Clinical associations with serum allergen-specific IgG4 antibodies

Possible approach for serodiagnosis of ascariasis by evaluation of immunoglobulin G4 response using Ascaris lumbricoides somatic antigen

Somatic antigen of Ascaris lumbricoides was purified to homogeneity (molecular mass, 34 kDa) by ammonium sulfate fractionation and successive chromatographic procedures, namely, gel permeation, ion exchange, and high-performance gel permeation liquid chromatographies. The antigen showed strong binding with immunoglobulin G (IgG) in Ascaris-infested patients and was cross-reactive with IgE and IgG in patients infested with other nematodes. It reacted specifically with IgG4 (P < 0.001) in 63 Ascaris-infested patients, which represented 65% of the total IgG response, though cross-reactivity with IgG1, IgG2, and IgG3 subclasses was observed, indicating the unique specificity of this test system and its potential utility in the serodiagnosis of ascariasis.

Serodiagnosis of ascariasis with specific IgG4 antibody and its use in an epidemiological study

In an earlier study Ascaris-specific IgG4 antibody was found to be elevated in cases of ascariasis. However, the usefulness of the elevated levels of this antibody in Ascaris infection as a diagnostic marker has not been well established. In India, in early 1999, blood samples of 83 cases of Ascaris infection, 35 cases of other nematode infection and 53 control subjects (without any helminth infection) were tested for anti-Ascaris IgG4 by ELISA. Further anti-Ascaris IgG4 levels in the blood of Ascaris-infected patients were determined, after eradication of the worms with drugs, at regular intervals to ascertain the duration of elevation of titre of the serological marker following initial infection. This information would indicate the sensitivity of the test as a diagnostic marker for recent infection. Blood samples of 422 rural people were also tested for anti-Ascaris IgG4 titre to ascertain the prevalence of ascariasis in the community. High levels of anti-Ascaris IgG4 antibody (OD 1.246 +/- 0.212) were found in all the 83 Ascaris-infected subjects compared to controls (OD 0.158 +/- 0.047). Anti-Ascaris IgG4 antibody levels of other nematode-infected subjects were comparable to the controls. Anthelmintic treatment of 8 Ascaris-infected subjects caused sequential fall of IgG4 level in their blood, and its titre reached control level within 6 months of deworming. Of 422 individuals from the rural community 229 (54.3%) had significantly high levels of specific IgG4 antibody against Ascaris excretory-secretory antigen, suggesting that they were infested with Ascaris. Thus, this study demonstrated that anti-Ascaris IgG4 antibody is a very sensitive and specific marker for the diagnosis of Ascaris infection. Utilizing this test, a significant number of a rural population could be diagnosed with Ascaris infection in West Bengal, India.

Evaluation of IgG4 response in ascariasis by ELISA for serodiagnosis

The excretory/secretory (ES) antigen(s) of Ascaris lumbricoides was fractionated into 10 fractions by gel chromatography on a Suparose 12 column in FPLC. Of these, the third fraction (Al III), showing binding activity with both IgE and IgG antibodies of A. lumbricoides infected patients' sera, was further resolved into 2 fractions (Al IIIa and Al IIIb) on passage through a Mono Q column. Al IIIb was found to be the most potent antigen due to its high binding affinity with IgE and IgG antibodies of Ascaris infected patients as evidenced by ELISA inhibition. Although a two to five-fold increase of serum IgE level was observed in all helminthic parasite infected patients studied compared to control subjects, Al IIIb specific IgE was detected in sera of all Ascaris infected and only 40% of hookworm infected patients. When Al IIIb was tested by ELISA with sera of control subjects, Ascaris, hookworm, Strongyloides and Trichuris infected patients, strong binding was observed with the IgE and also IgG of all the Ascaris infected patients; however, it cross-reacted with IgG in 50% of hookworm, 28.6% of Trichuris trichura and 22.2% of Strongyloides infected patients' sera; but with IgE only in 40% of hookworm infected patients' sera. Further study showed specific detection of IgG4 in all the serum samples of 65 Ascaris infected patients when Al IIIb antigen was allowed to react with different subclasses of IgG by ELISA, giving a sensitivity of 100%. Reactivities of Al IIIb with IgG1 and IgG3 were only 47.6 and 11.8% respectively and there was no reactivity with IgG2 subclass. No IgG4 reactivity against Al IIIb was observed in the sera of hookworm, Trichuris or Strongyloides infected patients and was similar to that observed with control subjects showing the 100% specificity of the test system. This study may therefore be regarded as a novel technique for serodiagnosis of ascariasis by measuring Ascaris specific IgG4.

Antibodies of different immunoglobulin isotypes in serum and bile of patients with clonorchiasis

Specimens of serum and bile from patients were assayed by an enzyme-linked immunosorbent assay to reveal antibodies specific to antigens from adult Clonorchis sinensis. Antibodies of the IgG isotype showed the greatest elevation during infection (Student's t-test, P < 0.001), whereas serum IgA and IgE and secretory IgA in bile were moderately elevated (P < 0.05). Major differences in the distribution of antibodies among the IgG subclasses were observed between patients who were and those who were not infected. IgG4 antibody levels were elevated in the serum and bile of infected patients, and there were significant correlations between the levels of IgG and IgG4 antibodies and the intensity of infection.

Toxoplasma antigens recognized by immunoglobulin G subclasses during acute and chronic infection

The immunoglobulin G (IgG) subclass response to Toxoplasma gondii antigens during the acute and chronic stages of T. gondii infection were studied by using immunoblots with reduced antigen (RA) and nonreduced antigen (NRA) preparations. Serum samples were from individuals with acute or chronic T. gondii infection, and sequential samples were from women who seroconverted during gestation and were treated with spiramycin. IgG1 antibodies were predominant in sera from each of the groups and recognized a large number of RA and NRA. In the latter group of patients, IgG1 and IgG3 were the first antibodies to appear in response to the infection. In all groups, an antigen with a molecular weight (MW) of 30,000 was the most intensely stained and frequently recognized by IgG1 antibodies in NRA preparations. In RA preparations, antigens of MW 35,000 and 30,000 were the most intensely stained and frequently recognized by IgG1 antibodies. An antigen with an MW of 22,000 was intensely stained in the IgG1 immunoblots of the NRA preparation and to a lesser extent in the RA preparation. In contrast to immunoblots with IgG1 antibodies, very few antigens in the RA and NRA preparations were detected by IgG2 and IgG3 antibodies; IgG4 antibodies rarely detected any antigens. Of interest was that IgG2 antibodies detected antigens distributed over the entire MW range, whereas those detected by IgG3 antibodies were located mostly below the 35,000 MW marker. Enzyme-linked immunosorbent assay results paralleled those of the immunoblots in that IgG1 antibodies were predominant.

Treatment of hay fever by Allerglobuline: a randomized double-blind study

Eighty patients suffering from documented hay fever have been entered in a double-blind randomized study with the purpose of evaluating the efficacy of Allerglobuline, a 10% human immunoglobulin preparation of placental origin, in the treatment of hay fever. The placebo was a 10% human albumin solution. The treatment started 6 weeks before the customary onset time of the clinical symptoms. It included a course of ten pre-seasonal intramuscular injections, with 1 vial (5 ml) given twice a week, and followed by a booster injection of 1 vial on 15 June and 30 June during the grass pollen season. As the two groups of patients were similar, it was possible to demonstrate a significant symptomatic relief of rhinitis and conjunctivitis in the treated group, compared with the control group (P less than 0.0001), and an improvement of the respiratory symptoms. Symptomatic improvement was already apparent at the onset of the pollen season and persisted during the following weeks. An appreciable reduction in the consumption of antihistamines could also be shown (P less than 0.0001). Furthermore, a lesser increase in the total IgE level and in the specific cereal and grass pollen RAST could be demonstrated. This treatment can be seriously considered for the management of severe pollen allergy, particularly in those cases that show a poor response to immunotherapy.

House dust mite-specific IgE, IgG1, and IgG4 antibodies in patients with perennial rhinitis

Serum samples were obtained from patients with house dust mite-sensitive nasal allergies before and 6 months after immunotherapy, and the level of immunoglobulin (Ig)E, IgG1, and IgG4 antibodies in those sera was determined by the enzyme-linked immunosorbent assay. The present data showed that the mite-specific IgG4 antibodies increased in patients who responded well to immunotherapy but not in those who responded poorly. It was suggested from the present study that IgG4 antibodies seem to act as "blocking antibodies" to reduce the allergic reaction in the target organ, and that an increase of allergen-specific IgG4 antibodies following immunotherapy can be of clinical benefit to patients suffering from mite-specific nasal allergy.

Humoral immunity to dietary antigens in atopic dermatitis. II. Analysis of IgE and IgG subclass antibodies

IgG subclass antibodies to two dietary antigens, ovalbumin (OA) and beta-lactoglobulin (BLG) were measured with quantitative ELISA-techniques in 16 patients with atopic dermatitis (AD) (6-21 years old) and closely matched controls. In addition, IgE-antibodies to OA, BLG and milk were determined with RAST. IgG subclass antibodies were frequently detected in IgG1 and IgG4 for both AD-patients and controls, quantitatively dominated by IgG4. The IgG4 anti-BLG antibody levels were significantly higher (P less than 0.001) in AD-patients (median: 1.1 microgram/ml, range: 0-24.0 microgram/ml) than in controls (median: 0.05 microgram/ml, range: 0-1.05 microgram/ml). No relation was found between IgG4 anti-BLG antibody levels, levels of IgE antibodies to milk or BLG, or severity of disease.

Immunoglobulin A, G and E levels in Egyptians with cancer: influence of schistosomiasis

The main patient series consisted of 415 Egyptians attending the Cairo Cancer Institute and comprising 286 bladder cancer, 97 breast cancer, 14 head and neck cancer and 18 gastrointestinal cancer cases. Also included in the study were 36 patients with active schistosomiasis and 89 health controls. Serum IgA, IgG, IgG subclasses, IgE, Schistosoma and Ascaris-specific IgE (RAST) and the acute-phase protein CRP were measured in all, or sub-sets, of the main patient group. The well-established increase in IgE and IgG levels, and the more recently reported increase in the levels of IgG3 and IgG4 subclasses in patients with schistosomiasis, were also found in bilharzial bladder cancer, indicating that humoral immunity persists in cancer-bearing patients. However, the plasma protein profile in bilharzial bladder cancer is further modified by significant increases in the levels of IgA, IgG, IgG1, IgG2 and CRP when compared to levels in patients with Bilharzia in the absence of neoplastic change. Patients with cancers not associated with parasitic infestation also had significant increases in their serum levels of IgG1, IgG2, IgG, IgE and CRP when compared to healthy Egyptian controls, but 41% of these non-bladder cancer patients showed IgE responses to previous parasitic infestations suggesting that any immunological response to cancer would be on the background of a variable non-specific increase of IgE.