The Changing Clinical Spectrum of Hypophysitis

The Growing Understanding of the Pituitary Implication in the Pathogenesis of Long COVID-19 Syndrome: A Narrative Review

Long COVID-19, also known as post-acute sequelae of SARS-CoV-2 infection, is a condition where individuals who have recovered from the acute phase of COVID-19 continue to experience a range of symptoms for weeks or even months afterward. While it was initially thought to primarily affect the respiratory system, it has become clear that Long COVID-19 can involve various organs and systems, including the endocrine system, which includes the pituitary gland. In the context of Long COVID-19, there is a growing understanding of the potential implications for the pituitary gland. The virus can directly affect the pituitary gland, leading to abnormalities in hormone production and regulation. This can result in symptoms such as fatigue, changes in appetite, and mood disturbances. Long COVID-19, the persistent and often debilitating condition following acute COVID-19 infection, may be explained by deficiencies in ACTH and Growth hormone production from the pituitary gland. Corticotropin insufficiency can result in the dysregulation of the body's stress response and can lead to prolonged feelings of stress, fatigue, and mood disturbances in Long COVID-19 patients. Simultaneously, somatotropin insufficiency can affect growth, muscle function, and energy metabolism, potentially causing symptoms such as muscle weakness, exercise intolerance, and changes in body composition. Recently, some authors have suggested the involvement of the pituitary gland in Post COVID-19 Syndrome. The exact mechanisms of viral action on infected cells remain under discussion, but inflammatory and autoimmune mechanisms are primarily implicated. The aim of our study will be to review the main pituitary complications following COVID-19 infection. Moreover, we will explain the possible involvement of the pituitary gland in the persistence of Post COVID-19 Syndrome.

Explaining Long COVID: A Pioneer Cross-Sectional Study Supporting the Endocrine Hypothesis

Context

In some patients, symptoms may persist after COVID-19, defined as long COVID. Its pathogenesis is still debated and many hypotheses have been raised.

Objective

Our primary objective was to evaluate the corticotroph and somatotroph functions of patients previously infected with SARS-CoV-2 and experiencing post-COVID-19 syndrome to detect any deficiencies that may explain long COVID.

Methods

A cross-sectional study was conducted including patients who had previously contracted SARS-CoV-2 with a postinfection period of 3 months or less to 15 months, divided into 2 groups. The first group (G1) comprised fully recovered patients, while the second group (G2) included patients experiencing long COVID. The primary outcome was the comparison of corticotroph and somatotroph functions.

Results

A total of 64 patients were divided into 2 groups, each consisting of 32 patients. G2 exhibited more frequently anterior pituitary deficits compared to G1 (P = .045): for the corticotroph axis (G1: 6.3% vs G2: 28.1%) and for the somatotroph axis (G1: 31.3% vs G2: 59.4%). Baseline cortisol level was significantly lower in G2 (G1: 13.37 µg/dL vs G2: 11.59 µg/dL) (P = .045). The peak cortisol level was also lower in G2 (G1: 23.60 µg/dL vs G2: 19.14 µg/dL) (P = .01). For the somatotroph axis, the insulin growth factor-1 level was lower in G2 (G1: 146.03 ng/mL vs G2: 132.25 ng/mL) (P = .369). The peak growth hormone level was also lower in G2 (G1: 4.82 ng/mL vs G2: 2.89 ng/mL) (P = .041).

Conclusion

The results showed that long COVID patients in our cohort were more likely to have anterior pituitary deficiencies. The endocrine hypothesis involving anterior pituitary insufficiency can be considered to explain long COVID.

From Genes to Therapy: Pituitary Adenomas in the Era of Precision Medicine

This review presents a comprehensive analysis of pituitary adenomas, a type of brain tumor with diverse behaviors and complexities. We cover various treatment approaches, including surgery, radiotherapy, chemotherapy, and their integration with newer treatments. Key to the discussion is the role of biomarkers in oncology for risk assessment, diagnosis, prognosis, and the monitoring of pituitary adenomas. We highlight advances in genomic, epigenomic, and transcriptomic analyses and their contributions to understanding the pathogenesis and molecular pathology of these tumors. Special attention is given to the molecular mechanisms, including the impact of epigenetic factors like histone modifications, DNA methylation, and transcriptomic changes on different subtypes of pituitary adenomas. The importance of the tumor immune microenvironment in tumor behavior and treatment response is thoroughly analyzed. We highlight potential breakthroughs and innovations for a more effective management and treatment of pituitary adenomas, while shedding light on the ongoing need for research and development in this field to translate scientific knowledge into clinical advancements, aiming to improve patient outcomes.

Unveiling the Etiopathogenic Spectrum of Hypophysitis: A Narrative Review

Hypophysitis, a rare inflammatory disorder of the pituitary gland, has seen an uptick in reported cases in recent years. Our objective is to summarize the most recent research on the etiopathogenesis, molecular mechanisms, and genetics of both primary and secondary hypophysitis. Primary autoimmune hypophysitis (PAH): During the acute phase of the disease, the pituitary gland in enlarged due to the infiltration of T and B lymphocytes. The chronic phase is characterized by progressive and irreversible pituitary atrophy. APA may play a role in the management, diagnosis, and prognosis of PAH. Specific autoantibodies such as anti-GH, anti-PIT-1, and anti-T-PIT have been found in patients with hypophysitis and hypopituitarism. A recent study suggested that a mechanism of escaping clonal deletion and mounting an immune response against self antigens can explain the unusual nature of the immune response observed in PAH patients. A cytokine array shows the presence of gamma-interferon and interleukin-17. Patients carrying mutations in the PIT1 or PROP1 genes may present PAH. Individuals carrying the HLA DQ8 haplotype are four times more likely to develop PAH. Immune checkpoint inhibitors induce hypophysitis (IIHs): IIHs is an increasingly frequent toxicity of in patients on treatment with inhibitors targeting cytotoxic T-lymphocyte antigen 4 (CTLA-4) and programmed cell death-1 (PD-1). ICIs inhibit the CTLA-4 pathway, leading to overactivation of T lymphocytes. The binding of PD-1/PD-L1 suppresses the activity of T cells, promotes the conversion of T-helpers into T-regulatory cells, and activates pro-survival signaling pathways in cancer cells. Cytokines play a crucial role in IIHs. B-cell infiltration has been observed in IIHs, suggesting that antibody-mediated pituitary injury may contribute. Genetic polymorphisms of CTLA-4 and PD-1 genes can increase the risk of IIHs. HLA alleles may also be involved in the onset of IIHs; this HLA association presents a possible alternative mechanistic hypothesis. IIHs may also be linked to a paraneoplastic syndrome triggered by ectopic expression of pituitary specific antigens. SARS-CoV-2-related hypophysitis: Recently, the literature has reported occurrences of hypophysitis associated with the SARS-CoV-2 virus; long COVID-19 may also present as infundibulo-neuro-hypophysitis. The virus enters the central nervous system because of its distinct interaction with angiotensin-converting enzyme receptors via spike proteins binding the capillary endothelium, and it directly damages the pituitary cells. The effect of SARS-CoV-2 can occur indirectly through inflammation and the release of cytokines. The exact mechanism remains ambiguous. The available data on endocrine complications associated with the SARS-CoV-2 vaccine are scant. Nonetheless, isolated cases of hypophysitis have been documented. Treatment of hypophysitis: Glucocorticoids are the cornerstone in managing primary hypophysitis, given their targeted action on inflammation. A better understanding of the etiopathogenesis and molecular mechanism of hypophysitis can lead to more effective and personalized treatment strategies.

The immune microenviroment in somatotropinomas: from biology to personalized and target therapy

Pituitary tumors are rare neoplasms, with a heterogeneous biological and clinical behavior, due to their clinical course, local invasive growth, resistance to conventional therapies and the risk of disease progression. Recent studies on tumor microenvironment (TME) provided new knowledge on the biology of these neoplasia, that may explain the different phenotypes of these tumors and suggest new biomarkers able to predict the prognosis and the treatment outcome. The identification of molecular markers that act as targets for biological therapies may open new perspectives in the medical treatments of aggressive pituitary tumors.In this paper, we will review data of TME and target therapies in somatotropinomas.

Executive summary of the consensus document on hypophysitis of the Neuroendocrinology Area of Knowledge of the Spanish Society of Endocrinology and Nutrition

The term hypophysitis is used to designate a heterogeneous group of pituitary conditions characterized by the presence of inflammatory infiltration of the adenohypophysis, neurohypophysis, or both. Although hypophysitis are rare disorders, the most common in clinical practice is lymphocytic hypophysitis, a primary hypophysitis characterized by lymphocytic infiltration, which predominantly affects women. Other forms of primary hypophysitis are associated with different autoimmune diseases. Hypophysitis can also be secondary to other disorders such as sellar and parasellar diseases, systemic diseases, paraneoplastic syndromes, infections, and drugs, including immune checkpoint inhibitors. The diagnostic evaluation should always include pituitary function tests and other analytical tests based on the suspected diagnosis. Pituitary magnetic resonance imaging is the investigation of choice for the morphological assessment of hypophysitis. Glucocorticoids are the mainstay of treatment for most symptomatic hypophysitis.

Isolated anterior pituitary dysfunction in adulthood

Hypopituitarism is defined as a complete or partial deficiency in one or more pituitary hormones. Anterior hypopituitarism includes secondary adrenal insufficiency, central hypothyroidism, hypogonadotropic hypogonadism, growth hormone deficiency and prolactin deficiency. Patients with hypopituitarism suffer from an increased disability and sick days, resulting in lower health status, higher cost of care and an increased mortality. In particular during adulthood, isolated pituitary deficits are not an uncommon finding; their clinical picture is represented by vague symptoms and unclear signs, which can be difficult to properly diagnose. This often becomes a challenge for the physician. Aim of this narrative review is to analyse, for each anterior pituitary deficit, the main related etiologies, the characteristic signs and symptoms, how to properly diagnose them (suggesting an easy and reproducible step-based approach), and eventually the treatment. In adulthood, the vast majority of isolated pituitary deficits are due to pituitary tumours, head trauma, pituitary surgery and brain radiotherapy. Immune-related dysfunctions represent a growing cause of isolated pituitary deficiencies, above all secondary to use of oncological drugs such as immune checkpoint inhibitors. The diagnosis of isolated pituitary deficiencies should be based on baseline hormonal assessments and/or dynamic tests. Establishing a proper diagnosis can be quite challenging: in fact, even if the diagnostic methods are becoming increasingly refined, a considerable proportion of isolated pituitary deficits still remains without a certain cause. While isolated ACTH and TSH deficiencies always require a prompt replacement treatment, gonadal replacement therapy requires a benefit-risk evaluation based on the presence of comorbidities, age and gender of the patient; finally, the need of growth hormone replacement therapies is still a matter of debate. On the other side, prolactin replacement therapy is still not available. In conclusion, our purpose is to offer a broad evaluation from causes to therapies of isolated anterior pituitary deficits in adulthood. This review will also include the evaluation of uncommon symptoms and main etiologies, the elements of suspicion of a genetic cause and protocols for diagnosis, follow-up and treatment.

Molecular and cellular mechanisms involved in tissue-specific metabolic modulation by SARS-CoV-2

Coronavirus disease 2019 (COVID-19) is triggered by the SARS-CoV-2, which is able to infect and cause dysfunction not only in lungs, but also in multiple organs, including central nervous system, skeletal muscle, kidneys, heart, liver, and intestine. Several metabolic disturbances are associated with cell damage or tissue injury, but the mechanisms involved are not yet fully elucidated. Some potential mechanisms involved in the COVID-19-induced tissue dysfunction are proposed, such as: (a) High expression and levels of proinflammatory cytokines, including TNF-α IL-6, IL-1β, INF-α and INF-β, increasing the systemic and tissue inflammatory state; (b) Induction of oxidative stress due to redox imbalance, resulting in cell injury or death induced by elevated production of reactive oxygen species; and (c) Deregulation of the renin-angiotensin-aldosterone system, exacerbating the inflammatory and oxidative stress responses. In this review, we discuss the main metabolic disturbances observed in different target tissues of SARS-CoV-2 and the potential mechanisms involved in these changes associated with the tissue dysfunction.

Hypophysitis

OBJECTIVE

Hypophysitis is considered a rare inflammatory disease of the pituitary gland. For a long time, primary autoimmune hypophysitis has stood out as the most relevant type of hypophysitis. However, with the advent of immunotherapy for the treatment of malignancies and identification of hypophysitis as an immune-related adverse event, hypophysitis has garnered increasing interest and recognition. Therefore, awareness, early recognition, and appropriate management are becoming important as the indication for immunomodulatory therapies broaden.

METHODS

In this review, we discuss the epidemiology, diagnosis, and treatment of hypophysitis with a focus on recent data and highlight subtypes of particular interest while recognizing the gaps in knowledge that remain.

RESULTS

Regardless of cause, symptoms and signs of hypophysitis may be related to mass effect (headache and visual disturbance) and hormonal disruption that warrant prompt evaluation. In the vast majority of cases, a diagnosis of hypophysitis can be made presumptively in the appropriate clinical context with radiologic findings consistent with hypophysitis and after the exclusion of other causes.

CONCLUSION

Although subtle differences currently exist in management and outcome expectations between primary and secondary causes of hypophysitis, universally, treatment is aimed at symptom management and hormonal replacement therapy.

Assessment of Neuroendocrine Changes and Hypothalamo-Pituitary Autoimmunity in Patients with COVID-19

SARS-CoV-2 may affect the hypothalamic-pituitary axis and pituitary dysfunction may occur. Therefore, we investigated neuroendocrine changes, in particular, secondary adrenal insufficiency, using a dynamic test and the role of autoimmunity in pituitary dysfunction in patients with COVID-19. The single-center, prospective, case-control study included patients with polymerase chain reaction (PCR)-confirmed COVID-19 and healthy controls. Basal hormone levels were measured, and the adrenocorticotropic hormone (ACTH) stimulation test was performed. Antipituitary (APA) and antihypothalamic antibodies (AHA) were also determined. We examined a total of 49 patients with COVID-19 and 28 healthy controls. The frequency of adrenal insufficiency in patients with COVID-19 was found as 8.2%. Patients with COVID-19 had lower free T₃, IGF-1, and total testosterone levels, and higher cortisol and prolactin levels when compared with controls. We also demonstrated the presence of APA in three and AHA in one of four patients with adrenal insufficiency. In conclusion, COVID-19 may result in adrenal insufficiency, thus routine screening of adrenal functions in these patients is needed. Endocrine disturbances in COVID-19 are similar to those seen in acute stressful conditions or infections. Pituitary or hypothalamic autoimmunity may play a role in neuroendocrine abnormalities in COVID-19.

The changing clinical spectrum of endocrine adverse events in cancer immunotherapy

Immune checkpoint inhibitors (ICIs) have revolutionized the treatment of several malignancies, improving patient survival and quality of life. Endocrinopathies have emerged as a clinically significant group of immune-related adverse events (IRAEs). Although the mechanism of ICI toxicities has not been clarified, inhibition of immune checkpoints reduces immune tolerance to autoantigens, resulting in the development of autoimmunity disorders. We report current evidence regarding endocrine IRAEs that may have diagnostic and therapeutic implications. Management should be focused on a multidisciplinary approach to reach a prompt diagnosis and an appropriate and safe treatment.

[Clinical and radiological diagnosis of hypophysitis: a review of literature and own data]

This article presents a literature review of the various forms of hypophysitis, its varieties, as well as the problem of radiation diagnosis and treatment of this pathology. Hypophysitis is a poorly understood and multifactorial disease which the difficulty of diagnosing is not only to a variety of nonspecific clinical manifestations and hormonal research data, but also the ambiguous results of MRI studies, the lack of clear MR patterns. The article reflects the main histological types of hypophysitis, the peculiarities of diagnosis in connection with general clinical symptoms, outlines the features of each type of hypophysitis with their own clinical observations. This review is devoted to modern ideas about the clinical course of hypophysitis, presented a set of characteristic diagnostic signs of the disease according to MRI and the treatment algorithms recommended today are also highlighted. The article summarizes data from foreign literature and our own clinical observations in order to develop an optimal protocol for MRI studies in patients with suspected hypophysitis, to develop recommendations for radiologists and endocrinologists for the correct results interpretation. The uniqueness of this review is the lack of data on the clinic, diagnosis and treatment of hypophysitis in the Russian literature today.

Early Pulse Glucocorticoid Therapy and Improved Hormonal Outcomes in Primary Hypophysitis

INTRODUCTION

The role of glucocorticoids in primary autoimmune hypophysitis (PAH) has been fraught with variability in regimens, leading to inconsistent outcomes in terms of anterior pituitary (AP) hormonal recovery. Hence, we aimed to compare the clinical, hormonal, and radiological outcomes of a standardized high-dose glucocorticoid therapy group (GTG) in PAH with a matched clinical observation group (COG).

METHODS

Thirty-nine retrospective patients with PAH evaluated and treated at a single center in western India from 1999 to 2019 with a median follow-up duration of 48 months were subdivided into the GTG (n = 18) and COG (n = 21) and compared for the outcomes.

RESULTS

Baseline demographic, hormonal, and radiological features matched between the groups, except pituitary height, which was significantly higher in GTG. Cortisol, thyroid, and gonadal axes were affected in 25 (64%), 22 (56%), and 21 (54%) patients, respectively, and central diabetes insipidus was seen in 7 (18%) patients. Panhypophysitis (PH) was the most common radiological subtype (n = 33, 84.6%). Resolution of mass effects was similar in both groups. Overall and complete AP hormonal recovery was significantly higher in the GTG than in the COG (12/14 [85.7%) vs. 6/14 [42.8%], p = 0.02; 10/14 [71.4%] vs. 1/14 [7.7%], p = 0.0007, respectively). Proportion of cases with empty sella were significantly higher in the COG (9/20 [45%] vs 1/17 [5.9%], p = 0.001). Among PH patients in the GTG (n = 17), we found duration from symptoms onset to treatment as the predictor of recovery.

CONCLUSION

In a PH subtype-predominant PAH cohort, a standardized high-dose glucocorticoid regimen resulted in higher overall and complete AP hormonal recovery than that in the COG. Initiation of glucocorticoids in the early disease course may have been contributory.

Recurrent autoimmune hypophysitis treated with rituximab: a case report

Background

Autoimmune hypophysitis is a rare condition that often results in enlargement of the pituitary gland and hypopituitarism due to inflammatory infiltration. Management of autoimmune hypophysitis can include long-term hormonal replacement and close control of the inflammatory pituitary mass. Mass-related symptoms in patients with autoimmune hypophysitis are treated with anti-inflammatory therapy, surgery, and/or radiotherapy.

Case presentation

We present a 25-year-old White man with visual field defects of the right eye, headache, and weight loss. Magnetic resonance imaging showed a sellar mass, and the patient underwent transcranial surgery. Histopathology revealed autoimmune hypophysitis with predominantly CD20 positive B-cell infiltration. Progression of visual field defects necessitated postoperatively anti-inflammatory treatment with prednisolone. Azathioprine was initiated under gradual tapering of prednisolone with stable conditions at first, but relapse followed after dose reduction. Therefore, rituximab treatment was initiated, which resulted in regression of the pituitary mass. Rituximab treatment was discontinued after 25 months. The patient has continuously been in remission for 4 years after rituximab treatment was stopped.

Conclusion

This case illustrates that rituximab might be an effective alternative treatment in B-cell predominant autoimmune hypophysitis.

Molecular and Genetic Immune Biomarkers of Primary and Immune-Therapy Induced Hypophysitis: From Laboratories to the Clinical Practice

Hypophysitis is a rare and potentially life-threatening disease, characterized by an elevated risk of complications, such as the occurrence of acute central hypoadrenalism, persistent hypopituitarism, or the extension of the inflammatory process to the neighboring neurological structures. In recent years, a large number of cases has been described. The diagnosis of hypophysitis is complex because it is based on clinical and radiological criteria. Due to this, the integration of molecular and genetic biomarkers can help physicians in the diagnosis of hypophysitis and play a role in predicting disease outcome. In this paper, we review current knowledge about molecular and genetic biomarkers of hypophysitis with the aim of suggesting a possible integration of these biomarkers in clinical practice.

Early and late endocrine complications of COVID-19

Endocrine system plays a vital role in controlling human homeostasis. Understanding the possible effects of COVID-19 on endocrine glands is crucial to prevent and manage endocrine disorders before and during hospitalization in COVID-19-infected patients as well as to follow them up properly upon recovery. Many endocrine glands such as pancreas, hypothalamus and pituitary, thyroid, adrenal glands, testes, and ovaries have been found to express angiotensin-converting enzyme 2 receptors, the main binding site of the virus. Since the pandemic outbreak, various publications focus on the aggravation of preexisting endocrine diseases by COVID-19 infection or the adverse prognosis of the disease in endocrine patients. However, data on endocrine disorders both during the phase of the infection (early complications) and upon recovery (late complications) are scarce. The aim of this review is to identify and discuss early and late endocrine complications of COVID-19. The majority of the available data refer to glucose dysregulation and its reciprocal effect on COVID-19 infection with the main interest focusing on the presentation of new onset of diabetes mellitus. Thyroid dysfunction with low triiodothyronine, low thyroid stimulating hormone, or subacute thyroiditis has been reported. Adrenal dysregulation and impaired spermatogenesis in affected men have been also reported. Complications of other endocrine glands are still not clear. Considering the recent onset of COVID-19 infection, the available follow-up data are limited, and therefore, long-term studies are required to evaluate certain effects of COVID-19 on the endocrine glands.

Early and late endocrine complications of COVID-19

Endocrine system plays a vital role in controlling human homeostasis. Understanding the possible effects of COVID-19 on endocrine glands is crucial to prevent and manage endocrine disorders before and during hospitalization in COVID-19-infected patients as well as to follow them up properly upon recovery. Many endocrine glands such as pancreas, hypothalamus and pituitary, thyroid, adrenal glands, testes, and ovaries have been found to express angiotensin-converting enzyme 2 receptors, the main binding site of the virus. Since the pandemic outbreak, various publications focus on the aggravation of preexisting endocrine diseases by COVID-19 infection or the adverse prognosis of the disease in endocrine patients. However, data on endocrine disorders both during the phase of the infection (early complications) and upon recovery (late complications) are scarce. The aim of this review is to identify and discuss early and late endocrine complications of COVID-19. The majority of the available data refer to glucose dysregulation and its reciprocal effect on COVID-19 infection with the main interest focusing on the presentation of new onset of diabetes mellitus. Thyroid dysfunction with low triiodothyronine, low thyroid stimulating hormone, or subacute thyroiditis has been reported. Adrenal dysregulation and impaired spermatogenesis in affected men have been also reported. Complications of other endocrine glands are still not clear. Considering the recent onset of COVID-19 infection, the available follow-up data are limited, and therefore, long-term studies are required to evaluate certain effects of COVID-19 on the endocrine glands.

Markers of humoral and cell-mediated immune response in primary autoimmune hypophysitis: a pilot study

INTRODUCTION

Primary autoimmune hypophysitis (PAHs) is a rare inflammatory disease of the pituitary gland. Although largely investigated, the pathogenesis of PAH is not completely clarified. We aimed to investigate the immune response in PAHs.

MATERIAL AND METHODS

Serum anti-pituitary and anti-hypothalamus antibodies (respectively APAs and AHAs) were investigated though an indirect immunofluorescence on monkey hypophysis and hypothalamus slides, serum cytokines though an array membrane and cell-mediated immunity though the white blood cells count.

RESULTS

Nineteen PAH cases entered the study. APA or AHA were identified in all cases. APA were detected in 13 patients (68.4%) and AHA in 13 patients (68.4%). Ten patients (52.6%) were simultaneously positive for both APA and AHA. The prevalence of APAs and AHAs was higher as compared to those observed in 50 health controls (respectively 14% p < 0.001 and 24% p = 0.004) and in 100 not-secreting pituitary adenoma (NFPAs) (respectively 22% p = 0.002 and 8% p < 0.001). Similarly, the prevalence of simultaneous positivity for APA and AHA (52.9%) was higher as compared to the those detected in patients affected by NFPAs (0%; p < 0.001) and in health controls (16% p = 0.002). No differences were identified between PAHs and controls at qualitative and quantitative analysis of serum cytokines and white blood cells count.

CONCLUSIONS

This study suggest that APA and AHA may be detected in an high percentage of PAH cases and that their simultaneous identification may be useful for the differential diagnosis between PAH and NFPAs, in an appropriate clinical context.

COVID-19 and the pituitary

BACKGROUND

Despite COVID-19 being identified as severe respiratory viral infection, progressively many relevant endocrine manifestations have been reported greatly contributing to the severity of the clinical presentation. Systemic involvement in COVID-19 is due to the ubiquitous expression of angiotensin-converting enzyme 2 (ACE2) receptor, responsible for the entry in the cells of SARS-CoV-2, Several reports in humans and animal models showed a significant ACE2 mRNA expression in hypothalamus and pituitary cells. Moreover, higher mortality and poorer outcomes have been widely described in COVID-19 patients with obesity, diabetes and vertebral fractures, which are all highly prevalent in subjects with pituitary dysfunctions.

AIM

To review the main endocrine manifestations of COVID-19 with their possible implications for pituitary diseases, the possible direct and indirect involvement of the pituitary gland in COVID-19, the impact of COVID-19 on the management of established pituitary diseases which can be already at increased risk for worse outcomes and on neurosurgical activities as well as vaccination.

CONCLUSIONS

Our review underlines that there could be a specific involvement of the pituitary gland which fits into a progressively shaping endocrine phenotype of COVID-19. Moreover, the care for pituitary diseases need to continue despite the restrictions due to the emergency. Several pituitary diseases, such as hypopituitarism and Cushing disease, or due to frequent comorbidities such as diabetes may be a risk factor for severe COVID-19 in affected patients. There is the urgent need to collect in international multicentric efforts data on all these aspects of the pituitary involvement in the pandemic in order to issue evidence driven recommendations for the management of pituitary patients in the persistent COVID-19 emergency.

COVID-19 and endocrine and metabolic diseases. An updated statement from the European Society of Endocrinology

BACKGROUND

COVID-19 has completely changed our daily clinical practice as well as our social relations. Many organs and biological systems are involved in SARS-Cov-2 infection, either due to direct virus-induced damage or to indirect effects that can have systemic consequences. Endocrine system is not only an exception but its involvement in COVID-19 is so relevant that an "endocrine phenotype" of COVID-19 has progressively acquired clinical relevance.

AIM

We have been appointed by the European Society of Endocrinology (ESE) to update with the current statement ESE members and the whole endocrine community on the emerging endocrine phenotype of COVID-19 and its implication for the prevention and management of the disease.

CONCLUSIONS

Diabetes has a major role in this phenotype since it is one of the most frequent comorbidities associated with severity and mortality of COVID-19. Careful management including treatment modifications may be required for protecting our patients rather with known diabetes from the most dangerous consequences of COVID-19 or hospitalized with COVID-19, but also in patients with SARS-CoV-2 induced newly onset diabetes. Obesity increases susceptibility to SARS-CoV-2 and the risk for COVID-19 adverse outcome. Adequate nutritional management needs to be granted to patients with obesity or undernourishment in order to limit their increased susceptibility and severity of COVID-19 infection. Lack of vitamin D, hypocalcemia and vertebral fractures have also emerged as frequent findings in the hospitalized COVID-19 population and may negatively impact on the outcome of such patients. Also, in patients with adrenal insufficiency prompt adaptation of glucocorticoid doses may be needed. Moreover, in this updated statement role of sex hormones as well as peculiar pituitary and thyroid aspects of COVID-19 have been included. Finally, in view of the mass vaccination, potential implications for endocrine patients should be considered.

Central adrenal insufficiency and diabetes insipidus as potential endocrine manifestations of COVID-19 infection: a case report

SARS-CoV-2 infection, responsible for the coronavirus disease-2019 (COVID-19) has rapidly spread, causing a global pandemic. COVID-19 can affect any organ system in the body due to overwhelming dysregulated immune response and long-term effects of the disease is still unknown. Endocrine complications associated with COVID-19 is exceedingly rare. Here we present a unique case of a 44-year-old female who developed adrenal insufficiency and central diabetes insipidus following COVID-19 infection.

Magnetic resonance imaging of the hypothalamo-pituitary region

The diagnosis and management of mass lesions in the sellar and parasellar areas remain challenging. When approaching patients with possible sellar or hypothalamic masses, it is important not only to focus on imaging but also detect possible pituitary hormone deficits or excess, in order to establish an appropriate diagnosis and initiate treatment. The imaging modalities used to characterize hypothalamic and pituitary lesions have significantly evolved over the course of the past several years. Computed tomography (CT) and CT angiography play a major role in detecting various sellar lesions, especially in patients who have contraindications to magnetic resonance imaging (MRI) and can also yield important information for surgical planning. However, MRI has become the gold standard for the detection and characterization of hypothalamic and pituitary tumors, infections, cystic, or vascular lesions. Indeed, the imaging characteristics of hypothalamic and sellar lesions can help narrow down the differential diagnosis preoperatively. In addition, MRI can help establish the relationship of mass lesions to surrounding structures. A pituitary MRI examination should be obtained if there is concern for mass effect (including visual loss, ophthalmoplegia, headache) or if there is clinical suspicion and laboratory evidence of either hypopituitarism or pituitary hormone excess. The information obtained from MRI images also provides us with assistance in planning surgery. Using intraoperative MRI can be very helpful in assessing the adequacy of tumor resection. In addition, MRI images yield reliable data that allow for noninvasive monitoring of patients postoperatively.

Hypothalamitis and pituitary atrophy

Hypothalamitis is a rare inflammatory disorder involving the hypothalamus and classified as primary, or isolated, and secondary hypothalamitis. Secondary hypothalamitis although very rare is more common than the primary one and may occur in patients affected by autoimmune diseases such as autoimmune hypophysitis, systemic autoimmune diseases, infective diseases in patients affected by immune-deficit, paraneoplastic encephalitis, or in patients treated with immune checkpoint inhibitors. In accordance with the rarity of this disease, diagnosis and management of hypothalamitis prove to be challenging. The diagnosis requires a high index of clinical suspicion. The main symptoms may be: various degrees of hypopituitarism, neuropsychiatric and behavioral disorders, and disturbances of autonomic and metabolic regulation. Magnetic resonance images play a crucial role in the diagnosis of hypothalamitis and in the exclusion of a neoplastic lesion. Therapeutic management should be oriented according to the disease etiology. In most cases, after ruling out infective hypothalamitis, the mainstay of therapy consists of immunosuppressive treatment. Great attention should be paid to hormonal replacement therapy, if partial or total hypopituitarism is present, in particular in patients affected by diabetes insipidus, central hypoadrenalism and hypothyroidism. According to the complexity of this disease, a multidisciplinary approach is strongly advocated to reach an early diagnosis and an integrated therapy.

Empty sella syndrome: Multiple endocrine disorders

Empty sella is a pituitary disorder characterized by the herniation of the subarachnoid space within the sella turcica. This is often associated with a variable degree of flattening of the pituitary gland. Empty sella has to be distinguished in primary and secondary forms. Primary empty sella (PES) excludes any history of previous pituitary pathologies such as previous surgical, pharmacologic, or radiotherapy treatment of the sellar region. PES is considered an idiopathic disease and may be associated with idiopathic intracranial hypertension. Secondary empty sella, however, may occur after the treatment of pituitary tumors through neurosurgery or drugs or radiotherapy, after spontaneous necrosis (ischemia or hemorrhage) of chiefly adenomas, after pituitary infectious processes, pituitary autoimmune diseases, or brain trauma. Empty sella, in the majority of cases, is only a neuroradiological finding, without any clinical implication. However, empty sella syndrome is defined in the presence of pituitary hormonal dysfunction (more frequently hypopituitarism) and/or neurological symptoms due to the possible coexisting of idiopathic intracranial hypertension. Empty sella syndrome represents a peculiar clinical entity, characterized by heterogeneity both in clinical manifestations and in hormonal alterations, sometimes reaching severe extremes. For a proper diagnosis, management, and follow-up of empty sella syndrome, a multidisciplinary approach with the integration of endocrine, neurological, and ophthalmological experts is strongly advocated.

Endocrine and metabolic aspects of the COVID-19 pandemic

COVID-19 infection has tremendously impacted our daily clinical practice as well as our social living organization. Virtually all organs and biological systems suffer from this new coronavirus infection, either because the virus targets directly specific tissues or because of indirect effects. Endocrine diseases are not an exception and some of endocrine organs are at risk of direct or indirect lesion by COVID-19. Although there is still no evidence of higher predisposition to contract the infection in patients with diabetes and/or obesity, the coexistence of these conditions contributes to a worse prognosis because both conditions confer an impaired immunologic system. Cytokines storm can be amplified by these two latter conditions thereby leading to multisystemic failure and death. Glycaemic control has been demonstrated to be crucial to avoiding long hospital stays, ICU requirement and also prevention of excessive mortality. Endocrine treatment modifications as a consequence of COVID-19 infection are required in a proactive manner, in order to avoid decompensation and eventual hospital admission. This is the case of diabetes and adrenal insufficiency in which prompt increase of insulin dosage and substitutive adrenal steroids through adoption of the sick day's rules should be warranted, as well as easy contact with the health care provider through telematic different modalities. New possible endocrinological targets of COVID-19 have been recently described and warrant a full study in the next future.

Clinical diagnosis and treatment of immune checkpoint inhibitors-related endocrine dysfunction

As a new class of antitumor drugs, immune checkpoint inhibitors (ICIs) have shown remarkable efficacy toward the treatment of various malignant tumors. By virtue of their targets and mechanisms of action, ICIs can cause autoimmune and inflammatory effects, termed as immune‐related adverse events (irAEs) and unlike the adverse reactions of traditional therapies, irAEs are occult and not fixed, with some serious adverse reactions forcing patients to stop treatment which might even affect their survival. Therefore, with the wide clinical application of ICIs, clinicians need to fully understand the possible adverse reactions of these drugs and devise reasonable treatment strategies to improve the survival rate and therapeutic effects of patients receiving ICIs. In this article, we review the incidence, clinical manifestations, diagnosis and treatment of immune‐related endocrine events that may occur with the administration of ICIs.

Pituitary Stalk Enlargement in Adults

Pathologies involving the pituitary stalk (PS) are generally revealed by the presence of diabetes insipidus. The availability of MRI provides a major diagnostic contribution by enabling the visualization of the site of the culprit lesion, especially when it is small. However, when only an enlarged PS is found, the etiological workup may be difficult, particularly because the biopsy of the stalk is difficult, harmful and often not contributive. The pathological proof of the etiology thus needs to be obtained indirectly. The aim of this article was to provide an accurate review of the literature about PS enlargement in adults describing the differences between the numerous etiologies involved and consequent different diagnostic approaches. The etiological diagnostic procedure begins with the search for possible other lesions suggestive of histiocytosis, sarcoidosis, tuberculosis or other etiologies elsewhere in the body that could be more easily biopsied. We usually perform neck, thorax, abdomen, and pelvis CT scan; positron emission tomography scan; bone scan; or other imaging methods when we suspect generalized lesions. Measurement of serum markers such as human chorionic gonadotropin, alpha-fetoprotein, angiotensin converting enzyme, and IgG4 may also be helpful. Obviously, in the presence of an underlying carcinoma (particularly breast or bronchopulmonary), one must first consider a metastasis located in the PS. In the case of an isolated PS enlargement, simple monitoring, without histological proof, can be proposed (by repeating MRI at 3-6 months) with the hypothesis of a germinoma (particularly in a teenager or a young adult) that, by increasing in size, necessitates a biopsy. In contrast, a spontaneous diminution of the lesion is suggestive of infundibulo-neurohypophysitis. We prefer not to initiate steroid therapy to monitor the spontaneous course when a watch-and-see attitude is preferred. However, in many cases, the etiological diagnosis remains uncertain, requiring either close monitoring of the lesion or, in exceptional situations, trying to obtain definitive pathological evidence by a biopsy, which, unfortunately, is in most cases performed by the transcranial route. If a simple surveillance is chosen, it has to be very prolonged (annual surveillance). Indeed, progression of histiocytosis or germinoma may be delayed.

Hypophysitis: An update on the novel forms, diagnosis and management of disorders of pituitary inflammation

Hypophysitis is a heterogeneous condition that leads to inflammation of the sella and/or suprasellar region, potentially resulting in hormonal deficiencies and/or mass effects. A preponderance of hypophysitis subtypes have an underlying autoimmune aetiology. The overall incidence and prevalence of hypophysitis has dramatically increased over the past decade, mainly due to increased awareness of the condition in the medical community, improvements in imaging techniques, and a rise in the occurrence of certain forms of hypophysitis such as IgG4 hypophysitis (IgG4Hy) and immune checkpoint inhibitor induced hypophysitis (ICIHy). The clinical presentation varies from an asymptomatic condition to a fatal disease often as a result of electrolyte abnormalities due to glucocorticoid deficiency in the context of adrenal crisis from central adrenal insufficiency. Milder forms of hypophysitis are treated with replacement of deficient hormones while more acute presentations with mass effects require glucocorticoid therapy, immunosuppressive therapy or surgery. Timely diagnosis and interventions are keys to prevention of the lethal complications of this disease. In this review, we provide an update on the recent advances in the field of pituitary autoimmunity, with an emphasis on autoimmune hypophysitis and novel forms of hypophysitis such as anti-PIT1 hypophysitis, IgG4Hy and ICIHy.

Hypophysitis induced by immune checkpoint inhibitors: a 10-year assessment

Introduction: Hypophysitis caused by immune checkpoint inhibitors (ICIs) has risen to the medical attention during the past decade. ICIs are monoclonal antibodies that block the interaction between molecules that normally inhibit the function of effector T cells, ultimately increasing their ability to destroy cancer cells but also causing immune-related adverse events, such as hypophysitis. Ipilimumab, a CTLA-4 blocker, was the first ICI approved from the Food and Drug Administration for advanced melanoma patients in 2011. Several additional ICIs targeting CTLA-4, PD-1, or PD-L1 are now used in many clinical trials, making it important for physicians to recognize and treat hypophysitis adequately.Areas covered: This review will provide insights into the mechanisms of pituitary toxicity, highlight the complexity of clinical phenotypes of ICI hypophysitis, and offer practical recommendations.Expert opinion: ICI hypophysitis differs in many respects from primary hypophysitis, and also according to the type of ICI that caused it. Its pathogenesis remains unknown, although the expression of CTLA-4 and PD-1 on pituitary cells could play a role. The diagnosis is mainly clinical since there are no specific serological markers and MRI findings are subtle. The treatment is based on long-term hormone replacement and does not typically require discontinuation of immunotherapy.