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BackgroundSome cases of apparently idiopathic GH deficiency (GHD) may be caused by pituitary autoimmunity.ObjectiveTo study the variations in pituitary function and antipituitary antibodies (APA) from childhood to transition age in patients with apparently idiopathic GHD.DesignWe conducted a longitudinal study.Patients and methodsPituitary function and APA detection by immunofluorescence were investigated in 24 childhood patients with isolated GHD before starting recombinant GH therapy and after the stopping of this therapy in transition age. Sera of patients positive for APA were processed by double immunofluorescence to identify their pituitary target.ResultsAt diagnosis, 16 out of 24 patients were APA positive targeting only somatotrophs (group 1), while the remaining eight were APA negative (group 2). When retested off therapy, 12 out of 16 patients in group 1 persisted being APA positive, while the remaining four became negative with recovery of pituitary function. All patients in group 2 persisted being APA negative but still showing GHD. Of the 12 patients persistently APA positive, eight with confirmed GHD showed APA still targeting somatotrophs, whereas four showed APA targeting only gonadotrophs associated with isolated hypogonadotropic hypogonadism (HH).ConclusionPatients with APA at middle but not at high titer in childhood may show a remission of autoimmune GHD in childhood after GH replacement therapy. As APA may shift their target in transition period, an early characterization of APA by double immunofluorescence is advisable in APA positive GHD patients showing delayed puberty, to allow an early diagnosis and an appropriate therapy, thus preventing the progression toward HH.

BACKGROUND: Chemokines play a key role in the recruitment of the immune cells into the autoimmune process. Thus, the simultaneous evaluation of circulating levels of Th1-related chemokines, such as CX chemokine ligand 10 (CXCL10) and macrophage inflammatory proteins 1α (CCL3/MIP-1α), and Th2-related chemokines, such as macrophage inflammatory proteins 1 β (CCL4/MIP-1β) could be useful in the approach to some autoimmune diseases, including autoimmune Addison's disease (AAD). AIM: To evaluate plasmatic levels of MIP-1α, MIP-1β, CXCL10 and adrenocortical antibodies in patients with AAD under treatment with corticosteroids. PATIENTS AND METHODS: Twelve women and 5 men (group 1) were divided in 2 subgroups: 9 subsjects with isolated AAD (group 1a) and 8 with AAD associated with chronic autoimmune thyroiditis (group 1b). MIP-1α, MIP- 1β and CXCL10 were evaluated in the serum of all patients and in 20 healthy controls, using a system for microarray suspension. RESULTS: The levels of MIP-1α, MIP-1β and CXCL10 resulted significantly increased vs controls (p

Context: Antipituitary antibodies (APA) recognizing GH-secreting cells may indicate an autoimmune pituitary involvement in adults with idiopathic GH deficiency (IGHD). Objective: We aimed 1) to investigate the presence of APA in prepubertal children with IGHD or idiopathic short stature (ISS), identifying the pituitary hormone-producing cells targeted by APA; and 2) to verify whether in patients with ISS the presence of APA could predict the development of GHD. Design: We performed a cross-sectional and partially longitudinal cohort study. Setting: The study was performed at the Endocrinology Unit and Pediatric Unit of the Second University and University Federico II of Naples, respectively. Patients: Twenty-six children with IGHD (group 1), 60 children with ISS (group 2), 33 children with GHD caused by lesions/abnormalities of the hypothalamus or pituitary (group 3), and 40 controls participated in the study. Nineteen children of group 2 were reevaluated after 2 yr. Main Outcome Measures: IGF-I levels, GH secretion, and APA (by indirect immunofluorescence) were evaluated in all participants. Results: At study entry, APA recognizing GH-producing cells were detected in seven of 26 children in group 1 and in 14 of 60 in group 2. Two years later, all eight initially APA-positive and all 11 APA-negative of the 19 reevaluated patients persisted positive and negative, respectively. The reevaluation of GH secretion in these patients revealed the development of GHD in all but one of the APA-positive children but in none of the APA-negative ones. Conclusions: IGHD in children can be frequently associated with APA targeting GH-secreting cells; thus, the detection of APA in children with ISS could identify those prone to develop GHD.

Recently, an increased incidence of central diabetes insipidus (CDI) in pregnancy, and less frequently in thepost partumperiod, 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 ofpost partumperiod 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 orpost partumautoimmune 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.

The role of antipituitary antibodies (APA) in autoimmune pituitary diseases still needs to be clarified. The aim of this study was 2-fold: first, to investigate the presence of APA in adults with idiopathic or acquired GH deficiency (GHD) and in adults with autoimmune endocrine diseases; and second, to evaluate whether in autoimmune endocrine patients APA titer is correlated to the pituitary function and particularly to GH secretion. We studied 12 adults with isolated and apparently idiopathic GHD who were treated with recombinant GH in childhood (group 1a), 14 patients with adult GHD secondary to surgery for pituitary and parasellar tumors (group 1b), and 180 patients with organ-specific autoimmune diseases (group 2). APA were evaluated by indirect immunofluorescence. In all APA-positive patients and in 20 APA-negative patients of group 2, GH secretion was investigated by testing its response to insulin-induced hypoglycemia (insulin tolerance test) and, when impaired, also to arginine. APA were found (at high titers) in 4 of 12 patients of group 1a (33.3%) but were absent in all patients in group 1b. APA were also found in 40 of 180 patients of group 2 (22.2%), 35 of them at low titers (group 2a) and 5 at high titers (group 2b). Twenty of the 140 autoimmune endocrine APA-negative patients studied (group 2c) and all APA-positive patients at low titers (group 2a) had normal pituitary function. Conversely, all APA-positive patients at high titers (groups 1a and 2b) had a severe isolated GHD. An inverse correlation between APA titers and GH peak serum response to insulin tolerance test in autoimmune endocrine patients was observed. Our results suggest that APA, when detected at high titers, may be considered a good diagnostic tool to highlight the possible occurrence of GHD in adults with autoimmune endocrine diseases. Moreover, they may indicate an autoimmune pituitary involvement in adults with apparently idiopathic GHD, suggesting that the prevalence of autoimmune GHD is much higher than that so far considered.

Diagnosis of autoimmune central diabetes insipidus (CDI) is based on the presence of autoantibodies to AVP-secreting cells (AVPcAb) or the coexistence of other autoimmune polyendocrine syndromes; moreover, it can be also suggested by the presence of lymphocytic infundibulo-neurohypophysitis, evidenced by biopsy of pituitary stalk and/or by pituitary stalk thickening on magnetic resonance imaging (MRI). However, so far, in clinical CDI patients with lymphocytic infundibulo-neurohypophysitis, AVPcAb have not been investigated and in those with or without autoimmune polyendocrine syndromes (APS), longitudinal studies on the behavior of AVPcAb alone, or of both AVPcAb and hypothalamic pituitary imaging on MRI are lacking. Aim of this work was to investigate in these patients the occurrence of AVPcAb (by indirect immunofluorescence) and of pituitary stalk thickening (by MRI) and their longitudinal changes during a follow-up period. We studied 22 patients, aged 29-53, with APS and complete CDI, grouped as follows: 10 with recent onset (< or =1.5 yr) of CDI (group 1a) and 12 with CDI of long-term duration (> or = 7 yr) (group 1b); moreover, a group of 13 patients with apparent idiopathic CDI of recent onset (

To evaluate the predictive factors of insulin requirement in newly diagnosed patients with unclassifiable diabetes, 54 consecutive patients, aged less than 35 years, were prospectively followed for 3 years or more. At entry, haemoglobin HbA1c, basal and stimulated C-peptide concentrations, HLA phenotype, islet cell antibodies (ICA) status, and serum levels of soluble CD8 antigen (sCD8) were evaluated. After a median time of 9 (range 2-32) months, 31 patients (group 1) required insulin therapy, whereas 23 patients (group 2) remained non-insulin-requiring after 36 months. Group 1 patients were younger (P0.05) and had higher HbA1c and sCD8 serum levels (P0.0001), respectively), a higher frequency of ICA positivity and of HLA DR3 and/or DR4 phenotype (P0.005 and P0.0001, respectively), and lower C-peptide concentrations (P0.005 and P0.0001, basal and stimulated, respectively) than group 2. The sensitivity, specificity, positive and negative predictive value, and overall accuracy for the subsequent insulin requirement were: sCD8 serum levels (737 U/ml), 100%, 65%, 79%, 100% and 85%, respectively; stimulated C-peptide (0.60 nmol/l), 71%, 96%, 96%, 74% and 81%, respectively; and ICA positivity (20 JDFU), 45%, 91%, 87%, 55% and 65%, respectively. Thus, higher sCD8 serum levels, low stimulated C-peptide concentrations and ICA positivity are the most powerful predictors of subsequent recourse to insulin therapy in young, newly detected patients with unclassifiable diabetes.

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.

Antipituitary antibodies (APA) but not antihypothalamus antibodies (AHA) are usually searched for in autoimmune hypopituitarism.Our objective was to search for AHA and characterize their hypothalamic target in patients with autoimmune hypopituitarism to clarify, on the basis of the cells stained by these antibodies, the occurrence of autoimmune subclinical/clinical central diabetes insipidus (CDI) and/or possible joint hypothalamic contribution to their hypopituitarism.We conducted a cross-sectional cohort study.Ninety-five APA-positive patients with autoimmune hypopituitarism, 60 without (group 1) and 35 with (group 2) lymphocytic hypophysitis, were studied in comparison with 20 patients with postsurgical hypopituitarism and 50 normal subjects.AHA by immunofluorescence and posterior pituitary function were evaluated; then AHA-positive sera were retested by double immunofluorescence to identify the hypothalamic cells targeted by AHA.AHA were detected at high titer in 12 patients in group 1 and in eight patients in group 2. They immunostained arginine vasopressin (AVP)-secreting cells in nine of 12 in group 1 and in four of eight in group 2. All AVP cell antibody-positive patients presented with subclinical/clinical CDI; in contrast, four patients with GH/ACTH deficiency but with APA staining only GH-secreting cells showed AHA targeting CRH- secreting cells.The occurrence of CDI in patients with lymphocytic hypophysitis seems due to an autoimmune hypothalamic involvement rather than an expansion of the pituitary inflammatory process. To search for AVP antibody in these patients may help to identify those of them prone to develop an autoimmune CDI. The detection of AHA targeting CRH-secreting cells in some patients with GH/ACTH deficiency but with APA targeting only GH-secreting cells indicates that an autoimmune aggression to hypothalamus is jointly responsible for their hypopituitarism.

ObjectiveCurrent data clearly demonstrate that sports-related chronic repetitive head trauma due to boxing might result in hypopituitarism. However, the mechanism of sports-related traumatic brain injury-induced pituitary dysfunction is still unclear. In order to understand whether autoimmune mechanisms could play a role in the pituitary dysfunction due to sports-related head trauma, we investigated the presence of antipituitary antibodies (APAs) and antihypothalamus antibodies (AHAs) in amateur boxers.Patients and designSixty-one actively competing (n=44) or retired (n=17) male boxers (mean age, 26 years; range, 17–53) who had been evaluated regarding pituitary functions previously were included in the study. In all boxers and in 60 age/sex-similar normal controls, AHAs and APAs were investigated by an indirect immunofluorescence method.ResultsAHAs were detected in 13 of 61 boxers (21.3%), and APAs were detected in 14 of 61 boxers (22.9%), but in none of the normal controls. Pituitary dysfunction was significantly higher in AHA-positive boxers (46.2%) than in AHA-negative boxers (10.4%) (P=0.003). There was a significant association between AHA positivity and hypopituitarism due to boxing (odds ratio: 7.37, 95% confidence interval 1.8–30.8). There was no significant association between APA positivity and hypopituitarism.ConclusionsThis study demonstrates for the first time the presence of AHAs and APAs in boxers who were exposed to sports-related head trauma. Moreover, the present investigation provides preliminary evidence that AHAs are associated with the development of pituitary dysfunction in boxers, thus suggesting that autoimmunity may have a role in the pathogenesis.

CONTEXT: Antipituitary antibodies (APA) are frequently present in patients with autoimmune polyendocrine syndrome (APS). DESIGN: The aim was to evaluate the predictive value of APA for the occurrence of hypopituitarism. A total of 149 APA-positive and 50 APA-negative patients with APS and normal pituitary function were longitudinally studied for 5 yr. METHODS: APA, by indirect immunofluorescence, and anterior pituitary function were assessed yearly in all patients. The risk for developing autoimmune pituitary dysfunction was calculated using survival and multivariate analysis. RESULTS: Hypopituitarism occurred in 28 of 149 (18.8%) APA-positive patients but in none of the 50 APA-negative patients. The immunostaining pattern in APA-positive patients involved either isolated pituitary cells [type 1 pattern; n=99 (66.4%)] or all pituitary cells [type 2 pattern; n=50 (33.6%)]. All patients developing pituitary dysfunction throughout the study span had a type 1 pattern. Kaplan-Meier curves for cumulative survival showed a significantly higher rate for developing hypopituitarism in relation to positive APA tests (P

ObjectiveTraumatic brain injury (TBI) is a devastating public health problem that may result in hypopituitarism. However, the mechanisms responsible for hypothalamic–pituitary dysfunction due to TBI are still unclear. Although the antibodies against neurons have been demonstrated in injured animal studies, investigations regarding the occurrence of antipituitary antibodies (APAs) in patients with TBI are lacking in the literature. In order to investigate whether autoimmune mechanisms could play a role in the pituitary dysfunction after TBI, we have planned this study aimed at investigating the presence of APA at the third year of TBI and association between the TBI-induced hypopituitarism and APA.Patients and designTwenty-nine (25 males and 4 females; age 36.5±2.3 years) patients who had completed a 3-year follow-up after TBI were included in the present study. APA and pituitary function were evaluated in all the patients 3 years after TBI; moreover, APAs were tested also in sera of 60 age-/sex-matched normal controls. The APAs were investigated by an indirect immunofluorescence method.ResultsAPAs were detected in 13 out of the 29 TBI patients (44.8%), but in none of the normal controls. Pituitary dysfunction development ratio was significantly higher in APA-positive patients (46.2%) when compared with APA-negative ones (12.5%; P=0.04). There was a significant association between APA positivity and hypopituitarism due to TBI (odds ratio: 2.25, 95% confidence intervals 1.1–4.6). Moreover, there was a significant positive correlation (r=0.74, P=0.004) between APA titer ratio and peak GH response to GHRH+GH related peptide (GHRP)-6 test, suggesting that high APA titers were associated with low GH response to GHRH+GHRP-6 test.ConclusionsThis study shows for the first time the presence of the APA in TBI patients 3 years after head trauma. Moreover, present investigation indicates preliminary evidence that APA may be associated with the development of TBI-induced pituitary dysfunction, thus suggesting that autoimmunity may contribute in the development of TBI-induced hypopituitarism. The presence of the association between APA and TBI-induced hypopituitarism may provide a new point of view in this field and promote further clinical and experimental studies.

ObjectiveWhile anti-pituitary antibodies (APAs) were detected in some patients with Sheehan's syndrome (SS) suggesting an autoimmune pituitary involvement in the development of their hypopituitarism, hypothalamic cell anti-hypothalamus antibodies (AHAs) have not been investigated so far.DesignThe aim of this study was to evaluate the presence of AHA and APA in SS patients to verify whether an autoimmune hypothalamic–pituitary process can contribute to their late hypopituitarism.MethodsTwenty women with SS with a duration of disease ranging from 3 to 40 years (median 25.5 years) were enrolled into the study. Out of 20 patients, 12 (60%) had panhypopituitarism and the others had partial hypopituitarism well corrected with appropriate replacement therapy. None of them had clinical central diabetes insipidus. AHA and APA were investigated by immunofluorescence method in all patients. In addition, a four-layer immunofluorescence method was used to verify whether AHA immunostained vasopressin-secreting cells (AVP-c) or not.ResultsAHAs were found in 8 out of 20 (40%) and APAs in 7 out of 20 (35%) patients with titers ranging from 1:32 to 1:128 and 1:16 to 1:32 respectively; however, in none of these positive patients AHA immunostained vasopressin cells. None of controls resulted positive for both antibodies.ConclusionsPatients with SS, even many years after the onset of SS, can show antibodies to pituitary and/or hypothalamic but not AVP-secreting cells. Antibodies to unknown hypothalamic cells (releasing factor-secreting cells) other than APAs suggest that an autoimmune process involving both the hypothalamus and pituitary gland may contribute to late pituitary dysfunction in SS patients.

LYH (lymphocytic hypophysitis) is an autoimmune disease of the pituitary gland which can present with varying degrees of pituitary hormonal impairment and/or with symptoms related to pituitary enlargement. In this review, we provide an overview of the epidemiology, diagnosis, pathogenesis, treatment, and the role of organ-specific and antipituitary antibodies as potential markers of LYH. In addition, although the mechanisms underlying LYH are not completely understood, the role of prolactin, which plays an important part in maintaining immune system homoeostasis and is increased in the disease, is considered.

J Clin Endocrinol Metab. 2007 Feb;92(2):604-7. Epub 2006 Nov 7. Antipituitary antibodies against gonadotropin-secreting cells in adult male patients with apparently idiopathic hypogonadotropic hypogonadism. De Bellis A, Sinisi AA, Conte M, Coronella C, Bellastella G, Esposito D, Pasquali D, Ruocco G, Bizzarro A, Bellastella A. SourceDepartment of Clinical and Experimental Medicine and Surgery F Magrassi, A Lanzara, Second University of Naples, Naples, Italy. annamaria.debellis@unina2.it Abstract CONTEXT: Hypogonadotropic hypogonadism (HH) can occur at any stage of life as an isolated congenital or acquired abnormality or within a more generalized pituitary or hypothalamic impairment. However, the defect in patients with idiopathic HH is still unknown. OBJECTIVE: The aim of this study was to investigate the prevalence of antipituitary antibodies (APA) in a group of HH patients with or without Kallmann's syndrome and to characterize their pituitary target. DESIGN: We conducted a cross-sectional cohort study. SETTING: The study was performed at the Endocrinology Unit of the Second University of Naples. PATIENTS: Twenty-one HH patients with normal sense of smell (group 1), 10 patients with Kallmann's syndrome (group 2), 13 patients with HH associated with other pituitary hormone deficiencies (group 3), and 50 normal controls were studied. MAIN OUTCOME MEASURES: APA were evaluated in patients and in controls by indirect immunofluorescence. Moreover, a magnetic resonance imaging (MRI) of the hypothalamic-pituitary region was performed in all three groups of patients. RESULTS: APA were detected at high titer in eight out of 21 patients in group 1 (38%) and in five of 13 in group 3 (38.4%), and at low titers in two out of 10 in group 2 (20%) and in three of 50 controls (6%). In patients of group 1, APA immunostained selectively gonadotropin-secreting cells, whereas in those of group 3, they immunostained other pituitary hormone-secreting cells also. None of patients in group 1 showed alterations on MRI, whereas all patients in group 2 showed aplasia/hypoplasia of the olfactory bulbs/tracts and/or of olfactory sulci. Among the five APA-positive patients in group 3, three had normal MRI, one had findings of empty sella, and one had findings of autoimmune hypophysitis. CONCLUSIONS: Our results suggest that some apparently idiopathic cases of HH, both isolated and associated with other pituitary impairment, can be caused by an early autoimmune process involving the gonadotrophs at pituitary level. Future longitudinal studies are needed to clarify the natural history of this process and the possible effect of early corticosteroid therapy.

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 IFNgamma 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.

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.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.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.

Summary Objective 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 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). Measurements APA were evaluated by a four-layer double indirect immunofluorescence technique. Results 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. Conclusions 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.

Lymphocytic hypophysitis (LYH) is a pituitary disease which can cause headache, changes in visual field and pituitary dysfunction. The clinical, histopathological and morphological findings and its association with other autoimmune disorders allow LYH to be included among the autoimmune diseases. Pituitary trans-sphenoidal biopsy is thought to be the diagnostic gold standard for LYH, even if some morphological findings on hypothalamic-pituitary magnetic resonance imaging (MRI) can suggest the occurrence of this disease. Despite the fact that organ-specific antibodies are good markers of many autoimmune endocrine diseases, the pathogenetic and diagnostic roles of anti-pituitary antibodies (APAs) in LYH are still under discussion. In fact, several methods have been used to detect APAs, but the conflicting results from different methods have impaired the clinical relevance of these antibodies. Recently, APAs have been detected by an immunofluorescence method in patients with selective idiopathic hypopituitarism (particularly in those with growth-hormone deficiency) and in adults with autoimmune endocrine diseases. The results suggest that only when they are present at high titres may they be considered a good marker of pituitary involvement, and in particular of growth-hormone-producing cells.

Primary adrenal insufficiency (PAI) is clinically evident in one in 8000 individuals. A correct etiological classification is critical for correct disease management. To update the diagnostic criteria for the etiological classification of PAI, a multicentric network was established in Italy, and 222 patients with PAI were studied. Both 21-hydroxylase and adrenal cortex autoantibodies (21OHAb and ACA, respectively) were tested in two independent laboratories on coded samples and found in 65-66% and 58-61% of cases, respectively. Autoimmune polyendocrine syndrome I was diagnosed in 11 of the 222 patients. Of the remaining 211 patients, 38 (18%) had a nonautoimmune form of PAI. In 145 subjects (65%), the presence of adrenal autoantibodies, without signs of other forms of PAI, led to a diagnosis of autoimmune Addison's disease. In six cases (3%), PAI remained idiopathic. Logistic regression analysis showed a 92.2-92.7% probability of correct reclassification for the two 21OHAb assays and 84.5-85.9% for the ACA assays. We conclude that the simultaneous presence of both 21OHAb and ACA permits unambiguous diagnosis of autoimmune Addison's, whereas subjects with low antibody titers should undergo both instrumental and biochemical tests to exclude other causes of PAI. Lastly, we developed a comprehensive flowchart for the classification of PAI for use in routine clinical practice.

Central diabetes insipidus (CDI) is a rare hypothalamus-pituitary disease due to the deficiency of arginine vasopressin (AVP) synthesis from the hypothalamus and/or secretion from the neurohypophysis. The etiology of CDI is unknown in over one third of cases, classified as idiopathic CDI. The aim of this study was 2-fold: 1) to evaluate the occurrence of circulating autoantibodies to AVP-secreting cells (AVPcAb), and 2) to correlate it to clinical (sex, age of disease onset, disease duration, and degree), immunological (clinical history of autoimmune diseases and presence of related organ-specific autoantibodies), and radiological features (neurohypophyseal bright spot, pituitary stalk thickening, and empty sella) in a large cohort of patients with apparently idiopathic CDI or CDI of known etiology. To this purpose, 150 patients with CDI were studied: 64 idiopathic, 6 familial, 12 associated to granulomatous diseases, and 68 secondary to cranial trauma, tumor, or surgery. AVPcAb were measured by an indirect immunofluorescence method. AVPcAb were found in 23.3% of CDI patients: 21 idiopathic (32.8%) and 14 nonidiopathic (16.3%; chi(2) = 13.1; P < 0.001). AVPcAb were independently associated with age less than 30 yr at disease onset (P = 0.001) in patients with idiopathic CDI and with history of autoimmune diseases (P = 0.006 and P = 0.02, respectively) and radiological evidence of pituitary stalk thickening (P = 0.02 and P = 0.003, respectively) in both idiopathic and nonidiopathic CDI. The likelihood of autoimmunity in one patient with apparently idiopathic CDI with age of disease onset less than 30 yr was 53%, it increased to 91% when history of autoimmune diseases was associated and to 99% when pituitary stalk thickening was further associated. In conclusion, autoimmunity is associated with one third of patients with apparently idiopathic CDI, which should therefore be classified as autoimmune CDI. Autoimmune CDI is highly likely in young patients with a clinical history of autoimmune diseases and radiological evidence of pituitary stalk thickening. Conversely, autoimmunity probably represents an epiphenomenon in patients with nonidiopathic CDI.

Serum autoantibodies against eye muscle antigens are closely linked with thyroid-associated ophthalmopathy (TAO), although their significance is unclear. The two antigens that are most often recognized are eye muscle membrane proteins with molecular masses of 55 and 64 kDa, as determined from immunoblotting with crude human or porcine eye muscle membranes. We cloned a fragment of the 55-kDa protein by screening an eye muscle expression library with affinity-purified anti-55 kDa protein antibody prepared from a TAO patient’s serum. A complementary DNA (cDNA) encoding a novel protein, which we have called G2s, was sequenced on both strands, and its size was 411 bp. The open reading frame of G2s corresponded to a 121-amino acid peptide with a size of 1.4 kb. Using the rapid amplification of 5′-cDNA ends technique we were able to clone an additional 0.3 kb of the protein. G2s did not share significant homologies with any other entered protein in computer databases and had one putative transmembrane domain. Using the 1.4 kb cDNA as probe in Northern blotting of a panel of messenger ribonucleic acids prepared from human tissues, the parent protein was shown to correspond to a large molecule of about 5.8 kb with a calculated molecular mass of approximately 220 kDa, consistent with earlier immunoblot studies performed in the absence of reducing agents. G2s was strongly expressed in eye muscle, thyroid, and other skeletal muscle and to a lesser extent in pancreas, liver, lung, and heart muscle, but not in kidney or orbital fibroblasts. We tested sera from patients with Graves’ hyperthyroidism with and without ophthalmopathy and from control patients and subjects for antibodies against a G2s fusion protein by immunoblotting and enzyme-linked immunosorbent assay. In immunoblotting, antibodies reactive with G2s were identified in 70% of patients with TAO of less than 3 yr duration, 53% with TAO of more than 3 yr duration, 36% with Graves’ hyperthyroidism without evident ophthalmopathy, 17% with Hashimoto’s thyroiditis, 3% with type 1 diabetes, 23% with nonimmunological thyroid disorders, and 16% of normal subjects. The prevalences, compared to normal values, were significant for the two groups of patients with TAO, but not for the other groups. Tests were positive in 54% of patients with active TAO, 33% with chronic ophthalmopathy, 36% with Graves’ hyperthyroidism, 54% with Hashimoto’s thyroiditis, 23% with type 1 diabetes, and in 11% of normal subjects using enzyme-linked immunosorbent assay. The antibodies predicted the development of the ocular myopathy subtype of TAO in six of seven patients and the congestive ophthalmopathy subtype in seven of eight patients, respectively, with Graves’ hyperthyroidism studied prospectively during and after antithyroid drug therapy. Antibodies reactive with G2s may be early markers of ophthalmopathy in patients with Graves’ hyperthyroidism. Because G2s is expressed in both thyroid and eye muscle, immunoreactivity against a shared epitope in the two tissues may explain the well known link between thyroid autoimmunity and ophthalmopathy.

Cytoplasmic autoantibodies to vasopressin-cells (AVPcAb) have been detected not only in patients with overt central diabetes insipidus (CDI), but also in patients with endocrine autoimmune diseases without CDI. This suggests that complete CDI can be preceded by a preclinical stage. Among 878 patients with endocrine autoimmune diseases without CDI, 9 patients found to be AVPcAb positive and 139 AVPcAb-negative controls were enrolled in this open prospective study. They were evaluated for AVPcAb and posterior pituitary function at least yearly for about 4 yr (range, 37‐ 48 months); during this span, magnetic resonance imaging (MRI) of posterior pituitary and stalk was performed only in the AVPcAb-positive patients. Five of the 9 AVPcAb-positive patients had normal posterior pituitary function at study entry. They were AVPcAb positive throughout the follow-up period. At later stages of the study, 3 of them developed partial CDI, and 1 developed complete CDI. The remaining 4 patients showed impaired response to the water deprivation test at study entry and were diagnosed as having partial CDI. Two of them agreed to receive desmopressin replacement for 1 yr. After this treatment, the patients became negative for AVPcAb and displayed normal posterior pituitary function until the end of the follow-up. Conversely, the 2 untreated patients with partial CDI remained AVPcAb positive. One of them developed overt CDI. None of the controls became AVPcAb positive or developed CDI. The normal hyperintense MRI signal of the posterior pituitary, present at study entry, persisted subsequently in all 9 AVPcAb-positive patients, including those developing overt CDI, only disappearing in the late phase of complete CDI. In asymptomatic subjects, the monitoring of AVPcAb, but not MRI, seems to be useful to predict a progression toward partial/overt CDI. Early desmopressin therapy in patients with partial CDI could interrupt or delay the autoimmune damage and the progression toward clinically overt CDI. (J Clin Endocrinol Metab 84: 3047‐3051, 1999)

Idiopathic Addison's disease is a chronic organ-specific autoimmune disorder with a long subclinical period characterized only by the presence of adrenal autoantibodies (AA) with or without adrenal function failure. The aim of this longitudinal study was to evaluate the behavior of AA using, an indirect fluorescence method, and adrenal function in 20 AA-positive and 50 AA-negative patients screened by an investigation of a large population of organ-specific autoimmune disease patients without clinical Addison's disease. As controls, 100 normal age-matched subjects were tested only once. In the 20 AA-positive and 50 negative patients, AA and adrenal functional tests were evaluated every 4 months for 5 yr. The AA-positive patients were grouped into 5 adrenal functional stages, specifically: stage 0, normal adrenal function; stage 1, high PRA and low (or normal) aldosterone levels alone; stage 2, along with impaired cortisol response to ACTH, stage 3, along with increased ACTH levels; and stage 4, clinically overt Addison's disease. On the basis of the behavior of AA, the 20 positive patients were grouped as follows: group A, 11 patients with AA titer of 1:8 or higher at the first observation and persistently AA positive in subsequent observations, with titers ranging from 1:8 to 1:64; group B, 6 patients with initial AA titers of 1:8 or lower and AA disappearance in subsequent observations; and group C, 3 patients with AA titer of 1:32 or higher, undergoing corticosteroid therapy after the start of the study and showing AA disappearance in subsequent observations. With respect to adrenal function in group A, 2 patients initially in stage 1 and 1 patient initially in stage 2 did not progress to the upper stages, whereas 5 patients initially in stage 0 and 3 initially in stage 1 progressed subsequently to the upper stages, in 2 cases reaching overt clinical Addison's disease (stage 4). On the other hand, all of the patients of group B showed both a spontaneous disappearance of AA and recovery of adrenal function during the study span. Also, the 3 patients of group C showed disappearance of AA after corticosteroid therapy with recovery of adrenal function. None of the 50 patients who were initially AA negative became AA positive subsequently or showed impairment of adrenal function. We reached the following conclusions. 1) AA, even if present initially in some subjects without clinical Addison's disease, can subsequently disappear. 2) Restoration of adrenal function after disappearance of AA indicates that a spontaneous remission of subclinical adrenocortical failure can occur.(ABSTRACT TRUNCATED AT 400 WORDS)

43 clinically euthyroid patients with unilateral exophthalmos were examined using clinical methods, echography, and computerized tomography. The functioning of the hypothalamic-hypophyseal-thyroid axis was investigated by measurements of TSH (before and after stimulation with TRH), thyroid hormones and antithyroglobulin antibodies. After a review of the literature, the results are discussed.

A 36-year-old woman with central diabetes insipidus (DI), diagnosed when she was 7, was referred to our Endocrine Unit in January 1993 for further hormonal investigations. Clinical and laboratory findings confirmed the diagnosis of central DI. Cranial computed tomography and magnetic resonance imaging showed only an empty sella. Moreover, we noted impaired glucose tolerance and unusual findings of subclinical adrenocortical failure, i.e. high plasma renin activity with normal aldosterone levels, high ACTH despite normal basal and ACTH-stimulated cortisol levels. Immunological study of the patient's serum showed the presence of arginine vasopressin (AVP)-secreting cell antibodies (Abs), steroid-producing cell Abs, adrenal and islet cell Abs. The following aspects of our case are stressed and discussed: (1) the presence of AVP-secreting cell Abs 29 years after the diagnosis of DI; (2) the association between DI, empty sella and subclinical autoimmune adrenocortical failure with unusual hormonal findings, and (3) impaired glucose tolerance with islet cell antibody positivity.

Summary OBJECTIVE Cytoplasmic autoantibodies to vasopressin cells (AVP) have been detected in patients with idiopathic central diabetes insipidus and only in one patient with endocrine autoimmune diseases without clinical diabetes insipidus. The aim of this study was to look for AVP cell antibodies (AVP-cell-Ab) in human sera of a large population of autoimmune endocrine disease patients without diabetes insipidus and to test whether an occurrence of these antibodies in some patients can be associated with partial impairment of posterior pituitary function. MEASUREMENT Sera from 410 patients (310 females, 100 males, age range 10–46 years) with autoimmune endocrine disorders (260 with thyroid autoimmune disease, and 150 with insulin dependent diabetes mellitus) without clinical diabetes insipidus, and from 100 normal subjects, were investigated for hypothalamic autoantibodies by an indirect immunofluorescence method. Positive sera were subsequently tested with specific rabbit anti AVP serum. RESULTS None of controls, but five out of 410 patients (1–2%) were AVP-cell-Ab positive. All positive and nine negative from the 410 screened patients were tested for posterior pituitary function. Two out of five AVP-cell-Ab positive patients showed partial diabetes Insipidus. CONCLUSION AVP cell antibodies can be shown in some patients with endocrine autoimmune disease without diabetes insipidus and can sometimes be associated with findings of partial posterior pituitary dysfunction. This suggests that clinical diabetes insipidus could be preceded by a long subclinical period characterized only by the occurrence of AVP-cell-Ab in the sera associated or followed by alterations in functional tests. Longitudinal studies are needed to confirm this hypothesis.