Results Of Immunological Tests Research Articles

Parry-Romberg Syndrome

The authors report an unusual case of Parry-Romberg syndrome (PRS). Magnetic resonance imaging and computed tomography scan of the craniofacial region and surgical correction of enophthalmos were performed. Results after the operative intervention included persistent palpebral edema and ecchymosis and transient choroid vasculitis of the right eye, highlighted with echography and fluorescein angiography. The fundus oculi examination showed retinal choroid folds. Immunological test results were weakly positive. The authors conclude enophthalmos, associated with right side hemi atrophy, and the transient choroids vasculitis support the diagnosis of PRS. Furthermore, it is suggested the case had an autoimmune etiology, rather than a hemi facial asymmetry caused by a facial trauma that occurred in puberty.

Neurocysticercosis

Neurocysticercosis is the most common helminthic disease of the nervous system and currently represents a major public health problem in developing countries of Latin America, Asia, and Africa, as well as in industrialized nations with a high immigration rate of people from endemic areas. The disease occurs when humans become the intermediate host in the life cycle of Taenia solium by ingesting its eggs from contaminated food. Neurocysticercosis is pleomorphic in its presentation due to individual differences in the number, size, and location of the parasites, as well as differences in the severity of the host's immune reaction to the parasite. Epilepsy, focal neurological signs, and intracranial hypertension are the most common clinical manifestations of the disease. The diagnosis of neurocysticercosis is based on clinical data, neuroimaging abnormalities, and the results of immunological tests. Two drugs, albendazole and praziquantel, are cysticidal and destroy most intracranial parasites; however, surgery may be necessary in the management of some forms of the disease, particularly hydrocephalus and intraventricular cysts. Although the development of modern diagnostic tests and the introduction of potent cestocidal drugs have increased our ability to make the diagnosis of neurocysticercosis and improved prognosis, some patients still have a torpid clinical course despite prompt diagnosis and proper therapy.

Signes cliniques et biologiques des néphropathies glomérulaires

Glomerular diseases are characterized by histological lesions that affect mainly glomeruli. The classification is based on renal pathology data, including the lesions observed on light microscopy and the results of immunofluorescence and electron microscopy examination. The two main glomerular symptoms are proteinuria and hematuria. These symptoms may be associated with blood hypertension and/or renal insufficiency. The predominance of one of these symptoms and the progression pattern allow to describe different clinical patterns: an acute nephritic syndrome, a nephrotic syndrome, a syndrome with recurrent macroscopic hematuria, a syndrome of rapidly progressive glomerulonephritis and a syndrome of chronic glomerulonephritis. The famillial history, the presence of extra-renal symptoms, the results of immunologic tests and of the renal biopsy allow in most cases to identify a precise type of glomerular disease.

Tinea manuum bullosa

We report a case of tinea manuum bullosa in a 36-year-old male, a crop and livestock farmer by trade. The lesion, resembling contact dermatitis, was located in the palm of the right hand. We isolated Trichophyton verrucosum. No other skin lesion was detected. Blood chemistry and immunology test results were normal. Treatment with terbinafine 250 mg day(-1) led to clinical and mycological healing.

Extention of the spectra of plant products for the diet in coeliac disease

The authors studied an extension of the sources of plant products for the diet in coeliac disease. This disease is induced by the components of glutenin proteins. In a collection of crops, they examined the contents of the total and protein nitrogen, the composition of protein fractions, the electrophoretic composition of reserve gluten and prolamine proteins, and the immunological determination of the gliadin amount using ELISA test. By immunological tests, gliadin content below 10 mg per 100 g of sample was found in the following species: amaranth (Amaranthus hypochondriacus and A. cruentus) followed by quinoa (Chenopodium quinoa), sorghum species – grain sorghum and sweet sorghum (Sorghum bicolor and S. saccharatum), millet (Panicum miliaceum), foxtail millet (Setaria italica ssp. maxima), broadrood (Digitaria sanguinalis) and buckwheat (Fagopyrum esculentum). These species can be considered as suitable for the diet in coeliac disease. Below-limit values were found in triticale (Triticosecale) and some oats varieties; this, however, will need some other tests. The analysed samples differred by the contents of crude protein and fraction structures of the protein complex. In pseudocereals amaranth, quinoa and buckwheat, the proportion of the soluble fractions of albumin and globulin was 50–65%. In grain sorghum, their proportion was 20.5%, in sweet sorghum 7.8%. In millet, foxtail millet, and broadrood, their proportion amounted to 12–13%. The proportion of prolamines was higher in sweet sorghum than in grain sorghum. Pseudocereals and millet contained 3–6% of prolamines, Italian millet 38.7%, and broadrood 23.1%, respectively. The two latter species had, however, lower contents of glutenins. In the other species studied, the contents of glutenins ranged from 12 to 22%. Electrophoretic analysis PAGE of prolamine proteins or SDS-PAGE ISTA, developed for gluten proteins, confirmed the results of immunological tests on the suitability of quinoa, grain sorghum, sweet sorghum, buckwheat, amaranth, broadrood, millet and foxtail millet for the diet in coeliac disease. These species did not contain prolamins or the content of -prolamins was negligible in the given samples. The tested species of wheat, triticale, and oats species were manifested as substandard or unhealthy for the diet.  

Empleo de leche de cabra en pacientes con alergia a las proteínas de la leche de vaca

Several epidemiological studies estimate that cow's milk allergy affects approximately 3-5 % of infants in industrialized countries. Infant formulae based on soy protein or hydrolysates free of cow's milk protein guarantee adequate nutritional development, although they may be inadequate for older patients. To evaluate the possibility of using goat's milk in these patients by investigating possible cross-reactivity between both proteins in vivo and in vitro. Twelve patients with cow's milk allergy were tested for tolerance to goat's milk protein through radioallergosorbent assay (RAST), specific IgE, skin prick and challenge tests. Only 25 % of the patients showed adequate immediate and late oral tolerance and had negative results of immunological tests for adverse reactions. The use of goat's milk cannot be recommended to patients with cow's milk allergy without investigation of possible tolerance by a specialist. For the 25 % of patients that tolerate goat's protein, goat's milk can be a excellent substitute in children older than 2 years old.

Retrospective dosimetry for Latvian workers at Chernobyl.

Between 1986 and 1991 approximately 6500 Latvian inhabitants were recruited for clean-up work at the Chernobyl nuclear power plant. Their absorbed doses are usually unknown, because less than half of them had their external exposure officially documented. Clinical investigations show a high morbidity rate for these clean-up workers when compared with that of the general population. In order to understand the causes of their diseases and the impact of ionising radiation, electron spin resonance (ESR) has been used to measure the absorbed doses in human tooth enamel. The doses estimated by ESR were between two and three times higher than previously documented and are in accord with the results of immunological and biological tests. The results may be explained by considering the effects of irradiation caused by long-lived incorporated radionuclides.

Reversible dilated cardiomyopathy after lobectomy for pulmonary sequestration

ruled out. The patient was not taking any cardiotoxic drug. She was given a diagnosis of idiopathic dilated cardiomyopathy. Oral diuretic and vasodilator treatment was given, and follow-up was recommended. Seven years later, she was admitted for increased shortness of breath and productive cough. Spirometric analysis performed in the pneumology service showed a mild air flow limitation. Allergic skin test responses were negative. A control echocardiogram did not show significant changes in the Pulmonary sequestration is a congenital malformation characterized by a pulmonary lobe or pulmonary segment that receives blood supply directly from the aorta. Classically, 2 forms are described. The first is intralobar sequestration, in which the anomalous lung tissue is contained within the visceral pleura. The blood supply comes directly from the aorta, and normal venous drainage through the pulmonary veins goes to the left atrium. The second form is extralobar sequestration, in which the abnormal lung tissue is separated from the normal lung by its own visceral pleural investment. The blood supply generally derives either from the abdominal aorta or the pulmonary artery, and the venous drainage is through the azygos vein or portal system.1 The relevance of this pathologic condition derives from the difficulty in diagnosis and the risk of development of severe pulmonary and cardiovascular complications. Heart failure usually appears during the neonatal period or childhood and in most patients is associated with congenital cardiac defects.2,3 We report the case of an adult patient without structural cardiac abnormalities in whom a dilated cardiomyopathy caused by an intralobar pulmonary sequestration undiagnosed for many years reverted after lobectomy. Clinical summary. A 30-year-old woman with no pathologic antecedents was seen in our center for increasing shortness of breath of 3 years’ duration. Physical examination revealed a systolic ejection murmur. Results of pulmonary auscultation, electrocardiography, and chest x-ray films were normal. An echocardiogram showed dilatation of the left ventricle and a mild reduction of the left ventricular ejection fraction (Table I). No regurgitations or blood flow accelerations were detected with Doppler ultrasonography. Biochemical and immunologic blood test results were within normal limits. Systemic diseases were REVERSIBLE DILATED CARDIOMYOPATHY AFTER LOBECTOMY FOR PULMONARY SEQUESTRATION

Current best practice for the health surveillance of enzyme workers in the soap and detergent industry.

This study defines current best practice for the health surveillance of workers who are potentially exposed to enzymes in the manufacture of enzymatic detergent products. It is recommended that health surveillance is performed 6-monthly for the first 2 years and annually thereafter. The health surveillance programme should include a respiratory questionnaire to detect symptoms, assessment of lung function to detect pre-symptomatic changes and an immunological test to detect specific immunoglobulin E (IgE) to enzymes. The International Union Against Tuberculosis and Lung Disease respiratory questionnaire should be used since it has been validated extensively for detecting asthma. Operators should observe the American Thoracic Society performance criteria for spirometers and standardized procedures for conducting spirometry. Since current airborne monitoring techniques for enzymes do not detect short-duration peak exposures, the incidence of employee sensitizations remains the most reliable measure of the integrity of environmental control. The Pepys skin prick test has been validated as a sensitive, specific and practical test for detecting specific IgE to many inhalant allergens including enzymes. For newly sensitized workers, a multi-cause investigation should be conducted to identify potential sources of exposure. Group results of immunological test results assist in the evaluation of workplace control measures, and should be used to monitor the effectiveness of hygiene and engineering programmes and to help prioritize areas for improvement. Positive responses to a questionnaire or abnormal spirometry should be assessed further. Occupational asthma should be excluded in any case of adult-onset asthma that starts or deteriorates during working life. This is particularly important because an accurate diagnosis of occupational asthma with early avoidance of exposure to its cause can result in remission of symptoms and restoration of lung function.

Incidence of community-acquired pneumonia requiring hospitalization. Results of a population-based active surveillance Study in Ohio. The Community-Based Pneumonia Incidence Study Group

Pneumonia is the leading cause of death due to infectious diseases in the United States; however, the incidence of most infections causing community-acquired pneumonia in adults is not well defined. We evaluated all adults, residing in 2 counties in Ohio, who were hospitalized in 1991 because of community-acquired pneumonia. Information about risk factors, symptoms, and outcome was collected through interview and medical chart review. Serum samples were collected from consenting individuals during the acute and convalescent phases, and specific etiologic diagnoses were assigned based on results of bacteriologic and immunologic tests. The incidence of community-acquired pneumonia requiring hospitalization in the study counties in 1991 was 266.8 per 100,000 population; the overall case-fatality rate was 8.8%. Pneumonia incidence was higher among blacks than whites (337.7/100,000 vs 253.9/ 100,000; P < .001), was higher among males than females (291.4 vs 244.8; P < .001), and increased with age (91.6/100,000 for persons aged < 45 years, 277.2/ 100,000 for persons aged 45-64 years, and 1012.3/ 100,000 for persons aged > or = 65 years; P < .001). Extrapolation from study incidence data showed the projected annual number of cases of community-acquired pneumonia requiring hospitalization in the United States to be 485,000. These data provide previously unavailable estimates of the annual number of cases that are due to Legionella species (8000-18,000), Mycoplasma pneumoniae (18,700-108,000), and Chlamydia pneumoniae (5890-49,700). These data provide information about the importance of community-acquired pneumonia and the relative and overall impact of specific causes of pneumonia. The study provides a basis for choosing optimal empiric pneumonia therapy, and allows interventions for prevention of pneumonia to be targeted at groups at greatest risk for serious illness and death.

Lymphocyte Subsets, Apoptosis, and Cytokines in Patients with Chronic Fatigue Syndrome

Whether immunologic abnormalities correlate with fatigue severity and functional impairment in chronic fatigue syndrome (CFS) was investigated. Blood mononuclear cells were immunophenotyped and circulating ex vivo-produced cytokines were measured in 76 CFS patients and 69 healthy matched controls. Expression of CD11b on CD8 cells was significantly decreased in CFS patients. However, the previously reported increased expression of CD38 and HLA-DR was not confirmed. There was no obvious difference in apoptosis in leukocyte cultures, circulating cytokines, and ex vivo production of interleukin (IL)-1 alpha and IL-1 receptor antagonist. Endotoxin-stimulated ex vivo production of tumor necrosis factor-alpha and IL-beta was significantly lower in CFS. The immunologic test results did not correlate with fatigue severity or psychologic well-being was measured by Checklist Individual Strength, Beck Depression Inventory, and Sickness Impact Profile. Thus, these immunologic tests cannot be used as diagnostic tools in individual CFS patients.

Pre-employment screening among trainee bakers.

To assess the prevalence of atopy in a vocational school so as to evaluate the feasibility of pre-employment screening. The prevalence of atopy by family diathesis, prick tests, immunoglobulin E (IgE) concentrations, and personal history of allergic respiratory diseases was investigated in 144 trainee bakers and 81 students on a graphic artists course (mean age 15.4 years). Skin sensitisation to wheat, rye, and barley flours, to alpha amylase, and to storage mites was also evaluated. Personal allergic symptoms were reported by 13.2% of the bakers and 14.7% of the graphic artists and there was a significant association between symptoms and atopy by prick tests (odds ratio (OR) 17.2; 95% confidence interval (95% CI) 5.27-56.4) and by family history (OR 3.11; 95% CI 1.02-9.53). When bakers were grouped according to the presence of allergic symptoms and results of immunological tests, 6.9% had asthma, 6.3% had rhinoconjunctivitis, and a high percentage (28.5%) were without symptoms but scored positive on prick tests or family symptoms. Skin sensitisation to storage mites had similar prevalences (16%) in the two groups of trainees and occurred nearly always in atopic people. Positive skin tests to wheat flour (3.5%), rye (0.7%), and alpha amylase (0.7%) were specific to bakers. Pre-employment screening is a useful source of medical information and allows for counseling. The presence of asthma, or of another allergic disease in a severe form, is suggested as a criterion for excluding students of a vocational school from training as bakers. Student bakers without allergic symptoms but atopic by other criteria should be informed about their risks of developing occupational asthma, and periodic check ups must be recommended. Screening studies in vocational school provide a better understanding of specificity of skin sensitisation to occupational allergens.

IMMUNOLOGIC ASSESSMENT OF INFECTIOUS DISEASES

Immunodiagnostic tests can be helpful if their results are interpreted carefully. The conclusions drawn from positive or negative immunologic test results are influenced by variables such as the type of assay used and the characteristics of the patient (e.g., age, immunocompetence, clinical syndrome). A negative Toxoplasma IgM result by IFA, for example, is not sufficient to exclude the diagnosis of acute toxoplasmosis because the test itself is not very sensitive. A falsenegative result can be devastating if the patient is a pregnant woman for whom the administration of antimicrobial agents such as pyrimethamine and spiramycin can cure or ameliorate fetal infection. 20 Conversely, a positive Toxoplasma IgM test result by IgM-ISAGA does not necessarily equate with acute infection, especially if the antibody titer is low; an erroneous diagnosis of gestational toxoplasmosis can lead to an unwarranted termination of pregnancy. Immunosuppressed patients often fail to mount adequate humoral or cellular immune responses to invading pathogens, and may require alternative methods of diagnosis, such as PCR. The extent of immunodiagnostic testing for a given patient depends to a large degree on why the testing is being done. Screening for the HBV carrier state requires testing for HBsAg. On the other hand, the best single test to screen for a prior HBV infection (regardless of carrier status) is measurement of anti-HBc. A jaundiced patient being assessed for the possibility of acute hepatitis B should be tested for HBsAg, anti-HBc IgM and IgG, and anti-HBs. Serologic tests frequently are requested for most of the infectious agents discussed in this article, but the intricacies of test result interpretation are not widely appreciated. Imprecise interpretation of serologic data can lead to incorrect diagnoses and inappropriate therapeutic interventions.

Pulmonary reactivity to vanadium pentoxide following subchronic inhalation exposure in a non-human primate animal model.

An experimental study was conducted to evaluate changes in pulmonary reactivity resulting from repeated vanadium pentoxide (V2O5) dust inhalation. The study assessed pulmonary reactivity to V2O5 through the use of provocation challenges, and compared V2O5 reactivity before and after subchronic V2O5 exposure. A total of 24 adult, male cynomolgus monkeys (Macaca fascicularis) were exposed by inhalation for 6 h per day, 5 days per week, for 26 weeks. Two V2O5-exposed groups (n = 8 each) received equal weekly V2O5 exposures (concentration x time) with different exposure profiles. One V2O5-exposed group received 0.1 mg V2O5 m-3 on Mondays, Wednesday and Fridays, with a twice-weekly peak exposure of 1.1 mg V2O5 m-3 on Tuesdays and Thursdays, and was included to investigate the influence of an exposure regimen with peaks on the development of pulmonary hyper-reactivity. The other V2O5-exposed group received a constant daily concentration of 0.5 mg V2O5 m-3. A control group (n = 8) received filtered, conditioned air. Pre-exposure challenges with V2O5 produced a concentration-dependent impairment in pulmonary function, characterized by airway obstructive changes (increased resistance and decreased flow). Analysis of respiratory cells recovered from the lung by bronchoalveolar lavage demonstrated that airway obstruction was accompanied by a significant influx of inflammatory cells into the lung. Subchronic V2O5 inhalation did not produce an increase in V2O5 reactivity in comparison to the control group, and cytological, immunological and skin test results indicate the absence of allergic sensitization. Instead, a trend toward decreased pulmonary reactivity was found following subchronic V2O5 inhalation.(ABSTRACT TRUNCATED AT 250 WORDS)

Predictors for live birth after unexplained spontaneous abortions: Correlations between immunologic test results, obstetric histories, and outcome of next pregnancy without treatment

Our objective was to determine whether results from tests for maternal serum antinuclear antibodies, cytotoxic antibodies to paternal lymphocytes, parental histocompatibility types, and blocking factors for maternal-paternal mixed lymphocyte reactions were predictive of pregnancy outcome without immunologic treatment. Pregnancy outcome data from 95 women with a history of unexplained recurrent spontaneous abortions who underwent immunologic tests at Jefferson Medical College were evaluated with multiple logistic regression analyses. The number of prior spontaneous abortions, history of another relevant diagnosis, parental sharing of one histocompatibility antigen, and maternal age were related to the outcome of the next pregnancy in women given no immunologic treatment ( p = 0.05). No significant correlation was found between results from the immunologic tests or other history characteristics evaluated and outcome of the next pregnancy. The immunologic tests evaluated were not clinically useful predictors of pregnancy outcome.

Morbidity study of extruder personnel with potential exposure to brominated dioxins and furans. I. Results of blood monitoring and immunological tests.

The potential for exposure of employees to polybrominated dibenzofurans (PBDFs) and dibenzo-p-dioxins (PBDDs) during extrusion blending of resins containing decabromodiphenyl ether was established through previous air monitoring (area samples) and biomonitoring studies. The findings presented herein are further biomonitoring results for 42 employees and immunological tests for exposed and referent employees. Among potentially exposed men, 2,3,7,8-TBDF and 2,3,7,8-TBDD concentrations in blood lipid ranged from non-detectable to 112 parts per trillion (ppt) and from non-detectable to 478 ppt respectively. Biomonitoring results correlated well with assignments in the extruder work area when adjusted for process changes and engineering improvements and provided biological half life estimates of between 1.1 and 1.9 years for 2,3,7,8-TBDF and between 2.9 and 10.8 years for 2,3,7,8-TBDD. Results for 16 measures of the immune system were examined in relation to exposure (exposed v referent group) and in relation to the biomonitoring data. Some individual trends in immunological parameters with exposure and covariates such as age and cigarette smoking were found (for example, an increase in complement C4 with increasing concentrations of PBDFs and PBDDs, increased lymphocyte subpopulation counts with cigarette smoking); however, the overall clinical assessment was that the immune system of exposed employees was not adversely impacted at these burdens of PBDFs and PBDDs.

Persistent centrilobular necroses in hepatic allografts

A biopsy study of 60 allografts from 53 patients after orthotopic liver transplantation (OLT) revealed prominent centrilobular necrosis (CN) in 18% of the grafts that were suitable for analysis. The lesions often had a “punched-out” appearance, sometimes with unusual features such as giant cell formation. Persistent CN developed 4 weeks to 6 months after OLT, and persisted in two cases for 2 years and longer. In some instances, CN disappeared or healed by scarring. We found no association between CN and rejection arteritis or arteriopathy. Ductopenic (chronic) rejection subsequently occurred in six of eight livers with CN. Overall, patients with persistent CN had a worse prognosis than control patients. A comparison of cases with matched controls failed to reveal significant differences with respect to perioperative factors such as ischemia time, immunologic test results such as lymphocyte crossmatches, drug administration—in particular, of azathioprine, frequency of cellular (acute) rejection or infection episodes, or frenquency of complications affecting major hepatic vessels or bile ducts. Morphologic evidence suggests that in some instances, rejection-induced endotheliitis/phlebitis of hepatic vein branches may lead to sinusoidal outflow blockage, sinusoidal dilatation, and dropout of hepatic cell plates. Although potentially reversible conditions such as ischemia or adverse drug reactions are among the possible causes of CN, severe rejection leading to ductopenia appears to be the most important underlying condition. Thus, presence of CN in repeated biopsy specimens from allografts should be considered a warning sign of irreversible rejection.

Effects of serum versus plasma on agglutination of antibody-coated indicator cells by human rheumatoid factors

Plasma and serum contain an inhibitor (1) of the agglutination of rabbit IgG-coated sheep erythrocytes by human rheumatoid factor (RF). Plasma but not serum contains an inhibitor of the inhibitor ( I I ) which allows RF to interact with its target. In normal blood, there is more I than I I , and I can be removed by solid-phase chromatography through concanavalin A (Con A). Plasma I I is heat labile being eliminated by heating at 56°C for 30 min. Addition of exogenous calcium clots EDTA plasma, causing an irreversible loss of I I , and suggesting its involvement in the clotting cascade. The absence of I I from Factor V-deficient plasma and destruction of I I by Russell's viper venom indicate I I either is associated with or is a part of Factor V. These findings suggest a balanced interplay between I and I I , and indicate results of immunological tests done in vitro may not accurately reflect immune function in vivo. This seems to represent an unexplored link between hemostasis and immunity.

Biochemical and immunologic characterization of cotton bract extract and its effect on in vitro cyclic AMP production : II. Green Bract

Cotton bract has been proposed as a probable byssinogenic agent. Mill workers are exposed to bract which has weathered in the field, but it is not known whether biologic effects of bract are due to intrinsic plant compound(s) or to contamination occurring during field weathering. Exposure of mononuclear leukocytes (MNL) to green bract extract (GBE) lowered basal cyclic AMP levels. Concomitant exposure of MNL to GBE plus agonist altered MNL cyclic AMP levels in a dose-dependent fashion. Differences between immunologic and pharmacologic test results of GBE and field-dried bract extract were mainly quantitative, suggesting the bioactive agent(s) in cotton bract is intrinsic to the plant.

Immunity after treatment of human schistosomiasis mansoni. I. Study design, pretreatment observations and the results of treatment

This paper describes the design of a study on immunity to reinfection after treatment of children with Schistosoma mansoni infections, the initial observations on transmission that led to the selection of the study population, the effects of treatment, and the results of immunological tests carried out before and at five weeks after treatment. Iietune village in Machakos District, Kenya, was selected on the basis of high prevalence and intensities of infection in a small preliminary survey, a stable population living in a small area amenable to detailed study, and a lack of previous intervention in the area. Subsequent observations over a pretreatment period of one year confirmed that prevalence and intensities of infection among children attending the local primary school were high. This was associated with extensive contact of members of the community with water-bodies shown to contain large numbers of infected snails. Analysis of pretreatment intensities of infection and water contact patterns in the schoolchildren allowed the selection of 129 children showing a broad scatter between: (a) high intensity, low water contact, and predicted to be non-immune, and (b) low intensity, high water contact, and predicted to be immune. These children were treated with oxamniquine, 30 mg/kg in divided doses. Five weeks after treatment, 70% of children showed apparent complete cure, and the over-all reduction in geometric mean egg output was 98·9%. Since these children represented only a small proportion of the whole community, there was no obvious reduction in transmission, as reflected by snail infection rates, during the following five-month period. Thus, we are in a position to determine whether successfully treated children do or do not become reinfected in a high transmission environment in which it will be possible to make direct estimates of exposure. Immunological tests carried out immediately before treatment were consistent with a pattern of high exposure leading to the early expression of immune responses in most infected children. Eosinophil levels were elevated in 61% of the children, all of whom showed detectable levels of antibodies against adult worm and egg antigens, as measured by ELISA. In addition, all patients showed antibodies capable of mediating eosinophil-dependent killing of schistosomula. At five weeks after treatment, eosinophil counts and anti-adult worm antibody levels had risen, whereas anti-egg antibodies remained grossly unchanged. The wide variation in the levels of responses shown by different individuals will allow us to test whether such responses are associated with resistance to reinfection during the follow-up period.