Strongyloides infection screening in transplant candidates: What is the best strategy?

BACKGROUND: The potential that Strongyloides stercoralis infection has to cause major morbidity and high mortality when the disseminated form occurs in transplant patients is of particular concern. METHODS: In this study, the objective was to observe S. stercoralis infection in patients who are candidates for transplantation by using parasitological, serological, and molecular techniques and to propose an algorithm for the detection of that infection in transplant candidates. RESULTS: By parasitological techniques, 10% of fecal samples were positive. Anti-Strongyloides antibodies immunoglobulin G were detected in 19.3% and 20.7% of patients by immunofluorescence assay and enzyme-linked immunosorbent assay, respectively. S. stercoralis DNA was observed in 17.3% of samples by conventional polymerase chain reaction and 32.7% of samples by quantitative polymerase chain reaction (qPCR). CONCLUSION: The set of results allows us to reinforce that a positive result by parasitological techniques and/or qPCR indicates that the specific treatment should be applied. However, the improvement of diagnostic techniques may suggest changes in the screening for strongyloidiasis in these patients.

Toxocara canis 30-35 kDa excretory-secretory antigen is an important marker in mice challenged by inocula containing different parasite load levels.

The Western-blotting technique was applied to identify antigenic fractions of excretory-secretory Toxocara canis antigen recognized by IgG antibodies throughout an experimental infection in mice challenged by different inocula. Mice were inoculated with 5, 50 and 500 embryonated eggs and serum samples were collected 15, 30, 60, 90 and 120 days post-infection. Serum samples were analyzed using an excretory-secretory Toxocara antigen. Antibodies recognized antigenic fractions from 30 to 90 kDa. The protein fraction of 30-35 kDa was the most frequently recognized regardless of the size of inoculum and the stage of infection represented by the different collection times, but the antigenic recognition was more evident in groups infected with 50 and 500 eggs. This study presents an antigenic panel of the excretory-secretory antigen of T. canis and suggests that the 30-35 kDa antigenic fraction is a promising marker of the infection and should be further explored in future studies on experimental toxocariasis.

Toxocara canis 30-35 kDa excretory-secretory antigen is an important marker in mice challenged by inocula containing different parasite load levels

ABSTRACT The Western-blotting technique was applied to identify antigenic fractions of excretory-secretory Toxocara canis antigen recognized by IgG antibodies throughout an experimental infection in mice challenged by different inocula. Mice were inoculated with 5, 50 and 500 embryonated eggs and serum samples were collected 15, 30, 60, 90 and 120 days post-infection. Serum samples were analyzed using an excretory-secretory Toxocara antigen. Antibodies recognized antigenic fractions from 30 to 90 kDa. The protein fraction of 30-35 kDa was the most frequently recognized regardless of the size of inoculum and the stage of infection represented by the different collection times, but the antigenic recognition was more evident in groups infected with 50 and 500 eggs. This study presents an antigenic panel of the excretory-secretory antigen of T. canis and suggests that the 30-35 kDa antigenic fraction is a promising marker of the infection and should be further explored in future studies on experimental toxocariasis.

A Novel Saliva RT-LAMP Workflow for Rapid Identification of COVID-19 Cases and Restraining Viral Spread.

Rapid diagnostics is pivotal to curb SARS-CoV-2 transmission, and saliva has emerged as a practical alternative to naso/oropharyngeal (NOP) specimens. We aimed to develop a direct RT-LAMP (reverse transcription loop-mediated isothermal amplification) workflow for viral detection in saliva, and to provide more information regarding its potential in curbing COVID-19 transmission. Clinical and contrived specimens were used to optimize formulations and sample processing protocols. Salivary viral load was determined in symptomatic patients to evaluate the clinical performance of the test and to characterize saliva based on age, gender and time from onset of symptoms. Our workflow achieved an overall sensitivity of 77.2% (n = 90), with 93.2% sensitivity, 97% specificity, and 0.895 Kappa for specimens containing >102 copies/µL (n = 77). Further analyses in saliva showed that viral load peaks in the first days of symptoms and decreases afterwards, and that viral load is ~10 times lower in females compared to males, and declines following symptom onset. NOP RT-PCR data did not yield relevant associations. This work suggests that saliva reflects the transmission dynamics better than NOP specimens, and reveals gender differences that may reflect higher transmission by males. This saliva RT-LAMP workflow can be applied to track viral spread and, to maximize detection, testing should be performed immediately after symptoms are presented, especially in females.

Diagnosis of human strongyloidiasis: Application in clinical practice.

This review considers the advantages and disadvantages of parasitological techniques, methods of detecting antibodies and antigens, as well as molecular biology techniques in the diagnosis of human strongyloidiasis. In addition, it elucidates the potential of different techniques for rapid and effective detection of clinical cases, thus enabling early treatment and preventing fatal consequences of this helminthiasis.

Tratamento farmacológico da estrongiloidíase em pacientes transplantados / Pharmacological treatment of strongilloidiasis in transplanted patients

O objetivo deste artigo foi comparar o uso da ivermectina e do albendazol em pacientes transplantados e relatar os respectivos sucessos terapêuticos nessa população. Foram analisados artigos que abordassem relatos de casos publicados nos últimos 4 anos no PubMed® relacionando os descritores "transplante de órgãos", "estrongiloidíase" e "tratamento". Foram encontrados e analisados dez relatos de caso que abordaram a estrongiloidíase em situa- ção pós-transplante contemplando 13 indivíduos. Desses, cinco (38,5%) utilizaram ambos os medicamentos, dos quais quatro (80%) se curaram, tendo recebido albendazol e ivermectina por via subcutânea (50%) ou albendazol e ivermectina por vias oral/ subcutânea (50%). O paciente que morreu recebeu albendazol e ivermectina por via subcutânea. Sete (53,8%) indivíduos utiliza- ram apenas ivermectina, dos quais três (42,8%) se curaram tendo recebido o medicamento oral (dois pacientes) ou subcutâneo (um paciente); dois (28,6%) morreram recebendo o medicamento via oral, dois (28,6%) usaram profilaticamente via oral e apenas um não manifestou sintomas. Apenas um (7,7%) indivíduo utilizou somente albendazol via oral tendo sobrevivido à infecção. A uti- lização combinada dos medicamentos ivermectina e albendazol parece ter efeito positivo no tratamento da estrongiloidíase. A administração da ivermectina por via subcutânea apresentou resultados promissores, contudo estudos controlados de siner- gia medicamentosa e vias de administração devem ser realizados para efetiva avaliação.

The objective of this article was to compare the use of ivermec- tin and albendazole in transplanted patients and to report the respective therapeutic successes in this population.Articles ad- dressing case reports published in the last 4 years in the PubMed relating the descriptors "organ transplantation", "strongyloidia- sis", and "treatment" were analyzed. Ten case reports addres- sing strongyloidiasis in a post-transplant situation, covering 13 individuals, were found and analyzed. Of these, five (38.5%) used both drugs of which 4 (80%) were cured having received subcu- taneous albendazole and ivermectin (50%) or oral/subcutaneous albendazole and ivermectin (50%). The patient who died received subcutaneous albenzadole and ivermectin. Seven (53.8%) indi- viduals used only ivermectin, of which three (42.8%) were cured having received the oral (2/3) or subcutaneous (1/3) medication, two (28.6%) died receiving the oral medication, and two (28.6%) used oral medication prophylactically, and only one did not show symptoms. Only one (7.7%) individual used only oral albenzadole and survived the infection. The combined use of the drugs iver- mectin and albendazole seems to have a positive effect on the treatment of strongyloidiasis. The administration of subcuta- neous Ivermectin has shown promising results; however, con- trolled studies of drug synergy and administration routes shall be performed for effective evaluation.

Evaluation of the Dot-ELISA as a diagnostic test for human strongyloidiasis based on the detection of IgA in saliva.

This study aimed to evaluate the use of saliva samples in the Dot-ELISA test for immunodiagnosis of human strongyloidiasis. The Dot-ELISA presented similar results to the ELISA test, with 70% and 60% sensitivity and 85% and 90% specificity, respectively, for IgA in the saliva. The Dot-ELISA with alternative saliva samples may be a suitable tool for diagnosing human strongyloidiasis, especially in populations with high levels of exposure to helminth.

Could mucin 16 and colony-stimulating factor 2-receptor beta possible graft versus host disease biomarkers? Medical hypotheses.

Graft versus host disease (GVHD) occurs after bone marrow transplantation and is one of the most important causes of death worldwide. Reviews demonstrated GVHD patients with involvement of various tissues and organs, such as salivary glands. The diagnosis of acute GVHD has been the biopsies and the histopathologic evaluation of tissue from an involved organ. These procedures are invasive. Saliva proteins as possible biomarker for GVHD could facilitate the management and diagnosis accuracy. For support the proposed hypotheses, in this pilot study we collected whole saliva samples from patients with undergoing allogeneic hematopoietic cell transplantation (HCT) and from healthy subjects. Samples were collected prospectively between pre-transplant, thirty days, one hundred and, two hundred days after transplant. The proteomic profile was analyzed using SDS-PAGE and LCMS-ESI-IT-TOF mass spectrometry. The relevant personal data, past medical history were also recorded. The most relevant proteins found exclusively in GVHD patients were: CSF2RB, Protocadherin (Pcdh) Fat 2 precursor, protein capicua homolog isoform CIC-S, MUC16 and RGPD8_HUMAN RANBP2. This study aims to conduct an initial evaluation of the possible presence of such biomarkers in saliva from GVHD patients, and suggested a potential application of proteomics analysis as a alternative method to diagnose GVHD.

DIAGNOSIS OF Strongyloides stercoralis INFECTION IN IMMUNOCOMPROMISED PATIENTS BY SEROLOGICAL AND MOLECULAR METHODS.

Strongyloidiasis is a potentially serious infection in immunocompromised patients. Thus, the availability of sensitive and specific diagnostic methods is desirable, especially in the context of immunosuppressed patients in whom the diagnosis and treatment of strongyloidiasis is of utmost importance. In this study, serological and molecular tools were used to diagnose Strongyloides stercoralis infections in immunosuppressed patients. Serum and stool samples were obtained from 52 patients. Stool samples were first analyzed by Lutz, Rugai, and Agar plate culture methods, and then by a quantitative real time polymerase chain reaction (qPCR). Serum samples were evaluated by an enzyme-linked immunosorbent assay (ELISA) using a soluble (AS) or a membrane fractions antigen (AM) obtained from alkaline solutions of the filariform larvae of Strongyloides venezuelensis. Of the 52 immunosuppressed patients, three (5.8%) were positive for S. stercoralis by parasitological methods, compared to two patients (3.8%) and one patient (1.9%) who were detected by ELISA using the AS and the AM antigens, respectively. S. stercoralis DNA was amplified in seven (13.5%) stool samples by qPCR. These results suggest the utility of qPCR as an alternative diagnostic tool for the diagnosis of S. stercoralis infection in immunocompromised patients, considering the possible severity of this helminthiasis in this group of patients.

IMMUNODIAGNOSIS OF HUMAN STRONGYLOIDIASIS: USE OF SIX DIFFERENT ANTIGENIC FRACTIONS FROM Strongyloides venezuelensis PARASITIC FEMALES.

The aim of this study was to evaluate six different antigenic fractions from Strongyloides venezuelensis parasitic females for the immunodiagnosis of human strongyloidiasis. Soluble and membrane fractions from S. venezuelensis parasitic females were prepared in phosphate-buffered saline (SSF and SMF, respectively), Tris-HCl (TSF and TMF, respectively), and an alkaline buffer (ASF and AMF, respectively). Serum samples obtained from patients with strongyloidiasis or, other parasitic diseases, and healthy individuals were analyzed by enzyme-linked immunosorbent assay (ELISA). Soluble fractions SSF, TSF, and ASF showed 85.0%, 75.0%, and 80.0% sensitivity and 93.1%, 93.1%, and 87.5% specificity, respectively. Membrane fractions SMF, TMF, and AMF showed 80.0%, 75.0%, and 85.0% sensitivity, and 95.8%, 90.3%, and 91.7% specificity, respectively. In conclusion, the present results suggest that the fractions obtained from parasitic females, especially the SSF and SMF, could be used as alternative antigen sources in the serodiagnosis of human strongyloidiasis.

Membrane fractions from Strongyloides venezuelensis in the immunodiagnosis of human strongyloidiasis.

Strongyloides venezuelensis is a parasitic nematode of rodents frequently used to obtain heterologous antigens for the immunological diagnosis of human strongyloidiasis. The aim of this study was to evaluate membrane fractions from S. venezuelensis for human strongyloidiasis immunodiagnosis. Soluble and membrane fractions were obtained in phosphate saline (SS and SM) and Tris-HCl (TS and TM) from filariform larvae of S. venezuelensis. Ninety-two serum samples (n = 92) were obtained from 20 strongyloidiasis patients (Group I), 32 from patients with other parasitic diseases (Group II), and 40 from healthy individuals (Group III), and were analyzed by enzyme-linked immunosorbent assay (ELISA). Soluble fractions (SS and TS) showed 90.0% sensitivity and 88.9% specificity, whereas the membrane fractions (SM and TM) showed 95.0% sensitivity and 94.4% specificity. The present results suggest the possible use of membrane fractions of S. venezuelensis as an alternative antigen for human strongyloidiasis immunodiagnosis.

Membrane fractions from Strongyloides venezuelensis in the immunodiagnosis of human strongyloidiasis / Frações de membrana de Strongyloides venezuelensis para o imunodiagnóstico da estrongiloidíase humana

Strongyloides venezuelensis is a parasitic nematode of rodents frequently used to obtain heterologous antigens for the immunological diagnosis of human strongyloidiasis. The aim of this study was to evaluate membrane fractions from S. venezuelensis for human strongyloidiasis immunodiagnosis. Soluble and membrane fractions were obtained in phosphate saline (SS and SM) and Tris-HCl (TS and TM) from filariform larvae of S. venezuelensis. Ninety-two serum samples (n = 92) were obtained from 20 strongyloidiasis patients (Group I), 32 from patients with other parasitic diseases (Group II), and 40 from healthy individuals (Group III), and were analyzed by enzyme-linked immunosorbent assay (ELISA). Soluble fractions (SS and TS) showed 90.0% sensitivity and 88.9% specificity, whereas the membrane fractions (SM and TM) showed 95.0% sensitivity and 94.4% specificity. The present results suggest the possible use of membrane fractions of S. venezuelensis as an alternative antigen for human strongyloidiasis immunodiagnosis.

Strongyloides venezuelensis é um nematódeo parasita de roedores, frequentemente usado como antígeno heterólogo para o diagnóstico imunológico da estrongiloidíase humana. O objetivo deste estudo foi avaliar frações de membrana de S. venezuelensis para o imunodiagnóstico da estrongiloidíase humana. Para tanto, frações solúveis e de membrana foram obtidas em solução salina fosfato (SS e MS) e Tris-HCl (ST e MT) de larvas filarioides de S. venezuelensis. Amostras de soro de 92 indivíduos, sendo 20 com estrongiloidíase (Grupo I); 32 com outras parasitoses (Grupo II), e 40 indivíduos saudáveis (Grupo III), foram analisadas pelo teste Imunoenzimático (ELISA). As frações solúveis (SS e ST) apresentaram 90,0% e 88,9%, enquanto que as frações de membrana (MS e MT) demonstraram 95,0% e 94,4%, de sensibilidade e especificidade, respectivamente. Os resultados obtidos permitem indicar as frações de membranas como antígeno alternativo para o diagnóstico da estrongiloidíase humana.

Parasitological and molecular diagnosis in experimental Strongyloides venezuelensis infection.

Strongyloides venezuelensis is a parasitic nematode of rats which is frequently used as a model to study human and animal strongyloidiasis. The aim of this study was to evaluate the correlation between parasitological and molecular diagnosis in Strongyloides venezuelensis infection. PCR assays were used to detect S. venezuelensis DNA in fecal samples obtained from experimentally infected Rattus norvegicus. The results showed a higher sensitivity of the PCR assay in detecting the infection compared to parasitological methods.