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Toxoplasmosis
Published in Vincenzo Berghella, Maternal-Fetal Evidence Based Guidelines, 2022
Corina N. Schoen, Elizabeth A. Morgan
The Sabin–Feldman dye test (SFDT) is still considered the “gold standard” for maternal infection [4]. It detects the presence of anti-Toxoplasma-specific antibodies (total Ig). The absolute antibody titer is also important: values over 250 IU/mL are considered highly suggestive of recent infection. IgG avidity testing is based on the increase in functional affinity (avidity) between Toxoplasma-specific IgG and antigen over time, as the host immune response evolves. Pregnant women with high avidity antibodies are those who have been infected at least 3–5 months earlier [25]. In a prospective cohort of 139 women, an avidity index above 30% was not associated with any positive AF testing or congenital infection [26]. Current testing cannot define which specific strain of T. gondii caused the antibody response, so that reinfection with the same or different strains cannot be determined.
Neuromuscular Junction Disorders
Published in Philip B. Gorelick, Fernando D. Testai, Graeme J. Hankey, Joanna M. Wardlaw, Hankey's Clinical Neurology, 2020
Diana Mnatsakanova, Qin Li Jiang
Acetylcholine receptor-binding antibody is the most specific serologic test and with current assays is positive in approximately 85% of patients with generalized disease and 50–65% of patients with ocular MG. Serum antibody titer does not correlate with clinical severity. High levels of acetylcholine receptor-modulating antibody may be associated with thymoma.
Relation of Antigliadin Antibodies to Gluten-Sensitive Enteropathy
Published in Tadeusz P. Chorzelski, Ernst H. Beutner, Vijay Kumar, Tadeusz K. Zalewski, Serologic Diagnosis of Celiac Disease, 2020
Wim Th. J. M. Hekkens, Marja van Twist - de Graaf
Figure 6 shows the antiprolamin antibody patterns of three celiac children. Figure 6A is of a patient on a normal diet. The IgG activity is most pronounced against gliadin, whereas this is the case with the IgA activity against hordein. The IgM antibody titer is obviously low, but there is some reactivity with two hordein proteins. From patient L-318 the IgG and IgA activity is mainly directed against gliadin; the activity against hordein is also considerable and in the case of IgM the most pronounced. Although the affinity for the different prolamin proteins is variable, the band patterns are very similar. The pattern of the same patient after a gluten-free diet of 11 months changed drastically (Figure 6B). On the whole the antibody titer became lower. Besides, the antigliadin antibody of the IgG and IgA antibodies decreased greatly. The main activity is left against hordein. Figure 6C shows the prolamin pattern of an untreated patient. The activities of G- and A-class antibodies against gliadin and hordein are striking. The pattern of antiprolamin antibodies we have found so far is inconsistent. No conclusion can be drawn regarding a special band or pattern that could be responsible for the toxicity from the blots obtained from about ten patients tested.
Evaluation of clinical, diagnostic features and therapeutic outcome of neurobrucellosis: a case series and review of literature
Published in International Journal of Neuroscience, 2022
Sudipta Patra, Vandana Kalwaje Eshwara, Aparna Ramakrishna Pai, Muralidhar Varma, Chiranjay Mukhopadhyay
Blood culture using the automated BacT/ALERT® 3D (bioMérieux, India) system and SAT using serum specimens were performed in all patients. Antibody titer ≥1:160 was considered as significant in serum specimens. CSF specimens were also subjected to culture, and tested for total cell count, protein, glucose, adenosine deaminase (ADA) and chloride. CSF abnormalities were considered as increased WBC count (>10 cells/mm3) with lymphocytic predominance, elevated protein levels (>45 mg/dL), and/or reduced glucose levels (<40 mg/dL). Isolated organisms were presumptively identified by Gram’s staining, oxidase test and Christensen’s urease test. Isolates were further confirmed by multiplex polymerase chain reaction (PCR) targeting the bcsp31 gene of Brucella for the simultaneous identification of genus Brucella (208 bp), Brucella abortus (498 bp), and Brucella melitensis (731 bp) [9].
Enhanced stability of foot-and-mouth disease vaccine antigens with a novel formulation
Published in Pharmaceutical Development and Technology, 2022
Jing Li, Rong Zhang, Huiqing Yang, Yanming Wei
Adjuvant, a key component, has an important effect on protein stability (Harmsen et al. 2015). This study showed the stability of vaccine prepared with ISA206, while the situation about other adjuvants, such as ISA201, was not clear. Thus, future investigation should be required to assess vaccine stability prepared with ISA201. In addition, antibody titer is an important parameter to evaluate vaccine quality. The problems of whether the formulation could influence the immunogenicity and whether stabilized vaccine contributes to antibody titer are the two considerable aspects to be fully considered. Therefore, further study should also take immune response in animals into account. Overall, these studies could provide a new insight into the improvement of the stability of inactivated vaccine.
An overview of advancement in aptasensors for influenza detection
Published in Expert Review of Molecular Diagnostics, 2022
Varsha Gautam, Ramesh Kumar, Vinod Kumar Jain, Suman Nagpal
It is perhaps another test for calibrating influenza typing recommended by WHO, with the principle being that the nucleic acids of viruses encode proteins, such as hemagglutinin, expressed on the viral surface [43]. Furthermore, HI assays have found wide use in the study of antigenic variations between strains in the surveillance of human influenza, i.e. allowing the identification of subtypes H3N8 and H7N7 of equine influenza. This also provides us knowledge of how much concentration of an antibody is present in the patient sample. The test is based on the influenza HA hemagglutination activity and the efficiency of HA specific antibodies to suppress the influenza virus by agglutinating the erythrocytes (Figure 5). These hemagglutinin proteins bind to or clump around erythrocytes to form a lattice that settles sporadically in the bottom of the test tube or microtiter well. The erythrocytes do not clump in the absence of viruses. Alternatively, forming a circular button. If antibodies against the suspected virus are present, the attachment of erythrocytes to viral protein hemagglutinin is inhibited. The results are expressed as hemagglutination titer, the highest dilution of serum that prevents hemagglutination. When there are no antibodies against the virus in the allantoic fluid, hemagglutination may occur in the wells diluted in sequence. A four-fold or greater rise in antibody titer from HI is considered evidence of infection. HI does not need cytopathy and doesn’t always occur in this assay for any influenza virus [44,45].