans R Soc
Trop Med Hyg 75: 54-71.
Evengard B, Hammarstrom L, Smith CIE, Johansson SGO, Linder E
1988. Subclass distribution and IgE responses after treatment
in human schistosomiasis. Clin Exp Immunol 73:
383-388.
Fallon PG, Doenhoff MJ 1994. Drug-resistant schistosomiasis:
resistance to praziquantel and oxamniquine induced in
Schistosoma mansoni in mice is drug specific. Am J
Trop Med Hyg 51: 83-88.
Gascan H, Gauchat JF, Aversa G, Van-Vlasselaer P, de Vries JE
1991. Ati-CD40 monoclonal antibodies or CD4+ T cell clones and
IL-4 induce IgG4 and IgE switching in purified human B cells
via different signaling pathways. J Immunol 174:
8-13.
Hagan P, Blumenthal MJ, Dunne D, Simpson AJG, Wilkins MA 1991.
Human IgE, IgG4, and resistance to reinfection with
Schistosoma haematobium. Nature 349: 243-245.
Iskander R, Das PK, Aalberse RC 1981. IgG4 antibodies in
Egyptian patients with schistosomiasis. Int Arch Allergy
Appl Immun 66: 200-207.
Jassim A, Hassan K, Catty D 1987. Antibody isotypes in human
schistosomiasis mansoni. Parasite Immunology 9:
627-650.
Katz N, Chaves A, Pellegrino J 1972. A simple device for
quantitative stool thick smear technique in schisotosomiasis
mansoni. Rev Inst Med Trop S o Paulo 14: 397-
400.
Katz N, Rochas RS, De Soriza CP, Filho PC, Bruce JI, Coles GE,
Kinoli GK 1991. Efficacy of alternating therapy with
oxamniquine and praziquantel to treat Schistosoma
mansoni in children following failure of first treatment.
Am J Trop Med Hyg 44: 509-512.
Klein F, Skavaril F, Vermeeren T, Vlug A, Duimel WJ 1985. The
quantification of human IgG subclasses for reference
preparation. Clin Chem Acta 150: 119.
McLaren ML, Lillywhite JE, Dunne DW, Doenhoff MJ, 1981.
Serodiagnosis of human Schistosoma mansoni infections:
enhanced sensitivity and specificity in ELISA using a fraction
containing S. mansoni eggs anti T1 and T2.
Trans R Soc Trop Med Hyg 75: 72-79.
Martin LK, Beaver PC 1968. Evaluation of the Kato thick smears
technique for the quantitative diagnosis of helmintic. Am J
Trop Med Hyg 17: 382-390.
Mendlovic F, Tarrab-Hazdai R, Arnon R 1987. Role of humoral
immunity and helper cell involvement in permissiveness to
infection of Schistosoma mansoni. Eur J Immunol
17: 1151-1157.
Modha J, Lambertucci JR, Doenhoff MJ, McLaren D 1990. Immune
dependence of schistosomicidal chemotherapy: an
ultrastructural study of Schistosoma mansoni adult worm
exposed to praziquantel and immune serum in vivo.
Parasite Immunol 12: 321-334.
Mott K, Cline B 1980. Advances in epidemiology survey
methodology and techniques in schistosomiasis. Bull WHO
58: 639-647.
Mott KE, Dixon H 1982. Collaborative study on antigens for
immunodiagnosis of schistosomiasis. Bull WHO 60:
729-753.
Noya O, Fermin S, Alarcon de Noya B, Losada S, Colmenares C,
Hermoso T 1995a. Humoral immune response of children with
chronic schistosomiasis. Isotypic recognition of adult worm
antigens. Parasite Immunol 17: 319-328.
Noya O, Losada S, Alarcon de Noya B, Gonzales S, Hermoso T,
Balzan C, Cesari IM 1995b. Effect of chemotherapy in immune
response to egg antigens of Schistosoma mansoni in
chronically infected children from areas of low transmission.
Parasite Immunol 17: 111-117.
Oliver-Gonzalez J, 1954. Anti-egg precipitins in sera of
humans infected with Schistosoma mansoni. J Infect
Dis 95: 86-91.
Pointier JP, McCullough F 1989. Biological control of the
snail hosts of Schistosoma mansoni in the Caribbean
area using Thiara spp. Acta Tropica 46:
147-155.
Reimer CB, Black CM, Holman RC, Wells TW, Ramirez RM, Sa-
Ferreira JA, Janet KA, Nicholson JKA, McDougal JS 1988.
Hypergammaglobulinemia associated with human immunodeficiency
virus infection. Monogr in Allerg 23: 83-96.
Reimer CB, Smith S, Wells T, Nakamura R, Keitges P, Williams
G, Hanson D, Dorsey D, 1982. Collaborative calibration of the
U.S. National and American Pathologists reference preparations
for specific serum proteins. Am J Clin Path 77:
12-19.
Rifaat M, Ismail I, El Mahallawy M, Awaad S, Essawy M 1969.
Comparative study of some immunological tests for
schistosomiasis before and after treatment. Trans R Soc
Trop Med Hyg 63: 338-342.
Rihet P, Demeure E, Bourgouis A, Prata A, Dessein AJ 1991.
Evidence for an association between human resistance to
Schistosoma mansoni and high anti-larval IgE levels.
Eu J Immunol 21: 2679-2686.
Rowe DS, Anderson SG, Tackett L 1970. A research standard for
human serum immunoglobulin D. Bull WHO 43: 607-
609.
Rowe DS, Grab B, Anderson SG 1972. An international reference
preparation for human serum immunoglobulins G, A and M:
content of immunoglobulin by weight. Bull WHO
46: 67-69.
Rowe DS, Grab B, Anderson SG 1973. An international reference
preparation for human serum immunoglobulin E. Bull WHO
49: 320-321.
Sabah AA, Fretcher C, Webbe C, Doenhoff MJ 1985.
Schistosoma mansoni reduced efficacy of chemotherapy in
infected T-cell deprived mice. Exp Parisit 60:
348-352.
Tavares Neto J, Prata A 1988. Reac o da forma hepato esplenica
da esquistosomose em relac o a raca. Rev Soc Bras Med
Trop 21: 131-133.
WHO 1985. The control of schistosomiasis. World Health
Organization Technical Report Series 728.
Xiao S, Catto BA, Webster LT 1985. Effects of praziquantel on
different developmental stages of Schistosoma mansoni
in vitro and in vivo. J Infect Dis
151: 1130-1137.
--------------------------------------------------------------
TABLE I Immunoparasitological characteristics of chronic
Schistosoma mansoni-infected patients
----------------------------------------------------------
Intensity of infection COPT (%)
Groups of eggs/g feces --------------------
patients n x+/-s bt/at x+/-s bt x+/-s at
--------------------------------------------------------------
R children 14 57+/-62/0 44+/-14 3+/-3
NR children 8 33+/-23/0 34+/-14 25+/-8
R adults 13 44+/-23/0 42+/-20 1+/-2
NR adults 8 51+/-55/0 47+/-15 33+/-13
COPT: Circumoval Precipitin Test; bt/at: before/after
praziquantel treatment; x+/-s: mean+/-standard deviation;
R/NR: responder/non-responder to praziquantel chemotherapy.
--------------------------------------------------------------
TABLE II Immunoglobulin isotypes in children before and
after treatment
--------------------------------------------------------------
Ig Controls Responders
x+/-s bt x+/-s at x+/-s
--------------------------------------------------------------
IgG 13.2+/-2.6 16.2+/-2.6^a 13.7+/-2.6
IgG1 9.3+/-2.1 12.8+/-2.8^a 10.3+/-2.7^b
IgG2 2.5+/-1.0 1.7+/-0.7^b 1.7+/-0.7^b
IgG3 0.6+/-0.4 0.7+/-0.31 0.7+/-0.4
IgG4 0.6+/-0.4 1.7+/-1.4^a 0.8+/-0.5^b
IgM 1.3+/-0.4 1.2+/-0.6 1.3+/-0.7
IgA 2.3+/-0.7 1.9+/-0.6 1.7+/-0.7
IgD 0.07+/-0.04 0.108+/-0.09 0.109+/-0.08
IgE 211+/-72 465+/-416^c 375+/-199^b
--------------------------------------------------------------
Table II. (continued)
--------------------------------------------------------------
Ig Non-responders
bt x+/-s at x+/-s
--------------------------------------------------------------
IgG 14.4+/-2.4 13.2+/-1.9
IgG1 9.7+/-1.7 9.5+/-1.3
IgG2 2.1+/-0.5 2.3+/-0.6
IgG3 0.5+/-0.3 0.6+/-0.4
IgG4 1.6+/-1.8 0.8+/-0.9
IgM 1.2+/-0.6 1.2+/-0.5
IgA 1.8+/-0.7 1.7+/-0.6
IgD 0.07+/-0.05 0.08+/-0.04
IgE 363+/-217 310+/-199
p value in comparison with the control group:^a: p<0.001, b:
p<0.05, c: p<0.01; bt/at: before/after treatment; IgG, IgG1,
IgG2, IgG3, IgG4, IgM, and IgA are expressed in mg/ml, IgE in
IU/ml, and IgD in mg/ml.
--------------------------------------------------------------
TABLE III Immunoglobulin isotypes in adults before and
after treatment
------------------------------------------------------------
Ig Controls Responders
x+/-s bt x+/-s at x+/-s
-------------------------------------------------------------
IgG 11.3+/-1.9 16.9+/-2.7^a 13.4+/-2.6^c
IgG1 7.4+/-1.5 10.4+/-2.3^a 8.8+/-1.8^b
IgG2 2.3+/-1.1 2.6+/-1.6 2.9+/-2.0
IgG3 0.4+/-0.2 0.7+/-0.2^a 0.7+/-0.3^a
IgG4 0.6+/-0.4 1.9+/-1.3^a 0.8+/-0.8
IgM 1.2+/-0.5 1.7+/-0.7^b 1.9+/-0.9^b
IgA 2.4+/-0.8 2.1+/-0.6 2.1+/-0.3
IgD 0.06+/-0.03 0.08+/-0.06 0.06+/-0.03
IgE 188+/-41 607+/-621^c 432+/-279^b
------------------------------------------------------------
TABLE III. (continued)
------------------------------------------------------------
Ig Non-responders
bt x+/-s at x+/-s
------------------------------------------------------------
IgG 16.1+/-3.5^a 14.1+/-3.2^c
IgG1 10.4+/-2.8^a 9.6+/-3.6
IgG2 2.8+/-1.2 2.6+/-0.6
IgG3 0.8+/-0.4^a 0.7+/-0.3
IgG4 2.4+/-1.3^a 1.8+/-1.2
IgM 1.3+/-0.7 1.1+/-0.7
IgA 2.1+/-0.5 1.9+/-0.5
IgD 0.08+/-0.06 0.06+/-0.03
IgE 747+/-777^c 371+/-299^c
p value in comparison with the control group:^a: p<0.001, b:
p<0.05, c: p<0.01; bt/at: before/after treatment; IgG, IgG1,
IgG2, IgG3, IgG4, IgM, and IgA are expressed in mg/ml, IgE in
IU/ml, and IgD in mg/ml.
--------------------------------------------------------------
Copyright 1996 Fundacao Oswaldo Cruz
|