Annamaria De Bellis

Prolactin and Autoimmunity

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, Addisons 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 Hashimotos thyroiditis, in Addisons 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.

Antipituitary antibodies after traumatic brain injury: is head trauma-induced pituitary dysfunction associated with autoimmunity?

OBJECTIVE Traumatic 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 DESIGN Twenty-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. Results APAs 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. CONCLUSIONS This 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.

Steroid-cell autoantibodies are preferentially expressed in women with premature ovarian failure who have adrenal autoimmunity.

OBJECTIVE To determine the prevalence of steroid-cell autoantibodies, 3beta-hydroxysteroid dehydrogenase (3beta-HSD) antibodies, 17alpha-hydroxylase (17alpha-OH) antibodies, and P450 side-chain cleavage antibodies in premature ovarian failure. DESIGN Cross-sectional, observational study. SETTING Academic research hospitals. PATIENT(S) Eighty-one women with premature ovarian failure, 20 women with Addison disease not associated with premature ovarian failure, 42 women with type 1 diabetes mellitus, and 90 healthy women. MAIN OUTCOME MEASURE(S) Serum levels of steroid-cell autoantibodies, 17alpha-OH antibodies, P450 side-chain cleavage antibodies, and 3beta-HSD antibodies. RESULT(S) Steroid-cell autoantibodies were present in none of 57 women with isolated premature ovarian failure or premature ovarian failure plus nonadrenal autoimmune disease and in 21 of 24 (87%) women with Addison disease-related premature ovarian failure. 17alpha-Hydroxylase antibodies and P450 side-chain cleavage antibodies were significantly more frequent in women positive for adrenal autoantibodies than in those negative for adrenal autoantibodies (50% vs. 0% and 71% vs. 2%, respectively). The presence of 17alpha-OH antibodies or P450 side-chain cleavage antibodies was strongly associated with presence of steroid-cell autoantibodies. Two of 24 (8%) women with Addison disease-related premature ovarian failure and 1 of 57 (2%) women with isolated premature ovarian failure or premature ovarian failure plus nonadrenal autoimmune disease were positive for 3beta-HSD antibodies. None of 20 adult women with autoimmune Addison disease and none of 42 adult women with type 1 diabetes mellitus not associated with premature ovarian failure was positive for 3beta-HSD antibodies. CONCLUSION(S) Markers of steroid-cell autoimmunity are found only rarely in idiopathic premature ovarian failure not associated with Addison disease. Most women with Addison disease-related premature ovarian failure were positive for steroid-cell autoantibodies, 17alpha-OH antibodies, or P450 side-chain cleavage antibodies. 3beta-Hydroxysteroid dehydrogenase antibodies do not appear to be a major marker of steroid-cell autoimmunity.

Investigation of antihypothalamus and antipituitary antibodies in amateur boxers: is chronic repetitive head trauma-induced pituitary dysfunction associated with autoimmunity?

OBJECTIVE Current 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 DESIGN Sixty-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. RESULTS AHAs 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. CONCLUSIONS This 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.

Anti-hypothalamus and anti-pituitary antibodies may contribute to perpetuate the hypopituitarism in patients with Sheehan's syndrome.

OBJECTIVE While anti-pituitary antibodies (APAs) were detected in some patients with Sheehans 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. DESIGN The 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. METHODS Twenty 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. RESULTS AHAs 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. CONCLUSIONS Patients 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.

Homozygous mutation in the prokineticin-receptor2 gene (Val274Asp) presenting as reversible Kallmann syndrome and persistent oligozoospermia: Case Report

Prokineticin 2 (Prok2) or prokineticin-receptor2 (Prok-R2) gene mutations are associated with Kallmann syndrome (KS). We describe a new homozygous mutation of Prok-R2 gene in a man displaying KS with an apparent reversal of hypogonadism. The proband, offspring of consanguineous parents, presented at age 19 years with absent puberty, no sense of smell, low testosterone and gonadotrophin levels. Magnetic resonance imaging showed olfactory bulb absence. The patient achieved virilization and spermatogenesis with gonadotrophin administration. Two years after discontinuing hormonal therapy, he maintained moderate oligozoospermia and normal testosterone levels. Prok2 and Prok-R2 gene sequence analyses were performed. The proband had a homozygous mutation in Prok-R2 exon 2 that harbours the c.T820>A base substitution, causing the introduction of an aspartic acid in place of valine at position 274 (Val274Asp). His mother had the same mutation in heterozygous state. This report describes a novel homozygous mutation of Prok-R2 gene in a man with variant KS, underlying the role of Prok-R2 gene in the olfactory and reproductive system development in humans. Present findings indicate that markedly delayed activation of gonadotrophin secretion may occur in some KS cases with definite gene defects, and that oligozoospermia might result from a variant form of reversible hypogonadotrophic hypogonadism.

Effects of somatostatin analog SOM230 on cell proliferation, apoptosis, and catecholamine levels in cultured pheochromocytoma cells

Surgery is the primary therapy for pheochromocytoma (PHEO), a catecholamine-producing tumor. Benign and malignant PHEO could develop recurrences, and the intraoperative risk of recurrent PHEO is an important unresolved issue. Non-surgical treatments of PHEO recurrence would therefore better prepare patients for reintervention as well as provide them with palliative management. We investigated the effects of the new somatostatin analog (pasireotide) SOM230 versus octreotide (OCT) in primary PHEO cell cultures (Pheo-c). Pheo-c from six benign surgical samples were set up and characterized by immunocytochemistry. Real-time PCR, using both PHEO tissues and Pheo-c, showed different levels of somatostatin receptor(1-5) mRNA expression. Cells treated with various doses of OCT or SOM230 for 48 and 72 h were analyzed to assess their effects on cell proliferation and apoptosis and catecholamine levels. Even if reduction of cell viability was observed in Pheo-c treated for 48 h with either OCT or SOM230 and this effect increased after 72 h, a more significant inhibition of cell growth as well as a significantly higher induction of apoptosis was seen in Pheo-c treated with SOM230 versus OCT. In particular, apoptosis in Pheo-c was detected after 48 h and was associated with increased expression and activation of caspase-3 and cleaved poly(ADP-ribose) polymerase. OCT 10(-6) M and SOM230 10(-7) M significantly reduced catecholamine levels. Our results indicate that while both OCT and SOM230 modulate cell growth and apoptosis and catecholamine levels in Pheo-c through specific receptors, SOM230 is more effective. This improves our knowledge on the mechanism of SOM230 action in PHEO and supports a possible therapeutic use in benign PHEO recurrence.

Predictive Role of the Immunostaining Pattern of Immunofluorescence and the Titers of Antipituitary Antibodies at Presentation for the Occurrence of Autoimmune Hypopituitarism in Patients with Autoimmune Polyendocrine Syndromes over a Five-Year Follow-Up

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<0.005), pattern of immunostaining (P<0.0001), and APA titers (P<0.000001). Cox regression analysis in APA-positive patients with a type 1 pattern demonstrated a significantly (P<0.0001) higher risk for the onset of hypopituitarism in relation to increasing titers of APA. CONCLUSIONS APA measurement by immunofluorescence may help to predict the occurrence of hypopituitarism but only when considering the immunostaining pattern and their titers. Combined evaluation of these parameters allows identifying patients at higher risk for pituitary autoimmune dysfunction, thus requiring a strict pituitary surveillance to disclose a preclinical phase of hypopituitarism and possibly interrupt therapeutically the progression to clinically overt disease.

Idiopathic central diabetes insipidus in children and young adults is commonly associated with vasopressin‐cell antibodies and markers of autoimmunity

Objectives  Autoimmune targeting of hypothalamic‐neurohypophyseal structures in children and young adults with posterior pituitary and anterior pituitary dysfunction, as well as pituitary stalk involvement, are not yet completely understood.

Impact of prophylactic central compartment neck dissection on locoregional recurrence of differentiated thyroid cancer in clinically node-negative patients: A retrospective study of a large clinical series

BACKGROUND In clinically node-negative patients with differentiated thyroid cancer (DTC), indications for routine central lymph node dissection (RCLD) are the subject of intensive research, and surgeons are divided between the pros and cons of this surgery. To better define the role of neck dissection in the treatment of DTC, we analyzed retrospectively the results in three centers in Italy. METHODS The clinical records of 752 clinically node-negative patients with DTC who underwent operative treatment between January 1998 and December 2005 in three endocrine surgery referral units were evaluated retrospectively. The complications and medium- and long-term outcomes of total thyroidectomy (TT) alone (performed in 390 patients: group A) and TT combined with bilateral RCLD (362 patients: group B) were analyzed and compared. RESULTS The incidence of permanent hypoparathyroidism and permanent unilateral vocal folds was 1% and 0.8% in group A and 3.6% and 1.7% in the group B, respectively. Bilateral temporary recurrent nerve palsy was observed in one of the 362 patients in group B. After a follow-up of 9.5 ± 3.5 years (mean ± SD), the locoregional recurrence rate with positive cervical lymph nodes was not substantially significantly different between the two groups. CONCLUSION In our series, TT combined with bilateral RCLD was associated with a greater rate of transient and permanent complications. Similar incidences of locoregional recurrence were reported in the two groups of patients. Considering the recent trend toward routine central lymphadenectomy, further studies are needed to evaluate the benefits of these different approaches.