Human serum antibody reactivity towards Paracoccidioides brasiliensis antigens treated with sodium metaperiodate

Abstract

In this study, we evaluated the profile of anti-Paracoccidioides brasiliensis immunoglobulin isotypes in serum from patients with the acute and chronic forms of paracoccidioidomycosis, using the whole Paracoccidioides brasiliensis antigen and the antigen treated with sodium metaperiodate. All the immunoglobulin isotypes present in the serum from patients with the acute and chronic forms of paracoccidioidomycosis presented higher reactivity towards the whole antigen than to the antigen treated with metaperiodate (P < 0.05). The reactivity of IgG and IgM to the antigen treated with metaperiodate was greater in serum from patients with the acute form of the disease (P < 0.05), while IgA was more reactive in serum from patients with the chronic form (P < 0.05). There was greater reactivity of IgG1 and IgG2 to the whole antigen and the antigen treated with metaperiodate in the serum from patients with paracoccidioidomycosis than there was in serum from patients with other parasitic infections (P < 0.05). Furthermore, IgG1 from patients with the acute form recognized the 19kDa, 27kDa and 31kDa antigens in the western blot test. Thus, the results suggest that modifications to the epitopes of Paracoccidioides brasiliensis antigens may help to improve the immunodiagnosis of paracoccidioidomycosis.

Standardization and validation of Dot-ELISA assay for Paracoccidioides brasiliensis antibody detection

“…Historically, DI assay has been the technique of choice in the diagnosis of PCM, immunoenzymatic reactions such as ELISA and IB have also been used for the anti- P. brasiliensis antibodies detection [ 3 , 10 , 12 , 22 , 31 , 41 , 42 ]. However, despite showing good sensitivity the latter two have low specificity, and often require the previous adsorption of serum samples from patients with paracoccidioidomycosis with Histoplasma capsulatum or Candida albicans , dilution of serum in galactose or sodium metaperiodate antigen (gp43) treatment [ 43 – 45 ].…”

Effects of metaperiodate and urea solutions on the serological diagnosis of human sporotrichosis using an indirect ELISA test

“…We used two different strategies in order to improve the sensibility and specificity of the ELISA assay. The first strategy consisted of the addition of 100 μL per well of a 40 mM sodium metaperiodate (Merk) solution in 0.1 M acetate buffer solution, for 30 min at 37°C, in a darkroom; this was performed after the step of sensitizing the plate with S. schenckii antigens in order to eliminate carbohydrate epitopes sensitive to periodate oxidation [20]. The second strategy consisted of the addition of 100 μL/well of 6 M urea solution in phosphate buffer saline-Tween 20(PBS-T) for 1, 5, 10, and 20 min, at room temperature, after the incubation period with serum samples and prior to addition of the conjugate antibody.…”

Characterization of Paracoccidioides brasiliensis by FT-IR spectroscopy and nanotechnology

“…Because PCM does not have a simple identification and the standard method for mycological examination has low sensitivity, the gold-based nanoprobes described here bring a more accurate, quickly and inexpensively method for PCM diagnosis [32]. The non-crosslinking method has been developed to increase the sensitivity and specificity of the test conducted in which provides the discrimination of aggregation states of nanoprobes [10][11][12]15].…”