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Purpose: This publication reviews the accepted knowledges and the findings still discussed on several features of autoimmune hypophysitis, including the most recently described forms, such as IgG4 and cancer immunotherapy- related hypophysitis. Methods: The most characteristic findings and the pending controversies were derived from a literature review and previous personal experiences. A single paragraph focused on some atypical examples of the disease presenting under confounding pretences. Results: Headache, visual field alterations and impaired pituitary secretion are the most frequent clinical findings of the disease. Pituitary biopsy, still considered the gold diagnostic standard, does not always receive consent from the patients. The role of magnetic resonance imaging is limited, as this disease may generate images similar to those of other diseases. The role of antipituitary and antihypothalamus antibodies is still discussed owing to methodological difficulties and also because the findings on the true pituitary antigen(s) are still debated. However, the low sensitivity and specificity of immunofluorescence, one of the more widely employed methods to detect these antibodies, may be improved, considering a predetermined cut-off titre and a particular kind of immunostaining. Conclusion: Autoimmune hypophysitis is a multifaceted disease, which may certainly be diagnosed by pituitary biopsy. However, the possible different clinical, laboratory and imaging features must be considered by the physician to avoid a misdiagnosis when examining a possibly affected patient. Therapeutic choice has to be made taking into account the clinical conditions and the degree of hypothalamic-pituitary involvement, but also considering that spontaneous remissions can occur. [ABSTRACT FROM AUTHOR]

Recently, an increased incidence of central diabetes insipidus (CDI) in pregnancy, and less frequently in the post partum period, has been reported, most probably favoured by some conditions occurring in pregnancy. This study was aimed at investigating the influence of pregnancy on a pre-existing potential/subclinical hypothalamic autoimmunity. We studied the longitudinal behaviour of arginine-vasopressin cell antibodies (AVPcAbs) and post-pituitary function in two young women with a positive history of autoimmune disease and presence of AVPcAbs, but without clinical CDI, and who became pregnant 5 and 7 months after our first observation. The behaviour of post-pituitary function and AVPcAbs (by immunofluorescence) was evaluated at baseline, during pregnancy and for 2 years after delivery. AVPcAbs, present at low/middle titres at baseline in both patients, showed a titre increase during pregnancy in one patient and after delivery in the other patient, with development of clinically overt CDI. Therapy with 1-deamino-8-D-arginine vasopressin (DDAVP) caused a prompt clinical remission. After a first unsuccessful attempt of withdrawal, the therapy was definitively stopped at the 6th and the 7th month of post partum period respectively, when AVPcAbs disappeared, accompanied by post-pituitary function recovery, persisting until the end of the follow-up. The determination of AVPcAbs is advisable in patients with autoimmune diseases planning their pregnancy, because they could be considered good predictive markers of gestational or post partum autoimmune CDI. The monitoring of AVPcAb titres and post-pituitary function during pregnancy in these patients may allow for an early diagnosis and an early replacement therapy, which could induce the disappearance of these antibodies with consequent complete remission of CDI. [ABSTRACT FROM AUTHOR]

Lymphocytic hypophysitis is characterized by an extensive infiltration of lymphocytic cells. Pituitary biopsy is the gold diagnostic standard for lymphocytic hypophysitis but the disease occurs with moderate or without pituitary enlargement. The role of antipituitary antibodies (APA) in autoimmune hypophysitis is still discussed due to various methodological difficulties. Indirect immunofluorescence, a widely employed method to detect APA at this time produces highly variable results due to the use of human or animal pituitary substrates. For many years the authors have conducted a re-evaluation of APA by immunofluorescence in patients with other autoimmune diseases and in patients with apparently idiopathic hypopituitarism, using pituitary from young baboons as substrate but considering a predetermined cut-off of the titer and immunofluorescence pattern. This procedure allowed us to find out those with autoimmune pituitary impairment and to foresee the kind of future hypopituitarism in those with pituitary function still normal. Moreover, in APA positive patients, the use of a second step of a double immunofluorescence method allowed identification of the pituitary cells targeted by APA, verifying the correspondence with the kind of hypopituitarism, also when present in subclinical stage. However, to carry out an international workshop comparing the detection of APA by immunofluorescence using different substrates could contribute to verify the best choice to improve the sensitivity and specificity of this method. [ABSTRACT FROM AUTHOR]

Rituximab, a B-cell depleting antibody, has been used for treatment of several autoimmune diseases. We report the effect of rituximab therapy on pituitary and platelet autoimmunity in a 36-yr old patient, positive for antiplatelet and antipituitary (APA) antibodies. The behavior of pituitary function and of APA by immunofluorescence, as well antibodies to platelets and platelet count, were investigated at start and subsequently every six months during Rituximab treatment. Rituximab treatment determined disappearance of antiplatelet antibodies with recovery of normal platelet count and disappearance of APA with recovery of pituitary-gonadal function. Rituximab determined a remission of both autoimmune processes, likely through a T cell inactivation and a depletion of autoreactive B-cells generation responsible for antiplatelet and antipituitary antibody production. [ABSTRACT FROM AUTHOR]

Background: Pituitary and thyroid autoimmunity can be triggered by pregnancy. We report the first association of combined growth hormone (GH) and prolactin secretion deficiency due to autoimmune damage to GH- and prolactin-secreting cells in a patient with postdelivery lactation failure, presenting subsequently with primary autoimmune hypothyroidism. Patient Findings: A 34-year-old woman presented with lactation failure following the delivery of her first child. She had a family history of hypothyroidism without a history of pituitary dysfunction. Physical examination did not show any abnormal findings. Laboratory investigations showed normal gonadotropin levels after the restoration of normal menstrual cycles following pregnancy, normal basal and stimulated cortisol levels, but an impaired GH response to insulin-induced hypoglycemia, and low basal prolactin and insulin-like growth factor-1 concentrations. Thyroid function was normal when initially investigated three months after delivery, but five months later, marked primary hypothyroidism (thyrotropin levels >100 mIU/L) occurred. Immunological investigation revealed the presence of antipituitary antibodies, identified by double immunofluorescence and targeting GH- and prolactin-secreting cells. Antithyroid antibodies, in the normal range three months postpartum, became significantly elevated when the hypothyroidism appeared. Autoimmune hypophysitis is responsible for selective or multiple pituitary-hormone deficiencies, sometimes involving thyrotropin secretion and causing secondary hypothyroidism, but usually associated with hyperprolactinemia. To our knowledge, this is the first observation of autoimmune hypopituitarism involving deficient growth hormone and prolactin secretion in a patient with lactation failure after delivery, subsequently followed by severe primary autoimmune hypothyroidism, thus falling into an unusual constellation of autoimmune polyendocrine syndrome type 3. Conclusions: Considering the well-known relationship between pregnancy and autoimmunity, an early postdelivery immunological and functional investigation in women presenting with disorders of lactation may be useful to detect potential pituitary and thyroid dysfunction even at a subclinical stage. [ABSTRACT FROM AUTHOR]

The findings in hyperthyroid patients with Graves' orbitopathy (GO) of antibodies against antigens shared between the thyroid and orbit, such as the TSH-receptor (TRAb) and a novel protein G2s (G2sAb), suggested a possible common therapeutic strategy. However, the gold therapeutic standard for hyperthyrodism in these patients remains still unsettled and is mainly based on personal experience. Studies on the effect of total thyroidectomy (TT) alone or followed by radioiodine ablation (RAI) of thyroid remnants showed often conflicting results. This longitudinal study was aimed at evaluating the influence of TT alone or followed by post-surgical RAI with respect to methimazole treatment on the activity and severity of GO in patients with hyperthyroidism and GO. Sixty consecutive patients with Graves' disease and mild/moderate GO were studied and grouped as follows: group 1, including 25 patients (16F, 9M) undergoing TT alone; group 2, including 10 patients (8F, 2M) undergoing TT followed by RAI for histological evidence of differentiated thyroid cancer; group 3, including 25 patients (18F, 7M) euthyroid under methimazole therapy, studied as controls. Clinical study of ophthalmopathy and measurements of TRAb and G2sAb were performed in all patients at start of the study (time of TT for group 1 and RAI after TT for group 2 and of the first finding of euthyroidism under methimazole treatment for group 3) and after 6, 12, 24 months. Patients of both groups 1 and 2 showed an early significant decrease and a further progressive reduction of the activity and severity of GO with a disappearance of TRAb and a decrease of G2sAb levels during the follow-up, without statistically significant differences between the two groups. Patients in group 3 showed a much later and less marked improvement of GO with persistence of TRAb and G2sAb positivity, even if with reduction of TRAb levels at 12 and 24 months. Our results suggest that in Graves' patients with large goiter or relapse of hyperthyroidism and mild/moderate GO, TT alone could be an advisable choice to treat hyperthyroidism also improving GO with reduction of cost/benefit ratio. [ABSTRACT FROM AUTHOR]

Summary Objective Antipituitary (APA) but not antihypothalamus antibodies (AHA) have been investigated in patients with idiopathic hypopituitarism. This study searched for APA and AHA in some of these patients to investigate whether pituitary or hypothalamic autoimmunity could play a role in their pituitary dysfunction. Design Sixty-six patients with selective idiopathic hypopituitarism were studied: 27 with ACTH deficiency, 20 with GH deficiency and 19 with hypogonadotropic hypogonadism. Twenty patients with hypopituitarism secondary to hypophysectomy and 50 healthy subjects were enrolled as controls. Measurements Antipituitary and AHA were evaluated by indirect immunofluorescence in sera of patients and controls. Positive sera were retested by a four-layer double immunofluorescence to identify the cells targeted by these antibodies. Results Antipituitary were present at high titre in 4 of 27 patients with ACTH deficiency (14·8%), 4 of 20 with GH deficiency (26%) and 5 of 19 with hypogonadotropic hypogonadism (21%) and targeted, respectively, corticotrophs, somatotrophs and gonadotrophs. AHA were found at high titre only in 5 patients with ACTH deficiency (18·5%), mostly targeting corticotrophin-releasing hormone-secreting cells; none of these 5 patients resulted positive for antipituitary antibodies. Among the controls, only 1 hypophysectomized patient resulted APA positive at low titre. Conclusions Our results suggest that in patients with selective idiopathic hypopituitarism, detection of APA or AHA could better characterize an autoimmune process involving the pituitary or hypothalamus, respectively. In particular, detection of antibodies targeting selectively ACTH-secreting or corticotrophin-releasing hormone-secreting cells may differentiate, respectively secondary from tertiary variants of autoimmune hypoadrenalism. [ABSTRACT FROM AUTHOR]

OBJECTIVES:The possible autoimmune involvement of the pituitary gland in patients with celiac disease (CD) has been suggested but demonstrated in only a few patients on gluten-free diet. We aimed to assess the prevalence and clinical meaning of anti-pituitary antibodies (APA) in children and adolescents with the newly diagnosed CD.METHODS:A total of 119 patients with CD (0.9–15.8 years old) attending the inpatient clinic of University Hospital were recruited for the cross-sectional study. Their height, weight, and body mass index (BMI) were recorded, and insulin-like growth factor-1 (IGF-1) and APA were assayed. APA was also determined in 98 sex- and age-matched controls.RESULTS:APA were detected in 50 patients (42.0%), 15 of them with high titer (30%) and 35 with low titer (70%), and in 2 control subjects at low titer (2%) (P<0.001). IGF-1 was higher in patients with negative than with low titer (P=0.02) or high titer APA (P=0.03). Height was more reduced in high-titer APA patients than in the negative ones (P<0.01). Height was positively correlated with IGF-1 (P<0.01) and negatively with chronological age (P=0.001). IGF-1 was positively correlated with BMI (P<0.001). For height prediction the regression analysis showed the rank order 1 for chronological age and 2 for IGF-1.CONCLUSIONS:In this paper we have shown a remarkable prevalence of positive APA in newly diagnosed CD patients. High APA titers are associated with height impairment, likely mediated by a reduction of IGF-1, thus suggesting that autoimmune pituitary process could induce a linear-growth impairment. [ABSTRACT FROM AUTHOR]

Hyperprolactinemia is often observed in lymphocytic hypophysitis (LYH). To clarify the possible autoimmune pituitary involvement in patients with apparently idiopathic hyperprolactinemia we investigated the presence of antipituitary antibodies (APA) in hyperprolactinemic patients with idiopathic hyperprolactinemia and in those with prolactinoma. Sixty-six hyperprolactinemic patients (52 F, 14 M age range 28–42 years, group1) were studied. Of them, 34 out of 66 showed clinical features of hyperprolactinemia and subsequently underwent cabergoline therapy; the 32 out of 66 patients without symptoms of hyperprolactinemia did not receive cabergoline therapy. Moreover, 32 patients (24 F/8M, age range 23–44 years) with hyperprolactinemia due to microprolactinoma (group 2) were also studied. APA, by immunofluorescence method, and anterior pituitary function were evaluated in both groups of patients. APA were present in 17 out of 66 (25.7%) patients in group 1 with titers ranging from 1/16 to 1/64. All patients of group 2 were considered APA negative because these antibodies were found at low titer (≤1:4) only in five of them. With regard to the function of other pituitary hormones, all APA-negative patients in group 1 and in group 2 showed a normal pituitary function; instead, a partial anterior pituitary impairment was observed in 6 out of 17 (35.3%) APA-positive patients. In asymptomatic patients with apparently idiopathic hyperprolactinemia, APA detection could be useful to disclose forms of potential/subclinical stage of LYH. A future longitudinal study of these patients submitted to cabergoline therapy or free of therapy may be helpful to clarify this assumption. [ABSTRACT FROM AUTHOR]

Introduction: Coeliac disease (CD) is usually associated with impaired growth in children. A gluten-free diet (GFD) induces a catch-up growth with the recovery of height in about 2 years. AIM AND DISCUSSION: The lack of the height improvement has been related to growth hormone (GH) secretion impairment. CD is an autoimmune disease often associated with other endocrine and non-endocrine autoimmune disease. The aim of this study was to evaluate antipituitary autoantibodies (APA) and antihypothalamus autoantibodies in CD children with poor clinical response to a GFD and growth hormone deficiency (GHD). We diagnosed CD on the basis of specific antibodies and endoscopic biopsies in 130 patients aged 1-15 years. Seven CD children, without catch-up growth after at least 12-months GFD, were tested for GH secretion and, in five out of seven patients, the diagnosis of GHD was made in the absence of metabolic and systemic diseases.Results: APA and antihypothalamus antibodies were detected by the indirect immunofluorescence method in the seven CD children without catch-up growth factor and in 25 CD children without growth impairment matched for sex and age, and in 58 healthy children as control groups. APA resulted positive at high titres in four out of five CD-GHD patients and were also positive at low titres (<1:8) in three of only CD children and in two out of 58 controls. Hypothalamic-pituitary magnetic resonance imaging (MRI) was normal in all patients except in one with cystic pineal. APA have been previously detected not only in adults with GHD, but also in idiopathic GHD children, suggesting the occurrence of an autoimmune hypophysitis in these patients.Conclusion: In our study, the presence of APA in CD children without catch-up growth after GFD seems to be able to identify an autoimmune form of hypophysitis involving the somatotrophs cells. [ABSTRACT FROM AUTHOR]

In order to investigate whether somatotrophs are the target of antipituitary antibodies (APA) in adult patients with growth hormone deficiency (GHD), we studied the sera of 37 APA positive patients. Patients were grouped as follows: nine patients with APA at high titre (> 1 : 8) affected by apparently idiopathic GHD; four of them (group 1a) with isolated GHD diagnosed during childhood and five with GHD diagnosed during adulthood associated with autoimmune endocrine diseases (group 1b), and 28 patients with autoimmune endocrine diseases without pituitary impairment, previously found positive for APA at low titre (1 : 8, group 2). APA were evaluated by a four-layer double indirect immunofluorescence technique. In group 1a patients, APA immunostained exclusively GH-producing cells. In group 1b patients, APA were directed not only to GH- but also to other pituitary hormone-producing cells. In group 2 patients, APA were directed selectively to PRL-producing cells and rarely to some GH-producing cells. In the present study, we demonstrated that GH-secreting cells are the target of the autoimmune reaction in autoimmune GHD and that the immunostaining of only the somatotrophs is typical of isolated GHD. In contrast, the finding of diffuse staining of APA indicates the need to search for other autoimmune diseases. Finally, the presence of APA at low titre directed against PRL-secreting cells in patients with autoimmune endocrine diseases in the absence of pituitary impairment, seems to be only a nonspecific marker of pituitary autoimmunity. A longitudinal study would be useful to clarify the relationship between the different pituitary cell involvement and the natural history of pituitary dysfunction in autoimmune hypophysitis. [ABSTRACT FROM AUTHOR]

The interrelationship between prolactin (PRL) and the immune system have been elucitaded in the last decade, opening new important horizons in the field of the immunoendocrinology. PRL is secreted not only by anterior pituitary gland but also by many extrapituitary sites including the immune cells. The endocrine/paracrine PRL has been shown to stimulate the immune cells by binding to PRL receptors. Increased PRL levels, frequently described in autoimmune diseases, could depend on the enhancement of coordinated bi-directional communications between PRL and the immune system observed in these diseases. Hyperprolactinemia has been described in the active phase of some non organ-specific autoimmune diseases, as systemic lupus erythematosus (SLE) and rheumatoid arthritis (RA) and organ-specific autoimmune diseases, as celiac disease, type 1 diabetes mellitus, Addison's disease, autoimmune thyroid diseases. In these diseases PRL increases the syntesis of IFNγ and IL-2 by Th1 lymphocytes. Moreover, PRL activates Th2 lymphocytes with autoantibody production. Of particular interest is the association between hyperprolactinemia and levels of anti DNA antibodies, islet cell antibodies (ICA), thyreoglobulin antibodies (TgAb), thyroperoxidase antibodies (TPOAb), adrenocortical antibodies (ACA), transglutaminase antibodies (tTGAb) in SLE, in type 1 diabetes mellitus, in Hashimoto's thyroiditis, in Addison's disease and in celiac disease, respectively. High levels of PRL have been also frequently detected in patients with lymphocytic hypophysitis (LYH). Several mechanisms have been invoked to explain the hyperprolactinemia in LYH. The PRL increase could be secondary to the inflammatory process of the pituitary gland but, on the other hand, this increase could have a role in enhancing the activity of the immune process in LYH. Moreover, the detection of antipituitary antibodies targeting PRL-secreting cells in some patients with idiopathic hyperprolactinemia suggests the occurrence of a possible silent LYH in these patients. Finally, the role of anti-prolactinemic drugs to inactivate the immune process in LYH is still discussed. [ABSTRACT FROM AUTHOR]

Summary objective To investigate whether variations over time of TSH-receptor antibodies (TRAb) and antibodies against G2s (G2sAb) and extraocular muscles (EMAb) can predict worsening of ophthalmopathy in Graves’ patients treated with intravenous glucocorticoid (IVGC) therapy. patients Of 65 consecutive patients with treated Graves’ disease and severe and active ophthalmopathy (GO) chosen to undergo IVGC treatment, only 57 patients, persistently euthyroid under methimazole therapy, were studied longitudinally for ocular parameters, TRAb, G2sAb and EMAb before therapy, at the end of therapy and, subsequently, every month for 21 months. measurements TRAb was detected by radioimmunoassay (RIA), G2sAb by enzyme-linked immunosorbent assay (ELISA) and EMAb by indirect immunofluorescence. results Forty-three out of 57 patients (75·4%, group 1) responded positively to therapy [improvement in diplopia and decrease in proptosis and clinical activity score (CAS)] but 14 (24·6%) did not (group 2). During follow-up after IVGC therapy, 12 out of 43 patients in group 1 (28%) showed a worsening in GO (group 1a), while 31 (72%) had stable ocular conditions or further improvement (group 1b). At the start of the study, TRAb, G2sAb and EMAb were not significantly different among the three groups. At the end of IVGC therapy TRAb levels decreased significantly with respect to starting values in all three groups of patients, whereas G2sAb and EMAb decreased significantly in groups 1a and 1b but not in group 2. During the subsequent follow-up, 10 patients in group 1a one/two months before and all 12 patients at the time of GO worsening showed an increase in G2sAb and EMAb but not in TRAb, which were consistently absent or present at low titre in all patients in this group. In group 1b TRAb, G2sAb and EMAb further decreased or became negative during the follow-up period. In all patients, TRAb were positively correlated with both CAS and proptosis only at the start of the study; by contrast, a significant correlation between both G2sAb and EMAb and diplopia was observed in groups 1a and 1b at all the times during the study, except one/two months before the worsening of GO in group 1a. conclusions Our results indicate that TRAb, G2sAb and EMAb can be considered sensitive markers of Graves’ ophthalmopathy during the initial stages of ophthalmopathy, but that only G2sAb and EMAb seem to be good predictive markers of the outcome in patients after corticosteroid therapy. Thus, taking into account the cost/benefit ratio, a longitudinal evaluation of either EMAb or G2sAb could be useful in monitoring the intravenous glucocorticoid therapy in patients with severe and active ophthalmopathy to predict a possible worsening of Graves’ ophthalmopathy. [ABSTRACT FROM AUTHOR]

The aim of this study was to detect linear arterial calcification (Mönckeberg's sclerosis) localized in feet, ankles, legs, knees and hands in an attempt to correlate the extent of calcification with the presence and severity of autonomic neuropathy as well as with microangiopathy (proliferative retinopathy, proteinuria >200 mg/ die) and peripheral neuropathy. Typical linear calcification were observed in 37 out of 41 (90.2%) patients with autonomic neuropathy and in none of those without autonomic neuropathy (p<0.001). These 37 patients were divided into two subgroups by cluster analysis: Subgroup A, including 18 subjects with calcification length ranging from 8 to 26 cm and moderate autonomic neuropathy, and Subgroup B, including 19 subjects with calcification length between 58 and 126 cm and severe autonomic neuropathy (p<0.0001 by Spearman's test). No difference in the length of arterial calcification was detected between patients with proteinuria >200 mg/24h and/or proliferative retinopathy and patients without these complications. A possible relationship between arterial calcification and peripheral neuropathy is difficult to evaluate; in fact, the majority of subjects having autonomic neuropathy had peripheral neuropathy, too. Vice versa, around 10% of patients without peripheral neuropathy but with autonomic neuropathy did not have Mönckeberg's sclerosis. Autonomic neuropathy is the principal factor responsible for calcification of the arterial media, and in addition the severity of the neuropathy, rather than the patient's age or the known disease duration seems to determine the extent of calcification. [ABSTRACT FROM AUTHOR]