IgG1, IgG4, and IgE antibody responses in human strongyloidiasis by ELISA using Strongyloides ratti saline extract as heterologous antigen

Abstract

The aim of this study was to evaluate total IgG, IgG1, IgG4, and IgE antibody responses in human strongyloidiasis by enzyme-linked immunosorbent assay (ELISA) using Strongyloides ratti saline extract as heterologous antigen for a possible clinical utility of the assay. A total of 40 serum samples of patients who were shedding Strongyloides stercoralis larvae in feces (group I), 30 sera from patients with other intestinal parasites (group II), and 30 sera from subjects with negative results in three parasitological assays (group III) were analyzed to detect total IgG, IgG1, IgG4, and IgE to Strongyloides spp. by ELISA and expressed in ELISA index. Levels of total IgG anti-Strongyloides spp. were significantly higher in patients of group I than in groups II (p=0.0005) and III (p<0.0001). Levels of specific IgG1, IgG4, and IgE of group I were also significantly higher than in groups II and III, respectively. There was a significant positive correlation between specific IgE and IgG4 (r=0.6524; p=0.0084) and IgG1 and IgG4 (r=0.5398; p=0.0171). It can be concluded that the detection of specific IgE, IgG1, and IgG4 subclasses rather than total IgG antibodies to Strongyloides spp. using the S. ratti antigen showed to be an additional tool for improving the serodiagnosis of human strongyloidiasis.

Detection of Strongyloides stercoralis infection among cancer patients in a major hospital in Kelantan, Malaysia

“…This result is consistent with two other published studies, which reported the activation of infection in patients with low immunity caused by chemotherapy. (19,21) Our observation that there is a higher percentage of patients with low ANC (≤ 1.5 × 10 3 cells/mL) among those who were positive for Strongyloides infection, as compared to those who were found negative by all tests, was also in agreement with earlier results.…”

“…in the chronic phase of Strongyloides infection, there is a decline in the level of IgE, while the level of total IgG remains elevated and IgG4 becomes detectable. (21,22) Furthermore, we found that the ELISAs for the detection of Strongyloides-specific IgG and IgG4 antibodies among cancer patients were significantly higher than those among healthy blood donors at the same hospital (data not shown). In another study by our group involving samples from 26 immunocompetent patients with parasitologically proven infection and 55 control samples, Strongyloides IgG-ELISA was found to be significantly more sensitive but less specific than IgG4-ELISA (p < 0.05).…”

Strongyloidiasis – the most neglected of the neglected tropical diseases?

“…Several immunological tests, such as ELISA, IFAT and Western blot, have also been described for the diagnosis of strongyloidiasis. 10,11 These assays show variable sensitivity and specificity depending on antigen preparation and immunoglobulin isotypes used, and on the population tested. In specific target populations, such as immigrants to non-endemic regions, serology has proven to be a valuable tool for screening and for the evaluation of therapies; 12 however, serology seems to lack sufficient sensitivity to diagnose recently acquired infections.…”

Real-Time Polymerase Chain Reaction for Detection of Strongyloides stercoralis in Stool

“…6 -8 Improvements to serological methods such as isotype detection and enzyme-linked immunosorbent assay using recombinant antigen are under evaluation. 7,9 Molecular methods are rapidly replacing the traditional culture methods. Real-time polymerase chain reaction (PCR) is reported to be specific and sensitive for the diagnosis of strongyloidiasis.…”