Antithyroglobulin monoclonal and autoantibodies cross-react with an orbital connective tissue membrane antigen: a possible mechanism for the association of ophthalmopathy with autoimmune thyroid disorders.

The possibility that Graves' ophthalmopathy and autoimmune thyroid disorders may be associated because of autoimmune reactions against antigens shared between human orbital and thyroid tissues was investigated using anti-thyroglobulin (Tg) monoclonal and autoantibodies. Eleven of 16 mouse monoclonal antibodies (MCAB) tested reacted, in an enzyme-linked immunosorbent assay (ELISA), with an antigen in human orbital connective tissue membranes (OCTmem), but not with the OCT soluble fraction, or with membrane or soluble fractions of human eye muscle, lacrimal gland or skin connective tissue. The anti-OCTmem activity was absorbed by OCTmem and Tg, but not by liver membranes or bovine serum albumin (BSA). In preliminary studies four out of 113 human MCAB against thyroid or orbital tissue antigens showed reactivity restricted to Tg and OCTmem. Sera from approximately 50% of patients with autoimmune thyroid disorders, with or without ophthalmopathy, also reacted with OCTmem. The autoantibody activity correlated closely with serum titres of antithyroglobulin but not with the presence, duration, or severity of the eye disease. The OCTmem reactivity was absorbed by Tg, thyroid membranes, and OCTmem but not liver membranes, membranes prepared from other orbital tissues, or BSA. The OCTmem-Tg shared antigen site appeared not to be native thyroglobulin since, (i) MCAB and serum autoantibodies did not react with the cytosol fraction of OCT, and (ii) because the membrane antigen was not solubilizable. Because not all patients with ophthalmopathy have detectable anti-Tg antibodies and, conversely, because not all patients with detectable anti-Tg antibodies develop ophthalmopathy it is unlikely that autoimmunity against a OCTmem-Tg shared antigen is the primary mechanism of Graves' ophthalmopathy, although this possibility has not been excluded. On the other hand the reaction of anti-Tg autoantibodies with OCT membranes may be a model for other autoimmune reactions against other thyroid-orbital tissue-shared antigens. While the pathogenesis of Graves' ophthalmopathy is likely to be multifactorial, humoral and cellular reactions against primary orbital antigens, thyroid-orbitol tissue shared antigens, or both, are likely to play important roles.     

Isotype and immunoglobulin subclass distribution of eye muscle membrane reactive antibodies in the serum of patients with thyroid-associated ophthalmopathy as detected in Western blotting.

We have determined the immunoglobulin (Ig) class (isotype) and IgG subclass of autoantibodies in the serum of patients with thyroid-associated ophthalmopathy (TAO) or autoimmune thyroid disorders without evident ophthalmopathy reactive in Western blotting with antigens of 55, 64, 75 and 95 kDa in pig eye muscle membrane (PEMM). The 22 sera studied were shown, previously, to contain IgG antibodies reactive with one or more of the four antigens. The majority of sera antibodies reactive with PEMM antigens were of two or more IgG subclasses. Of the IgG subclass specificities IgG3 and IgG4 subclass antibodies were, overall, the most common. We were unable to demonstrate IgG subclass restriction for antibodies reactive with the 95 or 55 kDa antigens in PEMM, antibody activity being equally distributed in all four subclasses tested. While most of the sera which recognized a 64 kDa antigen did so with an IgG4 antibody, all other subclasses were also represented. On the other hand all 13 sera reactive with a 75 kDa antigen did so using Ig of the IgG3 subclass and 12 of these used the IgG4 subclass as well, IgG1 and IgG2 subclasses being represented in only 3 and 4 sera, respectively. There were no differences, in respect to Ig class or IgG subclass distribution of eye muscle reactive antibodies between patients with Graves' hyperthyroidism with ophthalmopathy and those with Hashimoto's thyroiditis, and eye disease. Control sera from five normal subjects and three patients with nonautoimmune thyroid disorders did not contain antibodies reactive with these PEMM antigens of any Ig class or IgG subclass.(ABSTRACT TRUNCATED AT 250 WORDS)     

Cellular and humoral autoimmune responses against human eye muscle membrane antigen in Graves' disease

75 patients with Graves' disease (54 with ophthalmopathy) were investigated using the tests of leucocyte adherence inhibition and immune adsorption with 125I-labelled Staphylococcus Protein A, against human eye muscle "crude" membrane antigen. The results of positive leucocyte adherence inhibition (10 out of 26 vs. 1 out of 28, P less than 0.05) and anti-human eye muscle membrane antibody index (mean +/- S.D.) (1.89 +/- 1.20 vs. 0.84 +/- 0.38, P less than 0.001) showed a correlation with the patients with clinically active eye disease and the HLA-B8 antigen in Graves' ophthalmopathy (P less than 0.01). Positive leucocyte adherence inhibition was observed in 9 out of 21 cases of Graves' disease without ophthalmopathy, but its prognostic relevance has to be confirmed in the development of ophthalmopathy.     

Antibodies targeting the calcium binding skeletal muscle protein calsequestrin are specific markers of ophthalmopathy and sensitive indicators of ocular myopathy in patients with Graves' disease

We have identified several eye muscle antigens and studied the significance of the corresponding serum autoantibodies in patients with Graves' disease. Of these antigens, only calsequestrin is expressed more in eye muscle than other skeletal muscles, which could explain at least partly the specific involvement of eye muscle in patients with Graves' disease. Earlier, we found a modest relationship between anti-calsequestrin antibodies and ophthalmopathy, but in that study we used calsequestrin prepared from rabbit heart muscle and measured antibodies by immunoblotting. We have reinvestigated the prevalences of anti-calsequestrin antibodies in larger groups of well-characterized patients with thyroid autoimmunity with and without ophthalmopathy and control patients and healthy subjects, using standard enzyme-linked immunosorbent assay incorporating highly purified rabbit skeletal muscle calsequestrin, which has a 97% homology with human calsequestrin, as antigen. Anti-calsequestrin antibodies were detected in 78% of patients with active congestive ophthalmopathy, in 92% of those with active inflammation and eye muscle involvement, but in only 22% of patients with chronic, 'burnt out' disease. Tests were also positive in 5% of patients with Graves' hyperthyroidism without evident ophthalmopathy (two patients) and one patient with 'watery eyes' but no other clear signs of congestive ophthalmopathy and IgA nephropathy and no known thyroid disease, but in no patient with Hashimoto's thyroiditis, toxic nodular goitre, non-toxic multi-nodular goitre or diabetes, or age- and sex-matched healthy subjects. In serial studies of all 11 patients with Graves' hyperthyroidism who had active ophthalmopathy at the time of the first clinic visit, or developed eye signs during the first 6 months, and positive anti-calsequestrin antibodies in at least one sample, anti-calsequestrin antibodies correlated with the onset of ocular myopathy in six patients. Antibodies targeting calsequestrin appear to be specific markers for ophthalmopathy and sensitive indicators of the ocular myopathy subtype of ophthalmopathy in patients with thyroid autoimmunity. However, these results must be considered preliminary until a large prospective study of patients with newly diagnosed Graves' hyperthyroidism, in which serum levels of calsequestrin antibodies are correlated with clinical changes and orbital eye muscle and connective tissue/fat volumes, has been carried out.     

The balance shift in Th1/Th2 related IL-12/IL-5 cytokines in Graves' disease during methimazole therapy

Th1 and Th2-like cytokines are involved in the pathogenesis of Graves' disease. The shift in balance in IL-12/IL-5 cytokines was applied in judging the immunological events in 74 patients with Graves' disease (50 had ophthalmopathy) during methimazole therapy and in 15 controls. The serum levels of IL-12 and IL-5 were measured with enzyme-linked immunosorbent assay in all Graves' patients. Twelve cases for IL-5 and 20 cases for IL-12 were positive. In Graves' patients only those without ophthalmopathy had higher levels of IL-12 when compared to controls (192.66 +/- 29.19 vs. 85.09 +/- 8.95 pg/ml, P < 0.04). After 2 months of methimazole therapy in Graves' patients without ophthalmopathy an increase in the ratio of IL-12 to IL-5 was also observed as compared to those with eye symptoms (91.78 +/- 34.14 vs. 20.72 +/- 6.36, P < 0.015). Age-related difference in the serum level of IL-5 could be demonstrated between Graves' patients without and those with ophthalmopathy aged < or = 35 years (4.89 +/- 0.57 vs. 50.14 +/- 20.2 pg/ml, P < 0.002). No association was found among the serum levels of IL-5 or IL-12, thyroid hormones and TSH receptor antibodies. The results demonstrated a difference in the balance shift of IL-12/IL-5 between Graves' patients with and without ophthalmopathy. The increased ratio of IL-12 to IL-5 after methimazole therapy could be explained by the elevation of serum IL-12 due to methimazole therapy and the age-related decrease of serum IL-5.     

Assays of TSH-receptor antibodies in 576 patients with various thyroid disorders: their incidence, significance and clinical usefulness

The incidence and the significance of TSH-receptor antibodies in Graves' disease and in various thyroid disorders have been evaluated. TSH-binding inhibiting antibodies (TBIAb) and thyroid stimulating antibodies (TSAb) were detected in a large proportion of Graves' disease patients (TBIAb in 68.8% and TSAb in 77.8%), in a small number of patients with idiopathic myxoedema or Hashimoto's thyroiditis, and were not detected in patients with endemic euthyroid goitre, differentiated thyroid carcinoma and toxic adenoma. Furthermore, TSH-receptor antibodies were present in some patients with toxic multinodular goitre (TBIAb in 12.7% and TSAb in 15.9%). When TSH-receptor and other thyroid autoantibodies were compared, it was found that 13 of the 15 Graves' patients with negative tests for thyroglobulin and thyroid microsomal antibodies were positive for TSH-receptor antibodies. On the other hand, 9 of the 11 patients with toxic multinodular goitre who had positive TSH-receptor antibody tests, also had serum thyroglobulin and/or thyroid microsomal antibodies. No significant differences in the prevalence of TSH-receptor antibodies were found in Graves' patients irrespective of the presence of ophthalmopathy or pretibial myxoedema. Elevated TBIAb activity at the end of anti-thyroid drug treatment was found in 52.9% of Graves' patients who subsequently relapsed, while in Graves' patients in remission TBIAb was always negative. TSH-receptor antibody results were not predictive of the outcome of radioiodine treatment in Graves' disease. Finally no correlation could be found between TBIAb and TSAb in Graves' disease and Hashimoto's thyroiditis. In conclusion: the high incidence of TSH-receptor antibodies in Graves' disease confirms their pathogenetic role in the development of hyperthyroidism; TSH-receptor antibodies in Graves' disease are not significantly associated with the presence of ophthalmopathy or pretibial myxoedema; TSH-receptor antibody assays may be useful for the diagnosis of Graves' disease in the absence of other signs of autoimmunity. TBIAb seems to be a good predictor of relapse in Graves' patients treated with anti-thyroid drugs; a fraction of toxic multinodular goitre could be a nodular variant of Graves' disease.     

眼肌结合抗体的ELISA检测及应用

自猪和牛眼肌提取眼肌抗原，建立了检测人血清中眼肌结合抗体（ＥＭ－Ａｂ）的ＥＬＩＳＡ法。检测４０例甲亢患者阳性率为３０．０％，２３例ＳＬＥ患者阳性率为２６．９％，与正常对照组比较有显著差别（Ｐ〈０．０１）。ＥＭ－Ａｂ与甲状腺疾病的一些自身抗体无显著相关性，提示此是与眼病自身免疫反应有关的一种自身抗体。     

Endocrine ophthalmopathy: a re-evaluation of the association with thyroid autoantibodies.

Autoantibodies to the three major thyroid autoantigens, the TSH-receptor (TSH-R), thyroid peroxidase (TPO) and thyroglobulin (TG), have been investigated in 63 Graves' patients with severe endocrine ophthalmopathy. In agreement with other studies, TSH-R antibodies were detectable in 88% of patients and dominated the autoantibody spectrum. TPO antibodies were detectable in 60% of patients and TG antibodies in only 25% of patients. The prevalences, as well as the amounts, of all three thyroid autoantibodies were not significantly different from the values in 51 Graves' patients without clinically significant ophthalmopathy. However, in the subgroup of patients with TG antibodies, the ophthalmopathy patients displayed a shift towards IgG4 TG antibodies. Furthermore, in the same TG antibody positive subgroup, the amount of TSH-R antibody was significantly higher in the ophthalmopathy patients than in Graves' patients without ophthalmopathy. These qualitative differences in thyroid autoantibodies in patients with and without ophthalmopathy raise the possibility that further qualitative differences, such as thyroid autoantibody epitopes, may exist in patients with ophthalmopathy. Our observations, combined with recent evidence for the presence of TSH-R specific mRNA in retro-orbital tissue, suggest that it may be premature to dismiss the potential pathogenetic or diagnostic value of thyroid autoantibodies, particularly TSH-R antibodies, in Graves' ophthalmopathy.     

Methimazole blocks Graves' IgG but not interferon-gamma HLA-DR expression by thyroid cells

We have expanded our early observation that a potent Graves' IgG preparation induces HLA-DR expression on thyroid cells, by showing that four randomly-selected Graves' IgG's were also capable of inducing DR antigens on thyroid cells. The effect of Graves' IgG was specific to thyroid cells, as it did not induce MHC Class II molecule expression on endothelial cells whereas interferon-gamma and immune complexes did so. The anti-thyroid drug methimazole was capable of rapidly reducing Graves' IgG-induced DR expression but to a much lesser extent than brought about by interferon-gamma. We conclude that Graves' IgG propagates thyroid-specific autoaggression by continued induction of DR antigens and than an important means whereby methimazole brings about remission is by reducing this induction.     

Serum immunoglobulin levels in thyroid disease

Serum levels of IgG, IgA and IgM were assayed by radial immunodiffusion in 261 patients with eight categories of thyroid disease. These composed eighty-three patients with a first episode of untreated active Graves' disease (toxic diffuse goitre), ten with relapsed Graves' disease, seventeen with thyrotoxicosis due to a multinodular goitre, forty-nine with Hashimoto's thyroiditis, twenty-eight with primary (non-goitrous) myxoedema, forty with non-toxic goitre, eighteen with an adenoma and sixteen with euthyroid ophthalmopathy.

Eighteen (21·7%) patients with a first episode of Graves' disease had abnormally high IgG levels whereas eight (80%) of those who had relapsed after a course of Carbimazole had high levels. Those Graves' disease patients with raised IgG levels had a significantly higher 24-hr radioiodine uptake than those with normal levels. Eight (16·3%) patients with Hashimoto's thyroiditis had abnormally high levels of IgG associated with a higher incidence of thyroglobulin autoantibodies. Very few (<6%) patients with primary myxoedema, non-toxic goitre and adenoma had abnormal levels. Euthyroid patients with ophthalmopathy had a significantly lower mean IgG level than the corresponding mean level found in the group with active Graves' disease.

However, despite the differences between groups described above, there were no significant differences of mean IgG, IgA and IgM levels in seven of the eight groups when compared with normal subjects. Only the group with relapsed Graves' disease had a significantly higher mean IgG. None of the patients studied had abnormal IgM or IgA levels.

     

IgA class and subclass thyroid auto-antibodies in Graves' disease and Hashimoto's thyroiditis

The reported prevalence of IgA class thyroid antibodies in Hashimoto's thyroiditis is variable and the IgA subclass distribution in unknown, despite recent reports of IgG subclass restriction in the thyroid auto-antibody response. Using an ELISA, IgA class antibodies were found against thyroglobulin (Tg) and microsomes (Mic) in 40-52% of patients with Graves' disease and Hashimoto's thyroiditis, and, against thyroglobulin, they were detected in the absence of IgG antibodies in 10% of the cases. Both IgA1 and IgA2 subclasses were detected in all patients with IgA class antibodies, although a significantly higher proportion of IgA2 relative to IgA1 was found in microsomal compared with thyroglobulin antibodies. In view of the high turnover rate and unique complement-fixing properties of IgA2 antibodies, this class of thyroid auto-antibody may play an important role in determining the response in thyroid auto-immunity.     

Cell-mediated immunity to orbital tissue antigens in thyroid-associated ophthalmopathy determined using the leukocyte procoagulant activity assay.

While it is generally accepted that thyroid-associated ophthalmopathy (TAO), a progressive inflammatory disorder of the extraocular muscle and orbital connective tissue (OCT), is immunologically mediated the nature of the underlying abnormalities is poorly understood. Although there is considerable evidence for antibody-mediated immunity against both eye muscle (EM) and OCT antigens in TAO a role of cell-mediated immunity (CMI) has not been studied in detail. We have used a new sensitive test for CMI, the leukocyte procoagulant activity (LPCA) assay and tested blood leukocytes from patients with TAO and autoimmune thyroid disease (ATD) without evident ophthalmopathy for reactivity against pig eye muscle (PEM) and human thyroid and OCT membrane and soluble fractions. In some cases human EM fractions were also tested. Preparations of PEM membrane (PEMM) and human thyroid membrane induced a significant LPCA response in both groups of patients. PEM cytosol, human OCT membrane and cytosol and human spleen membrane did not evoke a significant response in either group of patients. There were significant positive correlations in patients with TAO between (i) LPCA in response to PEMM and that to human thyroid membrane and (ii) LPCA in response to human thyroid membrane and that to human EM membrane. In patients with TAO there were no significant associations between LPCA response to PEMM and the detection of serum antibodies to a 64 kDa EM membrane protein in immunoblotting, or between LPCA response to PEMM and the duration or severity of the ophthalmopathy or clinical evidence for eye muscle involvement. These findings confirm a role of cell-mediated immunity against eye muscle antigens in thyroid-associated ophthalmopathy.(ABSTRACT TRUNCATED AT 250 WORDS)     

Soluble interleukin-2 receptor in sera of patients with Graves' disease.

Activation of T lymphocytes has been found to be associated with an increase in soluble interleukin-2 receptor (sIL-2R) levels. The aim of this study was to investigate serum levels of sIL-2R in 20 untreated patients with Graves' disease and to relate these levels to disease activity and to TSH-receptor, anti-thyroglobulin, anti-microsomal and anti-eye muscle antibodies. sIL-2R levels were significantly increased in newly diagnosed Graves' patients compared with controls (667 +/- 270 vs 205 +/- 45 U/ml) (P less than 0.001). The sIL-2R levels were higher in patients with active infiltrative ophthalmology than in those without eye symptoms (810 +/- 313 vs 525 +/- 180 U/ml). All patients were treated with methimazole for at least 12 months. sIL-2R levels were normalized by methimazole treatment in the majority of patients without ophthalmopathy but not in those with ophthalmopathy. In five patients sIL-2R serum levels were studied after interruption of thyrostatic therapy. An increase was observed in three patients and hyperthyroidism subsequently relapsed in two of these. Furthermore, a correlation was found between soluble interleukin-2 receptor levels and TSH-receptor antibodies but not with other immune parameters examined. Serum sIL-2R represents a useful marker of immunological activity in Graves' disease.     

Secretor status and infection in patients with Graves' disease

We have demonstrated that the inability to secrete the water soluble glycoprotein form of the ABO blood group antigens into saliva is significantly more common in patients with Graves' disease than control subjects (40% vs 27%: P less than 0.025) but not among those with Hashimoto's thyroiditis or spontaneous primary atrophic hypothyroidism. Non-secretion is associated with increased susceptibility to infection and to asymptomatic carriage of some microorganisms. Although Yersinia enterocolitica has been found to express antigen cross reactive with the TSH receptor, we did not find an increased prevalence of Yersinia species in the faeces of 107 patients with Graves' disease. The isolation rate (less than 1%) was similar to that observed in the local population with diarrhoeal illness. Salivary IgA levels determined by whole cell ELISA with Y. enterocolitica 03 were not elevated in the majority of specimens examined. The results suggest that in contrast to reports from Scandinavia, there is no strong evidence that yersiniae play a role in the pathogenesis of Graves' disease among patients in South east Scotland. Non-secretors are significantly over represented among patients with several other autoimmune diseases; however, with the exception of antitubulin antibodies, non-secretors with Graves' disease did not have more antibodies to other human antigens than secretor patients.     

The pathogenetic connection between Graves' disease and chronic lymphocytic thyroiditis. (The role and incidence of thyroid stimulating antibodies)

Antibody-positivity to thyroid specific antigens (Htg, microsomal) and/or lymphocytic infiltration of the gland's parenchyma were observed in 207 (55%) of 377 patients with Graves's disease. Only in 48 (12.7%) of the cases were the findings in agreement with the criteria of chronic lymphocytic thyroiditis. Human thyroid stimulating antibody (HTSab) was detected in 135 (65%) of these 207 patients. In cases of Graves' disease associated with chronic lymphocytic thyroiditis, this proportion was found to be as high as 89.6% and attained even 100% in cases of Hashitoxicosis (39 patients). The presence of HTSab thus seems to form one of the features of patients with Hashitoxicosis. Infiltrative ophthalmopathy also showed a remarkably high incidence (59%) in this porcess. The typical prevalence of Graves' disease in females in the present material attained a 15:1 female-to-male ratio when the disease was associated with chronic lymphocytic thyroiditis. The results of the present study suggest that chronic lymphocytic thyroiditis associated with Graves' disease promotes the formation of thyroid stimulating antibodies.     

Alpha-fodrin as a putative autoantigen in Graves' ophthalmopathy

Alpha-fodrin, an intracellular organ-specific cytoskeleton protein is a recently identified autoantigen associated with Sicca- and Sjogren's syndrome (SS). SS frequently affects patients with Graves' ophthalmopathy (GO). We have therefore cloned and expressed the human recombinant 120-kDa fodrin-fragment. A sequential purification procedure was applied to isolate the recombinant protein. Using sera from patients with SS, the antigenicity of the purified fodrin fragment was demonstrated by immunoblotting. Sera from 144 patients with GO and 1200 blood donors were screened for the presence of anti-alpha-fodrin IgA and IgG antibodies by a newly developed ELISA using the human alpha-fodrin fragment as an autoantigen. In contrast to controls (<1% IgA only, P < 0.001) and to subjects with various autoimmune diseases (P < 0.001), alpha-fodrin antibodies were detected in 22% of patients with GO (n = 32). IgA and IgG antibodies were present in 21 (15%) and 14 (10%) GO subjects, respectively. A total of 45 patients with GO (31%) had at least one fodrin- or SS-antibody. GO patients with SS showed SS- and high titres of alpha-fodrin-antibodies. In GO patients, fodrin antibodies correlated with TPO- (P < 0.05) and SS-A (P = 0.002) antibodies. Thus, for the first time, antibodies reactive with fodrin are reported in patients with GO.     

Identification of autoantigen recognized by autoimmune ophthalmopathy sera with immunoblotting correlated with orbital computed tomography.

We have demonstrated that there is an antibody related to extraocular muscle enlargement in autoimmune ophthalmopathy (Graves' ophthalmopathy, thyroid-associated correlated with orbital computed tomography (CT). This study was designed to identify the autoantigen and to determine whether there are common antigens among the extraocular muscle, the lacrimal gland, and the thyroid. We prepared a 100,000g sediment fraction of porcine extraocular muscle, lacrimal gland, thyroid, and human thyroid, followed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and immunoblotting with sera from patients with Graves' disease, with or without ophthalmopathy, classified by symptoms and signs combined with orbital CT and normal controls. The results showed there was an approximately 55-kDa protein band which was recognized by the sera in 32.1% (9/28) of patients with autoimmune ophthalmopathy and in 47.3% (9/19) of patients with extraocular muscle enlargement demonstrated by orbital CT. It was significantly higher than the positive rates in patients without autoimmune ophthalmopathy and normal controls (15.8 and 11.1%, respectively, P < 0.025). However, there was no common antigen among the extraocular muscles, the lacrimal gland, and the thyroid. To further confirm this eye muscle-specific antigen, the approximately 55-kDa protein band was cut and solubilized from the nitrocellulose paper after SDS-PAGE, and electrophoretically transferred and used as an antigen in enzyme-linked immunosorbent assay. The absorbance was significantly higher in patients with autoimmune ophthalmopathy than patients without ophthalmopathy (P < 0.005), and normal controls (P < 0.01). Our findings suggest that an approximately 55-kDa protein may be a possible antigen in the eye muscle related to autoimmune ophthalmopathy.     

The specificity of serum and local antibodies in female gonorrhoea.

Immunoblotting has been used to compare the specificity of serum and local IgG and IgA antibodies in 13 women with gonorrhoea and in 13 controls. The technique allowed the simultaneous detection of antibodies to the major outer membrane proteins I, II, and III, pili and lipopolysaccharide; antibodies to another antigen which is probably a 'carbohydrate' were also detected. Serum and local IgG and IgA were found to be produced to several antigens during gonococcal infections, although the quantity of antibody was greater in serum. There was little change in the specificity of serum antibodies whereas the local response to LPS and pili increased over the two week study period. Serum antibody to LPS was more often IgG than IgA. Sera contained antibodies to 'carbohydrate', pili and lipopolysaccharide (LPS) whilst the local response was largely to the latter two antigens. Antibody to the outer membrane proteins was rarely detected. Control sera, but not vaginal washings, contained IgG and IgA to the major antigens but the staining of the immunoblots was less intense than those from patient's sera suggesting quantitative differences.     

IgG and IgA antibody levels to cow's milk are low at age 10 years in children born preterm

BACKGROUND: Both innate and specific defenses of the preterm infant are even less developed than those of term infants, and the immune systems of preterm infants might be skewed differently at birth. Their immune responses to food antigens started early in life might therefore differ from those of term infants. OBJECTIVE: We sought to compare antibody levels to cow's milk, ovalbumin, and gliadin at age 10 years in children who had been born either preterm or at term. METHODS: IgG and IgA isotype antibodies to whole cow's milk, beta-lactoglobulin, alpha-casein, and ovalbumin, as well as IgG antibody levels to gliadin and to tetanus and diphtheria toxoids, were measured for a group of 62 children born preterm and 61 control subjects born at term. These children were studied at the same time for atopy. RESULTS: Children born preterm had markedly lower levels of antibodies to cow's milk and to its protein fractions (P <.0001 for IgA and IgG antibodies to cow's milk and alpha-casein and IgG beta-lactoglobulin antibodies). IgG gliadin antibodies were also significantly lower in the preterm group (P =.03), although the difference was not significant for IgG ovalbumin antibodies. In the preterm group both those born before gestational week 30 and those given cow's milk-based formula early (before day 50) had the lowest levels of cow's milk antibodies. In the preterm group atopy was associated with low levels of IgG cow's milk antibodies but with high levels of IgG ovalbumin antibodies. CONCLUSIONS: Early introduction of food antigens into the immature gastrointestinal tract of preterm infants might result in tolerance. The presence of less atopy in these children might also be a result of tolerance development.     

Systemic immune response after mucosal immunization in patients with IgA nephropathy

Increased IgA production has been proposed as a portion of the etiology of IgA nephropathy. Indirect human data suggest that IgG and complement may be equally important. We have immunized 17 patients with IgA nephropathy and 27 controls with tetanus toxoid. They were nasally immunized and, 2 weeks later, received an im booster immunization. This protocol has been shown to result in an increased serum IgA1 antibody response to tetanus toxin (TT). Patients had higher serum IgG antibodies to TT before and after the im immunization than did controls (pre, 42 vs 13 U; post, 155 vs 71 U;P=0.004). Patients also had a greater increase in serum IgG antibodies (118 vs 58;P=0.02). After the im TT, patients had lower levels of serum IgA1 antibody to TT (115 vs 180;P=0.005) but the change in IgA1 antibodies was not significant. These data suggest that patients with IgA nephropathy may produce inappropriately large amounts of serum IgG antibodies to antigens encountered in the upper respiratory tree. Such antigens also induce a serum IgA1 response. Such a response could result in the formation of potentially nephritogenic immune complexes containing IgG, IgA1, and C3.