Severe hyponatremia and diabetes insipidus caused by low-dose cyclophosphamide in breast cancer patients: A case report and literature review

RATIONALE

Cyclophosphamide (CTX) is widely used in the treatment of malignancies and autoimmune diseases. Although severe hyponatremia caused by low-dose CTX chemotherapy is uncommon, it can lead to serious complications and even death.

PATIENT CONCERNS

A 44-year-old woman with left-sided breast cancer suddenly experienced headaches, disorientation and weakness after receiving low-dose neoadjuvant chemotherapy combined with CTX and doxorubicin.

DIAGNOSES

The patient pathology showed invasive breast carcinoma. She developed severe hyponatremia and a generalized seizure after completing the first cycle of neoadjuvant chemotherapy with CTX and doxorubicin. Laboratory tests showed a serum sodium of 118 mmol/L (normal range 135-145 mmol/L) and potassium sodium 3.16 mmol/L (normal range 3.5-5.5 mmol/L). Subsequently, the patient developed secondary diabetes insipidus 4 hours after sodium supplementation, her 24-hour urine volume was 4730 mL (normal range 1000-2000 mL/24 hours), and the urine specific gravity decreased to 1.005.

INTERVENTIONS

The patient was given intravenous sodium chloride (500 mL of 3%NaCl, 100 mL/hour) and potassium chloride (500 mL of 0.3%KCl, 250 mL/hour). Meanwhile, she was advised to reduce her water intake, and pituitrin was administered to prevent dehydration caused by diabetes insipidus.

OUTCOMES

The patient completely recovered after correcting of the serum sodium concentration (137 mmol/L) without any neurological deficits. After discontinuing pituitrin, her 24-hour urine volume was 2060 mL and the urine specific gravity was 1.015.

LESSONS

This is a typical case of severe hyponatremia induced by low-dose CTX. Clinicians and healthcare providers should be aware of this potential toxicity, and appropriate monitoring should be implemented.

The role of endoscopic endonasal salvage surgery in recurrent or residual craniopharyngioma after a transcranial approach: a systematic review

BACKGROUND

The management of craniopharyngiomas is challenging due to their high rate of recurrence following resection. Excision of recurrent tumors poses further surgical challenges due to loss of arachnoidal planes and adherence to anatomical structures. The endoscopic endonasal approach (EEA) offers a favorable alternative to transcranial approaches for primary craniopharyngiomas. However, the safety and efficacy of EEA for recurrent tumors, specifically after a prior transcranial approach, needs further investigation.

METHODS

We performed a systematic review using PubMed to develop a database of cases of recurrent craniopharyngiomas previously treated with a transcranial approach.

RESULTS

Fifteen articles were included in this review with a total of 75 cases. There were 50 males and 25 females with a mean age of 38 years (range 2-80). One prior transcranial surgery was done in 80.0% of cases, while 8.0% had two and 12.0% had more than two prior surgeries. Radiotherapy after transcranial resection was given in 18 cases (24.0%). Following EEA, vision improved in 60.0% of cases, and vision worsened in 8.6% of the cases. Of cases, 64.4% had pre-existing anterior hypopituitarism, and 43.8% had diabetes insipidus prior to EEA. New anterior hypopituitarism and diabetes insipidus developed in 24.6% and 21.9% of cases, respectively following EEA. Gross total resection (GTR) was achieved in 64.0%, subtotal resection in 32.0%, and partial resection in 4.0% revision EEA cases. GTR rate was higher in cases with no prior radiotherapy compared to cases with prior radiotherapy (72.0% vs 39.0%, p = 0.0372). The recurrence rate was 17.5% overall but was significantly lower at 10.0% following GTR (p = 0.0019). The average follow-up length was 41.2 months (range, 1-182 months).

CONCLUSION

The EEA can be utilized for resection of recurrent or residual craniopharyngiomas previously managed by a transcranial approach.

Persistent hypernatremia secondary to adipsic central diabetes insipidus in a patient with herpes-induced meningoencephalitis and COVID-19 infection: a case report

Central diabetes insipidus (CDI) typically manifests as a polyuria-polydipsia syndrome, in which normonatremia is generally maintained through the polydipsia. A 53-year-old woman presented with diabetic ketosis and hyperosmolar hyperglycemic syndrome. Her medical history included herpes meningoencephalitis, which was associated with confusion and amnesia. On physical examination, she was apyretic, confused, and had signs of extracellular dehydration. Her capillary glucose concentration was high and her urine was positive for ketones. Laboratory investigations revealed severe hyperglycemia, hypernatremia (plasma hyperosmolarity of 393.6 mOsm/L), and mild acute renal failure. In addition, she had a paucisymptomatic COVID-19 infection. Intravenous rehydration with isotonic saline solution and insulin therapy were effective at controlling the ketosis and ameliorating the hyperglycemia, but failed to normalize the hypernatremia and hyperosmolarity. She was not thirsty and had a urine output of 1 L/day, with urinary hypotonicity. Desmopressin administration reduced the hypernatremia and hyperosmolarity to within their normal ranges, and the patient's urinary osmolarity increased to 743 mOsm/L. Therefore, adipsic CDI was diagnosed. Endocrine investigations revealed isolated central hypothyroidism. The results of pituitary magnetic resonance imaging were normal. Thus, patients with impaired thirst may have an atypical presentation of CDI. In addition, the diagnosis of adipsic CDI is particularly challenging.

Urine concentration impairment in sickle cell anemia: genuine nephrogenic diabetes insipidus or osmotic diuresis?

The urine concentration impairment responsible for hyposthenuria in sickle cell nephropathy is currently thought to be a consequence of renal medulla lesions, which lead to nephrogenic diabetes insipidus. The objective of the present study was to investigate the mechanism of hyposthenuria in patients with sickle cell anemia. We performed an observational study of patients with homozygous SS sickle cell anemia and data available on the fasting plasma antidiuretic hormone (ADH) concentration. A total of 55 patients were analyzed. The fasting plasma ADH values ranged from 1.2 to 15.4 pg/mL, and 82% of the patients had elevated ADH values and low fasting urine osmolality (<505 mosmol/kgH2O). Plasma ADH was positively associated with plasma tonicity and natremia (P < 0.001). None of the patients experienced polyuria and fasting free water clearance was negative in all cases, thus, ruling out nephrogenic diabetes insipidus. The tertile groups did not differ with regard to fasting urine osmolality, plasma renin level, mGFR, or several hemolysis biomarkers. The negative fasting free water clearance in all cases and the strong association between 24-h osmolal clearance and 24-h diuresis favors the diagnosis of osmotic diuresis due to an impaired medullary gradient, rather than lesions to collecting tubule.NEW & NOTEWORTHY The urine concentration impairment in sickle cell anemia is an osmotic diuresis related to an impaired renal medullary gradient leading to an ADH plateau effect. The fasting plasma ADH was high in the context of a basic state of close-to-maximal urine concentration probably driven by short nephrons maintaining a cortex-outer medullary gradient (about 400 milliosmoles). The patients had a low daily osmoles intake without evidence of thirst dysregulation so no one experienced polyuria.

The Role of Tumor-Associated Hypothalamic Involvement in Surgical Treatment and Long-Term Outcome in Adult Patients with Craniopharyngioma

INTRODUCTION

Hypothalamic invasion in pediatric patients with craniopharyngioma negatively influences clinical outcomes. It has been shown that radiologic classification of hypothalamic invasion can effectively predict surgical strategies to minimize postoperative comorbidities in pediatric patients. However, no comparative analysis has been performed in adult patients with craniopharyngioma. This study implements the previously established radiologic classification to characterize postoperative morbidity, surgical outcome, and distress in adult patients with craniopharyngioma.

METHODS

Electronic medical records of 22 adult patients with craniopharyngioma were used to analyze patient demographics, surgical data, endocrinologic and ophthalmologic status, and histopathology in a retrospective single-center study. Questionnaires regarding postoperative distress (National Comprehensive Cancer Network Distress Thermometer and Problem List), comorbidities (Charlson Comorbidity Index), employment status, and need for supportive care were distributed. Magnetic resonance imaging scans were categorized according to Puget et al.

RESULTS

Patients with hypothalamic involvement show significantly higher rates of postoperative diabetes insipidus and higher scores on the National Comprehensive Cancer Network Distress Thermometer. This significant difference was lost when considering postoperative Puget grades. Puget grades 1 and 2 were found to be associated with the use of a subfrontal surgical approach (hazard ratio, 4.080; confidence interval, 1.153-14.431; P = 0.029).

CONCLUSIONS

Our results point toward a possible predictive role of preoperative hypothalamic invasion for postoperative diabetes insipidus as well as higher perceived levels of distress after surgery, which may be established in larger patient cohorts. Furthermore, a subfrontal surgical approach seems to be predicted by tumors with hypothalamic invasion. In this case, preoperative magnetic resonance imaging grading may help guide the planning of an optimal surgical strategy for adults with craniopharyngioma to reduce postoperative morbidity.

The Relationship Between Manifestation of Diabetes Insipidus and Estimated Glomerular Filtration Rate in Brain Death

OBJECTIVES

Systematic reviews have revealed that up to 50% of patients with brain death have residual hypothalamic/pituitary activity based on the absence of central diabetes insipidus (DI). We hypothesized that different degrees of renal dysfunction may impact the presence of DI in patients with brain death.

DESIGN

Single-center prospective data collection.

SETTING

ICUs in a tertiary academic hospital.

PATIENTS

All adult patients declared brain dead over 12 years.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

DI was diagnosed by polyuria, low urine specific gravity, and increasing serum sodium, measured in close proximity. Renal function was assessed by the estimated glomerular filtration rate (eGFR), calculated using the simplified modification of diet in renal disease equation. Analysis was completed in 192 of 234 patients with brain death after excluding those with missing data, those younger than 18 years and those on vasopressin infusions. One hundred twenty-two patients (63.5%) developed DI and 70 patients (36.5%) did not. The proportion of DI decreased significantly with decreasing eGFR: for eGFR greater than 60 mL/min, DI was present in 77.2%; for eGFR 15-60 mL/min, DI was present in 54.5%; for eGFR 14.9-9.8 mL/min, DI was present in 32%; none of the 14 patients with eGFR less than or equal to 9.7 mL/min ever experienced DI ( p < 0.001). Using logistic regression, for every 10 mL/min decrease in eGFR, the odds of DI decreased 0.83 times (95% CI, 0.76-0.90, p < 0.001).

CONCLUSIONS

Renal dysfunction significantly impacts DI's clinical manifestation in brain death. We report that patients who experience brain death with severe renal dysfunction may not develop clinical signs of DI.

Safety of withholding perioperative steroids for patients with pituitary resection with an intact hypothalamus-pituitary-adrenal axis: A meta-analysis of randomized clinical trials

INTRODUCTION

Several observational studies have evaluated the effects of pre-operative steroids (STER) for transsphenoidal pituitary removal in patients with an intact hypothalamus-pituitary-adrenal axis. However, a consensus built upon randomized studies has not been previously performed.

PURPOSE

To comprehensively evaluate the clinical effects of patients receiving STER when compared to those not receiving steroids (NOSTER) in transsphenoidal pituitary resection, a meta-analysis of randomized clinical trials (RCT) was conducted.

METHODS

A systematic review of the literature of RCTs comparing STER and NOSTER was performed in accordance with the PRISMA guidelines. Databases, including PUBMED, Cochrane Library, Web of Science, and Embase were queried. The primary outcomes were adrenal insufficiency (AI) and diabetes insipidus (DI) post-operatively.

RESULTS

A total of 4 final studies were included, in which 530 total patients were analyzed. The meta-analysis suggested that there was no significant difference between STER and NOSTER groups post-operatively related to transient AI (RR= 0.83, 95% CI [0.51-1.35], p = 0.45; I² = 52%), permanent AI (RR= 0.97, 95% CI [0.41-2.31], p = 0.95; I² = 0%), and permanent DI (RR= 0.62, 95% CI [0.16-2.33], p = 0.48; I² = 0%). Nevertheless, STER group had significantly lower rates of transient DI (RR= 0.60, 95% CI [0.38-0.95], p = 0.03; I² = 5%), and post-op hyponatremia (RR = 0.49, 95% CI [0.28-0.87], p = 0.02; I² = 0%).

CONCLUSION

This study demonstrates evidence from RCTs that patients receiving pre-operative STER are both safe and effective pre-operatively for resection of pituitary adenomas with an intact hypothalamus-pituitary-adrenal axis.

Pituitary metastases: a case series and scoping review

PURPOSE

To understand the natural history and optimal treatment strategy for pituitary gland metastasis.

METHODS

We performed both a retrospective chart review of patients treated at our institution and a scoping review of the topic.

RESULTS

The retrospective review identified seven patients with an average age of 59.6 years. Primary histologies included breast cancer (4), melanoma (1), renal cell carcinoma (1), and sarcoma (1). Two patients had anterior pituitary endocrine dysfunction, one of whom was the only patient with visual symptoms. All patients were treated with radiosurgery and two also underwent surgical resection. Overall survival ranged from 6.5 to 117 months. Literature review identified 166 patients from 71 studies. The most common primary cancer was lung (27.7%), followed by breast (18.7%) and renal (14.5%) cancer. 107 presented with endocrine dysfunction, including 41 cases of diabetes insipidus and 55 cases of hypopituitarism. 110 presented with visual compromise. 107 patients received radiotherapy, 96 underwent surgical resection and 44 received systemic chemotherapy/immunotherapy. Surgery was significantly associated with an increased likelihood of vision improvement and a decreased likelihood of endocrine normalization. Radiographic regression predicted visual improvement. Median overall survival was 9.9 months (range: 0.2-96).

CONCLUSIONS

This scoping review showed that both radiosurgery and surgical resection have been frequently used to treat pituitary metastases with good response. Vision improvement is more likely to happen following surgical resection, likely at the expense of endocrine dysfunction. Despite treatment and radiographic response, patient survival remains less than a year.

The safety of withholding hydrocortisone during preoperative periods in pituitary adenomas patients with an intact HPA axis: A meta-analysis of randomized controlled trials

OBJECTIVES

For patients with pituitary adenomas with an intact hypothalamus-pituitary-adrenal axis before surgery, whether routine steroid therapy is needed is still controversial. We conducted a meta-analysis to assess the safety of withholding hydrocortisone compared with hydrocortisone in pituitary adenoma patients during preoperative periods.

MATERIAL AND METHODS

We searched PubMed, Embase, Web of Science, and Cochrane Library databases up to November 2022 using inclusion and exclusion criteria. We employed either a fixed-effect or random-effect model for the analysis and assessed heterogeneity using the I2 statistic.

RESULTS

Three studies involving 512 patients out of 400 studies were conducted. The pooled data revealed a higher incidence of postoperative transient diabetes insipidus in the no-hydrocortisone group than in the hydrocortisone group (RR, 1.88; 95% CI, 1.13 to 3.12; p = 0.02). The cortisol level in the no-hydrocortisone group was lower than in the hydrocortisone group after tumor removal (mean difference, -36.82; 95% CI, -44.27 to -29.38; p < 0.00001) but higher on the second day after surgery (mean difference, 4.04; 95% CI, 2.38 to 5.71; p < 0.00001). No significant differences were observed in early adrenal insufficiency (RR, 1.04; 95% CI, 0.37 to 2.96; p = 0.93), adrenal insufficiency in the third month after surgery (RR, 1.56; 95% CI, 0.70 to 3.48; p = 0.28), cortisol level on the first day after surgery (mean difference, 0.24; 95% CI, -11.25 to 11.73; p = 0.97), postoperative permanent diabetes insipidus (RR, 1.61; 95% CI, 0.43 to 6.07; p = 0.48), postoperative delayed hyponatremia (RR, 1.06; 95% CI, 0.41 to 2.74; p = 0.91), or postoperative blood glucose level (mean difference, -0.41; 95% CI, -1.19 to 0.37; p = 0.31) between the no-hydrocortisone and hydrocortisone groups.

CONCLUSION

Withholding preoperative steroid therapy is safe for pituitary adenomas patients with an intact hypothalamus-pituitary-adrenal axis.

[Lithium-induced nephrogenic diabetes insipidus during acute intoxication: a case report]

In case of dehydration, lithium can cause acute intoxication. This picture is mainly manifested by neurological disorders that can go as far as coma, digestive disorders, hydroelectrolytic disorders, and cardiovascular disorders. We report the case of a patient followed for bipolar disorder for 20 years and treated with lithium for 14 years and who presented an acute lithium intoxication resulting from a diabetes insipidus. Our objective is to underline the importance of good hydration and strict monitoring of lithium levels especially in situations favouring dehydration, notably the polyuria of diabetes insipidus.

Characteristics and factors influencing hypothalamic pituitary dysfunction in patients with craniopharyngioma

Background

Craniopharyngioma is a benign tumor originating from the sellar region. Damages in this area caused by the tumor itself, surgery, or radiotherapy may result in severe hypothalamic-pituitary dysfunction (HPD) and eventually lead to a significant impairment in the long-term quality of life of patients. This study aimed to investigate the characteristics of HPD in patients with adamantinomatous craniopharyngioma (ACP) or papillary craniopharyngioma (PCP) and to identify the factors affecting HPD after surgery.

Methods

In this single-center retrospective study, a total of 742 patients with craniopharyngioma were included. The neuroendocrine function of these patients before and after surgery was investigated. The differences in hypothalamic-pituitary function between the ACP and PCP groups were compared. The factors influencing the aggravation of HPD after surgery were identified.

Results

The median follow-up after surgery was 15 months. Before surgery, the proportion of patients with diabetes insipidus (DI) and hyperprolactinemia in the PCP group was significantly higher than that in the ACP group (P<0.01), and the proportion of patients with adrenocortical hypofunction in the PCP group was significantly lower than that in the ACP group (P=0.03). Most cases of ACP originated in the sellar region, while most cases of PCP originated in the suprasellar region (P<0.01). More patients experienced adenohypophyseal hypofunction, DI, and hypothalamic obesity at postoperative follow-up than at onset in both the ACP and PCP groups (both P<0.01), with a higher increase observed in the ACP group (P<0.01). Older age at CP onset, tumor recurrence or progression, and ACP type were risk factors for postoperative aggravation of HPD in CP patients.

Conclusion

Surgical treatment significantly aggravated HPD in both the ACP and PCP groups, but the specific characteristics and risk factors leading to aggravation were different between the two groups.

Differences in clinical, hormonal, and radiological presentation and in surgical outcomes in patients presenting with and without pituitary apoplexy. A multicenter study of 245 cases

PURPOSE

To compare the clinical, hormonal, and radiological presentation and surgical outcomes of patients with macroadenomas presenting with pituitary apoplexy and patients not presenting pituitary apoplexy.

METHODS

Multicentre retrospective study of patients presenting with macroadenomas and pituitary apoplexy in three Spanish tertiary hospitals between 2008 and 2022. We selected as control group (non-pituitary apoplexy), patients with pituitary macroadenomas without apoplexy who underwent pituitary surgery between 2008 and 2020.

RESULTS

A total of 60 patients with apoplexy and 185 without apoplexy were enrolled. Patients with pituitary apoplexy were more frequently men (70% vs. 48.1%, p = 0.003), had higher prevalence of hypertension (43.3% vs. 26.0%, p = 0.011) and of obesity (23.3% vs. 9.7%, P = 0.007), were under treatment with anticoagulants more commonly (11.7% vs. 4.3%, P = 0.039) and had larger (27.5 ± 11.03 vs. 23.6 ± 12.55 mm, p = 0.035) and invasive pituitary macroadenomas more frequently (85.7% vs. 44.3%, P < 0.001) than those without apoplexy. Surgical remission was more frequent in patients with pituitary apoplexy than those without apoplexy (OR 4.55, P < 0.001), but they developed new pituitary deficits (OR 13.29, P < 0.001) and permanent diabetes insipidus (OR 3.40, P = 0.022) more commonly. However, visual improvement (OR 6.52, p < 0.001) and complete pituitary function recovery (OR 2.37, P < 0.001) was more common in patients without apoplexy.

CONCLUSION

Surgical resection is more common in patients presenting with pituitary apoplexy than those without apoplexy; however, visual improvement and complete recovery of pituitary function is more common in patients without apoplexy. The risk of new pituitary deficits and permanent diabetes insipidus is higher in patients with apoplexy than in those without it.

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.

Hand-Schüller-Christian syndrome combined with empty sella syndrome: A case report and literature review

RATIONAL

Hand-Schüller-Christian syndrome (HCS) is a rare disease with little clinical awareness, but the condition is more dangerous, and it combines with empty sella syndrome (ESS) which is extremely rare.

PRESENTATION

A 26-year-old male patient who had proptosis, headaches, and diabetes insipidus for more than 10 years, and chronic cough and wheeze for 8 years presented to our hospital due to an abrupt onset of chest pain for 2 days.

DIAGNOSIS

Hand-Schüller-Christian syndrome is diagnosed based on the typical clinical manifestations of diabetes insipidus and bilateral proptosis, magnetic resonance imaging (MRI) pituitary imaging and pathology. Empty sella syndrome is diagnosed based on hormonal indicators, clinical manifestations and MRI pituitary scan results. Type 1 respiratory failure and severe pneumonia can be diagnosed based on the results of clinical examination, chest imaging (including chest x-ray and computed tomography), pathology and blood gas analysis. Left pneumothorax can be diagnosed with chest imaging.

INTERVENTIONS

"Meropenem and Cefdinir" were given for antimicrobrial coverage, "Desmopressin acetate" for anti-diuretic treatment, "Forcodine" for cough relief, "Ambroxol and acetylcysteine" for phlegm reduction, and continuous closed chest drainage was performed.

OUTCOMES

The patient discharged after cough, wheezing, headache and other symptoms improved, and vital signs were stable. The patient has been followed up once a month for 17 months ongoing after discharge. At present, symptoms such as cough, sputum, and wheezing have improved considerably, and the mMRC score of dyspnea is 2 points. The reexamination of the chest X-ray shows that the absorption of lung exudates is better than before, and there is no recurrence of pneumothorax.

LESSONS

Consider whether isolated diabetic insipidus is related to HSC, and if so, conduct an MRI, a biopsy, and other examinations as soon as possible.

Effect of pituitary adenoma consistency on surgical outcomes in patients undergoing endonasal endoscopic transsphenoidal surgery

BACKGROUND

Most pituitary adenomas (PAs) are considered to have a soft tumor consistency. However, there is a non-negligible percentage (5-13%) of tumors presenting or exhibiting a fibrous consistency that would entail a more difficult and complicated surgical excision with higher surgical morbidity and mortality rates.

PURPOSE

To analyze the clinical consequences of PA tumor consistency on the surgical outcomes in patients undergoing endonasal endoscopic transsphenoidal (EET) pituitary surgery.

METHODS

An ambispective study of patients with PAs operated on through an EET approach in two Spanish tertiary hospitals over the last 12 years. A total of 226 consecutive interventions were carried out in the Neurosurgery Departments of the Hospital Universitario Ramón y Cajal (HURC) and the Hospital Universitario Puerta del Sur by the same neurosurgeon. PAs were grouped into soft (n = 150) and fibrous (n = 76). All patients underwent hormonal and magnetic resonance imaging (MRI) studies before and after surgery. In addition, neurosurgical complications were recorded in each patient.

RESULTS

Fibrous adenomas were independently associated with lower resection rates compared to soft adenomas (fibrous gross total resection [GTR] rate 48.7% vs. 76.3%, p &lt; 0.001), even in those adenomas without invasion of the cavernous sinus (Knosp grades 0, I, and II). There were more intraoperative cerebrospinal fluid (CSF) leaks in patients with fibrous PAs. Moreover, fibrous PAs showed higher rates of postoperative hypopituitarism, permanent diabetes insipidus (DI) and postoperative treatments (hormonal treatment and radiotherapy). The excision of a fibrous PA required a longer surgical time (22.5 min more than soft PAs, p = 0.014), regardless of other factors.

CONCLUSION

The consistency of the PAs significantly conditions both the results of surgery (lower resections rates), complications (higher incidence of postoperative hypopituitarism, permanent DI), and the prognosis (higher incidence of postoperative treatments) of the patient undergoing EET.

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.

The sellar region as presenting theater for hematologic malignancies-A 17-year single-center experience

Hematological neoplastic mass lesions of the sellar region are rare. We identified five cases of hematological malignancy with first presentation in the sellar region from our departmental database of 1,405 patients (0.36%) with sellar lesions diagnosed over the 17-year period (2005-2021). All patients were females (mean age 55.2 ± 3.4 years). One patient had multiple myeloma (MM), one patient had acute myeloid leukemia (AML), while three other patients had lymphoma (intravascular lymphoma (IVL, n = 1) or non-Hodgkin's lymphoma (NHL, n = 2). Most patients presented with ophthalmoplegia, and one patient with diabetes insipidus (DI), with short duration of symptoms (median 30 days). All patients had an elevated erythrocyte sedimentation rate and altered blood count, while patients with lymphoma had elevated lactate dehydrogenase (LDH). Sellar mass was demonstrated in three patients while the patient with IVL had an empty sella and in the AML patient posterior lobe T1W hyperintensity was lost. Two patients (IVL and NHL) presented with multiple anterior pituitary deficiencies and one patient (AML) had DI. All patients were treated with chemotherapy. Two patients responded well to treatment (one had reversed hypopituitarism), while three patients died. Differential diagnosis of sellar-parasellar pathology should include suspicion of hematological malignancy, particularly in patients with short duration of nonspecific symptoms, neurological signs (ophthalmoplegia), blood count alterations and LDH elevation, pituitary dysfunction and imaging features atypical for pituitary adenoma. Early diagnosis is crucial for timely initiation of hematological treatment aimed at inducing disease remission and partial or full recovery of pituitary function.

Postoperative complications after endoscope-assisted transsphenoidal surgery for pituitary adenomas: a case series, systematic review, and meta-analysis of the literature

PURPOSE

Endoscope-assisted transsphenoidal surgery over the last few years has led to more radical excision of pituitary adenomas (PAs) with a low complication rate. Systematic registration of complications by experienced surgical teams could help to improve this technique while ameliorating the patients' quality of life.

MATERIALS AND METHODS

One hundred ten endoscopic procedures were performed in 94 patients with PAs (37 functional) by the same neurosurgical team of a tertiary center during the period 2014-2019. Post-surgical complications were analyzed and compared with data published during the last 5 years in the PubMed and Cochrane databases by performing a systematic review and meta-analysis of the literature.

RESULTS

The overall complication rate in our series was 23.4%. Diabetes insipidus (DI) and intraoperative cerebrospinal fluid (CSF) leakage were the commonest complications (12.8%), followed by postoperative hypopituitarism (9.2%) and hematoma (8.5%) during the follow-up of 2.15 ± 1.4 years. Syndrome of inappropriate antidiuretic hormone secretion, meningitis, deep vein thrombosis, and hyposmia were rare (< 3%). Postoperative hypopituitarism was significantly associated with incidence of hematoma. No statistically significant association was found between PAs Hardy and Knosp scale grading or between patients' characteristics with the occurrence of postoperative complications. Our meta-analysis including nine studies found no significant differences comparing the complications of endoscopic versus microscopic surgery.

CONCLUSION

The endoscopic approach is safe when performed by experienced surgical teams. CSF leakage and DI were the commonest complications in our series; however, confirmation by larger studies is required. Meta-analysis showed no statistically significant differences in complication rates comparing endoscopic versus microscopic surgery.

Preoperative differentiation of hypophysitis and pituitary adenomas using a novel clinicoradiologic scoring system

PURPOSE

Hypophysitis can clinically and radiologically mimic other nonfunctioning masses of the sella turcica, complicating preoperative diagnosis. While sellar masses may be treated surgically, hypophysitis is often treated medically, so differentiating between them facilitates optimal management. The objective of our study was to develop a scoring system for the preoperative diagnosis of hypophysitis.

METHODS

A thorough literature review identified published hypophysitis cases, which were compared to a retrospective group of non-functioning pituitary adenomas (NFA) from our institution. A preoperative hypophysitis scoring system was developed and internally validated.

RESULTS

Fifty-six pathologically confirmed hypophysitis cases were identified in the literature. After excluding individual cases with missing values, 18 hypophysitis cases were compared to an age- and sex-matched control group of 56 NFAs. Diabetes insipidus (DI) (p < 0.001), infundibular thickening (p < 0.001), absence of cavernous sinus invasion (CSI) (p < 0.001), relation to pregnancy (p = 0.002), and absence of visual symptoms (p = 0.007) were significantly associated with hypophysitis. Stepwise logistic regression identified DI and infundibular thickening as positive predictors of hypophysitis. CSI and visual symptoms were negative predictors. A 6-point hypophysitis-risk scoring system was derived: + 2 for DI, + 2 for absence of CSI, + 1 for infundibular thickening, + 1 for absence of visual symptoms. Scores ≥ 3 supported a diagnosis of hypophysitis (AUC 0.96, sensitivity 100%, specificity 75%). The scoring system identified 100% of hypophysitis cases at our institution with an estimated 24.7% false-positive rate.

CONCLUSIONS

The proposed scoring system may aid preoperative diagnosis of hypophysitis, preventing unnecessary surgery in these patients.

Approach to the Patient: "Utility of the Copeptin Assay"

Copeptin derives from the same precursor peptide preprovasopressin as arginine vasopressin (AVP). The secretion of both peptides is stimulated by similar physiological processes, such as osmotic stimulation, hypovolemia, or stress. AVP is difficult to measure due to complex preanalytical requirements and due to technical difficulties. In the last years, copeptin was found to be a stable, sensitive, and simple to measure surrogate marker of AVP release. Different immunoassays exist to measure copeptin. The 2 assays which have most often be used in clinical studies are the original sandwich immunoluminometric assay and its automated immunofluorescent successor. In addition, various enzyme-linked immunosorbent assay have been developed. With the availability of the copeptin assay, the differential diagnosis of diabetes insipidus was recently revisited. The goal for this article is therefore to first review the physiology of copeptin, and second to describe its use as marker for the differential diagnosis of vasopressin-dependent fluid disorders, mainly diabetes insipidus but also hyper- and hyponatremia. Furthermore, we highlight the role of copeptin as prognostic marker in other acute and chronic diseases.

Course of Cushing`s disease and treatment outcomes in correlation with pituitary MRI in children

BACKGROUND

Cushing's disease (CD) is a rare disorder of a persistent cortisol excess caused by ACTH-secreting pituitary tumor (corticotropinoma). Transsphenoidal surgery (TSS) is a treatment of choice for СD, which effectiveness range is from 70 to 90%. Recurrence rate after successful treatment is about 25%. If surgical treatment is unsuccessful or recurrence appear, radiation treatment is the next therapeutic option, which effectiveness range is also 90%, but the hypopituitarism rate as side effect of treatment is higher. Preoperative predictors of remission and recurrence are still unexplored what leads to further investigations.

AIM

Analysis of remission and recurrence rates of pediatric CD after successful treatment according to preoperative MRI and therapeutic option.

MATERIALS AND METHODS

We conducted a retrospective analysis of 90 pediatric patients with CD who were observed between 1992 and 2020 at the Endocrinology Research Centre.

RESULTS

The most common clinical symptoms of CD were weight gain [94%] and growth retardation [72%]. Pituitary tumor was detected on radiological imaging in 53/90 patients [59%], there were no signs of visible adenoma in 37/90 of patients [41%]. 63 of 90 patients underwent TSS (70%), 27 patients underwent radiosurgery (30%). Remission rate after TSS was 71% [45/63], after radiosurgery - 85% [23/27]. There were no significant differences in remission rates after radical treatment according to preoperative MRI results (P=0.21 after TSS and P=0.87 after radiosurgery, х2 analysis). Recurrence after successful treatment was diagnosed in 10 patients. There were no significant differences in time to recurrence according to preoperative MRI results (P=0.055, х2 analysis). Time to recurrence was statistically different after TSS compared to radiosurgery (P=0.007, Kaplan-Meier analysis) and in the group with developed adrenal insufficiency in the early postoperative period (P=0.04, Kaplan-Meier analysis). Analysis of side effect of treatment showed that the frequency of growth hormone and gonadotrophin deficiency was statistically higher after radiosurgery (р&lt;0.01, Kruskel-Wallis ANOVA test). Diabetes insipidus was diagnosed only after TSS.

CONCLUSION

Results of our study didn`t allow to use MRI-results as predictor of effectiveness treatment in pediatric CD. Therapeutic option has an impact on time to recurrence, not on recurrence rates. The frequency of growth hormone and gonadotrophin deficiency was statistically higher after radiosurgery compared to TSS. Further studies are needed to identify predictors of remission and recurrence in CD.&gt;&lt; 0.01, Kruskel-Wallis ANOVA test). Diabetes insipidus was diagnosed only after TSS.

CONCLUSION

Results of our study didn`t allow to use MRI-results as predictor of effectiveness treatment in pediatric CD. Therapeutic option has an impact on time to recurrence, not on recurrence rates. The frequency of growth hormone and gonadotrophin deficiency was statistically higher after radiosurgery compared to TSS. Further studies are needed to identify predictors of remission and recurrence in CD.

A Rare Case of Pediatric Xanthoma Disseminatum With Diabetes Insipidus and BRAF p.V600E Mutation

ABSTRACT

Xanthoma disseminatum (XD) is a rare non-Langerhans cell histiocytosis characterized by xanthomatous lesions in the absence of hyperlipidemia. XD usually develops in young adults, and there are rare cases among children. BRAF mutations are frequent in Langerhans cell histiocytosis and Erdheim-Chester disease but absent or only rarely detected in other histiocytosis. Herein, we described a 6-year-old Chinese girl presented with generalized skin lesions and diabetes insipidus for 5 months. There were multiple periorbital xanthelasma with histopathological features of foamy histiocytes infiltration with Touton cells. Pituitary magnetic resonance imaging showed pituitary enlargement and pituitary stalk thickening. The presence of BRAF p.V600E mutation makes this case distinctive and also offers a potential therapeutic target. According to our review of the literature, this is the first pediatric XD with diabetes insipidus and BRAF mutation.

An Atypical Case of Late-Onset Wolfram Syndrome 1 without Diabetes Insipidus

Wolfram syndrome 1, a rare autosomal recessive neurodegenerative disease, is caused by mutations in the WFS1 gene. It is characterized by diabetes insipidus, diabetes mellitus, optic atrophy, and deafness (DIDMOAD), and other clinical manifestations such as urological and neurological disorders. Here we described the case of a patient with an atypical late-onset Wolfram syndrome 1 without DI. Our WS1 patient was a c.1620_1622delGTG (p.Trp540del)/c.124 C > T (p.Arg42*) heterozygous compound. The p.Arg42* nonsense mutation was also found in heterozygosity in his sister and niece, both suffering from psychiatric disorders. The p.Arg42* nonsense mutation has never been found in WS1 and its pathogenicity is unclear so far. Our study underlined the need to study a greater number of WS1 cases in order to better understand the clinical significance of many WFS1 variants.

Desmopressin treatment in dipsogenic form of primary polydipsia: keep serum osmolality marginally below thirst threshold for symptomatic relief

Dipsogenic polydipsia (DP), a distinct variety of primary polydipsia, is characterised by selective diminution of osmotic threshold for thirst leading to polydipsia and subsequent hypotonic polyuria. Seen in patients without underlying psychiatric illness, DP closely mimics central diabetes insipidus (CDI), making it difficult for clinicians to discriminate these two conditions from each other. Carefully performed osmotic stimulation study, incorporating objective assessment of threshold for thirst and arginine vasopressin (AVP) release is the key to differentiate DP from CDI or psychogenic polydipsia, also termed compulsive water drinking (CWD). Low thirst threshold and high AVP release threshold separate DP from CDI and CWD, respectively. Unlike CWD, desmopressin may be successfully used in DP without concomitant risk of hyponatremia. We describe a child, in whom an initial diagnosis of partial CDI was subsequently revised to DP based on osmotic stimulation test. The child was treated successfully with desmopressin therapy with a target to keep serum osmolality close to thirst threshold.

Fully endoscopic endonasal approach for the treatment of intrasellar arachnoid cysts

PURPOSE

To report our experience of endoscopic endonasal obliteration of symptomatic sellar arachnoid cyst (SAC).

METHODS

From 2002 to 2019, we retrospectively reported the data of 17 cases of SAC operated in Timone University Hospital, Marseille, France. Preoperative clinical findings were collected including main symptoms, visual function and endocrinological assessment. Surgical procedure was homogeneous and consisted in endonasal fully endoscopic surgical obliteration of the cyst cavity with fat graft. Post-operative outcomes, complication and follow-up was reported.

RESULTS

Visual disorders and/or headaches were the main symptoms. Our technique provided improvement for 83.3% of the patients suffering from visual disturbance and for 87.5% of those suffering from headaches. We reported 2 cases of cerebrospinal fluid (CSF) leakage (11.8%), but no meningitis. One case of definitive diabetes insipidus occurred and one case of postoperative syndrome of inappropriate antidiuretic hormone secretion was temporary. There was one case of recurrence reported. The mean follow-up was 39 months.

CONCLUSION

Patients with symptomatic SAC can be treated successfully by endoscopic endonasal obliteration of the cyst. This simple technique offers true benefits for the patients without craniotomy, but the complication rate remains high especially with the risk of CSF leakage. Special attention to skull base opening and closing could reduce this risk.

Safety of endoscopic endonasal biopsy for the pituitary stalk-hypothalamic lesions

PURPOSE

The indications for and the optimal biopsy approach in pituitary stalk-hypothalamic (PsH) lesions are controversial. Biopsies through an endoscopic endonasal approach (EEA) for PsH lesions have often been considered to cause the infundibulo-tuberal syndrome. The purpose of this study was to analyze the surgical and endocrinological safety of EEA biopsies for PsH lesions.

METHODS

A total of 39 consecutive patients who underwent an EEA biopsy between June 2011 and August 2020 in a single institute were retrospectively analyzed. The ophthalmological and endocrinological outcomes were assessed before and after surgery.

RESULTS

PsH lesions were confirmed to be diverse pathological diagnoses, ranging from lymphocytic hypophysitis to diffuse midline glioma, and the most common pathologic diagnosis was a germinoma (18 patients, 46.2%). No patients developed visual deterioration after the biopsy. In patients without preoperative panhypopituitarism, 13 out of 28 patients (46.4%) developed new anterior pituitary hormonal deficiencies after the biopsy. When the tissue was collected from the stalk, the endocrinological deterioration rate was 100% (6 of 6 patients), while the rate was 31.8% (7 of 22 patients) when tissue could be harvested from an extra-stalk lesion. The rate of newly developed permanent diabetes insipidus after surgery was 40.9% (9 of 22 patients). The median surgery time was 125 min, and there was no postoperative CSF leakage or infections noted.

CONCLUSIONS

An EEA biopsy for PsH lesions is a safe and efficient surgical method unless the tissue is collected from the stalk.

Ketoacidosis, Hypertriglyceridemia and Acute Pancreatitis Induced by Soft Drink Polydipsia in a Patient with Occult Central Diabetes Insipidus

A 21-year-old Japanese man without known diabetes mellitus had abdominal pain. The diagnosis was ketoacidosis and hypertriglyceridemia-induced acute pancreatitis. He had polydipsia and polyuria and had habitually drunk several soft drinks every day for two years. After hospitalization, despite adequate liquid intake, dehydration remained with hypotonic polyuria. Further examinations revealed the coexistence of central diabetes insipidus (CDI), possibly caused by lymphocytic infundibulo-neurohypophysitis, based on anti-rabphilin-3A antibody positivity. Although CDI had been undiagnosed for two years, over-consumption of sugar-rich soft drinks to ease thirst caused ketoacidosis, hypertriglyceridemia, and acute pancreatitis. There are no previous reports of this three-part combination of symptoms caused by CDI.

Analysis of thyroid involvement in children and adult Langerhans cell histiocytosis: An underestimated endocrine manifestation

BACKGROUND

Langerhans cell histiocytosis (LCH) is a rare disease caused by the clonal expansion of CD1a+/CD207+ LCH cells. The thyroid involvement in LCH has mostly been described in case reports.

METHODS

We retrospectively evaluated the clinical characteristics, diagnosis, and treatment of 27 children and adult patients with thyroid LCH in our center between 2010 and 2021.

RESULTS

The incidence of thyroid LCH was 14.00% (7/50) in children and 10.10% (20/198) in adults, respectively. Among patients with thyroid involvement, 81.5% presented with diabetes insipidus (DI) as the first symptom, and 51.9% complained of neck swelling or mass. Children and adults with thyroid LCH had higher frequencies of the hypothalamic-pituitary axis (HPA) (children: 100% vs. 62.8%, P=0.05; adult: 95% vs. 42.1%, P<0.001), the lung (children: 85.7% vs. 25.6%, P=0.004; adult: 70% vs. 50.6%, P=0.099), and a lower frequency of bone (children: 14.3% vs. 55.8%, P=0.049; adult: 45% vs. 73.6%, P=0.008) involvement than patients without thyroid involvement. Patients with thyroid LCH had a higher frequency of primary hypothyroidism and a lower frequency of euthyroidism than patients without it. The two major types of ultrasound imaging were diffuse (55%) and nodular type (45%). The standardized uptake value of thyroid on 18-F-fluorodeoxyglucose positron emission tomography/computed tomography was 5.3-12.8. The diagnoses were confirmed using thyroid aspiration (54.5%) or surgery (45.5%). In addition, thyroid LCH combined with papillary thyroid carcinoma was not rare (2/27).

CONCLUSION

Thyroid involvement in LCH is not rare. Furthermore, identifying thyroid involvement can facilitate the pathological diagnosis of LCH. Therefore, the possibility of thyroid LCH should be fully investigated in patients with DI, primary hypothyroidism, abnormal thyroid ultrasound results, and multi-system disease. In addition, thyroid aspiration can confirm suspected thyroid LCH. Finally, special attention should be paid to evaluating HPA and pulmonary involvement in thyroid LCH.

Upper urinary dilatation and treatment of 26 patients with diabetes insipidus: A single-center retrospective study

OBJECTIVE

To describe the urinary tract characteristics of diabetes insipidus (DI) patients with upper urinary tract dilatation (UUTD) using the video-urodynamic recordings (VUDS), UUTD and all urinary tract dysfunction (AUTD) systems, and to summarize the experience in the treatment of DI with UUTD.

METHODS

This retrospective study analyzed clinical data from 26 patients with DI, including micturition diary, water deprivation tests, imaging data and management. The UUTD and AUTD systems were used to evaluate the urinary tract characteristics. All patients were required to undergo VUDS, neurophysiologic tests to confirm the presence of neurogenic bladder (NB).

RESULTS

VUDS showed that the mean values for bladder capacity and bladder compliance were 575.0 ± 135.1 ml and 51.5 ± 33.6 cmH₂O in DI patients, and 42.3% (11/26) had a post-void residual >100 ml. NB was present in 6 (23.1%) of 26 DI patients with UUTD, and enterocystoplasty was recommended for two patients with poor bladder capacity, compliance and renal impairment. For the 24 remaining patients, medication combined with individualized and appropriate bladder management, including intermittent catheterization, indwelling catheter and regular voiding, achieved satisfactory results. High serum creatinine decreased from 248.0 ± 115.8 μmoI/L to 177.4 ± 92.8 μmoI/L in 12 patients from a population with a median of 108.1 μmoI/L (IQR: 79.9-206.5 μmoI/L). Forty-four dilated ureters showed significant improvement in the UUTD grade, and the median grade of 52 UUTD ureters decreased from 3 to 2.

CONCLUSION

Bladder distension, trabeculation and decreased or absent sensations were common features for DI patients with UUTD. Individualized therapy by medication combined with appropriate bladder management can improve UUTD and renal function in DI patients.

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.

Autosomal dominant familial neurohypophyseal diabetes insipidus caused by a novel missense mutation in AVP gene in a large Italian kindred

PURPOSE

Familial neurohypophysial diabetes insipidus (FNDI), commonly caused by autosomal dominant arginine vasopressin (AVP) mutations, is a rare condition in which vasopressin fails in regulating body's level of water with final polyuria and polydipsia. Genetic testing in familial cases of FNDI should be carry out to ensure adequate treatments and avoid disease manifestations especially in infants.

METHODS

In this study, we investigated three-generations of a large Italian family with clinical diagnosis of familial central diabetes insipidus for the presence of potential pathogenic mutations in the AVP gene.

RESULTS

We identified a heterozygous missense mutation (c.154 T > A; p.C52S) in AVP gene in all affected members studied of a large Italian family. In silico tools were used to investigate the pathogenic role of the mutation and three-dimensional protein structure predicted that the p.C52S impairs disulfide bridges formation resulting in misfolding of the protein.

CONCLUSIONS

This is the first study that identified a novel missense p.C52S mutation as causative of central diabetes insipidus in a large Italian pedigree.

Effects of oral macimorelin on copeptin and anterior pituitary hormones in healthy volunteers

PURPOSE

The test with the highest diagnostic accuracy for diabetes insipidus is copeptin measurement after hypertonic saline infusion. However, the procedure is cumbersome and unpleasant due to rapid sodium increase. An oral stimulation test would be highly desirable. Macimorelin, an oral ghrelin agonist, is a newly approved diagnostic test for growth hormone (GH) deficiency, but its effects on copeptin/vasopressin are unknown and the effects on other pituitary hormones only scarcely investigated.

METHODS

In this prospective, interventional, proof-of-concept study Copeptin and anterior pituitary hormones were measured in 28 healthy volunteers on two test days at baseline, 30, 45, 60, 90 and 120 min after a single dose of macimorelin (first visit: 0.5 mg/kg, second visit: 0.75 mg/kg).

RESULTS

Baseline copeptin levels were 5.26 pmol/L [1.57, 6.81] and did not change after macimorelin intake (0.5 mg/kg: maximal median change 0.40 [- 0.49, 0.65] pmol/L, p = 0.442; 0.75 mg/kg: - 0.13 [- 0.45, 0.17] pmol/L, p = 0.442. Median GH levels increased from 3.67 mU/L with a maximal median change of 94.66 [IQR 56.5; 110.96] mU/L, p < 0.001. No effect was seen on cortisol, ACTH, LH and FSH levels. Prolactin (max. median change 100 [2.5; 146.5] mU/L, p = 0.004) and free thyroxine (fT4) (0.5 [0.2; 0.8] pmol/L, p < 0.001) increased, whereas TSH decreased (- 0.18 [- 0.22, - 0.09] mU/L, p < 0.001).

CONCLUSION

We confirm an increase of GH upon macimorelin in healthy volunteers. However, macimorelin did not stimulate copeptin and therefore does not provide an oral test alternative for the diagnosis of diabetes insipidus. Additionally, a stimulatory effect was seen for prolactin and fT4, but not for ACTH and gonadotropic hormones.

REGISTRATION

The trial was registered on ClinicalTrials.gov (NCT03844217) on February 18, 2019.

Familial neurohypophyseal diabetes insipidus: clinical, genetic and functional studies of novel mutations in the arginine vasopressin gene

PURPOSE

Familial neurohypophyseal diabetes insipidus (FNDI) is a rare disorder characterized by childhood-onset progressive polyuria and polydipsia due to mutations in the arginine vasopressin (AVP) gene. The aim of the study was to describe the clinical and molecular characteristics of families with neurohypophyseal diabetes insipidus.

METHODS

Five Portuguese families with autosomal dominant FNDI underwent sequencing of the AVP gene and the identified mutations were functionally characterized by in vitro studies.

RESULTS

Three novel and two recurrent heterozygous mutations were identified in the AVP gene. These consisted of one initiation codon mutation in the signal peptide coding region (c.2T > C, p.Met1?), three missense mutations in the neurophysin II (NPII) coding region (c.154T > C, p.Cys52Arg; c.289C > G, p.Arg97Gly; and c.293G > C, p.Cys98Ser), and one nonsense mutation in the NPII coding region (c.343G > T, p.Glu115Ter). In vitro transfection of neuronal cells with expression vectors containing each mutation showed that the mutations resulted in intracellular retention of the vasopressin prohormone. Patients showed progressive symptoms of polyuria and polydipsia, but with wide variability in severity and age at onset. No clear genotype-phenotype correlation was observed.

CONCLUSION

The intracellular accumulation of mutant vasopressin precursors supports the role of cellular toxicity of the mutant proteins in the etiology of the disorder and explains the progressive onset of the disorder. These findings further expand the AVP mutational spectrum in FNDI and contribute to the understanding of the molecular pathogenic mechanisms involved in FNDI.

The role of reoperation after recurrence of Cushing's disease

Surgical failure or recurrence of Cushing's disease can be treated with medical therapy, radiotherapy, adrenalectomy, and/or repeat transsphenoidal surgery, all of which have their respective benefits and drawbacks. Redo transsphenoidal surgery has been shown to achieve at least short-term remission in about 40-80% of patients and is associated with low rates of morbidity and near-zero mortality, albeit higher rates of postoperative hypopituitarism, diabetes insipidus, and cerebrospinal fluid leak than initial resection. Despite this, recurrence may ensue in 50% of patients. When selecting patient candidates for reoperation, many predictors of postoperative outcomes have been proposed including imaging characteristics, histopathological staining, intraoperative tumor visualization, and tumor size, however no single predictor consistently predicts outcomes. Redo transsphenoidal surgery should be performed by an experienced pituitary surgeon and patients should be followed at a tertiary care center by a multidisciplinary team consisting of an experienced endocrinologist and neurosurgeon to monitor closely for remission and recurrence.

Autoimmune diabetes insipidus

Once central diabetes insipidus (CDI) has been diagnosed, every effort should be made to reveal its underlying cause. Autoimmune CDI should be considered in the differential diagnosis of idiopathic CDI and also of mass lesions of the sella region. An autoimmune etiology of CDI was first suggested in 1983 by the detection of autoantibodies to hypothalamic vasopressin-producing cells (AVPcAb) in adults and also in children with the disease, using the indirect immunofluorescence test. The major autoantigen for autoimmune CDI has now been recognized as rabphilin-3A, a protein of secretory vesicles of the neurohypophyseal system. The detection of autoantibodies to rabphilin-3A by Western blotting or of AVPcAb provides strong evidence for the diagnosis of autoimmune CDI. Autoimmune CDI is recognized mostly in patients who had also been diagnosed with endocrine autoimmune disorders. The radiological and morphological correlate with autoimmune DI is lymphocytic infundibuloneurohypophysitis (LINH) as detected by magnetic resonance imaging and biopsies that show massive infiltration of the posterior pituitary and the infundibulum with lymphocytes and some plasma cells, and fibrosis in the later stages of the disease. LINH may be associated with lymphocytic anterior hypophysitis. Both may either appear spontaneously or on treatment with immune checkpoint inhibitors.

Low arginine vasopressin levels in patients with diabetes insipidus are not associated with anaemia

OBJECTIVE

Arginine vasopressin (AVP) is released upon osmotic stimulation or hypovolaemia in order to maintain water balance. A recent study showed a role of AVP in haematopoiesis by stimulating red blood cell precursors, suggesting a higher risk of anaemia in patients with AVP deficiency. The objective was to explore the effect of low AVP levels in patients with central diabetes insipidus (cDI) and primary polydipsia (PP) on haemoglobin and the prevalence of anaemia.

METHODS

A total of 164 patients with either cDI (70, 43%) or PP (94, 57%) and 30 healthy volunteers from two prospective diagnostic studies performed in Switzerland, Germany and Brazil were studied. A standardized clinical and biochemical (eg copeptin, full blood count) assessment was performed. Haemoglobin and haematocrit levels and prevalence of anaemia (defined as haemoglobin values of <120 g/L in women and <130 g/L in men) were analysed.

RESULTS

Mean copeptin values were 2.63 pmol/L (±1.08) and 3.91 pmol/L (±4.28) in patients with cDI and PP and 24.76 pmol/L (±5.75) in healthy volunteers, P = .02. The prevalence of anaemia was low in all participants with 7.1%, 2.2% and 10% in cDI, PP and in healthy volunteers, P = .15. Mean haemoglobin values were similar in all groups: 139 g/L (±15.85), 140 g/L (±13.16) and 139 g/L (±13.05) in patients with cDI, PP and healthy volunteers, P = .90, as were mean haematocrit values with 41% in all groups (P = .85).

CONCLUSION

Chronic low AVP levels in patients with cDI and PP do not affect haemoglobin levels and prevalence of anaemia.

For Debate: Personalized Health Care: As Exemplified by Home Sodium Measurements in a Child with Central Diabetes Insipidus and Impaired Thirst Perception

BACKGROUND

We describe a 6-year old boy with central diabetes insipidus (CDI) caused by destruction of the pituitary gland due to treatment of an optical pathway glioma. He has been treated with chemotherapy and has had several debulking operations over the past years and consequently developed central hypocortisolism, hypothyroidism and CDI. The treatment of CDI was gravely complicated by an impaired thirst perception and compulsive drinking behavior. He was frequently seen at the ER or admitted due to dysregulation of fluid balance.

METHODS

In order to provide better self-reliance, home point of care testing (POCT) sodium measurement was introduced.

RESULTS

Realizing POCT sodium measurement resulted in a significant decrease of ER visits and clinical admissions due to dysregulation of fluid balance.

CONCLUSION

This case is an example of personalized health care and has led to better self-reliance and quality of life.