IgG4 and IgE anti-Strongyloides stercoralis as additional parameters in characterizing patients with diabetes from a hyperendemic area.

We report the detection of IgG, IgG1, IgG4 and IgE anti-Strongyloides stercoralis as complementary tool for screening in patients with diabetes in hyperendemic areas for strongyloidiasis. A panel of 119 serum samples were analyzed: 76 from patients with DM2 and 43 patients with other endocrine diseases and a positive correlation for total IgG levels with IgG4 (rs = 0.559; P = 0.024; n = 16) and IgG and IgE (rs = 0.585; P < 0.0001; n = 76) was found in the diabetes group.

IgY antibody and human neurocysticercosis: a novel approach on immunodiagnosis using Taenia crassiceps hydrophobic antigens.

Human neurocysticercosis (NCC) is a worldwide neglected disease caused by Taenia solium metacestode and responsible for various complications and neurological disorders. This study aimed to evaluate the use of specific immunoglobulin Y (IgY) produced by laying hens immunized with a hydrophobic fraction of Taenia crassiceps metacestodes (hFTc) in NCC diagnosis. Egg yolk IgY antibodies were fractionated, purified and characterized. Enzyme-linked immunosorbent assay (ELISA) was carried out to evaluate the production kinetics and avidity maturation of anti-hFTc IgY antibodies throughout the IgY obtention process. Antigen recognition tests were carried out by Western blotting and immunofluorescence antibody test using purified and specific anti-hFTc IgY antibodies for detection of parasitic antigens of T. crassiceps and T. solium metacestodes. Sandwich ELISA was performed to detect circulating immune complexes formed by IgG and parasitic antigens in human sera. The results showed high diagnostic values (93.2% sensitivity and 94.3% specificity) for immune complexes detection in human sera with confirmed NCC. In conclusion, specific IgY antibodies produced from immunized hens with hFTc antigens were efficient to detect T. solium immune complexes in human sera, being an innovative and potential tool for NCC immunodiagnosis.

Molecular and Immnune Diagnosis: Further Testing for Human Strongyloidiasis.

INTRODUCTION: Detection of Strongyloides stercoralis larvae is particularly challenging because only a small number of larvae are released into the feces, regardless of infection stage. OBJECTIVE: Our objective was to apply conventional polymerase chain reaction (PCR) to the detection of S. stercoralis DNA in feces samples to evaluate its performance in samples of patients with strongyloidiasis and compare results with those of immunodiagnosis. METHODS: Stool, serum, and saliva samples were collected from each individual (n = 48) at the clinic hospital of the State University of Londrina, Brazil, for parasitological, immunological, and molecular tests. Stool samples were processed via parasitological methods. Serum samples were used for immunoglobulin G (IgG) detection and saliva samples for IgA detection by ELISA. RESULTS: For amplification by conventional PCR, two different primers were used: species specific (101 bp) and genus specific (392 bp). The results showed that 34 (97.1%) of the 35 copro-positive individuals for S. stercoralis were positive for serum IgG and 19 (54.3%) were positive for salivary IgA. Regarding molecular analysis, both primers (species and genus specific) demonstrated positivity in 100% of the samples, which was confirmed by sequencing the positive samples. CONCLUSION: Complementary examinations of the parasitological method demonstrated excellent results in the context of the diagnosis of strongyloidiasis, especially in asymptomatic patients with irregular larval release in the feces.

Detection of parasite-specific IgG and IgA in paired serum and saliva samples for diagnosis of human strongyloidiasis in northern Paraná state, Brazil.

Human strongyloidiasis is an infection caused by the helminth Strongyloides stercoralis that can be fatal, especially in immunosuppressed patients. The aim of this study is to evaluate parasite-specific IgG and IgA levels using S. venezuelensis third-stage (L3) infective larvae alkaline extract as a heterologous antigen by ELISA in paired serum and saliva samples with improved sensitivity and specificity. Individuals from northern Paraná state, Brazil were divided into three groups: 30 patients copropositive for S. stercoralis (Group I); 30 clinically healthy individuals (Group II); and 30 patients copropositive for other parasites (Group III). The area under ROC curve (AUC), an overall index of diagnostic accuracy, and Kappa index were calculated. Data were analyzed using analysis of variance (ANOVA) followed by a Kruskal-Wallis test. Probability (p) values of <0.05 were regarded as significant. In Group I, IgG was detected in 96.7% serum and in 6.7% saliva samples. IgG was not detected in Group II. In Group III, cross-reactivity was observed for serum IgG in 26.7% and in 6.7% for saliva samples. In Group I, IgA was detected in 76.7% serum and 56.7% saliva samples. In Group II, 3.3% were positive for IgA in serum, whereas IgA was not detected in any saliva samples. Group III showed 6.7% serum and 26.7% saliva-positive samples. The sensitivity values for detection of IgG and IgA in serum samples were 96.7% and 76.7%, respectively. In saliva samples, the sensitivity values for detection of IgG and IgA were 6.7% and 56.7%, respectively. The specificity value was 100% for the detection of IgG in serum and for detection of IgG and IgA in saliva, and 96.7% for detection of IgA in serum samples. The proper choice of immunological diagnosis to supplement parasitological methods is essential to estimate the true prevalence of the parasite, and will permit analysis of population immune response profiles, particularly in northern Paraná state, where there are no previous reports.

Saline extract of Taenia saginata metacestodes as an alternative antigen for the immunodiagnosis of neurocysticercosis in human cerebrospinal fluid.

The aim of the present research was to test the application of Taenia saginata metacestodes as an alternative antigen for use in enzyme-linked immunosorbent assay (ELISA) and Western Blotting (WB) tests compared with the use of metacestodes antigen of Taenia solium in cerebrospinal fluid (CSF) samples. The samples were obtained from 35 patients with definitive neurocysticercosis (NCC)-group 1-and 44 patients with other neurological disorders (control)-group 2. The sensitivity and specificity of ELISA, using antigen obtained from T. solium, applied to the patients of group 1 yielded results of 100%. When the tests were conducted using T. saginata metacestodes, results were 100% and 93.2%, respectively. The 47-52-, 64-68-, and 70-kDa antigens showed high frequencies in CSF samples from patients with NCC when WB was conducted with both antigens. The results indicate that T. saginata metacestodes can be used as an alternative antigen for the diagnosis of human NCC in CSF samples.

Specific IgA and IgG antibodies in paired serum and breast milk samples in human strongyloidiasis.

Strongyloidiasis, caused by the nematode Strongyloides stercoralis, is one of the major worldwide parasitic infections in humans. Breastfeeding may offer a potential protection against this infection. Feces, serum and milk samples were obtained from 90 lactating women from Clinical Hospital of Universidade Federal de Uberlândia, Brazil. The fecal samples were collected for parasitological diagnosis and the serum and milk samples were examined for specific S. stercoralis IgA and IgG antibodies using the indirect fluorescent antibody test (IFAT) and enzyme-linked immunosorbent assay (ELISA). Fecal examination showed that the rate of prevalence of S. stercoralis infection in the lactating women was 4.4%. IFAT manifested a 16.7% positivity rate for specific IgA antibody in serum and a 28.9% rate in milk samples; specific IgG was 41.1% in serum and 25.5% in milk samples. According to ELISA the positivity rate for specific IgA antibody was 21.1% in serum and 42.2% in milk samples; specific IgG was 40% in serum and 18.9% in milk samples. In serum samples, these immunological tests showed a concurrence of 91.1% and 94.4%, respectively, in detecting specific IgA and IgG antibodies. In milk samples, they showed a concurrence of 70% and 78.9%, respectively, in detecting specific IgA and IgG antibodies. There was a statistically significant difference between concordant and discordant results of immunological tests (P<0.0001). IFAT and ELISA highly concurred in their detection of specific S. stercoralis IgA and IgG antibodies in serum and in milk samples reconfirming prior studies that the serological method is a complement to the direct diagnosis of the parasite, and suggesting that immunological methods using milk samples can also be helpful. Furthermore, in endemic areas, infants may acquire antibodies to S. stercoralis from breast milk, possibly, contributing to the enhancement of specific mucosal immunity against this parasite.

Parasitological and immunological diagnosis of Strongyloides stercoralis in patients with gastrointestinal cancer.

This study examined the frequency of Strongyloides stercoralis infection in patients with gastrointestinal cancer through parasitological and immunological tests. A total of 77 patients were evaluated, 33 with gastrointestinal cancer and 44 controls with other types of cancers. All the patients were undergoing chemotherapy and 14 (18.2%) were receiving concomitant radiotherapy. For a parasitological diagnosis, we applied the Baermann and Lutz methods. The immunological diagnosis involved the indirect fluorescence antibody test (IFAT) and enzyme linked immunosorbent assay (ELISA) to detect IgG antibodies using Strongyloides ratti antigens. The frequency of positive S. stercoralis in gastrointestinal cancer diagnosed by parasitological methods was 3 cases (9.1%), by serology it was 8 cases (24.2%). In the control group 1 case (2.3%) of S. stercoralis was diagnosed by parasitological methods and 2 cases (4.5%) by immunological tests (p<0.05). Patients with gastrointestinal cancer had a 6.7-fold greater chance of testing positive for S. stercoralis infection. Our data highlight the importance of parasitological and immunological diagnosis for S. stercoralis in patients with gastrointestinal cancer living in endemic areas of strongyloidiasis, since they have a higher risk of becoming infected with S. stercoralis than patients with other types of cancer.

Is there an association between positive Strongyloides stercoralis serology and diabetes mellitus?

The purpose of this study was to determine the frequency of association between positive Strongyloides stercoralis serology and diabetes mellitus. A total of 78 diabetic patients and 42 controls were evaluated. For a parasitological diagnosis, Baermann and Hoffman et al.'s methods were applied. The immunological diagnosis involved the indirect fluorescence antibody test, ELISA and Western blotting to detect IgG antibodies. The frequency of positive S. stercoralis serology in diabetics was 23% versus 7.1% in the control group (P<0.05). The odds ratio for diabetics was 3.9 (CI, 1.6-15.9, P<0.05). Diabetic patients with HbA(1c)< or =7 had a greater chance of testing negatively for S. stercoralis infection (OR: 1.5, P>0.05). Provided there are related cases of disseminated strongyloidiasis in diabetics and there is a higher frequency of asymptomaticity of the infection in this group, the immunological screening of these patients at risk could prevent severe and fatal outcomes of the disease.

Cryo-microtome sections of coproculture larvae of Strongyloides stercoralis and Strongyloides ratti as antigen sources for the immunodiagnosis of human strongyloidiasis

Comparou-se o emprego de cortes em congelacao de larvas de S. stercoralis e de S. ratti como fonte de antigenos na reacao de imunofluorescencia indireta (RIF) para o diagnostico da estrongiloidiase humana. Os antigenos foram obtidos de coproculturas de fezes humanas e de ratos, respectivamente. Soros de 123 individuos foram analisados sendo 54 de pacientes com estrongiloidiase e 69 controles. Empregou-se conjugado anti IgG humano marcado com fluorescencia nos titulos ideais de 10 para S. stercoralise 100 para S. ratti. A sensibilidade da RIF foi de 94,4 por cento e 92,5 por cento e a especificidade de 94,2 por cento e 97,1 por cento respectivamente para os antigenos de S. stercoralis e S. ratti...