Mineralocorticoids induce polyuria by reducing apical aquaporin-2 expression of the kidney in partial vasopressin deficiency

The symptoms of diabetes insipidus may be masked by the concurrence of adrenal insufficiency and emerge after the administration of hydrocortisone, occasionally at high doses. To elucidate the mechanism underlying polyuria induced by the administration of high-dose corticosteroids in the deficiency of arginine vasopressin (AVP), we first examined the secretion of AVP in three patients in whom polyuria was observed only after the administration of high-dose corticosteroids. Next, we examined the effects of dexamethasone or aldosterone on water balance in wild-type and familial neurohypophyseal diabetes insipidus (FNDI) model mice. A hypertonic saline test showed that AVP secretion was partially impaired in all patients. In one patient, there were no apparent changes in AVP secretion before and after the administration of high-dose corticosteroids. In FNDI mice, unlike dexamethasone, the administration of aldosterone increased urine volumes and decreased urine osmolality. Immunohistochemical analyses showed that, after the administration of aldosterone in FNDI mice, aquaporin-2 expression was decreased in the apical membrane and increased in the basolateral membrane in the collecting duct. These changes were not observed in wild-type mice. The present data suggest that treatment with mineralocorticoids induces polyuria by reducing aquaporin-2 expression in the apical membrane of the kidney in partial AVP deficiency.

Postpartum gestational diabetes insipidus related to preeclampsia: A case report

Gestational diabetes insipidus (GDI) is a rare complication of pregnancy thought to be due to increased vasopressinase produced by the placenta. It typically occurs at the end of the second or in the third trimester. This report describes a case of GDI diagnosed postpartum in the setting of newly diagnosed superimposed preeclampsia. A 39-year-old Hispanic woman (gravida 2 para 2) presented ten days postpartum with a persistent headache and elevated blood pressures in the setting of a history of chronic hypertension, meeting criteria for superimposed preeclampsia. Repeat lab work was notable for mild elevation of liver function enzymes. Despite normalization of blood pressures, her headache persisted and further workup revealed polyuria, suspected to be vasopressinase-induced diabetes insipidus. The patient was started on oral desmopressin with improvement of polyuria and symptoms.

Salt and Water: A Review of Hypernatremia

Serum sodium disorders are generally a marker of water balance in the body. Thus, hypernatremia is most often caused by an overall deficit of total body water. Other unique circumstances may lead to excess salt, without an impact on the body's total water volume. Hypernatremia is commonly acquired in both the hospital and community. As hypernatremia is associated with increased morbidity and mortality, treatment should be initiated promptly. In this review, we will discuss the pathophysiology and management of the main types of hypernatremia, which can be categorized as either a loss of water or gain of sodium that can be mediated by renal or extrarenal mechanisms.

Post-pituitary surgery copeptin analysis as a 'rule-out' test for post-operative diabetes insipidus

BACKGROUND

Diabetes insipidus (DI) is a recognised complication of pituitary surgery, with diagnosis requiring clinical observation aided by plasma and urine electrolytes and osmolalities. Copeptin is a stable surrogate marker of AVP release and has potential to facilitate prompt diagnosis of post-operative DI. This assay has been shown to accurately predict which patients are likely to develop DI following pituitary surgery.

OBJECTIVE

To determine whether copeptin analysis can be used to predict which patients are at risk of developing DI following trans-sphenoidal surgery (TSS).

METHODS

Seventy-eight patients undergoing TSS had samples taken for copeptin pre-operatively and at day 1 post-TSS. The majority of patients also had samples from day 2, day 8, and week 6 post-TSS. Results from patients who developed post-operative DI (based on clinical assessment, urine and plasma biochemistry and the need for treatment with DDAVP) were compared to those who did not. Patients with any evidence of pre-operative DI were excluded.

RESULTS

Of 78 patients assessed, 11 were clinically determined to have developed DI. Differences were observed between patients with DI and those without in post-operative samples. Of note, there was a significant difference in plasma copeptin at day 1 post-operation (p = 0.010 on Kruskal-Wallis test), with copeptin levels greater than 3.4 pmol/l helping to rule out DI (91% sensitivity, 55% specificity at this cut off).

CONCLUSION

In the post-TSS setting, copeptin is a useful rule-out test in patients with values above a defined threshold, which may facilitate earlier decision making and shorter hospital stays.

Aquaporins in Diabetes Insipidus

Disruption of water and electrolyte balance is frequently encountered in clinical medicine. Regulating water metabolism is critically important. Diabetes insipidus (DI) presented with excessive water loss from the kidney is a major disorder of water metabolism. To understanding the molecular and cellular mechanisms and pathophysiology of DI and rationales of clinical management of DI is important for both research and clinical practice. This chapter will first review various forms of DI focusing on central diabetes insipidus (CDI) and nephrogenic diabetes insipidus (NDI). This is followed by a discussion of regulatory mechanisms underlying CDI and NDI, with a focus on the regulatory axis of vasopressin, vasopressin receptor 2 (V2R) and the water channel molecule, aquaporin 2 (AQP2). The clinical manifestation, diagnosis, and management of various forms of DI will also be discussed with highlights of some of the latest therapeutic strategies that are developed from in vitro experiments and animal studies.

PINEAL GERMINOMA PRESENTED WITH PARALYSIS OF UPWARD GAZE AND DIABETES INSIPIDUS

Intracranial germ cell tumors (GCTs) include two categories: germinoma and non germinoma. The pineal gland and suprasellar are the most common site of involvement. The patient is a 14-year-old boy who presented with paralysis of upward gaze, polyuria, polydipsia and diplopia. Examination of vertical eye movements was impaired. Puberty then progressed to stage 3 of Marshall - Tanner and had stopped. In laboratory studies, the patient had anterior hypopituitarism and diabetes insipidus (DI). In pituitary and hypothalamic MRIs, a mass-like enlargement of the pituitary stalk and pineal region was seen, but due to the small size of the lesions, stereotactic biopsy was not possible. During this time, the patient developed recurrent attacks of hydrocephalus. Serum and CSF β-subunit of Human chorionic gonadotropin levels were negative. Treatment was not started because different lesions could cause disease in this area. After one year, a biopsy was performed and the germ cell tumor was diagnosed. Chemotherapy was started and after treatment the vision disorder and diplopia disappeared, but DI and pituitary dysfunction remained. Treatment of intracranial germinoma is multidisciplinary. GCTs are very sensitive to radiation therapy. They are treated with combination of chemotherapy, radiotherapy, surgery, endocrine therapy and have a good prognosis.

Combined Arginine and Insulin Stimulation Elicits a Robust and Consistent Copeptin Response in Short Children

INTRODUCTION

Copeptin, co-secreted with arginine vasopressin, is regulated by osmotic and volume stimuli but also responds to intravenous arginine and insulin-induced hypoglycemia. The serum copeptin response to the latter agents has been studied in adults but only to a limited extent in children. The objective of this study was to describe the copeptin response to combined arginine and insulin in children with normal posterior pituitary function.

METHODS

We conducted a prospective, single-arm assessment of serum copeptin concentrations in children (age 7-16 years, n = 38) undergoing growth hormone stimulation testing with an arginine-insulin tolerance test (AITT) for short stature or growth deceleration in a tertiary referral center. After overnight fasting, arginine (500 mg/kg) was administered between 0 and 30 min intravenously (IV) followed by insulin (0.1 units/kg IV) at 60 min. Copeptin serum concentrations were measured at baseline (0 min), at the post-arginine peak (60 min), and at the post-insulin peak (90 min; 30 min post-insulin), respectively. The main outcome was the peak copeptin concentration.

RESULTS

Mean ± SD copeptin concentrations increased from 9.9 ± 5.0 pmol/L at 0 min to 13.2 ± 5.8 pmol/L at 60 min (p < 0.0001 vs. 0 min) and 27.7 ± 14.2 pmol/L at 90 min (p < 0.0001 vs. 0 and 60 min). There was no significant correlation between copeptin concentrations and age, BMI, pubertal status, cortisol, growth hormone, or glucose concentrations.

DISCUSSION/CONCLUSION

Arginine and insulin appear to have an additive and consistent effect resulting in significant stimulation of copeptin secretion in children. The AITT may be a useful tool to evaluate for normal posterior pituitary function in this age-group, with potential implications for the evaluation of polyuria-polydipsia syndrome.

Idiopathic central diabetes insipidus in a large cohort of patients: the hypopituitarism ENEA rare observational (HEROS) study

Central Diabetes Insipidus (CDI) is mainly associated with structural pathologies of the hypothalamic-pituitary area. Etiologies underlying CDI are identified in most patients, however idiopathic CDI is reported in 13-17% of cases after excluding other etiologies. The Hypopituitarism ENEA Rare Observational Study (HEROS study) retrospectively collected data of patients with idiopathic CDI from 14 pituitary centers in 9 countries. The cohort included 92 patients (59 females 64%), mean age at diagnosis was 35.4 ± 20.7 years, and a mean follow up of 19.1 ± 13.5 years following CDI diagnosis. In 6 women, diagnosis was related to pregnancy. Of 83 patients with available data on pituitary imaging, 40(48%) had normal sellar imaging, and 43(52%) had pathology of the posterior pituitary or the stalk, including loss of the bright spot, posterior pituitary atrophy or stalk enlargement. Anterior pituitary hormone deficiencies at presentation included hypogonadism in 6 (6.5%) patients (5 females), and hypocortisolism in one; during follow-up new anterior pituitary deficiencies developed in 6 patients. Replacement treatment with desmopressin was given to all patients except one, usually with an oral preparation. During follow up, no underlying disease causing CDI was identified in any patient. Patients with idiopathic CDI following investigation at baseline are stable with no specific etiology depicted during long-term follow-up.

Changing the name of diabetes insipidus: a position statement of The Working Group for Renaming Diabetes Insipidus

"What's in a name? That which we call a rose/By any other name would smell as sweet." (Juliet, from Romeo and Juliet by William Shakespeare). Shakespeare's implication is that a name is nothing but a word and it therefore represents a convention with no intrinsic meaning. Whilst this may be relevant to romantic literature, disease names do have real meanings, and consequences, in medicine. Hence, there must be a very good rational for changing the name of a disease that has a centuries-old historical context. A working group of representatives from national and international endocrinology and pediatric endocrine societies now proposes changing the name of "diabetes insipidus" to "Arginine Vasopressin Deficiency (AVP-D)" for central etiologies, and "Arginine Vasopressin Resistance (AVP-R)" for nephrogenic etiologies. This editorial provides both the historical context and the rational for this proposed name change.

Impact of surgical factors on delayed hyponatremia in patients with nonfunctioning pituitary adenoma after endonasal endoscopic transsphenoidal procedure

PURPOSE

Delayed hyponatremia can occur after pituitary surgery, resulting in prolonged hospitalization. However, the influence of surgical factors after such a procedure has not been well established. The impact of surgery and related factors on delayed hyponatremia was investigated.

METHODS

This was a retrospective analysis of 137 consecutive patients who underwent transsphenoidal surgery for a nonfunctioning pituitary adenoma between 2008 and 2019. Preoperative (demographics, comorbidities), intraoperative (resection extent, operation time, blood loss volume, cerebrospinal fluid leak, tumor consistency), and postoperative [hematoma, meningitis, diabetes insipidus (DI), hormonal assessment] data were collected, with statistical analysis of each factor performed.

RESULTS

Among the 137 patients, delayed hyponatremia occurred in 31 (22.6%). Multivariate analysis revealed that those with hypertension had a significantly higher likelihood of avoiding delayed hyponatremia (p = 0.004). Although no correlations of direct surgical factors with delayed hyponatremia were found, multivariate analysis of indirect surgical factors showed that presence of a firm tumor, transient DI, and meningitis were significantly associated with delayed hyponatremia (p = 0.014, 0.001, and 0.047, respectively). There was also a significant association of severe hyponatremia with appearance of symptoms (p = 0.002).

CONCLUSION

There was a tendency for hypertension to be associated with delayed hyponatremia avoidance, with indirect surgical factors including tumor consistency, transient DI, and meningitis found to have an influence on delayed hyponatremia. It was concluded that attention should be given to non-hypertensive patients with a firm tumor, transient DI, or meningitis after pituitary surgery, as delayed hyponatremia may occur.

Central diabetes insipidus and burn trauma

Diabetes insipidus (DI) is characterized by polyuria and polydipsia. In most cases, the condition results from either an inadequate release or resistance to the activity of antidiuretic hormone in the renal collecting tubules. The underlying pathophysiology may be related to destruction the destruction or degeneration of neurons from inflammatory, autoimmune diseases, vascular diseases, Langerhans cell histiocytosis, sarcoidosis, or trauma. However, a large majority of diabetes insipidus cases (50%) are considered idiopathic. An exceedingly rare cause of idiopathic central DI occurs in burn injuries, which has only been reported in eight cases. We present an extremely rare case of idiopathic DI in a 15-year-old male with 76% total body surface area (TBSA) burns with the development of idiopathic central DI. An extensive literature review was accomplished to compare this case with the small number of previously reported case reports of idiopathic DI in burn patients.

Lay Summary

Diabetes insipidus (DI) is a rare complication of burn injuries that results from the destruction of neurons involved in the secretion of antidiuretic hormone from the pituitary gland. Only eight cases of DI have been reported in the literature in association to burn injuries. The patient in this case report received immediate fluid resuscitation, burn treatment, and intensive observation after the initial burn injury. The rapid response was likely the main reason for the absence of neurological damage as reported in the CT image. Therefore, the treatment of burn injuries remains an important step for reducing neurological damage and hormonal dysregulation leading to diabetes insipidus.

Erdheim-Chester disease: Typical radiologic findings of a multisystemic disease

Erdheim-Chester disease is a rare and multisystemic entity. It results from the infiltration of tissues by foamy histiocytes. The etiology is unknown, but there are mutations in the MAPK pathway in over 80% of patients, more frequently BRAF mutation. The most commonly affected organs and systems are the skeleton, central nervous system, cardiovascular system, kidney, lungs, and skin. The most common clinical manifestations are bone pain, usually in the lower limbs, and diabetes insipidus. The diagnosis is challenging. It requires a combination of clinical, radiological, histopathological, and molecular findings. We present the case of a patient with typical clinical and radiological manifestations: bone pain and diabetes insipidus at presentation, bilateral long bone cortical sclerosis, hairy kidney appearance, coated aorta, right atrium pseudotumor, and periorbital masses.

Endocrine manifestations of paediatric intracranial germ cell tumours: from diagnosis to long-term follow-up

PURPOSE

We examined endocrine manifestations in a cohort of paediatric patients with IC-GCTs at diagnosis and during follow-up, integrating clinical, radiological, histopathological and laboratory data.

METHODS

Diabetes insipidus (DI), growth hormone deficiency (GHD), hypothyroidism, adrenal insufficiency, precocious puberty (PP)/hypogonadism were diagnosed clinically and biochemically. The prevalence of endocrine manifestations was compared to survival rates.

RESULTS

Our population included 55 children (37 males, 18 females) diagnosed with IC-GCT with a median follow-up of 78.9 months from diagnosis (range 0.5-249.9). At tumour diagnosis, 50.9% patients displayed endocrinopathies: among them, 85.7% were affected by DI, 57.1% central adrenal insufficiency, 50% central hypothyroidism, 28.5% GHD, 10.7% hypogonadotrophic hypogonadism, 10.7% PP. These patients presented predominantly with suprasellar germinoma. If not diagnosed previously, endocrine disorders arose 15.15 months (1.3-404.2) after end of treatment (EOT) in 16.4% patients. At least one endocrinopathy was identified in 67.3% of subjects at last follow-up visit, especially GHD and adrenal insufficiency. DI, hypothyroidism, and adrenal insufficiency occurred earlier than other abnormalities and frequently preceded tumour diagnosis. Subjects with and without endocrine manifestations who survived beyond 12 months after EOT did not show significant difference in overall survival and progression-free survival (p = 0.28 and p = 0.88, respectively).

CONCLUSION

Endocrinopathies were common presenting symptoms in our population. If present at diagnosis, they often persisted hence after. The spectrum of endocrinopathies expanded during follow-up up to 33.7 years after EOT. Although they did not seem to affect survival rate in our cohort, close lifelong surveillance is mandatory to provide the best care for these patients.

Renal water transport in health and disease

Saving body water by optimal reabsorption of water filtered by the kidney leading to excretion of urine with concentrations of solutes largely above that of plasma allowed vertebrate species to leave the aquatic environment to live on solid ground. Filtered water is reabsorbed for 70% and 20% by proximal tubules and thin descending limbs of Henle, respectively. These two nephron segments express the water channel aquaporin-1 located along both apical and basolateral membranes. In the proximal tubule, the paracellular pathway accounts for at least 30% of water reabsorption, and the tight-junction core protein claudin-2 plays a key role in this permeability. The ascending limb of Henle and the distal convoluted tubule are impermeant to water and are responsible for urine dilution. The water balance is adjusted along the collecting system, i.e. connecting tubule and the collecting duct, under the control of arginine-vasopressin (AVP). AVP is synthesized by the hypothalamus and released in response to an increase in extracellular osmolality or stimulation of baroreceptors by decreased blood pressure. In response to AVP, aquaporin-2 water channels stored in subapical intracellular vesicles are translocated to the apical plasma membrane and raise the water permeability of the collecting system. The basolateral step of water reabsorption is mediated by aquaporin-3 and -4, which are constitutively expressed. Drugs targeting water transport include classical diuretics, which primarily inhibit sodium transport; the new class of SGLT2 inhibitors, which promotes osmotic diuresis and the non-peptidic antagonists of the V2 receptor, which are pure aquaretic drugs. Disturbed water balance includes diabetes insipidus and hyponatremias. Diabetes insipidus is characterized by polyuria and polydipsia. It is either related to a deficit in AVP secretion called central diabetes insipidus that can be treated by AVP analogs or to a peripheral defect in AVP response called nephrogenic diabetes insipidus. Diabetes insipidus can be either of genetic origin or acquired. Hyponatremia is a common disorder most often related to free water excess relying on overstimulated or inappropriate AVP secretion. The assessment of blood volume is key for the diagnosis and treatment of hyponatremia, which can be classified as hypo-, eu-, or hypervolemic.

Diabetes Insipidus after Vasopressin Withdrawal: A Scoping Review

Objectives

The objective of this study is to synthesize the current literature about the relationship between the occurrence of diabetes insipidus (DI), its diagnosis criteria, and management after withdrawal of vasopressin (VP) in critically ill.

Data sources

This scoping review followed the recommendations of Preferred Reporting Items for Systematic Review and Meta-Analyses for Scoping Review (PRISMA-ScR). The search literature was conducted in MEDLINE and EMBASE databases, until March 2022. A manual search was also conducted in order to include articles that were not identified in the initial search performed in the databases.

Study selection and data extraction

The selection of studies and extraction of data were carried out in a paired and independent manner. There was no restriction regarding the language of publication of the included manuscripts.

Data synthesis

The analysis included 17 studies (16 case reports and one retrospective cohort). All studies used VP, with a median time of drug infusion of 48 hours (IQR: 16-72) and DI incidence of 1.53%. The diagnosis of DI was based on diuresis output and concomitant hypernatremia or changes in serum sodium concentration, with median time to symptoms onset after discontinuation of VP of 5 hours (IQR: 3-10). The treatment of DI consisted mainly of fluid management and the use of desmopressin.

Conclusions

DI after VP withdrawal was present in 51 patients described in 17 studies, but diagnosis and management varied among each report. Using the available data, we propose a diagnosis suggestion and a flowchart for managing patients with DI after withdrawal of VP in the Intensive Care Unit. Multicentric collaborative research is urgently needed to obtain more quality data on this topic.

How to cite this article

Pérsico RS, Viana MV, Viana LV. Diabetes Insipidus after Vasopressin Withdrawal: A Scoping Review. Indian J Crit Care Med 2022;26(7):846-852.

Change in cephalocaudal tumor cavity diameter after transsphenoidal surgery is a predictor of diabetes insipidus in pituitary adenoma

Objective

To assess the factors influencing the development of diabetes insipidus after transsphenoidal surgery for pituitary adenomas.

Methods

We retrospectively analyzed the clinical data of patients with pituitary adenoma who underwent transsphenoidal surgery. The pituitary gland was assessed using a 3.0 T magnetic resonance imaging, and the predictors of postoperative diabetes insipidus were determined through univariate and multivariate analyses.

Results

A total of 212 eligible patients with pituitary adenomas were included; 82 (38.7%) cases developed postoperative diabetes insipidus while 130 cases (61.3%) did not. Diabetes insipidus was transient in 80 (37.7%) patients and permanent in 2 (0.9%) patients. The results of logistic regression analyses showed that the change in cephalocaudal tumor cavity diameter after transsphenoidal surgery was associated with the occurrence of postoperative diabetes insipidus.

Conclusions

Change in cephalocaudal tumor cavity diameter after transsphenoidal surgery may play an important role in predicting diabetes insipidus onset in patients with a pituitary adenoma.

The value of intraoperative MRI for resection of functional pituitary adenomas-a critical assessment of a consecutive single-center series of 114 cases

This series sought to evaluate the role of intraoperative MRI (iMRI) for resection of functional pituitary adenomas (FPAs). We retrospectively reviewed clinical data of 114 consecutive FPAs with excessive hormone secretion treated with transsphenoidal surgery and iMRI during 01/2010–12/2017. We focused on iMRI findings, extend of resection and postoperative hormonal remission. Variables of incomplete resections and persistent hormone excess were evaluated by binary regression. Patients with FPAs presented with hypercortisolism (n = 23, 20%), acromegaly (n = 56, 49%), and as prolactinomas (n = 35, 31%) resistant to medical treatment. Preoperative MRI showed 81 macroadenomas (71%) and optic system involvement in 41 cases (36%). IMRI was suggestive for residual tumor in 51 cases (45%). Re-inspection of the cavity cleared equivocal findings in 16 cases (14%). Additional tumor was removed in 22 cases (19%). Complete resection was achieved in 95 cases (83%). Postoperative morbidity was low (1.7% revision surgeries, 0.8% permanent diabetes insipidus). Overall hormonal remission-rate was 59% (hypercortisolism 78%, acromegaly 52%, prolactinoma 57%). Supra- and parasellar invasion and preoperative visual impairment were significant predictors for incomplete resections despite use of iMRI. Risk for persistent hormone excess was increased sevenfold after incomplete resections. IMRI enabled reliable identification of tumor remnants during surgery and triggered further resection in a considerable proportion of cases. Nevertheless, tumor size and invasiveness set persistent boundaries to the completeness of resections. The low rate of surgical complications could point at a less invasive iMRI-guided surgical approach while achieving a complete tumor resection was a crucial determinant for hormonal outcome.

Copeptin in fluid disorders and stress

Copeptin, a glycosylated peptide of 39 amino acids, is the C-terminal segment of arginine vasopressin (AVP) precursor peptide, which is consisted of two other fragments, vasopressin and neurophysin Ⅱ. The main physiological functions of AVP are fluid and osmotic balance, cardiovascular homeostasis and regulation of the endocrine stress response. Numerous studies have demonstrated that the endogenous AVP in plasma is a meaningful biomarker to guide diagnosis and therapy of diseases associated with fluids disorders and stress. However, due to its instability, short half-time life in circulation and lack of readily available AVP assays, clinical measurement of AVP is restricted. In contrast to AVP, copeptin which is released in an equimolar mode with AVP from the pituitary, has emerged as a stable and simple-to-measure surrogate marker of AVP and displays excellent potential in diagnosis, differentiation and prognosis of various diseases. This review will discuss the studies on the clinical value of copeptin in different diseases, especially in AVP-dependent fluids disorders, as well as issues and prospects of the application of this potential biomarker.

Predictive factors of postoperative diabetes insipidus in 333 patients undergoing transsphenoidal surgery for non-functioning pituitary adenoma

PURPOSE

Diabetes insipidus (DI) following transsphenoidal surgery (TSS) is a common complication. Although postoperative DI often occurs in patients with craniopharyngioma and Rathke's cleft cyst, postoperative DI in patients with non-functioning pituitary adenoma (NFPA) has not been fully examined. We clarified the clinical characteristics and magnetic resonance imaging (MRI) findings predicting postoperative DI in NFPAs.

METHODS

A total of 333 patients undergoing initial TSS for NFPA were included in this retrospective study. Hyperintensity (HI) in the posterior pituitary lobe was evaluated on preoperative T1-weighted MRI. Based on the findings of HI patients were divided into three groups as follows: HI was not detected (Disappearance group), HI located intrasellarly (Intrasellar group), and HI located suprasellarly (Suprasellar group).

RESULTS

The overall rate of DI was 21.9%, including permanent DI in 0.6%. DI occurred at postoperative day 1 (72.6%) or day 2 (19.2%) and improved within 7 days in most cases (87.7%). Univariable and multivariable analyses showed that the predictive factors of DI were a younger age (odds ratio [OR] 0.97, 95% confidence interval [CI] 0.95-0.99, P = 0.0037) and larger tumor diameter (OR 1.04, 95% CI 1.01-1.08, P = 0.0155). The rate of DI was highest in the Disappearance group (43.8%) followed by the Intrasellar group (26.0%). The OR was 2.17 in the Intrasellar group compared with the Suprasellar group (95% CI 1.17-4.02, P = 0.0141).

CONCLUSIONS

Factors predicting DI following TSS for NFPA were a younger age, larger tumor size, and the location of intrasellar HI on preoperative T1-weighted MRI.

Pulmonary Langerhans cell histiocytosis and multiple system involvement: A case report

BACKGROUND

Pulmonary Langerhans cell histiocytosis (PLCH) is a relatively rare type of lung disease, common in middle-aged smoking men. It is characterized by proliferation and infiltration of Langerhans cells, and the formation of multiple parabronchial mesenchymal nodules in lung tissue, and may lead to organ dysfunction. There are no typical symptoms and signs, and it is easily misdiagnosed or missed, and therefore deserves clinical attention and further discussion.

CASE SUMMARY

We describe the case of a nonsmoking 46-year-old man with PLCH diagnosed based on clinical manifestations of fever and dry cough, with a history of hypothyroidism and diabetes insipidus for 9 years. Computed tomography (CT)- and CT-guided puncture examinations revealed no abnormalities, and he ultimately underwent thoracoscopic biopsy to confirm the diagnosis. The pathological diagnosis was PLCH. Thyroid function was maintained by medication. Pituitary magnetic resonance imaging showed that the pituitary stalk had become thinner.

CONCLUSION

LCH often involves multiple systems. Moreover, the pathogenesis is not clear, clinical manifestations lack specificity, and diagnosis requires special attention. Diagnosis of PLCH can significantly benefit from comprehensive multidisciplinary analysis.

The cascade to a serendipitous discovery of lithium-induced nephrogenic diabetes insipidus

Lithium therapy is a common treatment for affective disorders and is widely regarded as a lifesaving drug. However, because its elimination is almost wholly unchanged via the kidneys, both acute and long-term adverse effects relating to toxicity may occur, including declining renal function and nephrogenic diabetes insipidus (DI). DI may be difficult to detect and is frequently preceded by dehydration and which, in our patient, was discovered by chance. We describe a case of an elderly woman on chronic lithium therapy for bipolar affective disorder who initially presented with dehydration from vomiting but possibly developed extra-pontine myelinolysis (EPM) after over-zealous correction of hyponatraemia. Steroids administered appeared to have prevented further progression but a persisting hyperosmolar state then alerted us to the presence of nephrogenic DI. Although both conditions were later successfully reversed with no obvious chronic sequelae, the recovery of the patient was protracted. Clinicians should be vigilant for complications of managing dehydration states in people prescribed with lithium.

Functional analyses of three different mutations in the AVP-NPII gene causing familial neurohypophyseal diabetes insipidus

PURPOSE

Familial neurohypophyseal diabetes insipidus (FNDI), a rare disorder, which is clinically characterized by polyuria and polydipsia, results from mutations in the arginine vasopressin-neurophysin II (AVP-NPII) gene. The aim of this study was to perform functional analyses of three different mutations (p.G45C, 207_209delGGC, and p.G88V) defined in the AVP-NPII gene of patients diagnosed with FNDI, which are not included in the literature.

METHODS

For functional analysis studies, the relevant mutations were created using PCR-based site-directed mutagenesis and restriction fragment replacement strategy and expressed in Neuro2A cells. AVP secretion into the cell culture medium was determined by radioimmunoassay (RIA) analysis. Fluorescence imaging studies were conducted to determine the differences in the intracellular trafficking of wild-type (WT) and mutant AVP-NPII precursors. Molecular dynamics (MD) simulations were performed to determine the changing of the conformational properties of domains for both WT and 207-209delGGC mutant structures and dynamics behavior of residues.

RESULTS

Reduced levels of AVP in the supernatant culture medium of p.G45C and p.G88V transfected cells compared to 207_209delGGC and WT cells were found. Fluorescence imaging studies showed that a substantial portion of the mutant p.G45C and p.G88V AVP-NPII precursors appeared to be located in the endoplasmic reticulum (ER), whereas 207_209delGGC and WT AVP-NPII precursors were distributed throughout the cytoplasm.

CONCLUSIONS

The mutations p.G45C and p.G88V cause a failure in the intracellular trafficking of mutant AVP-NPII precursors. However, 207_209delGGC mutation does not result in impaired cellular trafficking, probably due to not having any significant effect in processes such as the proper folding, gain of three-dimensional structure, or processing. These results will provide valuable information for understanding the influence of mutations on the function of the AVP precursor hormone and cellular trafficking. Therefore, this study will contribute to elucidate the mechanisms of the molecular pathology of AVP-NPII mutations.