Immune complexes as a tool for strongyloidiasis immunodiagnosis in kidney and liver transplant candidate.

Strongyloidiasis is a chronic and asymptomatic infection in immunocompetent patients. Immunocompromised patients, such as organ transplant candidates, can develop severe forms of this disease, and the best way to prevent progression to these forms is early diagnosis. Serological techniques using specific IgG and immune complexes (IC) detection can help in the diagnosis of these patients. This study aimed to detect specific anti-Strongyloides IC and IgG antibodies in kidney transplant (KT) and liver transplant (LT) candidates. A total of 100 blood samples was collected from transplant candidates (50 blood samples each from KT and LT candidates). Serum was obtained and analysed using enzyme-linked immunosorbent assay for IC and IgG detections. The IC levels showed frequencies of 18% and 2% in the KT and LT groups, respectively, whereas anti-Strongyloides IgG was detected in 34% and 12% of KT and LT candidates, respectively. The correlation between IC and IgG detection is poor in KT candidates, while in LT candidates, there is a significant positive correlation. The detection of IC can be an additional tool for the diagnosis of strongyloidiasis, especially when associated with the detection of specific IgG anti-Strongyloides antibodies.

In-vitro biological evaluation of 3,3',5,5'-tetramethoxy-biphenyl-4,4'-diol and molecular docking studies on trypanothione reductase and Gp63 from Leishmania amazonensis demonstrated anti-leishmania potential.

Available treatments for leishmaniasis have been widely used since the 1940s but come at a high cost, variable efficacy, high toxicity, and adverse side-effects. 3,3',5,5'-Tetramethoxy-biphenyl-4,4'-diol (TMBP) was synthesized through laccase-catalysis of 2,6-dimethoxyphenol and displayed antioxidant and anticancer activity, and is considered a potential drug candidate. Thus, this study aimed to evaluate the anti-leishmanial effect of TMBP against promastigote and amastigote forms of Leishmania (L.) amazonensis and investigated the mechanisms involved in parasite death. TMBP treatment inhibited the proliferation (IC50 0.62-0.86 µM) and induced the death of promastigote forms by generating reactive oxygen species and mitochondrial dysfunction. In intracellular amastigotes, TMBP reduced the percentage of infected macrophages, being 62.7 times more selective to the parasite (CC50 53.93 µM). TMBP did not hemolyze sheep erythrocytes; indicative of low cytotoxicity. Additionally, molecular docking analysis on two enzyme targets of L. amazonensis: trypanothione reductase (TR) and leishmanolysin (Gp63), suggested that the hydroxyl group could be a pharmacophoric group due to its binding affinity by hydrogen bonds with residues at the active site of both enzymes. TMBP was more selective to the Gp63 target than TR. This is the first report that TMBP is a promising compound to act as an anti-leishmanial agent.

Glucantime reduces mechanical hyperalgesia in cutaneous leishmaniasis and complete Freund's adjuvant models of chronic inflammatory pain.

OBJECTIVES: To evaluate the analgesic effect of Glucantime (antimoniate N-methylglucamine) in Leishmania amazonensis infection and complete Freund's adjuvant (CFA), chronic paw inflammation model, in BALB/c mice. METHODS: Two models of chronic inflammatory pain in BALB/c mice paw were used: infection with L. amazonensis and CFA stimulation. Both animals models received daily treatment with Glucantime (10 mg/kg, i.p.) and during the treatment was measured the mechanical hyperalgesia with electronic version of von Frey filaments. After the treatment, the paw skin sample was collected for analysis of myeloperoxidase (MPO) and N-acetyl-ß-glucosaminidase (NAG) activity, and IL-1ß, TNF-α, IL-6, IFN-γ and IL-10 cytokines production by ELISA. KEY FINDINGS: Leishmania amazonensis-induced chronic inflammation with significant increase in mechanical hyperalgesia, MPO and NAG activity, and IL-1ß, TNF-α and IL-6 production in the paw skin. Glucantime (10 mg/kg, i.p.) inhibited L. amazonensis-induced mechanical hyperalgesia and IL-1ß and IL-6 cytokines productions. In chronic inflammatory model induced by CFA, Glucantime treatment during 7 days inhibited CFA-induced mechanical hyperalgesia, MPO and NAG activity, and IL-1ß, TNF-α, IL-6 and IFN-γ production as well as increased IL-10 production. CONCLUSIONS: Our data demonstrated that Glucantime reduced the chronic inflammatory pain induced by L. amazonensis and CFA stimuli by inhibiting the hyperalgesic cytokines production.

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.

Detergent fraction of heterologous antigen to detect IgA and IgG in strongyloidiasis using saliva and serum paired samples.

Strongyloides stercoralis causes chronic asymptomatic infections in immunocompetent human hosts and systemic invasion in immunocompromised patients, developing into a fatal hyperinfection syndrome. IgA and IgG detection in saliva and serum paired samples were tested using total saline extract from Strongyloides venezuelensis (SE(*)) and its detergent phase (D) extracted with Triton X-114. Saliva and serum paired samples were obtained from: 25 patients with confirmed strongyloidiasis; 25 patients with other parasitoses and 20 from apparently healthy individuals. Sensitivity, specificity, diagnostic efficiency, positive and negative predictive values and likelihood ratio were calculated at the optimum point of reaction. Using D phase sensitivity and specificity to detect IgA in saliva were 76.0% and 88.9% and in serum 80.0% and 86.7%, respectively. To detect IgG, D phase showed sensitivity and specificity of 88.0% and 88.9% in saliva and 88.0% and 84.4% in serum, respectively. D phase proved to be specific and efficient and could be utilized as an alternative antigen for IgA and IgG detection in saliva and serum samples for strongyloidiasis diagnosis.