Thyroid gland disorders in primary Sjögren's syndrome

OBJECTIVES

To evaluate the frequency of thyroid disorders in primary Sjögen's syndrome.

PATIENTS AND METHODS

121 consecutive patients meeting Vitali's criteria for primary Sjögren's syndrome and 74 with rheumatoid arthritis underwent thyroid hormone assays, tests for antimicrosomal and antithyroglobulin antibodies, tests for antinuclear antibodies and antibodies to extractable nuclear antigens. Antimicrosomal and antithyroglobulin antibodies were also assayed in 404 controls.

RESULTS

frequencies were calculated separately in males and females, and data in females were subjected to statistical analysis. As compared with controls, Sjögren's syndrome patients were more likely to have antimicrosomal antibodies (9% versus 17.6%, P < 0.05) and both Sjögren's syndrome and rheumatoid arthritis patients were more likely to have antithyroglobulin antibodies (1% versus 13.4% and 10.9%, respectively, P < 0.0001). Hypothyroidism was more common among Sjögren's syndrome patients (13.4%) than rheumatoid arthritis patients (3.1%) (P < 0.05). Sjögren's syndrome patients with thyroid disorders were less likely to have antinuclear antibodies, rheumatoid factors or a Chisholm's stage 3 or 4 lip biopsy.

CONCLUSIONS

our data confirm that thyroid disorders are more common in primary Sjögren's syndrome than in rheumatoid arthritis and controls. Production of autoantibodies and severe histologic lesions were less common in Sjögren's syndrome patients with than without thyroid disorders.

Hormonal responses during various phases of autoimmune adrenal failure: no evidence for 21-hydroxylase enzyme activity inhibition in vivo

Adrenal autoantibodies (ACA) are markers of adrenal cortex involvement in idiopathic Addison's disease. Recently the 21-hydroxylase (21-OH) enzyme has been discovered to be the major autoantigen of the ACA. A potential role of these antibodies in determining adrenal failure by inhibition of the 21-OH has been recently postulated. To test this hypothesis, cortisol and aldosterone (final products of adrenal steroid synthesis) and 17-hydroxyprogesterone (17-OH-progesterone) (as a marker of 21-OH impairment) have been investigated in baseline conditions and after ACTH (1-24) stimulation test in a group of 42 patients positive for both ACA and 21-OH autoantibodies. Patients were divided into five groups according to the stages (0-4) of adrenal failure. With progression toward overt Addison's disease, baseline 17-OH-progesterone, cortisol, and aldosterone remained almost unchanged but with impairment of their responses to ACTH (1-24) stimulation. The 17-OH-progesterone/cortisol ration remained normal both in basal conditions and after stimulation at stages 0-3. At stage 4 (overt Addison's disease), this ratio increased in baseline condition with no changes after ACTH (1-24), probably because of persistent 17-OH-progesterone gonadal production. In conclusion, there was a progressive and concomitant impairment of the synthesis of all steroids tested over various phases of adrenal failure. The pattern of response of the 17-OH-progesterone/cortisol ratio to ACTH stimulation in patients with 21-OH autoantibodies was not consistent with the autoantibodies inhibiting the 21-OH activity. This suggests that the inhibiting effect of 21-OH autoantibodies on 21-OH activity is not usually evident in vivo.

An immunological and genetic study of patients with gestational diabetes mellitus

The aim of the study was to evaluate the frequency of islet cell (ICA) and insulin (IAA) antibodies and of HLA antigen typing in a group of subjects diagnosed with gestational diabetes mellitus (GDM) in a screening-diagnostic program during pregnancy. ICA, complement-fixing (CF) ICA and other autoantibodies, absolute number and percentage of lymphocyte subpopulations, and HLA antigens were evaluated in 68 women with GDM and compared with those of matched controls. ICA were found in 2 (2.9%) and IAA in 1 (1.5%). Both ICA-positive women had CF-ICA; one of them was receiving insulin therapy. while the other was on a special diet. No correlations were found between ICA and IAA, nor between IAA and insulin treatment. As far as lymphocyte subsets were concerned, we found a significant increase in the absolute number of total and activated (CD3+HLA-DR+) T lymphocytes and a significant increase in the absolute number and percentage of suppressor/cytotoxic T lymphocytes (CD8) and NK lymphocytes (CD57) in GDM patients compared with normal pregnant controls. Concerning frequency for HLA A, B, C, DR antigens in the GDM population, only Cw7 was found to be significantly increased and A10 significantly decreased in comparison with controls. Our study suggests that GDM is a heterogeneous disorder in which few patients present with the immunologic and genetic markers of type 1 diabetes.

Absence of circulating adrenal autoantibodies in adult-onset X-linked adrenoleukodystrophy

X-linked adrenoleukodystrophy (ALD) is a frequent cause of adrenal insufficiency in young-adult patients with Addison's disease. As the contribution of an autoimmune process in the destruction of steroid cells in ALD is unclear, the aim of the present study was to evaluate the occurrence of adrenal-, thyroid- and islet-specific and non organ-specific autoantibodies in adult ALD patients. In all 5 patients, Addison's disease was the first manifestation of ALD. None of the ALD patients were positive for adrenal cortex autoantibodies in an indirect immunofluorescence assay, or for 21-hydroxylase autoantibodies in a radiobinding assay with recombinant human antigen. Similarly, we found neither non-organ specific autoantibodies (such as anti-nuclear, anti-ribosomal, anti-mitochondria, anti-smooth-muscle, anti-liver/kidney microsomal or anti-reticulin autoantibodies), nor islet-cell antibodies or glutamic acid decarboxylase (GAD65 or GAD67) autoantibodies, nor thyroglobulin autoantibodies in the sera of the 5 ALD patients. Two out of five patients were positive for thyroid microsomal autoantibodies. One of the two latter thyroid antibody-positive patients had clinical symptoms of hypothyroidism, and the other presented high levels of circulating TSH but no clinical signs or symptoms of hypothyroidism. Our study demonstrates that adult ALD is not immediately associated with the presence of adrenal autoantibodies and suggests that adrenal insufficiency is not mediated by an autoimmune process in adult ALD patients.

Complement-fixing islet cell antibodies in type-1 diabetes can trigger the assembly of the terminal complement complex on human islet cells and are potentially cytotoxic

Forty-one sera of patients with IDDM (insulin-dependent diabetes mellitus) containing complement-fixing islet cell antibodies were analyzed for their ability to activate TCC (terminal complement complex). Eighteen sera were found to promote deposition of TCC on human islets of pancreatic cryostat sections with a nonhomogeneous pattern of distribution corresponding to that of insulin. Activation of TCC by IDDM serum and binding of this complex to islet cells was confirmed using purified islets. Flow cytometric analysis of islet cell treated with a TCC+ IDDM serum showed IgG binding to the cell surface. The same serum had a cytotoxic effect on islet cells in the presence of human C. These results obtained with a homologous system of C activation by IDDM sera suggest that TCC may contribute, at least in part, to the pancreatic beta cell damage.

Autoantibodies to steroidogenic enzymes in autoimmune polyglandular syndrome, Addison's disease, and premature ovarian failure

Autoantibodies to steroidogenic enzymes, steroid 17 alpha-hydroxylase (17 alpha-OH), cytochrome P450 side-chain cleavage enzyme (P450scc), and steroid 21-hydroxylase (21-OH), were measured using specific and sensitive immunoprecipitation assays (IPAs) in patients with various forms of autoimmune adrenal disease. Autoantibodies to 17 alpha-OH were detected in 6 of 11 (55%) patients with autoimmune polyglandular syndrome (APS) type I, 8 of 24 (33%) patients with APS type II, 11 of 56 (20%) patients with adrenal cortex antibody (ACA; measured by immunofluorescence)-positive patients without Addison's disease, and only 3 of 64 (5%) patients with Addison's disease. Autoantibodies to P450scc were found at a prevalence similar to those to 17 alpha-OH: in 5 of 11 (45%) APS type I patients, 10 of 24 (42%) APS type II patients, 11 of 56 (20%) ACA-positive patients without Addison's disease, and only 6 of 64 (9%) patients of the Addison disease group. Autoantibodies to 21-OH were found in a majority of patients with APS type I (7 of 11;64%), APS type II (23 of 24; 96%), Addison's disease (41 of 64; 64%), and ACA-positive patients without Addison's disease (48 of 56; 86%). All sera that were positive for 17 alpha-OH or P450scc were also positive for 21-OH autoantibodies, except in 1 case. There was good agreement between the presence of ACA measured by immunofluorescence and 21-OH antibodies measured by IPA in all patient groups studied, and this indicates that 21-OH is a major autoantigen in adrenal autoimmune disease regardless of whether the disease presents as isolated Addison's disease or APS type I or type II. Autoantibodies to 17 alpha-OH and P450scc appeared to be the major components of the steroid-producing cell antibodies measured by immunofluorescence. No autoantibodies to 21-OH, 17 alpha-OH, or P450scc were detected in 17 sera from patients with premature ovarian failure without evidence of adrenal autoimmunity (as judged by immunofluorescence studies), except for 1 serum in which low levels of 17 alpha-OH antibodies were found. Overall, our studies indicate that 35S-labeled 17 alpha-OH, P450scc, and 21-OH can be used successfully in IPAs for their respective autoantibodies. Assays such as these may well be valuable in the immunological assessment of patients at risk for or suspected of adrenal autoimmunity.

Type 2 polyglandular autoimmune disease (Schmidt's syndrome)

Data on clinical, genetic, and immunological aspects of sixty patients with type 2 polyglandular autoimmune disease (PGAD) are presented. The literature on this is reviewed and discussed.

Pancreatic exocrine involvement in primary Sjögren's syndrome

Exocrine pancreatic involvement of primary Sjögren's syndrome (SS) was studied. Pancreatic enzyme levels (total amylase, pancreatic isoamylase and immunoreactive trypsin) along with anti-ductuli antibodies (Ab) were studied in 77 patients with primary SS. In 10 patients with normal and 10 with abnormal enzyme levels pancreatic CT scans were also obtained. All enzyme levels were significantly increased in comparison to the control group. Immunoreactive trypsin was found to be the most frequently increased enzyme (35.3% of pSS patients). Anti-ductuli Ab were not found in any patient. Pancreatic CT scans were normal in all subjects with enzymatic increase, whereas 2 abnormal scans were demonstrated in patients without enzyme changes. Our study suggests that exocrine pancreatic involvement is frequent when measured by enzyme levels. Nevertheless, we were unable to demonstrate any morphological lesion by CT scan.

An immunohistochemical study of immunological phenomena in minor salivary glands in patients with Sjögren's syndrome

Using different monoclonal antibodies, we performed an immunofluorescent technique on labial salivary glands in order to investigate the immunological phenomena involved in Sjögren's syndrome (SS). An aberrant expression of HLA-DR molecules was detected on cytoplasm of epithelial labial salivary cells in 9 out of 19 (47%) patients, with SS. No such expression was found in 8 patients without SS or in 3 normal controls. HLA-DQ molecules were demonstrated also in two out of ten SS patients without HLA-DR. A lymphocytic infiltration was not correlated with the expression of class II molecules. T cells bearing gamma delta receptors were not detected. The intracellular adhesion molecules (ICAM-1) and lymphocyte function associated antigen-1 (LFA-1) were not found on epithelial glandular salivary cells of patients and controls. In conclusion, these data suggested that the absence of ICAM-1 and LFA-1 in salivary cells and the absence of infiltrating T cells bearing gamma delta receptors exclude their immunopathogenetic role in SS; moreover, these data demonstrated that the aberrant expression of HLA class II molecules on epithelial salivary cells of patients with SS is not a phenomenon correlated with the lymphocytic infiltration.

Frequency of Hashimoto's thyroiditis in children with type 1 diabetes mellitus

A total of 1419 children with type 1 diabetes mellitus was investigated in order to assess the true frequency of Hashimoto's thyroiditis (HT), diagnosed by microsomal and/or thyroglobulin autoantibodies, by ultrasound and in many cases also by fine needle biopsy. According to these criteria, 55 cases (3.9%) of HT were identified, a number significantly higher (P < 0.0001) than the distribution reported in the normal paediatric population. No typical antibody pattern was seen prior to the onset of HT, nor was an antibody threshold level found which could have been diagnostic for this disease. Patients with subclinical hypothyroidism were treated with L-thyroxine and were investigated regarding the behaviour of anti-thyroid autoantibodies; however, no significant changes were seen. The data showed a high frequency of HT in diabetic children, and therefore we recommend that children with type 1 diabetes mellitus should be screened for thyroid autoantibodies and those positive should undergo periodic thyroid function testing.

Follicular thyroid cells of autoimmune thyroiditis may coexpress ICAM-1 (CD54) and its natural ligand LFA-1 (CD11a/CD18)

The leukocyte functional associated antigen-1 (LFA-1)-intercellular adhesion molecule-1 (CD11a-CD18/CD54) intercellular adhesion system plays a crucial role in several immunologic phenomena, including adhesion between lymphocytes and epithelial cells. In previous studies evidence for CD54 expression on thyroid follicular cells in Hashimoto's thyroiditis was provided. In this study we evaluated the possible expression of CD11a and CD18 antigens on thyrocytes of patients with Hashimoto's thyroiditis and on thyrocytes of patients with Graves' disease and simple goiter as controls; we used both alkaline phosphatase immunostaining and indirect immunofluorescence on cryostatic tissue sections. The results showed that LFA-1 (both CD11a and CD18) positivity on thyroid follicles may occur in glands of patients with Hashimoto's disease, with a pattern very similar to that of CD54: this was observed in five of seven specimens. Conversely, no positivity was observed in tissues from patients with Graves' disease or goiter: notably, isolated follicular cells from Graves' goiter tissues are induced in culture to express CD54, but not LFA-1. Using double-staining techniques, we were able to show that in specimens from patients with Hashimoto's disease, the same follicular structures coexpressed LFA-1 and CD54. Such a coexpression of the two ligands further emphasizes the possible role of this adhesion system in the pathogenesis of epithelial damage, through bidirectional interactions between thyroid epithelial cells and infiltrating LFA-1 or CD54-positive mononuclear cells.

Immunoprecipitation assay for autoantibodies to steroid 21-hydroxylase in autoimmune adrenal diseases

Adrenal autoantibodies characteristic of autoimmune Addison disease are directed towards steroid 21-hydroxylase (21-OH; EC 1.14.99.10). We describe a new assay to measure 21-OH autoantibodies (21-OH Abs), based on immunoprecipitation by the antibodies of 35S-labeled human 21-OH. Using this immunoprecipitation assay (IPA), we detected 21-OH Abs in 42 of 64 (66%) patients with Addison disease and in 14 of 19 (74%) patients with autoimmune polyendocrine syndromes type I and type II. No 21-OH Abs were detected by the IPA in any patients with Addison disease attributable to tuberculosis (n = 9) or adrenoleukodystrophy (n = 9) or in patients with autoimmune thyroid disease (n = 28), systemic lupus erythematosus (n = 10), myasthenia gravis (n = 10), rheumatoid arthritis (n = 10), or insulin-dependent diabetes mellitus (n = 12). None of the 26 sera from healthy normal blood donors was positive for 21-OH Abs by the assay. We found good agreement between 21-OH Abs measured by IPA and by Western blotting (r = 0.83, n = 123, P < 0.001). The inter- and intraassay CVs for IPA were well < 10% at high, medium, and low concentrations of 21-OH Abs. Overall, our studies indicate that the IPA provides a specific, sensitive, and convenient system for measuring 21-OH Abs.

Immunoprecipitation assay for autoantibodies to steroid 21-hydroxylase in autoimmune adrenal diseases

Adrenal autoantibodies characteristic of autoimmune Addison disease are directed towards steroid 21-hydroxylase (21-OH; EC 1.14.99.10). We describe a new assay to measure 21-OH autoantibodies (21-OH Abs), based on immunoprecipitation by the antibodies of 35S-labeled human 21-OH. Using this immunoprecipitation assay (IPA), we detected 21-OH Abs in 42 of 64 (66%) patients with Addison disease and in 14 of 19 (74%) patients with autoimmune polyendocrine syndromes type I and type II. No 21-OH Abs were detected by the IPA in any patients with Addison disease attributable to tuberculosis (n = 9) or adrenoleukodystrophy (n = 9) or in patients with autoimmune thyroid disease (n = 28), systemic lupus erythematosus (n = 10), myasthenia gravis (n = 10), rheumatoid arthritis (n = 10), or insulin-dependent diabetes mellitus (n = 12). None of the 26 sera from healthy normal blood donors was positive for 21-OH Abs by the assay. We found good agreement between 21-OH Abs measured by IPA and by Western blotting (r = 0.83, n = 123, P &lt; 0.001). The inter- and intraassay CVs for IPA were well &lt; 10% at high, medium, and low concentrations of 21-OH Abs. Overall, our studies indicate that the IPA provides a specific, sensitive, and convenient system for measuring 21-OH Abs.

Natural course of subclinical hypothyroidism in Down's syndrome: prospective study results and therapeutic considerations

Pathogenesis, natural course and therapeutic management of subclinical hypothyroidism (SH) in Down's syndrome (DS) remain object of debate in literature. In the present study thyroid function, antithyroid antibody (ATA) prevalence and serum lipid concentrations were investigated in a group of 344 Down patients (DP) and data were compared with those obtained from a control group of 257 age and sex matched healthy subjects. Thyroid function and ATA prevalence were also studied in 120 parents of DP. SH prevalence was clearly higher in DP (32.5% of cases) than in controls (1.1%) and parents (0%). Similarly, ATA prevalence was higher in DP (18% of cases) than in controls (5.8%) and parents (6.6%). In spite of this, no correlation was found in DP between SH and ATA prevalences, since ATA were detected in 18.7% of SH-DP and in 15.8% of euthyroid DP. Thus, circulating ATA were not detected in the majority of SH-DP. No significant differences regarding T4, FT4, T3 and serum lipid levels among SH and euthyroid DP and controls were found. Moreover, TSH levels were only slightly increased, generally less than 10 microU/ml, in most cases of SH-DP. Follow-up was longer than 24 months (range 2-7 years, mean 3.1) in a group of 201 DP: two different patterns of SH course were observed, mainly depending on the presence or the absence of circulating ATA. In particular, 35.7% of ATA-positive SH-DP developed a clinically evident thyroid disease (overt hypothyroidism or hyperthyroidism), while no similar case was recorded among ATA-negative SH-DP.(ABSTRACT TRUNCATED AT 250 WORDS)

24-hour blood pressure profile in Addison's disease

The purpose of this study was to evaluate the circadian blood pressure rhythmicity in patients with primary adrenal insufficiency. Ten newly diagnosed and untreated patients with Addison's disease, 17 addisonian patients (including the previous 10) following an adequate regimen of corticosteroid replacement therapy, and 15 healthy subjects as a control group were studied. Twenty-four-hour ambulatory blood pressure and heart rate were measured automatically every 30 min using a Takeda TM-2420 recorder. The runs test, used for detecting blood pressure diurnal rhythm, was compatible with a rhythm in 2 of 10 patients with untreated Addison's disease, in 13 of 17 patients with treated Addison's disease, and in 13 of 15 normals. Six of eight addisonian patients showing no evidence of blood pressure rhythm in the untreated state acquired circadian periodicity during therapy. An analysis of blood pressure readings by Fourier series with four harmonics showed that blood pressure mesor was lower in untreated than in treated addisonian and normal subjects (P < .05). The nocturnal fall was smaller for systolic and diastolic blood pressure in untreated than in treated addisonian and normal subjects (P < .05). Adrenocortical insufficiency is often characterized by loss of circadian blood pressure rhythm, and normal rhythm can be reestablished by replacement therapy. Lack of cortisol rhythm or persistent activation of the renin-angiotensin system and sympathetic tone may play a role in this phenomenon.

Early adrenal hypofunction in patients with organ-specific autoantibodies and no clinical adrenal insufficiency

Idiopathic Addison's disease occurs frequently in association with other organ-specific autoimmune diseases, and autoantibodies to adrenal cortex are markers of this condition. A variable asymptomatic period with subtle adrenal dysfunction may precede the onset of clinical manifestations. We studied the pituitary-adrenal axis by measuring plasma ACTH, cortisol, and 17 alpha-hydroxyprogesterone after ovine CRH (100 micrograms as an iv bolus) stimulation in 19 patients with organ-specific autoimmune disease and adrenal autoantibodies, in whom adrenal steroids were normal under baseline conditions and normally responsive to a standard ACTH stimulation test (250 micrograms). In all subjects, oCRH produced a normal increase in plasma ACTH. Plasma cortisol, which was normoresponsive in 11 subjects, showed little or no increase in 8 subjects. Two of these patients developed overt adrenal failure after 1 yr. The 17 alpha-hydroxyprogesterone response to oCRH, tested in 10 of 19 patients, paralleled that of plasma cortisol, excluding a steroidogenic block at the 21-hydroxylase site. Our data demonstrate the existence of a very early phase of Addison's disease in which adrenal function shows an impaired response to ovine CRH-stimulated ACTH.

Lack of immunohistological changes in the islets of nondiabetic, autoimmune, polyendocrine patients with beta-selective GAD-specific islet cell antibodies

We examined the pancreases from three nondiabetic, autoimmune, polyendocrine patients with islet cell antibodies (ICAs) and glutamic acid decarboxylase (GAD) antibodies who died without developing insulin-dependent diabetes mellitus (IDDM). All three patients had the beta-selective GAD-specific ICA subtype and antibodies to the GAD-derived 50 kD tryptic fragment. None had whole islet ICA or antibodies to the non-GAD-derived 37k islet antigen, which appear to be more closely associated with IDDM than antibodies to GAD. The three patients also were negative for insulin autoantibodies. Islets within pancreas from patients 1 and 2 appeared well preserved as assessed by hematoxylin and eosin staining. In these two patients, insulin content, as assessed by indirect immunofluorescence on cryostat sections, was normal. Patient 3 had a prolonged postmortem time, and the islet insulin content was reduced slightly. In all three pancreases, no evidence was found of increased human leukocyte antigen class I or de novo class II molecule expression on islet cells, and islet infiltration by T- or B-cells or macrophages was not detected. Islet capillary endothelial cells did not show signs of hypertrophy. No immunoglobulin or complement deposition within or around islets was found. These data indicate that humoral GAD autoimmunity does not necessarily associate with visible beta-cell damage.

The natural history of pre-type 1 (insulin-dependent) diabetes mellitus in patients with autoimmune endocrine diseases

An 11-year prospective study was carried out in 180 non-diabetic patients with organ-specific autoimmune diseases to evaluate islet cell antibodies in predicting Type 1 (insulin-dependent) diabetes mellitus. Islet cell antibodies were characterised according to titres, persistence, complement-fixing ability, and pattern. During follow-up, 14 of 46 patients with islet cell antibodies persistently greater than 5 Juvenile Diabetes Foundation Units (JDF-U) (30.4%), none of 23 with islet cell antibodies between 2.5 and 5 JDF-U or fluctuating, and 3 of 109 without islet cell antibodies (2.7%), developed diabetes. The cumulative risk of developing diabetes was 70%, 0%, and 4%, respectively. All the patients who developed diabetes were females. Eight progressed to insulin-dependence acutely, four showed a transient period of non-insulin-dependence, while two were still insulin-free. No difference was found in titres of islet cell antibodies for the risk of diabetes. Complement-fixing islet cell antibodies enhanced the cumulative risk for the disease in patients with conventional islet cell antibodies at low-middle (> or = 2.5-40 JDF-U), but not at high (> or = 80 JDF-U) titres. Forty-two patients with islet cell antibodies were investigated for the whole or the selective pattern. In the presence of the whole pattern the cumulative risk for diabetes rose to 100%, while with the selective pattern it declined to 34%. The whole pattern was found in 83% of patients who developed Type 1 diabetes acutely. In patients with organ-specific autoimmune diseases, the whole islet cell antibody pattern greatly enhances the prediction for diabetes.

B cell activation and human immunodeficiency virus infection. V. Phenotypic and functional alterations in CD5+ and CD5- B cell subsets

B cell dysregulation is a hallmark of human immunodeficiency virus infection. Since B lymphocytes comprise two distinct subpopulations, CD5+ and CD5- cells, we addressed their individual phenotypic and functional behavior. Seropositive patients with both limited and advanced disease progression had an increased percentage of peripheral blood CD5+ B cells, compared to seronegative controls (20.1 +/- 2.1 and 22.7 +/- 5.7, respectively, vs 17.0 +/- 3.4 in controls); however, due to the lymphopenia and reduced number of circulating B cells in infected individuals, the absolute number of CD19+CD5+ lymphocytes was actually reduced. Although HIV-specific antibodies were synthesized spontaneously in vitro only by CD5- B cells, a 10-fold lower degree of spontaneous, non-HIV-specific activation was also displayed by unstimulated CD5+ B cells. These findings indicate that B cell dysregulation during HIV infection involves both the CD5- and the CD5+ B cell compartments; moreover, in view of the putative role of CD5+ B cells in autoimmune phenomena and IL-10 production, these data reinforce the possibility that B cell dysfunction might be causally involved in AIDS pathogenesis.

Susceptibility of human trophoblast to killing by human complement and the role of the complement regulatory proteins

The susceptibility of trophoblast to cytolysis by human complement was investigated using cells purified to over 90% from first trimester placentae. Two assay systems were employed to measure the killing of trophoblasts, an antibody-dependent complement-mediated cytolysis and the reactive lysis. The antibody obtained from a patient with Addison's disease reacted specifically with syncytiotrophoblasts and induced a dose-dependent killing of the cells not exceeding 50% even in the presence of excess antibody and complement. The percentage of cells killed by the terminal complement complex in the reactive lysis system was somewhat higher, reaching values of 60%. Immunofluorescence analysis revealed the presence of CD46 and CD59 on all syncytiotrophoblasts, whereas CD55 was only detected on approximately 30% of the cells. Inhibition of CD46 and CD59 resulted in increased susceptibility of syncytiotrophoblasts to complement lysis. The protective function of CD55 could not be evaluated because of its reduced expression on isolated trophoblasts. These results suggest that syncytiotrophoblasts may be killed by complement and that membrane regulators to some extent protect these cells from complement damage.

Susceptibility of human trophoblast to killing by human complement and the role of the complement regulatory proteins

The susceptibility of trophoblast to cytolysis by human complement was investigated using cells purified to over 90% from first trimester placentae. Two assay systems were employed to measure the killing of trophoblasts, an antibody-dependent complement-mediated cytolysis and the reactive lysis. The antibody obtained from a patient with Addison's disease reacted specifically with syncytiotrophoblasts and induced a dose-dependent killing of the cells not exceeding 50% even in the presence of excess antibody and complement. The percentage of cells killed by the terminal complement complex in the reactive lysis system was somewhat higher, reaching values of 60%. Immunofluorescence analysis revealed the presence of CD46 and CD59 on all syncytiotrophoblasts, whereas CD55 was only detected on approximately 30% of the cells. Inhibition of CD46 and CD59 resulted in increased susceptibility of syncytiotrophoblasts to complement lysis. The protective function of CD55 could not be evaluated because of its reduced expression on isolated trophoblasts. These results suggest that syncytiotrophoblasts may be killed by complement and that membrane regulators to some extent protect these cells from complement damage.

Premature ovarian failure: autoimmunity and natural history

OBJECTIVE

We studied the association of clinical and latent autoimmune diseases with circulating steroid-producing cells autoantibodies (SCA) in patients with premature ovarian failure (Group I). We investigated the presence of SCA in patients with organ-specific autoimmune diseases but without hypogonadism (Group II). We assessed whether SCA can be considered markers of hypergonadotrophic hypogonadism.

DESIGN

In Groups I and II blood samples were taken at diagnosis. In a subset of patients with SCA without hypogonadism blood samples were taken at least yearly for 6 years for immunological and functional tests.

PATIENTS

Group I included 50 females, aged 16-39 years; Group II included 3677 patients, aged 6-79 years, divided into Subgroup IIA (99 with Addison's disease alone or associated with other endocrinopathies or with hypoparathyroidism) and Subgroup IIB (3578 with insulin-dependent diabetes mellitus or thyroid autoimmune diseases). The follow-up group included nine subjects, aged 5-31 years (seven females and two males).

MEASUREMENTS

SCA and other organ-specific autoantibodies were detected by standard indirect immunofluorescence using normal human tissues or passive haemagglutination tests. Gonadal functional tests included evaluation of FSH and LH levels by a RIA method; adrenocortical function included evaluation of cortisol and ACTH plasma levels by a RIA method.

RESULTS

Three subgroups were identified in Group I on the basis of clinical autoimmune disease. 9/50 (18%) patients were found to have an Addison's disease (Subgroup IA) and in this subgroup SCA were present in 7/9 (78%); 10/50 (20%) had other autoimmune diseases (Subgroup IB) and SCA were found in 1/10 (10%); 31/50 (62%) did not have other clinical autoimmune diseases (Subgroup IC) and 1/31 (3%) had SCA. SCA were significantly increased in Subgroup IA vs IB (P = 0.017) and vs IC (P = 0.00002). In Group II, SCA were found in 20/3677 (0.5%); in particular, SCA were detected in 18/99 (18%) of the patients in Subgroup IIA and in 2/3578 (0.06%) of the patients in Subgroup IIB. The frequency of SCA in Subgroup IIA was found to be significantly increased with respect to that found in Subgroup IIB (P = 0.001 x 10(-5)). During follow-up, 3/7 females (42.8%) but 0/2 males developed hypergonadotrophic hypogonadism with a latency period of 10, 13 and 15 years, respectively. Three females and two males lacked clinical Addison's disease at the beginning of the study, but during follow-up 1/3 female and 2/2 males developed clinical Addison's disease with a mean latency period of 13 months.

CONCLUSIONS

The results confirm the strong relationship between premature ovarian failure and other clinical autoimmune diseases, as well as the strong link existing between primary ovarian failure, Addison's disease and antibodies to steroid-producing cells. The study also suggests that in females antibodies to steroid-producing cells are serological markers of both potential hypergonadotrophic hypogonadism, and Addison's disease; however, in males these antibodies may be considered only as markers of potential Addison's disease.