The present work proposed to correlate serum antibody avidity and salivary antibody titers as parameters for time of infection and antigen exposure in a cohort study evaluating leprosy patients in different periods of treatment. Colorimetric enzyme-immunoassays for salivary antibodies, serum antibody IgG titers and avidities were performed in the samples. Anti-PGL-1 IgA and IgM salivary antibod...

BACKGROUND Early diagnosis of congenital toxoplasmosis (CT) is difficult when specific immunoglobulin M (IgM) antibodies are absent, or if persist for months, in the newborn infant's blood. OBJECTIVES To study the risk factors of neonatal toxoplasmosis and to compare different immunologic profiles (Toxoplasma-specific IgM, IgA antibodies and the avidity of IgG antibodies) with polymerase chai...

The measurement of the avidity of cytomegalovirus (CMV) immunoglobulin G (IgG) antibodies has been shown by several investigators to be useful in identifying and excluding primary CMV infections in pregnant women. In this work, we examined the diagnostic utility of reflex testing of CMV IgM-positive specimens from pregnant women by using a CMV IgG avidity assay. The utility of this approach was...

The seroprevalence of toxoplasmosis in 832 pregnant women in Miracema, Rio de Janeiro, was determined and 75.1% (625) and 2.0% (17) were anti-Toxoplasma gondii IgG and IgM positive, respectively. Out of the 17 IgM positive pregnant women, only one had low avidity IgG corresponding to the acute phase of the infection. All the other women presented with high avidity IgG and also presented with re...

BACKGROUND Interpretation of positive cytomegalovirus (CMV) immunoglobulin M (IgM) in the first trimester of pregnancy is ill-defined. We aimed to quantify the risk of fetal transmission in women with positive CMV IgM in the first trimester. METHODS A retrospective cohort of women (2009-2011) was tested for CMV immunoglobulin G (IgG) and IgM before 14 weeks of gestation. IgG avidity was teste...

Toxoplasmosis is an usually asymptomatic worldwide disseminated infection. In its congenital presentation it may lead to abortion or fetal malformations. Antenatal evaluation is considered of paramount importance to identify seronegative women and allow for prophylaxis. Recent improvements in sensitivity of IgM tests has made IgM detection an extremely protracted acute phase marker, and IgG avi...

An enzyme-linked immunosorbent assay-based immunoglobulin G (IgG) antibody avidity test was evaluated by using sera from 57 patients with acute dengue infection. Overall, 55 of 57 patients were correctly classified (27 of 27 with primary dengue and 28 of 30 with secondary dengue). We conclude that the IgG avidity test can be useful for differentiating between acute, primary, and secondary dengu...

The present work investigated the serum antibody profiles in 37 patients with American tegumentary leishmaniasis, who were attended at Hospital de Clinicas - Universidade Federal de Uberlandia, MG, Brazil. The immunoglobulin class and IgG subclass profiles were analyzed by indirect ELISA using Leishmania (Leishmania) amazonensis soluble antigen. The antibody avidity was determined by 6 M urea t...

Antibody avidity for antigens following disease or vaccination increases with affinity maturation and somatic hypermutation. In this study, we followed children and adults in Bangladesh for 1 year following oral cholera vaccination and measured the avidity of antibodies to the T cell-dependent antigen cholera toxin B subunit (CTB) and the T cell-independent antigen lipopolysaccharide (LPS) in c...