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Query: UNIPROT:O75191 (H. influenzae)
 4,961 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Rapid diagnosis of Haemophilus influenzae type b meningitis is possible using immunological tests for capsular antigen (polyribophosphate, PRP), such as countercurrent immunoelectrophoresis (CIE) and latex particle agglutination (LPA). We compared two tests in monkeys with evolving, serially quantitated H. influenzae type b bacteremia (n = 23) and meningitis (n = 21). In vitro, the LPA test was sensitive to 0.5 ng of PRP/ml of saline, and the CIE test was sensitive to 1.0 ng/ml; in serum, however, CIE detected 5.0 ng of PRP/ml, whereas the sensitivity of LPA was unchanged. LPA detected PRP earlier in the course of bacteremia (mean, 12 h after onset; range, 4 to 36 h) than did CIE (mean, 45 h; range, 4 to 168 h) (P less than 0.01). A positive LPA test required greater than or equal to 100 bacteria per ml of blood, whereas CIE required greater than or equal to 1,000/ml. PRP accumulated with continuing blood stream infection, aiding detection of low-grade bacteremia. LPA detected antigen in cerebrospinal fluid (CSF) earlier in the course of meningitis and at a lower bacteria density than did CIE. Both methods detected antigen reliably with greater than or equal to 1,000 bacteria per ml of CSF. A close correlation existed between CSF concentrations of capsular antigen and bacteria (r = 0.90, P less than 0.001). We conclude that the LPA method permits earlier diagnosis of H. influenzae type b infection in part because of its greater sensitivity.
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PMID:Comparison of two antigen detection techniques in a primate model of Haemophilus influenzae type b infection. 11 34

Haemophilus influenzae type b polysaccharide-conjugate vaccines elicit protective antibody responses in young infants. One of these conjugates, polysaccharide linked to outer membrane protein complex (PRP-OMPC), is produced by linking the capsular polysaccharide to an outer membrane protein complex derived from group B Neisseria meningitidis. The outer membrane protein complex contains T cell carrier epitopes that elicit T cell-dependent antibody responses. OMPC also has been shown to increase the antibody response to other proteins administered concurrently that are not covalently linked (i.e., acts as an adjuvant). In this study PRP-OMPC immunized mice demonstrated significant increases in spleen size as well as in splenocyte number as compared to saline controls (p < 0.01, p < 0.001, respectively). No such increase was noted after immunization with another H. influenzae type b-conjugate vaccine, oligosaccharide linked to a variant of diphtheria toxin. By analytic flow cytometry, the mice immunized with PRP-OMPC demonstrated an increase in large splenocytes expressing the Ag Mac-1 (CD11b, CR3). Furthermore, the spleens on histologic examination were characterized by an increase in the red pulp area consisting predominantly of cells of macrophage morphology. By immunohistochemical staining, the cells were identified as macrophages due to expression of Mac-1 and p150,95 (CD11C) Ag. After PRP-OMPC immunization, severe combined immunodeficient mice also demonstrated significant splenomegaly with an increase in macrophages identified by expression of Mac-1 and MHC class II Ag. Thus PRP-OMPC vaccine resulted in T cell-independent splenomegaly with an increase number of macrophages. We propose that this unique property may confer increased immunogenicity to PRP-OMPC through macrophage activation and cytokine release. Furthermore, the effect on macrophages may explain the "adjuvant" capacity of OMPC.
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PMID:Effect of Haemophilus influenzae polysaccharide outer membrane protein complex conjugate vaccine on macrophages. 146 Feb 86

A study on natural immunity to Haemophilus influenzae type b (Hib) was carried out in the province of Siena on 474 subjects ranging in age from 3 days to 70 years. The titration of antibody to capsular polysaccharide (PRP) was performed by the radioantigen-binding assay (RABA) method. A total of 66.67% of the population studied presented an antibody level considered to be protective (greater than or equal to 0.15 microgram ml-1). Seropositivity was 5.7% in the 5-7 month age group and 29.09% in the 8-17 month age group. This rose progressively in successive age groups reaching 79.54% between 4 and 6 years old and a value greater than 90% after 7 years old. From 3 to 17 months even the geometric mean of antibodies to PRP was below the protective limit. Our data indicate that, even in Italy, the majority of the infant population is not protected against H. influenzae, and therefore that vaccination should also be introduced in this country.
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PMID:Immunity to Haemophilus influenzae type b on sample population from central Italy. 150 41

Maternal immunization with the capsular polysaccharide (PRP) vaccine of Haemophilus influenzae type b has been shown to extend the time that protective levels of maternal antibody are detected in infants. In a randomized, blinded trial, PRP or placebo was administered uneventfully to 213 women in the third trimester of pregnancy. Infants born to PRP recipients had significantly higher levels of antibody to PRP than did infants born to placebo recipients: 2.73 micrograms/ml compared with 0.33 microgram/ml. It was estimated that infants of mothers who received the PRP vaccine would be protected for an average of 4 months compared to an average of only 2 months for those of mothers who received placebo. Infants were followed for invasive H. influenzae type b disease through the first year of life; none was detected.
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PMID:Maternal immunization with the capsular polysaccharide vaccine for Haemophilus influenzae type b. 158 47

Antibodies directed against the capsular polysaccharide (polyribosyl ribitol phosphate [PRP]) or the outer membrane proteins (OMP) of Haemophilus influenzae type b (Hib) promote bactericidal activity, complement 3 (C3) binding, and ingestion by phagocytic cells. To assess the relative contribution of anti-OMP to host defense against Hib, we compared the opsonic activities of anti-PRP and anti-OMP as reflected by the amounts of C3 bound to the bacterial surface. Immunoglobulin G (IgG) fractions containing either anti-PRP or anti-OMP were incubated with Hib in the presence of a C5-deficient complement source. C3, total IgG, and IgG subclasses bound to the bacteria were quantified by enzyme-linked immunosorbent assay. The maximum amount of C3 which could be bound to Hib was greater in the presence of anti-PRP than in the presence of anti-OMP. Also, except at low IgG concentrations, the rate of increase in bound C3 as a function of increasing IgG concentration was greater for anti-PRP than for anti-OMP. Hib-bound anti-OMP consisted primarily of IgG1 and IgG3, whereas bound anti-PRP was primarily IgG1 and IgG2. Thus, the potential for C3 binding to Hib is greater in the presence of anti-PRP than in the presence of anti-OMP, probably because of the larger number of binding sites available to the former. Nonetheless, OMP appear to provide important targets for opsonic antibody and would be logical components of a PRP-conjugate vaccine or may be efficacious as vaccines against nontypeable H. influenzae.
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PMID:Complement component 3 binding to Haemophilus influenzae type b in the presence of anticapsular and anti-outer membrane antibodies. 172 83

We performed a double-blind, randomized trial to compare the immunogenicity and reactogenicity of four conjugate Haemophilus influenzae type b vaccines given to infants 2, 4, and 6 months of age. Adverse reactions attributable to the vaccines were few and minor. The rates of systemic reactions did not differ among the various vaccines and were similar to those seen among children receiving conventional diphtheria-tetanus-pertussis vaccine. However, the four conjugate H. influenzae type b vaccines differed markedly in ability to stimulate antibody production. Mean antibody levels after three injections of polyribosylribitol phosphate conjugated with mutant diphtheria protein (PRP-CRM) or polyribosylribitol phosphate conjugated with tetanus toxoid (PRP-T) were 3.08 micrograms/ml and 3.64 micrograms/ml, respectively, significantly higher than those after the use of polyribosylribitol phosphate conjugated with outer-membrane protein of Neisseria meningitidis (PRP-OMP) (1.14 micrograms/ml) or polyribosylribitol phosphate conjugated with diphtheria toxoid (PRP-D) (0.28 microgram/ml). Only PRP-OMP produced a clinically pertinent elevation in antibody level after two injections (0.84 microgram/ml); the third injection of PRP-OMP produced a modest but statistically significant further elevation in mean antibody level (1.14 micrograms/ml). Only 29% of infants receiving PRP-D had antibody levels of 1 micrograms/ml, compared with 55%, 75%, and 83% of those receiving PRP-OMP, PRP-CRM, and PRP-T, respectively. We conclude that all four vaccines are safe and that all but PRP-D appear appropriate for use in a primary immunization series during infancy. The unique serologic response to PRP-OMP offers both advantages and disadvantages in comparison with PRP-CRM and PRP-T.
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PMID:Comparative trial in infants of four conjugate Haemophilus influenzae type b vaccines. 162 87

Disease caused by H. influenzae type b is a world-wide problem of major proportions that affects both developed and developing countries. Young children are at particularly high risk of developing serious invasive infections. There has been tremendous recent progress in the development of vaccines that are immunogenic even in young infants. Clinical trials have demonstrated the efficacy of these polysaccharide-protein conjugate vaccines in infants. Two of these vaccines have been licensed in the United States for use in infants, and licensure of a third conjugate vaccine is expected soon. Many questions still remain to be answered. Are there significant differences in the efficacy for infants of the different licensed conjugate vaccines? Are the differences in the recommended schedules of immunization for the different vaccines justified? Would a combination of an initial dose of PRP-OMP (which is the most immunogenic vaccine in 2-month-old children) followed by subsequent doses of HbOC or PRP-T provide better overall protection than a schedule that uses only a single vaccine? Although much more research remains to be done, these vaccines, which have been recommended for routine universal immunization of infants in the United States, give us the capability of effectively preventing this potentially devastating infection of children.
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PMID:The epidemiology and prevention of disease caused by Haemophilus influenzae type b. 176 9

Immunization with Haemophilus vaccine is undertaken to prevent invasive infections due to Haemophilus influenzae type b. Purulent meningitis is the most frequent chiefly in less than 2 years infants. Vaccine is composed of purified PRP which is poorly immunogenic and protective before two years. Actual vaccines are conjugate with protein which give them a protective and immunogenic power in very long young infants. They must be included in the schedule of infants immunizations, and fitting to other immunizations (DTP-Polio) is the best. The frequency of H. influenzae meningitis is high in tropics and those vaccines should be very useful. Cost of vaccine and inclusion in EPI are yet discussed for infants in tropical areas.
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PMID:[Haemophilus vaccines. Their importance in tropical pediatrics]. 181 37

The antibody response to three Haemophilus influenzae type b vaccines was examined in 134 infants 17 to 22 months of age. Sera were collected from each subject before and 1 month after vaccination with either purified H. influenzae type b capsular polysaccharide (polyribosyl-ribitol phosphate (PRP] or one of two protein-conjugated vaccines (PRP-D or HbOC). Comparison of the two conjugate vaccines revealed that HbOC produced an antibody response greater than or equal to 1.0 micrograms/ml in 96% compared with 72% who were vaccinated with PRP-D (P less than 0.05). The isotype distribution of the antibodies produced by the two vaccines was similar. While all of the vaccines resulted in higher concentrations of anticapsular IgG1 than IgG2, the IgG1:IgG2 ratio was significantly higher in subjects immunized with HbOC. The IgG1:IgG2 ratio was similar in subjects immunized with PRP or PRP-D. The clinical significance of these observations remains to be determined.
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PMID:Prospective comparison of the immune response of infants to three Haemophilus influenzae type b vaccines. 206 19

Haemophilus influenzae type b is responsible for an estimated 15,000 to 20,000 cases of meningitis per year in the United States, mainly in children 2 months to 5 years old. The mortality rate from meningitis due to H influenzae type b infections ranges from 5% to 10%. Despite antibiotic treatment, up to 35% of survivors have permanent neurologic sequelae. In addition to meningitis, H. influenzae type b is responsible for other invasive infections, including epiglottitis, septicemia, cellulitis, septic arthritis, osteomyelitis, pneumonia, pericarditis, and otitis media; approximately 30,000 cases H influenzae diseases occur annually in the United States. The diseases peak in incidence between 6 and 12 months of age, with almost one half of the cases occurring before 1 year of age. About 75% of disease caused by H influenzae type b occurs in children younger than 24 months old. The incidence of disease is higher in children of certain groups, including blacks, Hispanics, Eskimos and Native Americans, young children attending day-care facilities, patients with asplenia or antibody-deficiency syndromes, and children of lower socioeconomic status. There is considerable evidence that antibody to the capsular polysaccharide (polyribosylribitol-phosphate [PRP] of H influenzae type b is protective.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Immunogenicity of a new Haemophilus influenzae type b conjugate vaccine (meningococcal protein conjugate) (PedvaxHIB). 210 17


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