Clinical, subclinical and potential autoimmune diseases in an Italian population of children with coeliac disease

BACKGROUND Several studies have suggested a link between coeliac disease and other autoimmune diseases. AIM To compare the presence of autoimmune disease in children with coeliac disease and in controls. METHODS When coeliac disease was diagnosed, 267 children were evaluated for clinical autoimmune disease (with signs/symptoms), subclinical autoimmune disease (with autoantibodies and subclinical impairment of the target organ) or potential autoimmune disease (with autoantibodies only) and compared with 220 healthy controls. 170 coeliac disease patients were followed up for a mean 47 +/- 31 months, in complete remission on a gluten-free diet. Ninety-nine controls were followed up for 45 +/- 33 months. RESULTS When coeliac disease was diagnosed, 71 (27%) children had autoimmune disease vs. 1% among the controls (P < 0.001): 31 had clinical autoimmune disease and 40 had subclinical or potential autoimmune disease. During the follow-up, the clinical autoimmune disease cases slightly decreased from 12% to 11%, while the potential autoimmune disease cases increased from 14% to 21%. Of the 99 controls, none had any variation in their autoantibody profile. CONCLUSIONS Gluten-free diet does not modify the natural history of autoimmunity in patients with coeliac disease. However, gluten-free diet seems to produce a favourable effect on the previously present clinical autoimmune disease and to prevent the development of new clinical autoimmune disease, but does not affect the onset of potential autoimmunity, which tends to increase with time.

Vitiligo associated with other autoimmune diseases: polyglandular autoimmune syndrome types 3B+C and 4

Vitiligo is a common skin disease characterized by depigmented maculae resulting from a reduction of the number and function of melanocytes. Many studies suggest that vitiligo might be an autoimmune disease. Vitiligo has been frequently described in association with other autoimmune diseases. Among the diseases described in association with vitiligo are the so-called autoimmune polyglandular syndromes (APS). Vitiligo can be present in all types of APS but the most frequent association appears to be in APS-3. APS-3 was defined as the association between autoimmune thyroiditis and another autoimmune disease. Here we report one patient with thyroiditis, vitiligo and autoimmune gastritis (APS-3B+C), one patient with chronic autoimmune thyroiditis, vitiligo and alopecia (APS-3C), and one case of a young patient with type 1 diabetes mellitus and vitiligo (APS-4), according to the newest classification. We stress the importance of a thorough assessment for autoimmune diseases in selected patients with vitiligo.

Pancreatic autoantibodies in Italian patients with newly diagnosed type 1 diabetes mellitus over the age of 20 years

The aim was to estimate the prevalence of the serological markers of pancreatic autoimmunity in a cohort of Italian patients with type 1 diabetes mellitus occurring after 20 years of age in order to determine the prevalence of autoimmune diabetes and the most sensitive autoantibody combination to be employed for the diagnosis. We investigated 57 patients (31 males and 26 females) at clinical diagnosis of type 1 diabetes. 35 patients were 21-40 years and 22 were 41-72 years of age. Autoantibodies to islet-cells (ICA) were detected by indirect immunofluorescence, while those against glutamic acid decarboxylase (GADA), tyrosine-phosphatase (IA2A) and insulin (IAA) were detected by radiobinding assays. A positive test for at least one of the pancreatic autoantibodies was found in 45 of the 57 patients (78.9%). Coupling two antibody tests, GADA and/or IAA were found in 73.7%, ICA and/or GADA in 71.9%, while GADA and/or IA2A were found in 70.2% of the patients. The most frequently positive test was for GADA (66.7%). In general, the frequency of diabetes-related antibodies was higher in the 21-40-year-old group compared to the 41-72-year-old group and in females than males. Based on the detection of pancreatic autoantibodies determination, the great majority of the adult patients with recent onset type 1 diabetes were found to be autoimmune in nature. The best cost/benefit combination is provided by coupling the detection of GADA and ICA.

Is hepatitis C virus a risk factor for thyroid autoimmunity?

The role of hepatitis C virus (HCV) in inducing thyroid autoimmunity is still under discussion and to assess the prevalence of thyroid autoantibodies and thyroid disease in the general population and to analyse the role of HCV in inducing thyroid autoimmunity. We studied 697 subjects residing in Arsita (a small town in central Italy). Thyroid autoantibodies and nonorgan-specific autoantibodies (NOSAs) were tested in each subject, who were also screened for anti-HCV antibodies; all subjects found positive to HCV-RNA were considered as being HCV-infected. Thyroid function tests were performed in all subjects positive for thyroid autoantibody. Seventy-one subjects were found HCV-positive; four of these (5.6%) were positive for at least one thyroid autoantibody, as opposed to 7 (4.9%) of the 142 sex- and age-matched controls of the same population (P = n.s.). Thyroid dysfunction was found in 2/4 HCV-positive, and in 1/7 HCV-negative subjects with thyroid autoantibodies (P = n.s.). NOSAs were significantly more common in HCV-positive than in HCV-negative subjects (P < 0.0001). Hence HCV per se is not responsible for thyroid autoimmune dysfunction, whereas HCV does seem to induce NOSAs. It should be taken into account, however, that the phenotypic expression of autoimmune diseases is obviously influenced by a number of risk factors, including genetic predisposition, female sex and infectious agents, that could trigger the onset of the disease.

Parathyroid and autoimmunity

Data in favor of chronic hypoparathyroidism as an autoimmune disease are examined. The article takes into consideration the different clinical forms, genetic patterns, histopathology, animal models, cellular immunity, circulating autoantibodies, target autoantigens, clinical manifestations, laboratory diagnosis and therapy. Furthermore, data on 71 Italian patients with chronic hypoparathyroidism are presented.

X-linked adrenoleukodystrophy with olivopontocerebellar atrophy

X-linked adrenoleukodystrophy (X-ALD) is a rare neurological disorder characterized by adrenal, gonadal and nervous system dysfunction. Patients usually develop spinal cord degeneration with involvement of the cerebral white matter. While a spinocerebellar variant has been described, the selective involvement of cerebellar white matter is very rare. We report the case of a patient affected by X-ALD whose clinical and magnetic resonance imaging (MRI) results resembled olivopontocerebellar atrophy. He was a 29-year-old mentally retarded man, who began to complain of slowly progressive gait ataxia after an 8-year history of Addison's disease. Serial MRI revealed marked cerebellar atrophy involving the inferior cerebellar vermis and brainstem, but sparing the supratentorial white matter. The diagnosis of X-ALD was confirmed by elevated levels of very long-chain fatty acids in the serum. After 2 years follow-up, the patient developed spastic paraparesis. The patient represents an unusual clinical presentation of X-ALD, as further confirmed by the MRI results. Consequently, cerebellar symptoms should be considered as a clinical presentation of X-ALD. Early recognition of this rare disorder would be useful for genetic counselling and therapy.

Lymphocyte subsets and cytokines in women with gestational diabetes mellitus and their newborn

This study aimed to identify potential immunological markers for predicting type 1 diabetes in patients with gestational diabetes mellitus (GDM) and any immunological impairment in their newborn. In 62 GDM patients and 74 women with normal glucose tolerance (NGT), and their babies, we assessed total lymphocytes, T lymphocyte subsets CD3 and CD8 expressing T cell receptor (TCR) alpha/beta or gamma/delta, CD16 and CD19, pancreatic autoantibodies and cytokines (IL-5, IL-2, soluble receptor IL-2). At delivery, umbilical cord blood samples were taken for lymphocyte subpopulations and cytokine measurements. GDM mothers had higher levels of total lymphocytes, CD8 expressing TCR gamma/delta, and lower levels of CD3 expressing TCR alpha/beta than NGT controls. Insulin-treated GDM mothers had lower CD4 and CD4/CD8 ratios, and higher CD8 and IL-5 than diet-treated GDM or controls. Five women were positive for pancreatic autoantibodies, with lower CD4 (p<0.01) and CD4/CD8 ratios (p<0.05), and higher CD8 (p<0.03) and CD19 than GDM and control mothers negative for autoantibodies. GDM newborn had higher CD8 gamma/delta and lower CD16 than NGT babies. There were no significant differences in TNF-alpha concentrations in the cord blood obtained from the GDM and NGT newborn. In conclusion, GDM women and their newborn have lymphocyte subset impairments, which are more important in patients positive for autoantibodies and/or treated with insulin.

Isolation and characterisation of a human monoclonal autoantibody to the islet cell autoantigen IA-2

A hybridoma secreting a human monoclonal autoantibody to the islet cell autoantigen IA-2 was prepared from peripheral lymphocytes of a patient with type 1 diabetes and Graves' disease using EBV infection followed by fusion with a mouse/human hybrid cell line. The monoclonal antibody (M13) is an IgG1/kappa and in an immunofluorescence test M13 at 1 microg/mL showed islet cell antibody reactivity equivalent to 40 JDF units. M13 IgG bound (35)S-labelled IA-2 (26% at 100 microg/mL) and (125)I-labelled IA-2 (34% at 100 microg/mL) in an immunoprecipitation assay and reacted well with IA-2 in western blotting analysis. Amino acids 777-808 in the PTP domain of IA-2 were found to be important for M13 binding in an analysis using modified (35)S-labelled IA-2 proteins. M13 V region genes were from VH1-3, D3-22, JH4b, VKI DPK8/Vd+ and JK3 genes and showed a high replacement/silent mutation ratio for both the heavy (11.0) and the light (6.0) chain genes. Mouse monoclonal antibodies (mMAbs) reactive with at least three different epitopes within IA-2 aa 604-686 corresponding to the juxtamembrane domain were also obtained. F(ab')(2) or Fab from the mMAbs inhibited serum IA-2 autoantibody binding to IA-2 in 20/22 diabetic sera whereas M13 F(ab')(2) caused inhibition in only 6/22 sera. M13 is representative of some patient serum IA-2 autoantibodies and as such provides a useful tool to study autoimmune responses to IA-2.

Antigenic differences between neurological and diabetic patients with anti-glutamic acid decarboxylase antibodies

Antibodies to glutamic acid decarboxylase (GADAb) are found in Stiff-Person syndrome, type 1 diabetes, cerebellar ataxia and other neurological disorders (such as epilepsy and myoclonus) involving the GABAergic ways. GADAb are usually detected by immunohistochemistry (IHC), radioimmunoassay (RIA) or enzyme-linked immunosorbent assay (ELISA). This study analysed the serum of 14 patients with neurological disorders who were positive by IHC for GADAb. The performance of a commercial RIA was compared with in-house immunoblotting and ELISA methods using recombinant GAD65 (rGAD65). RIA was positive in 14 of 14, immunoblotting was positive in seven of 14 and ELISA in 12 of 14. There was no correlation between the RIA result and the ELISA optical densities. Using a sodium thiocyanate chaotrope system with ELISA to determine antibody affinity, we found no significant correlation between antibody affinity and the RIA result. A consensus should be defined concerning which assay could be used as the gold standard for detecting GADAb. The most intriguing finding was that GAD antibodies from uncomplicated diabetics do not appear to recognize GAD in frozen sections from the rat cerebellum, whereas GAD antibodies from neurologically compromised diabetics do. A working proposal is therefore that type 1 diabetic patients with unusual neurological symptoms should be tested for GADAb both by RIA and IHC.

Mechanism of inhibition of cytochrome P450 C21 enzyme activity by autoantibodies from patients with Addison's disease

OBJECTIVE

To study possible mechanisms for the inhibition of cytochrome P450 C21 (steroid 21-hydroxylase) enzyme activity by P450 C21 autoantibodies (Abs) in vitro.

DESIGN

Two possible mechanisms for the inhibition of P450 C21 enzyme activity by P450 C21 Abs were studied: (a) conformational changes in the P450 C21 molecule induced by Ab binding and (b) the effects of Ab binding to P450 C21 on the electron transfer from the nicotinamide adenine dinucleotide phosphate reduced (NADPH) cytochrome P450 reductase (CPR) to P450 C21.

METHODS

The effect of P450 C21 Ab binding on the conformation of recombinant P450 C21 in yeast microsomes was studied using an analysis of the dithionite-reduced CO difference spectra. The effect of P450 C21 Abs on electron transfer was assessed by analysis of reduction of P450 C21 in the microsomes in the presence of CO after addition of NADPH.

RESULTS

Our studies confirmed the inhibiting effect of P450 C21 Abs on P450 C21 enzyme activity. Binding of the Abs did not induce significant change in the P450 C21 peak at 450nm (native form) and did not produce a detectable peak at 420 nm (denatured form) in the dithionite-reduced CO difference spectra. This indicated that conformation of P450 C21 around the heme was not altered compared with the native structure. However, incubation of the P450 C21 in yeast microsomes with P450 C21 Ab inhibited the fast phase electron transfer from the CPR to P450 C21.

CONCLUSIONS

Our observations suggested that the mechanism by which P450 C21 Abs inhibit P450 C21 enzyme activity most likely involves inhibition of the interaction between the CPR and P450 C21.

Autoimmune polyglandular syndrome Type 2: the tip of an iceberg?

Autoimmune polyglandular syndromes (APS) are conditions characterized by the association of two or more organ-specific disorders. Type 2 APS is defined by the occurrence of Addison's disease with thyroid autoimmune disease and/or Type 1 diabetes mellitus. Clinically overt disorders are considered only the tip of the autoimmune iceberg, since latent forms are much more frequent. Historical, clinical, genetic, and immunological aspects of Type 2 APS are reviewed. Furthermore, data on 146 personal cases of Type 2 APS are also reported.

The spectrum of antineuronal autoantibodies in a series of neurological patients

The aim of the present study is to identify the range of neurological disorders expressing antineuronal antibodies, evaluate the number of different patterns of reactivity that can be detected, and analyse the contribution of these studies to the identification of subgroups of patients. The records of 882 patients were reviewed and their sera and cerebrospinal fluids tested for antineuronal antibodies. Patients were initially divided into four groups according to suspected clinical diagnosis. Autoantibodies were detected by immunohistochemistry, Western blot of gradient-separated neuronal and recombinant proteins and by RIA. Cerebellar degeneration and sensory neuropathies were the most common neurological disorders in which paraneoplastic-related anti-neuronal antibodies were detected. However, in addition to PCA1/anti-Yo and ANNA1/anti-Hu antibodies, we found other reactivities in six patients with cerebellar degeneration: anti-GAD in three females and atypical in the other cases. The widest range of different anti-neuronal antibodies was detected in patients with peripheral sensory neuropathy. Few patients with Stiff-Person syndrome, temporal lobe epilepsy and myoclonus harboured anti-GAD antibodies. Atypical antibodies were detected in single cases with motor neuron disorder and multiple system atrophy. No anti-neuronal antibodies were detected in patients with neurological complications of connective tissue disorders other than Sjögren's syndrome, or in neurological diseases other than motor neuron disease and multiple system atrophy. Our study shows that the spectrum of neurological disorders in which anti-neuronal antibodies can be detected is wider than previously thought. In addition, we found patterns of neuronal staining and Western blot reactivity that differed from those so far reported. This may permit identification of subgroups of patients in whom strategies directed at removing and/or suppressing antibody production could be of some benefit.

Anti-ganglioside antibodies in children with coeliac disease: correlation with gluten-free diet and neurological complications

BACKGROUND

Emerging evidence points to humoural mechanisms in neurological complications of coeliac disease. Immunoglobulin G anti-ganglioside antibodies have been reported in coeliac disease patients with neuropathy, suggesting an immune response to peripheral nerve antigens. No data are so far available on anti-ganglioside antibodies in coeliac disease children or on antibody modifications after gluten-free diet.

AIM

To evaluate the presence of antibodies to ganglioside antigens in children with coeliac disease, their modification after gluten-free diet, and possible correlations with neurological manifestations.

METHODS

Sera from 42 coeliac disease children, before and after gluten-free diet, were tested by enzyme-linked immunosorbent assay for the presence of antibodies (immunoglobulin M, immunoglobulin A, immunoglobulin G) to gangliosides. Thirty-five sera of age-matched children with dyspepsia were used as control.

RESULTS

High anti-ganglioside antibodies titres were present in two patients. In one patient, antibody titre reversed after gluten-free diet, whereas in the other one the titre increased after diet. Neither one complained of neurological symptoms.

CONCLUSIONS

Anti-ganglioside antibodies do not seem to correlate with gluten ingestion or with neurological manifestations in children with coeliac disease. Mechanisms different from gluten exposure may be implicated in the antibody production. An ongoing prospective study will help clarify the role, if any, of these antibodies in coeliac disease.

Assessment of adrenocortical function and autoantibodies in a baby born to a mother with autoimmune polyglandular syndrome Type 2

We describe the case of a baby born to a mother with Addison's disease in the context of Autoimmune Polyendocrine Syndrome Type 2. Adrenal cortex autoantibodies and steroid 21-hydroxylase autoantibodies were detectable in the sera of both mother and baby, suggesting the transplacental passage of these autoantibodies. Adrenal autoantibodies were present in the baby's serum at delivery, at 3, 6 and till 34 months of age but no signs of clinical or subclinical adrenal insufficiency were found in the baby during the observation period. These data suggest that the presence of adrenal autoantibodies in serum alone is not a sufficient cause for the development of autoimmune adrenalitis.

Fatal toxic epidermal necrolysis in autoimmune polyglandular syndrome type I

Autoimmune polyglandular syndrome Type I (APS I) is a disorder defined by the presence of at least two of the following diseases: Addison's disease, hypoparathyroidism, and chronic mucocutaneous candidiasis. We present the case of a 45-yr-old woman, affected by APS I, in chronic treatment with betamethasone. She was referred to a Division of General Medicine for jaundice, ascites and peripheral edema attributed to worsening of pre-existing autoimmune chronic hepatitis. During hospitalization, the following drugs were given: Amoxicillin/Clavulanic acid and Levofloxacin for bronchopneumonia, Furosemide and Canreonate for renal impairment, Pantoprazole for gastric protection, and Itraconazole for oral candidiasis. After about a month, she developed widespread, sheet-like, epidermal detachment, with painful lesions of the conjunctiva, lips and mouth. Toxic epidermal necrolysis (TEN) was diagnosed, and the patient was transferred to a Burn Center, where she died 10 days after the first onset of cutaneous rash. Autoptic and histopathological findings (epidermal necrosis and detachment, lymphomonocytic infiltration of the dermis) confirmed the clinical diagnosis. TEN is a usually drug-induced cutaneous inflammatory disorder characterized by extensive epidermal detachment and frequent mucosal involvement. It has also been associated with immuno-mediated disorders (HIV infection, graft-vs-host disease, systemic lupus erythematosus, mixed essential cryoglobulinemia), in keeping with immuno-mediated pathogenesis. We present, to our knowledge, the first report of TEN in a patient with APS I, and suggest that some pathogenetic mechanisms of APS I are shared with TEN. We stress how such a disease can occur in an autoimmune syndrome, even during corticosteroid treatment.

Graves' ophthalmopathy and atrophic thyroiditis: a case report

Graves' ophthalmopathy (GO)--also known as thyroid-associated orbitopathy or ophthalmopathy--usually affects patients with Graves' disease. Antibodies stimulating the TSH receptor are thought to be involved in the pathogenesis of this important and disabling extra-thyroidal manifestation of Graves' disease. Less frequently, GO occurs in subjects who neither have nor have ever shown evidence of thyroid dysfunction ("euthyroid GO"), while the occurrence of GO in patients with autoimmune Hashimoto's thyroiditis is thought to be quite rare and has sporadically been reported. The late and abrupt occurrence of severe GO without hyperthyroidism in an 88-yr-old woman with primary myxedema due to atrophic thyroiditis must be considered as an exceptional event. In this patient, GO was combined with elevated titres of serum auto-antibodies directed against the TSH receptor, while serum levels of anti-thyroglobulin and thyroperoxidase antibodies were within the normal range or only occasionally slightly above the normal values.

Type 1 diabetes mellitus in patients with chronic hepatitis C before and after interferon therapy

Type 1 diabetes mellitus is the result of an autoimmune process characterized by pancreatic beta cell destruction. It has been reported that chronic hepatitis C infection is associated with type 2 diabetes mellitus, but not with type 1. Although the prevalence of markers of pancreatic autoimmunity in hepatitis C virus-positive patients is not significantly different to that reported in the general population, it increases during alpha-interferon therapy from 3 to 7%, probably due to the immunostimulatory effects of this cytokine. To date, 31 case reports of type 1 diabetes mellitus related to interferon treatment have been published. Type 1 diabetes mellitus occurs more frequently in patients treated for chronic hepatitis C than for other conditions and is irreversible in most cases. In 50% of these patients, markers of pancreatic autoimmunity predated treatment, the majority of cases having a genetic predisposition. Thus, in predisposed individuals, alpha-interferon can either induce or accelerate a diabetogenic process already underway. We suggest that islet cell autoantibodies and glutamic acid decarboxylase autoantibodies should be investigated before and during interferon treatment in order to identify subjects at high risk of developing type 1 diabetes mellitus.

Autoantibodies to steroidogenic enzymes in patients with premature ovarian failure with and without Addison's disease

DESIGN

Adrenal cortex autoantibodies (ACA), steroid-producing cell autoantibodies (StCA) and autoantibodies (Abs) to steroidogenic enzymes in three groups of patients with premature ovarian failure (POF), 15 with autoimmune Addison's disease (AD), 26 with non-adrenal autoimmune diseases and 31 with isolated POF, have been assessed.

METHODS

ACA and StCA were measured using an immunofluorescence technique. Abs to 21-hydroxylase (21-OH), to 17alpha-hydroxylase (17alpha-OH) and to cytochrome P450 side-chain cleavage (P450scc) were measured using an immunoprecipitation assay.

RESULTS

Seventy-three percent of patients with POF and AD were positive for StCA, 93% for 17alpha-OH and/or P450scc Abs, 93% for ACA and 100% for 21-OH Abs. Among patients with POF and non-adrenal autoimmune diseases, 8% were positive for StCA, 12% for 17alpha-OH and/or P450scc Abs, and 8% and 12% for ACA and 21-OH Abs respectively. StCA, 17alpha-OH and/or P450scc Abs were all found in 10% of patients with isolated POF, and 13% had ACA and 21-OH Abs. All StCA-, 17alpha-OH- and/or P450scc Abs-positive patients were also positive for ACA and 21-OH Abs. Two patients with isolated POF who were ACA and 21-OH Ab positive developed AD 3 and 5 Years after the onset of POF.

CONCLUSION

This study has shown that, when POF is associated with AD, StCA, 17alpha-OH and/or P450scc Abs are present in the majority of patients, while in the other two groups these Abs are detectable in a much lower proportion of patients. Measurement of ACA/21-OH Abs in some patients with POF may be important in identifying patients at risk of developing overt AD.

Low frequency of autoantibodies to islet cell, glutamic acid decarboxylase, and second-islet antigen in patients with gestational diabetes mellitus: a follow-up study

The aim of the study was to determine the frequency of patients with gestational diabetes mellitus (GDM) who have serological markers typical of autoimmune type 1 DM. The specific pancreatic markers, ICAs, glutamic decarboxylase (GADAbs), and second islet antigen (IA2Abs), were measured in 70 women with GDM during the pregnancy and after delivery. ICAs were measured by indirect immunofluorescence and GADAbs and IA2Abs were determined by a radiobinding assay with recombinant antigens. On entering the study, 1 of 70 (1.4%) patients was positive for both ICAs (80 JDF-U) and GADAbs (167 U/mL), while another (1.4%) was positive for ICAs (40 JDF-U). None of the patients was positive for IA2Abs. During follow-up, positivity was maintained unchanged in the two positive patients. Four previously negative patients had seroconversion: one for both ICAs (20 JDF-U) and GADAbs (49.3 U/mL) and the other three for GADAbs (1.8, 1.4, and 15.3 U/mL, respectively). The IA2Abs remained negative in all patients. Overall, during the observation period 6 of 70 (8.6%) patients had or developed autoantibodies against endocrine pancreas. During follow-up 15 patients developed clinical DM (10 type 2, 5 type 1) and 7 demonstrated impaired glucose tolerance (IGT) after OGTT. No correlations were demonstrated between the immunological patterns and the evolution in DM. In patients with GDM, the frequency of pancreatic autoantibodies varies during the pregnancy and after delivery, but a small subgroup of patients bearing these markers is identifiable. GDM is a complex syndrome, constituted by different types of diabetes mellitus where the autoimmune form is very rare.

The number of markers of pancreatic autoimmunity is proportional to the risk for type 1 diabetes mellitus in Italian and English patients with organ-specific autoimmune diseases

An 11-year prospective study was carried out in 226 patients with organ-specific autoimmune disease (OSAD) coming from northern Italy and southern England. Patients were investigated for diabetes-related autoantibodies (ICAs, GADAbs, and IA2Abs) in order to evaluate the best immunological combination in predicting type 1 DM. One hundred twenty-eight patients were ICA positive (77 Italian and 51 English), and 98 were ICA negative. ICAs were detected by immunofluorescence technique on human pancreas, whereas GADAbs and IA2Abs were found by immunoprecipitation assay. During follow-up, 33 of 128 (25.8%) ICA(+) (26% of Italian and 25.5% of English) and 2 of 98 (2%) ICA(-) patients developed type 1 DM (17 with acute-onset, and 18 with non-acute-onset disease). Among ICA(+) patients, three subgroups were considered: ICA(+) alone; ICA and GADAb(+); ICA, GADAb, and IA2Ab(+). Patients who were only ICA(+) had a predictive value for type 1 DM of 4.7%, with an annual incidence of 0.7%, and a cumulative risk of 6%. ICA and GADAb(+) patients had a predictive value of 17.5%, with an annual incidence of 2%, and a cumulative risk of 20%. ICA, GADAb, and IA2Ab(+) patients had a predictive value of 72, with an annual incidence of 13%, and a cumulative risk of 87%. Patients having three immunological markers revealed a prevalence increased in HLA-DR3 and/or -DR4, but reduced in HLA-DR2 haplotypes. The risk for type 1 DM increased proportionally with the number of diabetes-related antibodies, which were also related to the presence of genetic markers of disease susceptibility.

Prevalence of coeliac disease in primary biliary cirrhosis and of antimitochondrial antibodies in adult coeliac disease patients in Italy

BACKGROUND

Although an association between primary biliary cirrhosis and coeliac disease has recently been reported in Northern Europe, there are still conflicting data concerning this issue.

AIM

To evaluate both the prevalence of coeliac disease in a series of primary biliary cirrhosis patients and that of antimitochondrial antibodies in a series of adult biopsy proven coeliac disease patients from Northern Italy.

PATIENTS AND METHODS

A total of 87 primary biliary cirrhosis patients (79 female, 8 male) were screened for both IgA-transglutaminase antibodies and antiendomysium antibodies and, in those with either IgA-transglutaminase antibodies or antiendomysium antibodies positivity, upper endoscopy with distal duodenum biopsy was offered. In those who refused upper endoscopy, the intestinal permeability test with lactulose/mannitol excretion was performed.

RESULTS

Antiendomysium antibodies positivity was detected in 3 subjects (3.4%), all of whom had serum IgA-transglutaminase antibodies above the normal range, and fulfilled the diagnosis of coeliac disease. Of 21 other patients with serum IgA-transglutaminase antibodies above the normal range, 17 underwent upper endoscopy which revealed normal duodenum architecture. The remaining 4 patients underwent the lactulose/mannitol excretion test which was within the normal range. Sera from 108 adult coeliac disease patients were tested for antimitochondrial antibodies and positivity was found in 4 patients (3.7%): all had normal liver biochemistry tests, whereas 2 of them also presented thyroid disease. Antibodies directed to the 74-kDa polypeptide of antimitochondrial antibodies were found in 3 out of 4 antimitochondrial antibodies+ve patients.

CONCLUSIONS

These results suggest an association between primary biliary cirrhosis and coeliac disease similar to that observed in the Northern European series. In conclusion, screening for coeliac disease with antiendomysium antibodies in primary biliary cirrhosis is justified, and screening for antimitochondrial antibodies is advisable in adult coeliac disease patients.

Pancreatic autoantibodies in Italian patients with newly diagnosed type 1 diabetes mellitus under the age of 20 years

We analyzed 97 children and young persons (< 20 years of age) with newly diagnosed diabetes for antibodies to islet cells (ICAs), glutamic acid decarboxylase (GADAbs), second-islet antigen (IA2Abs), and insulin (IAAs) in order to evaluate the prevalence of immune-mediated type 1 diabetes, as well as to recognize which autoantibody combination is better associated with the disease. A positive result for one or more diabetes-related antibodies evaluated was found in 92 children (94.8%): 41 females (95.3%) and 51 males (94.4%). With regard to single autoantibody testing, ICA levels were found to be positive in 84 patients (86.6%), GADAbs in 71 (73.2%), IA2Abs in 60 (61.8%), and IAAs in 51 (52.6%) patients. Combining the determination of at least two autoantibodies, ICAs and/or GADAbs were more frequently detectable than other antibody combinations, being positive in 89 patients (91.8%). Our data indicate that the vast majority of cases of type 1 diabetes in children may be considered as immune-mediated, that multiple autoantibody analysis improves identification of the disease, and that first-level screening is provided by the combined detection of ICAs and GADAbs.