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Convalescent Sera (convalescent + sera)
Selected AbstractsNeutralizing antibody response variation against dengue 3 strainsJOURNAL OF MEDICAL VIROLOGY, Issue 10 2008Mayling Alvarez Abstract To evaluate the neutralizing antibody activity of a human sera panel against seven strains of the homotypic virus. Sera were collected from DENV-3 immune individuals. Two DENV-3 genotypes and strains isolated at different time-points during the 2000 and 2001,2002 Havana epidemics were included. A panel of 20 late convalescent sera collected 16,18 months after acute illness from DF and DHF patients are studied. These individuals were infected during the 2001,2002 Havana DENV-3 epidemic. All but four sera collected from DF cases had a secondary DENV-1/DENV-3 infection. Sera neutralizing antibody titer against the seven DENV-3 strains were determined by plaque reduction neutralization technique. Sera samples were tested simultaneously. Studied sera showed higher levels of neutralizing antibodies to DENV-3 strains of genotype III compared to genotype V. Interesting, higher levels of neutralizing antibodies were detected to DENV-3 strain isolated at the end of the epidemic 2001,2002. An increased tendency of GMT of neutralizing antibodies according to epidemic evolution was observed for the 2001,2002 outbreak. In general, antibody levels in sera collected from DF cases were higher. Differences in the neutralization capacity of immune DENV-3 sera tested against two homologous genotypes including strains of the same genotype are demonstrated. Observed results suggest that virus changed in the course of the epidemic. The implications of this finding in terms of dengue pathogenesis and vaccine development need to be considered. J. Med. Virol. 80:1783,1789, 2008. © 2008 Wiley-Liss, Inc. [source] Identification of immunogenic cell wall-associated proteins of Streptococcus suis serotype 2PROTEINS: STRUCTURE, FUNCTION AND BIOINFORMATICS, Issue 17 2008Anding Zhang Abstract Streptococcus suis serotype 2 (SS2) is a porcine and human pathogen with adhesive and invasive properties. The absence of suitable vaccine or virulent marker can be the bottleneck to control SS2 infection. An immunoproteome-based approach was developed to identify candidate antigens of SS2 for vaccine development. Hyperimmune sera, convalescent sera, and control sera were analyzed for reactivity by Western Blot against SS2 cell wall-associated proteins (WAPs) separated by 2-DE. A total of 34 proteins were identified by immunoproteomic analysis, of which 15 were recognized by both hyperimmune sera and convalescent sera, including most WAPs currently characterized as SS2 vaccine candidate antigens: muramidase-released protein (MRP), surface protein SP1 (Sao), and glyceraldehyde-3-phosphate dehydrogenase (GapdH). The novel immunogenic proteins may be developed as alternative antigens for further study of SS2 vaccine and diagnostics. [source] Antibody response to the patient's own Haemophilus influenzae isolate can support the aetiology in lower respiratory tract infectionsAPMIS, Issue 4-5 2004Brief report In order to understand the clinical importance of Haemophilus influenzae isolated from sputum samples, an indirect immunofluorescence (IF) assay was developed, using the patient's own isolate as the antigen. The method was tested on samples from six patients with lower respiratory tract infection (LRTI) and H. influenzae isolated from blood (n=2), sputum (n=3) or both (n=1), and on two healthy adults with H. influenzae isolated from the nasopharynx. Between acute and convalescent sera, a four-fold IgG antibody increase was achieved in five of six LRTI patients, including the three blood culture-positive patients. One LRTI patient and the two asymptomatic carriers showed stable antibody levels against their own isolate. Although small, the study indicates that indirect IF can be a promising tool for determining whether a H. influenzae strain represents the probable cause of infection or just a strain colonising the airways. More extensive studies should be performed in order to establish the usefulness of the assay. [source] Determination of pertactin IgG antibodies for the diagnosis of pertussisCLINICAL MICROBIOLOGY AND INFECTION, Issue 7 2003B. Trollfors Objective, To compare increases in serum IgG antibody against pertactin with increases in IgG against pertussis toxin and filamentous hemagglutinin (FHA) in non-vaccinated children, children vaccinated with pertussis toxoid, and adults, all with culture-confirmed pertussis. Methods, During a double-blind, placebo-controlled, efficacy trial of a monocomponent pertussis toxoid vaccine, acute and convalescent sera were obtained from study children and family members with suspected pertussis. In the present study, IgG antibodies against pertactin, pertussis toxin and FHA (determined by ELISA) were compared in 207 individuals with culture-verified pertussis and paroxysmal cough for ,,21 days. Results, Significant increases in geometric mean serum IgG against all antigens occurred in non-vaccinated children, but more children responded against pertussis toxin and FHA than against pertactin (96%, 97%, and 62%, respectively). Of the children who had pertussis even though they were vaccinated with the pertussis toxoid vaccine, 97% responded to FHA, while responses to pertussis toxin and pertactin were less common (68% and 61%, respectively). In the 20 adults, the proportions of responders to FHA, pertussis toxin and pertactin were 90%, 80% and 55%, respectively. Conclusion, Determination of IgG against pertussis toxin and FHA in paired sera in non-vaccinated children with pertussis is a more sensitive diagnostic tool than determination of IgG against pertactin. Pertactin IgG determinations might be of value as a complement to the other antibody assays in vaccinated children and in adults. [source] | ||||||||||