Objective: To assess the value of detecting IgA antibodies for the diagnosis of a recently acquired primary Toxoplasma infection.
Methods: IgA antibodies were screened in sera from 87 women with different serological profiles of Toxoplasma gondii IgM and IgG antibodies and Toxoplasma-specific IgG avidity. The IgM and IgG antibodies and the IgG avidity were measured with an automated Vitek Immuno Diagnostic Assay System (VIDAS). Anti-T.gondii IgA was measured with Platelia Toxo IgA TMB kits.
Results: All 12 sera obtained from women with clinical and/or serological evidence of a recently acquired Toxoplasma infection were positive for IgA. In 42 serum samples obtained more than 6 months after T. gondii infection from women with no clinical evidence of infection, but who had a positive IgM test and a high IgG avidity index, the IgA-enzyme linked immunosorbent assay (ELISA) test results were positive, negative, and doubtful in 16 (38.1%), 23 (54.8%), and 3 (7.1%) sera, respectively. In eight women, IgA was detected in sera collected more than 9 months after the onset of infection. The IgA test result was also positive in 11 of 12 sera (91.7%) obtained from women with no clinical evidence of toxoplasmosis, but who had a positive IgM test and a borderline IgG avidity index. The IgA-ELISA was negative in 21 sera obtained more than 2 years after the onset of T. gondii infection from women with no clinical evidence of toxoplasmosis, but who had a negative IgM test and a positive IgG test.
Conclusion: These results show that IgA is not a dependable marker for a recently acquired primary Toxoplasma infection.
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http://dx.doi.org/10.1002/pd.2052 | DOI Listing |
Unlabelled: How changes in the quality of anti-viral antibody (Ab) responses due to pre-existing or acquired CD4 T cell insufficiency affect virus evolution during persistent infection are unknown. Using mouse polyomavirus (MuPyV), we found that CD4 T cell depletion before infection results in short-lived plasma cells secreting low-avidity antiviral IgG with limited BCR diversity and weak virus-neutralizing ability. CD4 T cell deficiency during persistent infection incurs a shift from a T-dependent (TD) to T-independent (TI) Ab response, resembling the pre-existing TI Ab response.
View Article and Find Full Text PDFCureus
November 2024
Microbiology, Madras Medical College, Rajiv Gandhi Government General Hospital, Chennai, IND.
Introduction Cytomegalovirus (CMV) is often associated with mortality and significant morbidity following renal transplantation leading to graft rejection or dysfunction. Primary CMV infection refers to the first detection of the virus in a person who has no prior evidence of CMV exposure before transplantation. CMV has a unique property called latency.
View Article and Find Full Text PDFWorld J Virol
December 2024
OIE Reference Center for West Nile Disease, Istituto Zooprofilattico Sperimentale, G. Caporale, Teramo 64100, Italy.
Background: The diagnosis of West Nile virus (WNV) is challenging due to short-term and low-level viremia, flavivirus cross-reactivity, and long immunoglobulin M (IgM) persistence.
Aim: To evaluate different methods for WNV detection [reverse transcription-polymerase chain reaction (RT-PCR), IgM/IgG antibodies, IgG avidity] in serum, cerebrospinal fluid (CSF), and urine samples of patients with confirmed WNV infection.
Methods: The study included patients with confirmed WNV neuroinvasive infection ( = 62), asymptomatic WNV seropositive individuals ( = 22), and individuals with false-positive WNV IgM antibodies ( = 30).
Exp Parasitol
January 2025
Laboratory of Molecular Parasitology, Scientific Center of Zoology and Hydroecology, NASRA, 7P. Sevak St, Yerevan, 0014, Armenia; Laboratory of Zology, Research Institute of Biology, Yerevan State University, 1 Alex Manoogian, Yerevan, 0025, Republic of Armenia.
Toxoplasmosis which is caused by T. gondii, is common among humans and animals. T.
View Article and Find Full Text PDFLong-term allograft survival is limited by humoral-associated chronic allograft rejection, suggesting inadequate constraint of humoral alloimmunity by contemporary immunosuppression. Heterogeneity in alloreactive B cells and the incomplete definition of which B cells participate in chronic rejection in immunosuppressed transplant recipients limits our ability to develop effective therapies. Using a double-fluorochrome single-HLA tetramer approach combined with single-cell culture, we investigated the B-cell receptor (BCR) repertoire characteristics, avidity, and phenotype of donor HLA-DQ reactive B cells in a transplant recipient with end-stage donor specific antibody (DSA)-associated cardiac allograft vasculopathy while receiving maintenance immunosuppression (tacrolimus, mycophenolate mofetil, prednisone).
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