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Query: UMLS:C0348321 (Haemophilus)
 15,372 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Antibody deficiency syndromes can be quantitative or qualitative. The major categories of antibody deficiency syndrome are: (1) X-linked agammaglobulinemia, involving the maturation arrest in the development of the B cells; (2) transient agammaglobulinemia, which affects both sexes is often associated with defective T helper function for immunoglobulin production; (3) acquired agammaglobulinemia, a heterogeneous disorder caused by a primary B cell defect, absence of B cells, presence of B cells but with an activation defect, failure of helper factor production by T cells or increase in suppressor cells; (4) IgG2 and IgG3 subclass deficiencies, causing significant and recurrent infections and, with IgG2, a significant impairment of the ability to respond to carbohydrate antigens such as Haemophilus influenzae, pneumococcus and meningococcus; (5) qualitative antibody deficiency syndrome in the response to carbohydrate antigens, presenting as recurrent infection and involving the inability of the patient to respond to immunization with polysaccharide antigens such as Haemophilus influenzae type b; (6) antibody deficiency states associated with T cell dysfunction. Impairment of T cell function, which is required for B cell activation, presents often as antibody deficiency syndrome. In these cases, total gamma-globulin level is normal, but the quality of the antibody is very poor.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Antibody deficiency syndromes and novel immunodeficiencies. 304 59

Serum IgG contains 4 subclasses, IgG1 (60-66%), IgG2 (20-30%), IgG3 (less than or equal to 5%) and IgG4. Individual subclasses vary with respect to their physicochemical and biological properties. IgG subclass concentrations in serum are age dependent. IgG1 and IgG3 reach near to adult levels around the age of 3, IgG2 and IgG4 after the age of 6. Antibodies of certain specificities generally belong to a certain isotype (subclass) due to the isotype restriction. Patients with subclass deficiencies often suffer from recurrent infections. Those with IgG2 deficiency (often occurring with IgA and IgG4 deficiency) develop recurrent infection of the upper and lower respiratory tract often caused by pyogenic microorganisms (Haemophilus, Pneumococcus). Since early initiation of IVIG substitution therapy has a beneficial effect on long term prognosis the importance of early diagnosis is apparent.
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PMID:[Clinico-immunologic aspects of IgG subclass deficiency]. 305 27

The development of total immunoglobulin G (IgG) antibodies and antibodies of the four IgG subclasses in serum against Haemophilus influenzae type b capsular polysaccharide (CPS) was studied in 24 children and 11 adults with invasive Haemophilus influenzae type b infections, by using an enzyme-linked immunosorbent assay. None of the 8 children aged 10 months or younger had increases in the IgG class or in any of the IgG subclasses. In contrast, 14 of 16 children between 10 months and 6 years of age and 10 of 11 adults had significant increases in total IgG, IgG1, or IgG2 antibodies in various combinations, but none of them had increases in IgG3 or IgG4 antibodies. The increases in IgG1 and IgG2 antibodies in the children were of similar magnitudes. Of 11 adult patients, 9 had significant increases in IgG2 antibodies, while only 4 had increases in IgG1 antibodies. In conclusion, this study shows that children younger than approximately 1 year have no IgG response to H. influenzae type b CPS, while individuals above this age have a mixed IgG1 and IgG2 response.
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PMID:Development of serum antibodies of the immunoglobulin G class and subclasses against the capsular polysaccharide of Haemophilus influenzae type b in children and adults with invasive infections. 326 42

Serum IgG subclasses were measured by a competitive indirect immunoassay with monoclonal antibodies in 31 leukemic patients before and after bone marrow transplantation. Antibodies to Hemophilus influenzae type b (Hib) capsular polysaccharide were determined in 28 cases. Abnormally low or borderline subclass (mostly IgG2 and IgG4) levels were found late after transplant in 23 infected and noninfected patients. These levels persisted for as long as 25 months, in association with low or borderline IgA levels in 78% of the cases. IgG2, IgG4, and IgA often showed a parallel evolution, whereas IgG1, IgG3, and IgM often varied together in the opposite way. Class but not subclass deficiencies were more frequent in patients with graft-v-host disease (GVHD). Subclass abnormalities predominated in infected patients, with mean levels correlating with the severity of infections; however, the abnormalities are not clearly predictive of infections in individual cases. Most patients with Hib pneumonia showed virtually no IgG antibody response to Hib, and one-half of the patients had a moderate IgM and IgA response. In the whole series, many sera collected greater than 1 year after graft contained very low or undetectable antibodies. Correlation between anti-Hib antibody and IgG2 levels was significant but weak because of discrepancies that were only partially explained by the subclass distribution of the antibodies.
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PMID:Long lasting IgG subclass and antibacterial polysaccharide antibody deficiency after allogeneic bone marrow transplantation. 330 61

The safety and immunogenicity of Haemophilus influenzae type b (Hib) capsular polysaccharide (CPS) alone, or covalently bound to tetanus toxoid in saline solution (Hib-TT) or adsorbed onto AI(OH)3 (Hib-TT ads), were evaluated after one injection into 18- to 23-month-old healthy children in Sweden. No side reactions were elicited by Hib CPS; side reactions elicited by the two conjugates were similar and comparable to those reported for diphtheria and tetanus toxoids adsorbed. Hib-TT was the most immunogenic of the three vaccines, eliciting about 10-fold higher antibody levels than Hib CPS; of 28 vaccinees, all had greater than 1.0 microgram Ab/mL serum after immunization with Hib-TT. Increases of Hib CPS antibodies within immunoglobulin classes induced by the three vaccines were, in decreasing order, IgG greater than IgM greater than IgA. Within IgG subclasses, rises in IgG1 Hib CPS antibodies were the most frequent, followed by IgG2; some vaccinees with high postimmunization levels also had rises in IgG3 and one in IgG4. Immunization-induced Hib CPS antibodies were bactericidal. Hib-TT also elicited higher levels of tetanus toxoid antibodies than Hib-TT ads; these tetanus toxoid antibodies neutralized tetanus toxin in vivo.
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PMID:Clinical and immunologic responses to the capsular polysaccharide of Haemophilus influenzae type b alone or conjugated to tetanus toxoid in 18- to 23-month-old children. 336 79

The biologic activity of different human IgG subclass antibodies directed against the Haemophilus influenzae type b (Hib) capsular polysaccharide (PRP) was compared by using an in vitro complement-mediated bactericidal assay and an in vivo passive protection assay in infant rats. An IgG pool was made by Sephacryl S-300 chromatography of sera from adults immunized with PRP vaccine. An IgG2 subclass fraction was prepared by column immunoabsorption of the IgG pool with anti-IgG1 monoclonal antibody. An IgG1 subclass fraction was eluted from the affinity matrix. IgG1, IgG2, IgG3, and IgG4 concentrations in the fractions were measured by solid-phase competitive radioimmunoassays, and anti-PRP antibody was measured by a modified Farr assay. Each fraction was greater than 90% pure IgG2 or IgG1, respectively. There were no significant differences in the minimal anti-PRP antibody concentrations required to kill 50% of Hib cells in vitro (IgG, 0.22; IgG1, 0.21; and IgG2, 0.42 microgram/ml). Similarly, equivalent amounts of anti-PRP antibody of the IgG1 or IgG2 fractions protected against bacteremia (IgG1, 0.12; IgG2, 0.24 microgram per rat). IgG absorbed to remove anti-PRP antibody was neither bactericidal nor protective. Thus IgG1 and IgG2 anti-PRP antibody have equivalent functional activities against Hib as determined by these biologic assays.
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PMID:Functional activity of different IgG subclass antibodies against type b capsular polysaccharide of Haemophilus influenzae. 348 28

Thirty-one of 75 patients with recurrent upper respiratory infections were found to have immunoglobulin G subclass deficiencies with normal levels of total immunoglobulin G in a clinical allergy and asthma practice. Sixteen were IgG3 deficient, thirteen IgG2 deficient, and two were IgG1 deficient. Only one patient had an IgA deficiency. Two patients have normal IgG with decreased PRP titers. Serum antibody titers to the capsular polysaccharide of Haemophilus influenzae type B (HibCP) were found to be low in seven patients. Other investigators have established relationships between these deficiencies and recurrent infections. When investigating patients with recurrent infections, it seems prudent to look beyond simple quantitative immunoglobulins.
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PMID:IgG subtype abnormalities with normal total IgG in a clinical allergy practice. 349 Jan 98

In this study we investigated the in vitro mitogenic properties of the capsular carbohydrate of Hemophilus influenzae b, polyribosylribitolphosphate (PRP). PRP was found to be a potent polyclonal activator of murine B lymphocytes. PRP induced normal B cells to undergo blastogenesis, DNA synthesis, and differentiation to IgM and IgG secretion. IgG3 accounted for the majority of the IgG. No PRP-specific antibody was detectable, indicating the polyclonal origin of the secreted immunoglobulin (Ig). T lymphocytes were neither activated by PRP nor required for B cell proliferation or Ig secretion. In addition, T cell-depleted spleen cells also depleted of accessory (A) cells by passage through Sephadex G-10 retained responsiveness to PRP. Trace lipopolysaccharide (LPS) contamination was not responsible for the mitogenic effect, as shown by the ability of C3H/HeJ spleen cells to proliferate in response to PRP and by the failure of polymyxin B to inhibit PRP-induced DNA synthesis. The B cell responses induced by PRP and LPS were similar with respect to T cell and A cell independence, to the magnitude of DNA synthesis, and to Ig secretion and the Ig isotypes expressed. These data, taken with the finding that the combination of optimal doses of PRP and LPS did not give an additive DNA synthetic response, indicate that PRP and LPS were activating similar B cell populations. However, in contrast to LPS, PRP was capable of inducing significant DNA synthesis in cultures containing as few as 1,000 B cells, suggesting that PRP-driven proliferation was less dependent on cellular interactions than the response to LPS. The differential ability of PRP and LPS to stimulate C3H/HeJ B cells and to stimulate B cell proliferation at low density indicates basic differences between these two mitogens in their mechanisms of B cell activation.
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PMID:The type-specific capsular carbohydrate of Hemophilus influenzae B is a potent mitogen for murine B lymphocytes. 221 62

We studied 20 children with recurrent sinopulmonary infections and serum IgG levels within the normal range, who had selective IgG-subclass deficiency. Twelve of the children were IgG2 deficient, five were IgG3 deficient, and three were deficient in both IgG2 and IgG3. IgA deficiency was present in 3 of the 20 patients. In the children with IgG2 deficiency, serum antibody concentrations to the capsular polysaccharide of Hemophilus influenzae type B (Hib) were significantly lower than those in age-matched controls, both before and after immunization with the Hib capsular polysaccharide antigen, which elicits antibody predominantly of the IgG2 subclass. In contrast, their serum antibody titers to the tetanus and diphtheria toxoid protein antigens, which elicit antibody predominantly of the IgG1 subclass, were normal in comparison with those of age-matched controls. These results suggest that impairment of the antibody response to specific microbial antigens predisposes patients with selective IgG-subclass deficiencies to recurrent infections. Thus, as an aid in determining therapy, children with recurrent infections and normal total serum IgG should be evaluated for this condition.
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PMID:Recurrent sinopulmonary infection and impaired antibody response to bacterial capsular polysaccharide antigen in children with selective IgG-subclass deficiency. 387 40

Selective IgG subclass (IgGSc) deficiencies are frequently found in association with recurrent infections in childhood. IgG1 deficiency is the most severe and is associated with features typical of panhypogammaglobulinaemia. Immunoglobulin replacement therapy is usually required. IgG2 deficiency is associated with recurrent infections with encapsulated bacteria such as Haemophilus influenzae and Streptococcus pneumoniae. IgG2 deficiency may be transient in children under five years of age and patients improve with antibiotics and immunisation. IgG3 and IgG4 deficiency are commonly found in children with recurrent infections and may indicate a disordered immune system since absence of these antibodies alone appears insufficient to cause symptoms. Children may also have selective IgGSc deficiencies in the absence of recurrent infections. This is explained by compensatory factors in other parts of the immune system. Measurement of IgGSc levels should be based on highly specific polyclonal antisera which show no IgGSc cross-reactivity. Most monoclonal antibodies are unsatisfactory since allotypes are detected variably, leading to excess reporting of IgGSc deficiencies and Mabs cannot be used for nephelometric or turbidimetric methods.
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PMID:IgG subclasses in childhood infections. 761 65


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