Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0348321 (Haemophilus)
 15,372 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

An international collaborative study was conducted at ten sites to examine the performance of enzyme immunoassays (EIAs) for the quantitation of IgG1, IgG2, IgG3, IgG4 and total IgG anti-Haemophilus influenzae type b (Hib) capsular polysaccharide in human serum. All groups used the same reagents: microtiter plates coated with polyribosylribitol phosphate (PRP) conjugated to poly-L-lysine (PLL), reference, control and test human sera, biotin-conjugated International Union of Immunological Societies (IUIS)-documented monoclonal anti-human IgG1-4 and IgG Pan detection antibodies, avidin-peroxidase and TMB substrate. Initial mixing of soluble PRP antigen or an equal volume of buffer with the 20 test sera prior to analysis confirmed PRP antigen specificity in all five EIAs with greater than 80% competitive inhibition at most sites. Positive correlation between the total IgG anti-Hib and sum of IgG1-4 anti-Hib was demonstrated (r2 = 0.99, Y = 1.13X -0.15). Good agreement was shown between the total IgG anti-Hib as measured by EIA and the total Hib-specific antibodies measured by the current radiolabeled antigen binding assay (r2 = 0.97, Y = 4.6X -5.8). Assay parallelism was demonstrated with an average interdilutional %CV of 22% and parallel dose-response curve slopes. The interdilutional %CVs were calculated as an average per sample of the variation of microgram/ml (corrected for dilution) at different dilutions per laboratory for all participating sites. The interlaboratory variation was the only performance parameter studied that exceeded the target level of 35% CV in all IgG1-4 and total IgG anti-Hib assays. IgG subclass distributions in the test sera demonstrated a predominance of IgG1 anti-Hib in the pediatric serum pools and IgG2 anti-Hib in the adult sera, with low but detectable levels of IgG3 and IgG4 anti-Hib in each group.
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PMID:Quantitation of human IgG subclass antibodies to Haemophilus influenzae type b capsular polysaccharide. Results of an international collaborative study using enzyme immunoassay methodology. 156 20

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

Eighty-five children received three injections of a vaccine consisting of Haemophilus influenzae type b (Hib) capsular polysaccharide (CPS) conjugated to tetanus toxoid (TT) (Hib-TT) at 3, 5 and 12 months of age according to the vaccination schedule for Swedish children. Diphtheria-tetanus toxoid vaccine was concurrently injected at another site. Two dosages, 7.5 and 15 micrograms, of Hib CPS were studied. No serious reactions occurred. Hib-TT elicited fewer local reactions than diphtheria-tetanus toxoid vaccine. Significant increases in Hib CPS serum antibodies occurred after all injections in both dosage groups with virtually no differences between the two groups. After the first and second injections geometric mean serum antibody concentrations of both dosage groups combined increased to 0.49 and 3.71 micrograms/ml and 81 and 99% of the vaccinees, respectively, had concentrations greater than 0.15 micrograms/ml. After the third dose geometric mean concentrations increased to 13.7 micrograms/ml and all had concentrations greater than 0.15 micrograms/ml. The geometric mean Hib CPS antibody concentrations decreased to 1.24 micrograms/ml 18 months after the third injection, but 97% still had concentrations greater than 0.15 micrograms/ml. The rise of Hib CPS antibodies was mostly in the IgG class. The most pronounced increase was seen in the IgG1 subclass but there were also increase in IgG2 and IgG3. Protective concentrations of TT antibodies were found in all postimmunization sera. In conclusion Hib-TT is safe and immunogenic in infants and should be protective from 6 to 30 months and probably longer thereafter.
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PMID:Persistence of serum antibodies elicited by Haemophilus influenzae type b-tetanus toxoid conjugate vaccine in infants vaccinated at 3, 5 and 12 months of age. 189 Dec 86

Sixty-one patients with chronic sinusitis who were referred for an allergy evaluation were evaluated for immunologic competence including assessment of quantitative serum immunoglobulin levels, IgG subclass levels, and response to pneumococcal and Haemophilus influenzae vaccines. In addition to chronic sinus disease, recurrent otitis media and asthma exacerbation were common problems in this group. Five patients had an elevated age-adjusted IgE level and 22 patients had positive prick tests to one or more environmental inhalants; these findings suggest an allergic component in this subgroup. Twelve additional patients had highly reactive intradermal tests to common environmental allergens, which also may be clinically significant for underlying atopy. Eleven patients had low immunoglobulin levels, 6 had low immunoglobulin levels and vaccine hyporesponsiveness, and 17 had poor vaccine response only. Thus, 34 of 61 patients with refractory sinusitis had abnormal results on immune studies, with depressed IgG3 levels and poor response to pneumococcal antigen 7 being most common. In addition to allergy, immunologic incompetence may be an important etiologic factor in patients with chronic, refractory sinusitis.
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PMID:Immunologic defects in patients with refractory sinusitis. 194 19

An association between humoral immune deficiency and childhood autoimmune disease has been previously established. We describe a 7-year-old male with severe autoimmune disease, recurrent infections, a marked deficiency of IgG2 and IgG4, and an inability to respond to polysaccharide antigens. This child was also found to have isolated growth hormone (GH) deficiency. Laboratory results included a positive anti-smooth muscle antibody, a positive Raji-cell assay for immune complexes, and normal levels of IgG, IgM, and IgA. IgG subclasses revealed an IgG1 of 1225 (normal for age, 280-1120 mg/dl), IgG2 of less than 10 (30-630 mg/dl), IgG3 of 36 (40-250 mg/dl), and IgG4 of less than 4 (11-620 mg/dl). No increase in antibody titer was noted to either Pneumovax or unconjugated Haemophilus influenzae vaccine. Numbers of circulating B cells (CD19) were markedly diminished (less than 0.5%). Liver biopsies have shown chronic active hepatitis. Somatomedin C was 0.28 U/ml (normal for age, 0.5-2.06 U/ml). Challenge with either L-dopa or clonidine produced a peak GH response of 2.3 ng/ml (normals = greater than 7 ng/ml). Children with autoimmune disorders should be evaluated for IgG subclass deficiencies and ability to make antibody in response to antigen challenge regardless of the serum immunoglobulin levels. Growth failure in immune-deficient children should not be assumed to be due to chronic illness or recurrent infections. Other etiologies for growth failure should be sought.
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PMID:Association of autoimmunity with IgG2 and IgG4 subclass deficiency in a growth hormone-deficient child. 208 46

Humoral immune parameters were studied in 13 patients with end-stage renal failure on maintenance hemodialysis. Serum IgA, IgM and IgG concentrations were comparable to control values from 14 healthy blood donors. IgG subclass analysis revealed significantly increased IgG1 levels in the patients when compared to controls (p less than 0.01). In 3 patients, IgG2 deficiency was found, in one case associated with low IgG3 level. Concentrations and subclass composition of naturally occurring antibodies to Haemophilus influenzae type b (Hib) polysaccharide (PS) were measured using an indirect ELISA. In patients IgM and IgG, including IgG1 and IgG2 antibodies to Hib, presented no difference from controls. Subclass analysis of Hib specific IgG antibodies revealed that IgG2 accounted for a substantial amount of the anti-Hib PS antibody response in controls as well as in patients. We conclude that patients on maintenance hemodialysis present imbalances of immunoglobulin levels. However, the antibody response to certain PS antigens could remain unaffected by renal failure.
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PMID:Serum immunoglobulin levels and natural antibodies to Haemophilus influenzae in hemodialysis patients: evidence for IgG subclass imbalances. 223 47

To understand the relevance of subnormal serum concentrations of IgG2, we measured IgG2 in serum of 575 healthy children and identified 11 with concentrations greater than 2 SD less than the mean for age. The levels of IgG2 present were similar to those found in symptomatic children with IgG2 subclass deficiency associated with antibody deficiency. The 11 children ranged in age from 1 to 14 y (mean = 5.7). Detailed clinical information was available on 10 of the 11 children and each was matched for age with two controls. The median number of visits/y to the doctor for infectious illnesses was identical for the two groups (1.0). Nine of the children with subnormal IgG2 were followed for 1 to 5 y (mean = 2.3). All nine children had normal serum concentrations of IgA, IgG1, IgG3, and IgG4 but seven had persistently subnormal or low-normal serum IgG2 concentrations. One of these seven children also had a subnormal serum concentration of IgG, and one had subnormal IgM. Antibody responses to Haemophilus b polysaccharide vaccine were normal in five of six who were immunized. In vitro secretion of Ig by mitogen-stimulated peripheral blood mononuclear cells was measured in six of seven children with persistently subnormal or low-normal IgG2; five showed decreased secretion of IgG2, and two of the five also had subnormal secretion of IgG1 and IgG3. An important implication of this study is that the subnormal concentrations of serum IgG2 found in infection-prone children are not a sufficient explanation for their increased susceptibility to infection.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Clinical and immunologic characteristics of healthy children with subnormal serum concentrations of IgG2. 229 65

To characterize more fully the immunologic basis for increased susceptibility to infection in patients with low serum concentrations of IgG2, we identified eight infection-prone children, 1 to 2 years of age, with serum IgG2 concentrations greater than 2 SD below the mean for age and followed their serologic and clinical courses for 1 to 3 years. Two of the eight children became clinically and immunologically normal and may have had transient IgG2 deficiency with an exaggerated developmental delay of this late-maturing subclass. The remaining six subjects had persistently subnormal or low-normal serum IgG2 levels and continued to experience frequent infections. All six of these children responded poorly to Haemophilus influenzae type b (Hib) polysaccharide, and four of six responded poorly to Streptococcus pneumoniae type 3 polysaccharide. Both IgG1 and IgG2-specific antibody responses to these vaccines were abnormal. Three of these six children also responded poorly to tetanus toxoid, an antigen that normally induces a predominant IgG1 response. Although five of these six children produced antibodies in response to Hib polysaccharide protein conjugate vaccine, three of four given Hib oligosaccharide CRM conjugate vaccine required booster doses to respond, a pattern of response characteristic of infants less than 6 months of age. Further, although serum concentrations of IgG1 were normal, peripheral blood mononuclear cells from four of six children tested produced extremely small amounts of IgG1 and IgG3 as well as IgG2. Finally, varied patterns of abnormalities of IgG, IgA, IgM, and IgG4 became apparent in five of the six children with persistently low serum IgG2 values. This study demonstrates that subnormal serum concentrations of IgG2 may be associated with varied patterns of immunologic dysfunction, some of which are evolving and may be responsible for increased susceptibility of these children to infection.
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PMID:Subnormal serum concentrations of IgG2 in children with frequent infections associated with varied patterns of immunologic dysfunction. 231 99

Selective IgG subclass deficiencies and/or selectively impaired antibody responses to bacterial capsular polysaccharide antigens have been increasingly reported. In this report, 13 children with recurrent infections and deficient antibody responses to polysaccharide antigens are described. Serum IgG2 subclass concentrations were normal in all the patients, and two children had low IgG3 levels. Mean serum antibody concentrations to the capsular polysaccharide antigens of Streptococcus pneumoniae and Haemophilus influenzae were significantly decreased after immunizations, but antibody responses to diphtheria and tetanus toxoids were normal. The identification of children with selective antibody deficiencies and recurrent infections has prompted a multicenter, double-blind, placebo-controlled study to evaluate the efficacy and safety of intravenous immune globulin therapy in these patients.
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PMID:Patients with Igg subclass and/or selective antibody deficiency to polysaccharide antigens: initiation of a controlled clinical trial of intravenous immune globulin. 267 97

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 coften occurring with IgA and IgG4 deficiency) develop recurrent infection of the upper and lower respiratory tract often caused by pyogenic microorganisms (Haemophilus, Pneumo-(occus). 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]. 268 36


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