Pituitary-related immune adverse events induced by programmed death Protein-1 inhibitors differ clinically from hypophysitis.

OBJECTIVE: We aimed to elucidate the clinical features of pituitary immune-related adverse events (irAEs) induced by PD-1 inhibitors in a Chinese cohort and the previous literatures. PATIENTS AND DESIGN AND MEASUREMENTS: We retrospectively analysed the clinical manifestations, laboratory examination findings, imaging features and treatments of 14 patients with pituitary irAEs caused by PD-1 inhibitors in our cohort. In addition, we searched PubMed for all English articles on pituitary irAEs induced by PD-1 inhibitors published from 1950 to 2023. A total of 47 articles were included, and the clinical characteristics of 94 patients with pituitary irAEs induced by PD-1 inhibitors in these literatures were compared to the characteristics of our cohort. RESULTS: Among the 14 patients in our cohort with pituitary irAEs induced by PD-1 inhibitors, 12 patients (85.71%, 12/14) exhibited isolated ACTH deficiency (IAD), 100.0% (14/14) of the central adrenocortical insufficiency, and 2 patients showed more than one hypothalamic-pituitary axis injury (14.29%, 2/14). Pituitary magnetic resonance imaging in all the 14 patients showed no pituitary enlargement. In previous studies we reviewed, 82.98% of the total (78/94) presented with pituitary irAEs as IAD, 100.0% (94/94) of the central adrenocortical insufficiency, and 78.33% of the patients showed no abnormality of the pituitary gland (47/60). The pituitary irAEs caused by PD-1 inhibitors did not involve typical manifestations of hypophysitis, such as pituitary enlargement, headache, visual field defects, and multiple pituitary function impairments in our cohort and the previous literatures. CONCLUSION: In our study, pituitary immune-related adverse reactions induced by PD-1 inhibitors mainly manifested isolated ACTH deficiency rather than hypophysitis.

Pituitary-Related Adverse Events and Onset Patterns Caused by Immune Checkpoint Inhibitors: Analysis Using the Japanese Adverse Drug Event Report Database.

Background and Objectives: One type of immune-related adverse event caused by immune checkpoint inhibitors (ICIs) is pituitary-related adverse events. The management of pituitary-related adverse events is important because they can be fatal if not treated promptly. Therefore, this study was conducted to investigate the onset of pituitary-related adverse events using the Japanese Adverse Drug Report (JADER) database. Materials and Methods: Cases registered in the JADER database from 2004 to 2019 were used. The target drugs were ipilimumab, nivolumab, pembrolizumab, avelumab, atezolizumab, and durvalumab, and the target adverse events were the high-level terms "Anterior pituitary hypofunction," "Anterior pituitary hyperfunction," "Posterior pituitary disorder," and "Pituitary neoplasm" in the Medical Dictionary for Regulatory Activities, Japanese version (MedDRA/J). The information component (IC) was used for signal detection and IC delta (ICΔ) was used for women-related signals. Onset timing and patterns were analyzed using the Weibull distribution. Results: Signals were detected with ipilimumab, nivolumab, pembrolizumab, and atezolizumab in "Anterior pituitary hypofunction," with ICs and 95% credible intervals (95%CrI) of 5.53 (5.30-5.69), 4.96 (4.79-5.08), 4.04 (3.76-4.25), and 2.40 (1.53-3.00). Significant signals were detected in women, except for atezolizumab. Additionally, the time of onset was classified as the wear-out failure type. Inverse signals were detected with ipilimumab and nivolumab in "Posterior pituitary disorder," with ICs (95%CrI) of -1.24 (-2.80--0.26), and -0.89 (-1.64--0.37). Conclusions: Anterior pituitary hypofunction is likely to occur with the long-term administration of ipilimumab, nivolumab, and pembrolizumab. Further investigation is needed to determine the differences in the tendencies to detect signals in the anterior and posterior pituitaries between ipilimumab and nivolumab.

Lipotoxicity suppresses the synthesis of growth hormone in pituitary somatotrophs via endoplasmic reticulum stress.

Lipotoxicity has been shown to cause dysfunction of many organs and tissues. However, it is unclear whether lipotoxicity is harmful to the somatotrophs, a kind of cell that synthesize growth hormone (GH) in the pituitary. In this study, we performed an epidemiological study, serum levels of triglyceride (TG) and GH showed a negative correlation, even after adjustment for potential confounders. In an animal study, male Sprague-Dawley rats were fed a high-fat diet (HFD) or a control diet for 28 weeks. HFD rats showed impaired GH synthesis, resulting in a decrease in circulating GH levels. The expression of pituitary Pit-1, a key transcription factor of GH, was inhibited. We found that the inositol-requiring enzyme 1α (IRE1α) pathway of endoplasmic reticulum (ER) stress was triggered in HFD rat pituitary glands and palmitic acid-treated GH3 cells, respectively. On the contrary, applying 4-phenyl butyric acid (4-PBA) to alleviate ER stress or 4µ8c to specifically block the IRE1α pathway attenuated the impairment of both Pit-1 and GH expression. In conclusion, we demonstrated that lipotoxicity directly inhibits the synthesis of GH, probably by reducing Pit-1 expression. The IRE1α signaling pathway of ER stress may play an important role in this process.

Immune checkpoint inhibitor-associated pituitary adverse events: an observational, retrospective, disproportionality study.

PURPOSE: The aim of this study was to identify and characterize immune checkpoint inhibitors (ICIs)-associated pituitary adverse events (AEs). METHODS: This is a retrospective disproportionality study based on VigiBase, the World Health Organization (WHO) global database of individual case safety reports (ICSRs), with a study period from January 1, 2011 to March 6, 2019. Information component (IC) and reporting odds ratio (ROR) are measures of disproportionate analysis. IC was used to evaluate the association between ICIs and pituitary AEs, while ROR was used to evaluate the differences in reporting of pituitary AEs between different ICI subgroups. RESULTS: The following ICI-associated pituitary diseases have been increasingly reported: hypophysitis (835 reports; information component 6.74 [95% CI 6.63-6.83]), hypopituitarism (268; 6.12 [95% CI 5.92-6.27]), pituitary enlargement (28; 5.19 [95% CI 4.57-5.63]). The anti-CTLA-4 subgroup had a stronger association with hypophysitis/hypopituitarism than the anti-PD (anti-PD-1 or anti-PD-L1) subgroup (ROR 8.0 [95% CI 6.7-9.6]). Among ICI-associated hypophysitis/hypopituitarism cases, the proportion of male was higher than female (630 [63.9%] vs 356 [36.1%]). Anti-CTLA-4 subgroup and ICI combination (nivolumab plus ipilimumab) subgroup both had a significantly earlier onset time than anti-PD subgroup (67 days [IQR 48-87]; 90 [IQR 34-155]; 140 [IQR 62-218], both p < 0.05). Other endocrinopathies that co-occurred with hypophysitis/hypopituitarism were adrenal insufficiency, thyroid dysfunction, diabetes mellitus and diabetes insipidus. Gastrointestinal disorder was the most common concurrent disease except for endocrinopathies. CONCLUSIONS: ICI-associated pituitary adverse events have significantly increased, and their clinical characteristics should be kept in mind by oncologists and endocrinologists who manage patients treated by immunotherapy.

Disorder of hypothalamic-pituitary-gonadal axis induced by abusing of anabolic-androgenic steroids for short time: A case report.

The aim of this study was to evaluate the hypothalamic-pituitary-gonadal axis functionality on a bodybuilding competitioner before, during and after the use of anabolic-androgenic steroids. A young healthy man was followed up for 4 months. The subject reported his drug administration protocol through periodic interviews and performed laboratory tests to monitor the function of his hypothalamic-pituitary-gonadal axis. Time 1 (before the steroids use) shows all hormones levels (follicle-stimulating hormone = 4,2 mUI/ml, luteinising hormone = 3,7 mUI/ml and total testosterone = 5,7 ng/ml) within reference values. In Time 2, after 8 weeks on steroids abuse, a complete hypothalamic-pituitary-gonadal axis derangement is evident with noticeable negative feedback (follicle-stimulating hormone = 1,47 mUI/ml, luteinising hormone = 0,1 mUI/ml and total testosterone = 1,47 ng/ml). At the third moment (40 days after Time 2), we can see a tendency to recovery, however, the serum levels of the investigated hormones were still considerably lower than the baseline values. At the end, we could conclude that the use of anabolic-androgenic steroids, at supraphysiological dosages, even for a short time (8 weeks), causes severe disorder in the hypothalamic-pituitary-gonadal axis. The endogenous testosterone synthesis was severely compromised by important decline in serum luteinising hormone levels.

[Endocrinopathies induced by immune checkpoint inhibitors]. / Endocrinopathies induites par les inhibiteurs de points de contrôle immunitaire.

Immune checkpoint Inhibitors are new immunomodulatory treatments that have proven their anti-tumor efficacy in several advanced cancers. Nevertheless, their use has paved the way for multiple immunological adverse effects that affect many systems and organs including endocrine glands such as the pituitary, thyroid, adrenal and pancreas. Hypophysitis is the most common complication of anti-CTLA-4 monoclonal antibodies, while anti-PD-1 and anti-PD-L1 antibodies cause more thyroid complications. Adrenal insufficiency and type 1 diabetes are relatively less common. Endocrinologists and primary care physicians as well as oncologists are likely to deal with these complications and as such, knowledge of these drugs and their side effects is essential for good practice.

Les inhibiteurs de points de contrôle immunitaire sont des nouveaux traitements immunomodulateurs qui ont prouvé leur efficacité antitumorale dans plusieurs cancers avancés. Néanmoins, leur utilisation a ouvert la voie à de multiples effets indésirables immunologiques touchant plusieurs systèmes et organes dont les glandes endocrines comme l'hypophyse, la thyroïde, les surrénales et le pancréas. L'hypophysite constitue la complication la plus fréquente des anticorps monoclonaux anti-CTLA-4, alors que ceux anti-PD-1 et anti-PD-L1 provoquent plus de complications thyroïdiennes. Les insuffisances surrénaliennes et le diabète de type 1 sont relativement moins fréquents. Les endocrinologues et les médecins de premier recours, tout comme les oncologues, sont susceptibles de prendre en charge ces complications et de ce fait, une connaissance spécifique de ces médicaments et de leurs effets indésirables est indispensable à la bonne pratique.

Ipilimumab-induced hypophysitis: review of the literature.

PURPOSE: Ipilimumab is a human monoclonal antibody against cytotoxic T-lymphocyte antigen 4 available as an immunotherapy mainly for advanced melanoma. It induces an activation of T cells, resulting in an immune-mediated anti-tumor response and also immune-related adverse events, including hypophysitis. The aim of this review is to identify and discuss features concerning ipilimumab-induced hypophysitis (IIH). DESIGN: A MEDLINE research of all years of publication of IIH was conducted. We gathered information regarding clinical, radiologic and laboratory features of 71 cases recorded in the literature. RESULTS: In our review, IIH was more frequent among older and male patients. Fatigue and headache were the most frequent initial clinical manifestations of IIH and enlargement of the pituitary gland at MRI was present in the majority of patients. Those who received more than 3 cycles of ipilimumab had more fatigue (p = 0.04) and arthritis (p = 0.04). Adrenal insufficiency was more prevalent in men (p = 0.007). Glucocorticoid therapy and hormone replacement were required in most patients and pituitary function recovery was uncommon. Low prolactin at diagnosis tended to predict permanent pituitary dysfunction (p = 0.07). CONCLUSION: Hypopituitarism as a consequence of IIH, if not promptly recognized, can lead to potentially fatal events, such as adrenal insufficiency. IIH can be easily managed with glucocorticoids and hormonal replacement; therefore, physicians should be familiar with the key aspects of this condition. More studies to develop screening protocols and therapeutic intervention algorithms should be performed to decrease morbidity related to IIH.

Ipilimumab-induced hypophysitis and uveitis in a patient with metastatic melanoma and a history of ipilimumab-induced skin rash.

Ipilimumab, a monoclonal antibody that blocks cytotoxic T-lymphocyte-associated antigen-4, leading to enhanced T-cell activation and proliferation, is associated with improved overall survival in melanoma. Its use can result in immune-related adverse events, the most common of which are skin rash, diarrhea, and colitis. Ipilimumab-induced hypophysitis is uncommon, mostly involves anterior pituitary, and is associated with abnormalities in pituitary MRI, whereas uveitis has been rarely reported. These immune-related adverse events occur during therapy. This report describes a patient who developed uveitis and hypophysitis involving both anterior and posterior pituitary, without MRI findings more than 3 weeks after the fourth dose of ipilimumab. This case illustrates the unusual presentation of and diagnostic challenges associated with ipilimumab-induced immune-related adverse events.

Pituitary side effects of old and new drugs.

INTRODUCTION: Pituitary function is influenced by several drugs, including anti-depressant, opioids, glucocorticoids, chemotherapeutic agents, immunomodulators and the newly developed tyrosine kinase inhibitors. In most instances, treatment with these drugs negatively affects pituitary function, but in rare cases an activation of specific hypothalamic-pituitary axes may be observed. Several of the observed pituitary side effects are reversible after drug withdrawal, but pituitary function deficiency may persist long-term. In addition to the well known drugs, recent evidence shows that also non-steroidal anti-inflammatory drugs impair gonadal axis at pituitary level, while antipsychotic phenothiazines alter TSH response to TRH and TSH levels. Atypical antipsychotics may decrease TRH-stimulated TSH. Tricyclic antidepressant drugs interfere with the hypothalamo-pituitary-thyroid axis by decreasing TSH response to TRH. Anabolic-androgenic steroids, marijuana, cocaine, methamphetamines, and opioid narcotics negatively impact fertility, also acting at hypothalamic-pituitary level. CONCLUSIONS: Many of the drugs administered routinely in the intensive care unit significantly impact the hypothalamic-pituitary axis. Therefore, an increased awareness on pituitary side effects of drugs commonly used in clinical practice is necessary in order to rule out possible pharmacological interference when assessing patients with pituitary deficiencies.

Hypophysitis induced by monoclonal antibodies to cytotoxic T lymphocyte antigen 4: challenges from a new cause of a rare disease.

Specific human monoclonal antibodies antagonize cytotoxic T-lymphocyte antigen 4 (anti-CTLA-4 mAbs), a negative regulator of the immune system, inducing unrestrained T-cell activation. In patients with advanced or metastatic melanoma, one of these agents, ipilimumab, produced considerable disease control rates and, for the first time, a clear improvement in overall survival outcomes. However, accumulating clinical experience with anti-CTLA-4 mAbs identified a novel syndrome of autoimmune and autoinflammatory side effects, designated as "immune-related adverse events," including mainly rash, colitis, and hepatitis. Autoimmune hypophysitis has emerged as a distinctive side effect induced by anti-CTLA-4 mAbs. This condition may be life threatening because of adrenal insufficiency if not promptly recognized, but it may easily be diagnosed and treated if clinically suspected. Hypopituitarism caused by these agents is rarely reversible and prolonged or life-long substitutive hormonal treatment is often required. The precise mechanism of injury to the pituitary triggered by anti-CTLA-4 mAbs is yet to be fully elucidated.

Pituitary enlargement following ipilimumab without long term endocrine dysfunction.

Ipilimumab, a monoclonal antibody against CTLA-4, is used in the treatment of melanoma and renal cell cancer. Hypophysitis is one of the more common adverse events, usually presenting with headache, pituitary enlargement and hypopituitarism, mostly ACTH deficiency, which is usually permanent. We describe a series of 3 cases developing pituitary enlargement in keeping with hypophysitis after ipilimumab without any long-term pituitary hormone deficiencies. This illustrates that a comprehensive endocrine assessment is required even when pituitary enlargement is present.

Anti-pituitary antibodies and susceptible human leukocyte antigen alleles as predictive biomarkers for pituitary dysfunction induced by immune checkpoint inhibitors.

BACKGROUND: Pituitary dysfunction is a life-threatening immune-related adverse event (irAE) induced by immune checkpoint inhibitors (ICIs). To date, it is not possible to identify patients who may develop pituitary irAEs prior to ICI treatment. The aim of this study was to characterize the predisposition for ICI-induced pituitary irAEs by analyzing anti-pituitary antibodies (APAs) and human leukocyte antigens (HLAs). METHODS: In this case-control study, APAs and HLA alleles were analyzed in 62 patients (17 who developed ICI-induced isolated adrenocorticotropic hormone deficiency (ICI-IAD), 5 who developed ICI-induced hypophysitis (ICI-H) and 40 who did not develop pituitary irAEs) treated with ICIs between November 2, 2015, and March 31, 2020, at Nagoya University Hospital. The main outcome measures in this study were the association between the development of pituitary irAEs with APAs at baseline and after treatment and HLA alleles. RESULTS: Eleven of 17 (64.7%) patients who developed ICI-IAD had APAs at baseline, whereas APAs were positive only in 1 of 40 (2.5%) control patients. Although APAs were negative at baseline in all patients who developed ICI-H, they had become positive before the onset of ICI-H in 3 of 4 patients several weeks after ipilimumab administration. At the onset of ICI-IAD and ICI-H, APAs were positive in 15 of 17 (88.2%) and 4 of 5 (80%) patients, respectively. The prevalence of HLA-Cw12, HLA-DR15, HLA-DQ7, and HLA-DPw9 was significantly higher in patients with ICI-IAD, whereas that of HLA-Cw12 and HLA-DR15 was significantly higher in patients with ICI-H than in controls. CONCLUSIONS: This study showed distinct and overlapped patterns of APAs and HLA alleles between ICI-IAD and ICI-H. Our findings also showed that positive APAs at baseline and after treatment, together with susceptible HLA alleles, could become predictive biomarkers for ICI-IAD and ICI-H, respectively. TRIAL REGISTRATION NUMBER: UMIN000019024.

Anti-CTLA-4 antibody therapy associated autoimmune hypophysitis: serious immune related adverse events across a spectrum of cancer subtypes.

Anti-cytotoxic T-lymphocyte antigen-4 (CTLA-4) therapies represent a novel approach to cancer treatment via disruption of immune tolerance to antigens located on tumor cells. Disruption of immune tolerance, however, may occur at a cost. A host of immune related adverse events (IRAEs) are associated with anti-CTLA-4 therapy. Autoimmune hypophysitis has been reported in up to 17% of patients with melanoma and renal cell carcinoma treated with this therapy. Familiarity with the spectrum of IRAEs connected to these therapies is paramount for endocrinologists, oncologists and those involved in the care of these subjects. We review here key aspects of diagnosis and treatment of anti-CTLA-4 antibody therapy resultant IRAEs. We describe the first two cases of hypopituitarism in prostate cancer subjects undergoing experimental therapy with ipilimumab. The clinical evidence strongly suggests that the prostate cancer subjects developed autoimmune hypophysitis as a consequence of anti-CTLA-4 treatment. High dose glucocorticoid treatment resulted in markedly improved symptoms, and resolution of focal symptoms and diabetes insipidus. One subject recovered pituitary-thyroid axis function after 9 months; however, both continue to require GC replacement. These cases highlight the importance of early screening and treatment for hypopituitarism in all subjects undergoing treatment with anti-CTLA-4 therapy to prevent a potentially fatal outcome from secondary adrenal insufficiency, a readily treatable disease. We recommend mandatory long term follow-up to monitor the development of other hormonal deficits.

Pituitary dysfunction induced by immune checkpoint inhibitors is associated with better overall survival in both malignant melanoma and non-small cell lung carcinoma: a prospective study.

BACKGROUND: Several immune-related adverse events (irAEs) are reported to be associated with therapeutic efficacy of immune checkpoint inhibitors, yet whether pituitary dysfunction, a life-threatening irAE, affects overall survival (OS) in patients with malignancies is unclear. This prospective study examined the association of pituitary dysfunction (pituitary-irAE) with OS of patients with non-small cell lung carcinoma (NSCLC) or malignant melanoma (MM). METHODS: A total of 174 patients (NSCLC, 108; MM, 66) treated with ipilimumab, nivolumab, pembrolizumab, or atezolizumab at Nagoya University Hospital were evaluated for OS and the development of pituitary-irAE. Kaplan-Meier curves of OS as a function of the development of pituitary-irAE were produced with the log-rank test as a primary endpoint. RESULTS: Pituitary-irAE was observed in 16 patients (4 (3.7%) with NSCLC, 12 (18.2%) with MM) having two different disease types: hypophysitis with deficiency of multiple anterior pituitary hormones accompanied by pituitary enlargement, and isolated adrenocorticotropic hormone (ACTH) deficiency without pituitary enlargement. Among these patients, 6 developed pituitary-irAE while being treated with ipilimumab (6/25 patients (24.0%) treated with ipilimumab) and 10 developed pituitary-irAE during treatment with nivolumab or pembrolizumab (10/167 (6.0%)). All 16 patients had ACTH deficiency and were treated with physiological doses of hydrocortisone. The development of pituitary-irAE was associated with better OS in patients with NSCLC (not reached vs 441 (95% CI not calculated) days, p<0.05) and MM (885 (95% CI 434 to 1336) vs 298 (95% CI 84 to 512) days, p<0.05). CONCLUSIONS: In our study cohort, the incidence of pituitary-irAE was higher than previously reported and the development of pituitary-irAE predicted better prognosis for both NSCLC and MM when patients were treated with physiological doses of hydrocortisone. CLINICAL TRIALS REGISTRATION: UMIN000019024.

Light Microscopic Evaluation of Acute and Chronic Hypophyseal Endocrinopathy in a Kaolin-Induced Hydrocephalus Model.

AIM: To demonstrate progression of acute and chronic endocrinopathies in a kaolin-induced hydrocephalus model using light microscopy. MATERIAL AND METHODS: Adult male Sprague-Dawley rats (n = 48) were divided into six groups. Hydrocephalus was induced by intracisternal injection of kaolin solution in the acute and chronic kaolin groups, whereas an identical volume of sterile saline was injected into the sham groups. RESULTS: Somatotropic cell concentrations were lower in the kaolin groups compared with their controls, but there was no difference in somatotropic cell concentration between the acute and chronic kaolin groups. Corticotropic cell concentrations were higher in the acute kaolin and sham groups compared with acute controls. Thyrotropic cell numbers were higher in the acute sham and kaolin groups compared with their controls, and although thyrotropic cell concentations were higher in the acute kaolin group than the acute sham group. No differences were observed between the acute and chronic controls and sham and kaolin groups regarding mammotropicand gonadototropic cell concentations. CONCLUSION: Somatotropic cells are most affected by hydrocephalus that causes pituitary dysfunction, and this effect was more prominent under acute and chronic phases.

Pituitary-adrenal dysfunction caused by nivolumab for head and neck cancer.

Nivolumab exerts antitumor effects by inhibiting binding of PD-L1 to PD-1, and offers proven effectiveness in various disease areas, including cancers of the head and neck. The mechanisms of action lead nivolumab to induce immune-related adverse events (irAE). We report a case of pituitary-adrenal dysfunction to isolated adrenocorticotropic hormone (ACTH) deficiency as an irAE of nivolumab in a patient treated for head and neck cancer. This is the first report of an irAE of nivolumab in the field of head and neck squamous cell cancer. The patient was a man in his 50s with cancer of the tongue and hypopharynx that recurred after chemoradiotherapy, surgery and chemotherapy. After starting nivolumab, irAEs developed after 8 courses. The case was managed from the early stages in collaboration with the endocrinology department. Pituitary-adrenal hypofunction due to isolated ACTH deficiency was diagnosed on the basis of endocrine tests. The patient responded to hydrocortisone replacement therapy and has been able to continue treatment with nivolumab while continuing oral hydrocortisone. Although irAEs involving pituitary gland disorders are rare, these events can become life-threatening when severe. Early diagnosis and treatment are essential and require regular blood sampling and collaboration with specialists from an early stage.

Characteristics and relative numbers of lethal snake bite cases in medicolegal practice in central Myanmar - A five year study.

Clinical and pathological case files of lethal snakebites were reviewed from the Magway Region General Hospital, Magway, Myanmar, over a five-year period (January 2013 December 2017). A total of 2069 postmortem examinations were performed which included 84 cases of lethal snake bite (4.1%). The annual numbers ranged from 10 out of a total of 268 autopsies in 2013 (3.7%), to 31 out of a total of 501 autopsies in 2016 (6.2%). There were 54 males (64%) and 30 females (36%) (M:F = 1.9:1; age range 5-75yrs, mean 33yrs). The most common time for lethal envenomation was August (16/84-19%), the middle of the monsoon season. 45/84 (54%) had acute renal failure, 27/84 (32%) were shocked, and the remaining 12/84 (14%) had disseminated intravascular coagulation. Twenty cases (24%) died within 24 h after envenomation. Fang marks were identified on the legs (either right or left) in 73/84 cases (87%) and on the arms in five cases (6%). The predominant findings at autopsy were of acute renal injury (82/84-98%), pituitary haemorrhage/necrosis (36/84-43%), and adrenal gland haemorrhage (30/84-36%). Despite the reduction in fatalities over the years snakebite from Russell's viper in particular remains an important contributor to mortality in central Myanmar despite the availability of antivenom.

Effect of long-term cabergoline therapy on the immunological pattern and pituitary function of patients with idiopathic hyperprolactinaemia positive for antipituitary antibodies.

OBJECTIVE: The occurrence of antipituitary antibodies (APA) in patients with idiopathic hyperprolactinaemia (IH) and the effects of dopamine agonists on these antibodies and long-term pituitary function outcome have been so far not evaluated. This longitudinal study was aimed at investigating, in patients with IH the occurrence of APA and the effect of cabergoline on the pituitary function and behaviour of APA. DESIGN: Sixty-six patients with IH were studied. APA (by indirect immunofluorescence) and pituitary function were investigated every year for 3 years. RESULTS: Seventeen patients resulted APA positive (Group 1) and 49 APA negative (Group 2). Eight patients of Group 1 (Group 1a) and 24 of Group 2 (Group 2a) were asymptomatic and then not treated; instead, nine patients in Group 1 (Group 1b) and 25 in Group 2 (Group 2b), showing symptoms of hyperprolactinaemia, were treated with cabergoline for 2 years. Among the untreated patients, during the follow-up, those with APA positive (Group 1a) showed an increase of APA titres and PRL levels with partial pituitary impairment in some of them; instead those with APA negative (Group 2a) persisted negative with normal pituitary function despite persistent hyperprolactinaemia. Among the treated patients, those with APA positive (Group 1b) showed normalization of PRL levels, APA disappearance and recovery of pituitary function (when initially impaired) during cabergoline treatment, persisting also at last observation (off-therapy). Instead all patients of Group 2b persisted with APA negative during the follow-up with normalization of PRL levels and stable normal pituitary function during cabergoline therapy but showing a further increase of PRL at the last observation. CONCLUSIONS: The presence of APA in some patients with IH suggests a possible occurrence of autoimmune hypophysitis at potential/subclinical stage; an early and prolonged cabergoline therapy could interrupt the progression to an overt clinical stage of the disease. However, the small amount of patients investigated suggests caution against generalization of our assumption and prompts to further controlled studies on a more numerous population to verify these conclusions.

Effects of treadmill exercise on hypoactivity of the hypothalamo-pituitary-adrenal axis induced by chronic administration of corticosterone in rats.

The stress response alters behavior, autonomic function and secretion of multiple hormones, including CRF, ACTH, and glucocorticoid, through the HPA axis. Consecutive stress exposures lead to HPA axis dysregulation such as hyperactivity in Alzheimer's disease and depression, and hypoactivity in post-traumatic stress disorder. In the present study, we established a model of hypoactivated HPA axis in rat through chronic administration of corticosterone (40mg/kg, s.c.) for 19 consecutive days. In this model, CRF mRNA expression in the hypothalamus and ACTH levels in serum were significantly decreased by chronic administration of corticosterone. In addition, the effect of treadmill exercise was investigated in our hypoactivated HPA axis rat model. Treadmill exercise recovered the dysregulated hypoactivity of the HPA axis induced by corticosterone administration for 19 days. The results of the present study suggest that treadmill exercise may aid recovery of hypoactivated HPA axis dysregulation in psychological diseases such as post-traumatic stress disorder.

24-Hour rhythm in gene expression of nitric oxide synthase and heme-peroxidase in anterior pituitary of ethanol-fed rats.

Chronic exposure of rats to ethanol results in significant changes in pituitary hormone secretion. However, identification of the site(s) and mechanism of action of ethanol to induce these effects remains elusive. Free radical damage at the adenohypophyseal level may play a role in the decline in serum gonadotropin levels in ethanol-fed rats. Since 24-h changes in redox state occurred, we analyzed the 24-h changes in pituitary gene expression of the prooxidant enzymes nitric oxide synthase (NOS) 1 and 2, and of heme oxygenase-1 (HO-1) enzyme, and in plasma NO(2)(-) and NO(3)(-) (NO(x)) levels, in ethanol and control rats. Male rats, 35-day-old, received a liquid diet for 4 weeks. The ethanol-fed group received a similar diet to controls except for that maltose was isocalorically replaced by ethanol. Animals were killed at six time intervals during a 24-h cycle. Anterior pituitary mRNA levels encoding NOS1, NOS2 and HO-1 were measured by real-time PCR analysis. Plasma NO(x) concentration was determined by the Griess reaction. Ethanol feeding of prepubertal rats changed significantly the 24-h pattern of expression of NOS1, NOS2 and HO-1 in the adenohypophysis and augmented NOS2 and HO-1 mRNA levels. Peak values for the three enzymes in ethanol-fed rats occurred at the beginning of the scotophase (i.e., at 21:00 h). Ethanol feeding augmented mean values plasma NO(x) levels with a maximum at 13:00 h while in controls a biphasic pattern was observed, with peaks at 09:00 h and 17:00-21:00 h. One of the mechanisms by which ethanol augments oxidative damage in the adenohypophysis may include overproduction of nitric oxide and carbon monoxide.