Studies on anti-rabphilin-3A antibodies in 15 consecutive patients presenting with central diabetes insipidus at a single referral center.

Central diabetes insipidus (CDI) is a rare condition caused by various underlying diseases including inflammatory and autoimmune diseases, and neoplasms. Obtaining an accurate definitive diagnosis of the underlying cause of CDI is difficult. Recently, anti-rabphilin-3A antibodies were demonstrated to be a highly sensitive and specific marker of lymphocytic infundibuloneurohypophysitis (LINH). Here, we report a detailed case series, and evaluated the significance of anti-rabphilin-3A antibodies in differentiating the etiologies of CDI. A prospective analysis was conducted in 15 consecutive patients with CDI from 2013 to 2020 at a single referral center. Anti-rabphilin-3A antibodies were measured and the relationship between antibody positivity and the clinical/histopathological diagnoses was evaluated. Among 15 CDI patients, the positive anti-rabphilin-3A antibodies were found in 4 of 5 LINH cases, 3 of 4 lymphocytic panhypophysitis (LPH) cases, one of 2 sarcoidosis cases, and one intracranial germinoma case, respectively. Two Rathke cleft cyst cases and one craniopharyngioma case were negative. This is the first report of anti-rabphilin-3A antibodies positivity in CDI patients with biopsy-proven LPH. Measurement of anti-rabphilin-3A antibodies may be valuable for differentiating CDI etiologies.

Type 1 diabetes mellitus following COVID-19 RNA-based vaccine.

The epidemic of coronavirus disease-2019 (COVID-19) is the major public health issue in the world. COVID-19 vaccines are one of the most effective strategies against COVID-19. Here we report a 36-year-old female patient who had thirst, polydipsia, polyuria, palpitations, loss of appetite, and fatigue 3 days after the first dose of COVID-19 RNA-based vaccines without a prior history of diabetes. Ten days after vaccination, she visited our hospital with diabetic ketoacidosis and was diagnosed with type 1 diabetes. Hyperglycemia (501 mg/dL), anion gap metabolic acidosis and ketonuria were observed. The glycated hemoglobin level was 7.0%. Islet-related autoantibodies were all negative. The glucagon tolerance test revealed attenuated secretion of insulin. Human leukocyte antigen was haplotype DRB1*0405-DQB1*0401, which was associated with type 1 diabetes in Japan. The present case suggests that COVID-19 RNA-based vaccines might trigger the onset of type 1 diabetes, even in subjects without prior histories of diabetes.

Fulminant Type 1 Diabetes Mellitus Developed about Half a Year after Discontinuation of Immune Checkpoint Inhibitor Combination Therapy with Nivolumab and Ipilimumab: A Case Report.

The cytotoxic T-lymphocyte antigen-4 and programmed cell death 1 pathways are novel therapeutic targets in immune checkpoint inhibitor (ICI) therapy for cancer. However, they may cause endocrine-related adverse events, including hypophysitis, autoimmune thyroiditis and type 1 diabetes mellitus (DM). Moreover, delayed immune-related adverse events (irAEs) after discontinuation of ICI therapy have been reported. Here we report a 60-year-old female patient with advanced renal cell carcinoma with brain metastasis who was treated with nivolumab, ipilimumab and prednisolone. At the 3rd course of combination therapy, the administration was discontinued due to the onset of colitis and the dosage of prednisolone was increased. About half a year after discontinuation, she was admitted to the hospital with general malaise, hyperglycemia (330 mg/dL) and diabetic ketoacidosis. Glycated hemoglobin level was 6.5%. Islet-related autoantibodies were negative. The glucagon tolerance test showed complete depletion of insulin. Therefore, we diagnosed fulminant type 1 DM and treated with multiple daily injections of insulin. The onset of type 1 DM was rapid in many cases treated with combination therapy of ICIs. The present case is a rare case in which fulminant type 1 DM developed about half a year after discontinuation of nivolumab and ipilimumab. The literature shows two cases of type 1 DM occurring 4 months after discontinuation of ICI therapy by nivolumab or atezolizumab. The present case indicates that regular monitoring is mandatory for fulminant type 1 DM and other delayed irAEs after discontinuation of ICI therapy even under the low-dose prednisolone treatment.

Sight-Threatening Graves' Ophthalmopathy during the Third Trimester of Pregnancy: A Case Report.

Dysthyroid optic neuropathy is a severe manifestation of Graves' ophthalmopathy that can result in permanent vision loss. We report a 37-year-old pregnant woman with Graves' ophthalmopathy which was deteriorated to dysthyroid optic neuropathy in the third trimester of pregnancy. Diplopia, bilateral eye lid retraction, lid edema and proptosis were observed in the 29th week of gestation. Thyroid-stimulating hormone (TSH) level was decreased with a normal level of free triiodothyronine (FT3) and an upper normal level of free thyroxine (FT4). Anti-TSH receptor antibodies (16.2 IU/L, reference range < 2.0 IU/L) and thyroid stimulating antibody (4,443%, reference range < 120%) were positive. Magnetic resonance imaging (MRI) demonstrated a significant enlargement of the extraocular muscles with a high signal intensity on T2-weighted image. She was diagnosed as Graves' ophthalmopathy and subclinical hyperthyroidism, and followed without treatment. In the 34th week of gestation, the symptom of color vision abnormality appeared, suggesting dysthyroid optic neuropathy. She delivered a female infant during the 36th week of gestation. Four days after delivery, she had a spontaneous orbital pain. MRI showed that the extraocular muscles were more enlarged than the findings in the 29th week of gestation. FT3 and FT4 levels were mildly elevated. Dysthyroid optic neuropathy was diagnosed. She was treated with methylprednisolone pulse therapy and retrobulbar injections of betamethasone valerate, and the ocular symptoms improved. The present case shows that the glucocorticoid therapy performed one week after delivery is effective against Graves' ophthalmopathy which was deteriorated to dysthyroid optic neuropathy during the third trimester of pregnancy.

Painless Thyroiditis and Fulminant Type 1 Diabetes Mellitus in a Patient Treated with an Immune Checkpoint Inhibitor, Nivolumab.

The programmed cell death-1 (PD-1) pathway is a novel therapeutic target in immune checkpoint therapy for cancer. Nivolumab, an anti-PD-1 monoclonal antibody, blocks PD-1 and can restore anti-cancer immune responses by disrupting the signal that inhibits T-cell activation. Nivolumab may induce endocrine-related adverse events, including hypophysitis, autoimmune thyroiditis, and type 1 diabetes mellitus. Here we report a 68-year-old female patient with advanced renal cell carcinoma who was treated with nivolumab. She had positive anti-thyroglobulin antibodies and anti-thyroid peroxidase antibodies with slightly elevated thyroid-stimulating hormone (9.048 µU/mL), and was diagnosed as chronic thyroiditis with subclinical hypothyroidism before nivolumab therapy. She developed painless thyroiditis after the first cycle of the therapy (Day 14). At the 7th cycle of nivolumab therapy (Day 98), hyperglycemia (473 mg/dL) was noted, whereas glycated hemoglobin level was 6.9%. Islet-related autoantibodies were all negative. The glucagon tolerance test showed complete depletion of insulin. Human leukocyte antigen typing showed haplotype DRB1*09:01-DQB1*03:03, which was reported to be closely associated with type 1 diabetes mellitus in Japan. Fulminant type 1 diabetes mellitus was diagnosed, and she was immediately treated with multiple daily injections of insulin. Fulminant type 1 diabetes mellitus is characterized by rapid-onset diabetic ketoacidosis, and negative islet-related autoantibodies, and was proposed as a novel subtype of non-autoimmune diabetes. Preceding painless thyroiditis with positive thyroid autoantibodies observed in the present case, however, raises the possibility that autoimmune mechanisms are involved in the pathogenesis of nivolumab-induced fulminant type 1 diabetes mellitus.

Usefulness of anti-rabphilin-3A antibodies for diagnosing central diabetes insipidus in the third trimester of pregnancy.

We report a 27-year-old pregnant woman with polyuria, polydipsia and headache in the third trimester of pregnancy. Hypernatremia (153 mEq/L), high plasma osmolality (300 mOsm/kgH2O) and low urinary osmolality (92 mOsm/kgH2O) were observed at the admission to our hospital. Plasma arginine vasopressin (AVP) level was inappropriately low (2.2 pg/mL) compared to the high plasma osmolality. Plasma AVP responses to hypertonic-saline infusion were blunted, and her urine osmolality increased in response to desmopressin. The diagnosis of central diabetes insipidus was made from these results. Magnetic resonance imaging (MRI) of hypothalamic-pituitary region demonstrated a significant enlargement of the pituitary stalk, suggesting the presence of hypophysitis. In addition, serum anti-rabphilin-3A antibodies that have been recently reported as a biomarker of lymphocytic infundibulo-neurohypophysitis, were positive. Diabetes insipidus continued after delivery, suggesting that polyuria was not mainly due to excessive vasopressinase activity or reduced renal sensitivity to AVP by prostaglandin E2 that can cause temporal polyuria during pregnancy. We therefore clinically diagnosed central diabetes insipidus due to lymphocytic infundibulo-neurohypophysitis, without performing invasive transsphenoidal pituitary biopsy. This case suggested the usefulness of anti-rabphilin-3A antibodies for the etiological diagnosis of central diabetes insipidus during pregnancy.

Bromocriptine, a dopamine agonist, increases growth hormone secretion in a patient with acromegaly.

Bromocriptine, a potent D2-dopamine agonist, suppresses growth hormone (GH) secretion in most patients with acromegaly and has been approved for the treatment of acromegaly. Here we report a patient with acromegaly who showed increased GH secretion after administration of bromocriptine. A 70-year-old man with acromegalic manifestation was admitted to our hospital because of a pituitary tumor invading to the right cavernous sinus detected by brain magnetic resonance imaging. Serum GH and insulin-like growth factor-I (IGF-I) levels were elevated in several occasions (GH: 15.0-51.7 ng/mL, reference range: <2.47 ng/mL; and IGF-I: 776-856 ng/mL, reference range: 57-175 ng/mL). Effect of bromocriptine on serum GH levels was then studied because pre-operative treatment with a D2-dopamine agonist was planned in order to reduce the tumor size and serum GH levels before surgery. After oral administration of 2.5 mg of bromocriptine, serum GH levels were unexpectedly increased from 30.7 ng/mL to 189 ng/mL, despite the fact that the levels of prolactin (PRL) were decreased from 4.2 ng/mL to 0.6 ng/mL. By contrast, serum GH levels were decreased by a somatostatin analogue, octreotide. Transsphenoidal surgery of the pituitary tumor was performed after treatment of octreotide. Histological analysis and immunohistochemistry revealed a GH-producing pituitary adenoma positive for D2-dopamine receptor. This case of acromegaly suggests that the preliminary test with a single administration of a short-acting D2-dopamine agonist, bromocriptine, is mandatory before the long-term therapy with a D2-dopamine agonist in patients with GH-secreting pituitary tumors.

Papillary thyroid carcinoma in one of identical twin patients with Pendred syndrome.

Pendred syndrome is an autosomal recessive disorder characterized by sensorineural deafness, a partial defect in iodide organification, and dyshormonogenetic goiter. Several cases of Pendred syndrome with follicular thyroid carcinomas were reported previously. Here we report identical twin patients with Pendred syndrome, who had thyroid tumors with distinct histopathological findings. 34-year-old identical twins with congenital deafness and goiter were referred to our hospital with complaint of neck discomfort. The genetic testing showed that these twin patients were compound heterozygotes carrying the same two mutations in the Pendred's syndrome (PDS / SLC26A4) gene (c2168A > G and ins2110GCTGG), which confirmed the diagnoses of Pendred syndrome. They underwent thyroidectomy. Histological examination of the thyroid tumors resected from these twin patients revealed follicular variant of papillary thyroid carcinoma, and diffuse and nodular goiter without any evidence of malignancy, respectively. To our knowledge, the former is the first case of follicular variant of papillary thyroid carcinoma in Pendred Syndrome.

Prediction of late (24-hour) radioactive iodine uptake using early (3-hour) uptake values in Japanese patients with Graves' disease.

Measurement of 24-hour radioactive iodine uptake (RAIU), which is commonly used to calculate the dose of radioiodine (RI) therapy, cannot be accomplished in a single day. The purpose of this study was to predict 24-hour RAIU from 3-hour RAIU in Japanese patients with Graves' disease, and to investigate other factors that could be used to predict 24-hour RAIU. A total of 66 Japanese patients (14 men and 52 women; age, 17-83 years) with Graves' disease who had undergone both 3-hour and 24-hour ¹²³I RAIU measurements between January 2006 and September 2011 were included in this study. Stepwise multiple regression analyses were performed in order to identify factors that could be used to predict 24-hour RAIU. The investigated factors were gender, age, thyroid volume, TSH, free thyroxine (FT4), free triiodothyronine (FT3), serum creatinine, second generation assay TSH receptor antibody (TRAb2), antithyroid drugs discontinuation period (ADP), iodine restriction period and 3-hour RAIU. The ADP was converted to an ordinal scale ADP score (ADPS) for multiple regression analyses. Multiple regression analyses showed that 3-hour RAIU (P < 0.001), FT3 (P < 0.001) and ADPS (P < 0.001) were statistically significant predictive factors of 24-hour RAIU. The relationship between 24-hour RAIU (LU) and 3-hour RAIU (EU), FT3 and ADPS was: LU = 11.5 + 29.1 × log10 EU + 23.0 × log10 FT3 - 2.7 × ADPS (r = 0.82, P < 0.001). The present results indicate that prediction of LU from EU, FT3 and ADPS is feasible in Japanese patients with Graves' disease.

ACTH response to desmopressin in a patient with acromegaly; expression of corticotropin-releasing factor, urocortins and vasopressin V1b receptor in GH-producing pituitary adenoma.

GH-producing pituitary adenomas frequently co-produce other certain anterior pituitary hormones, such as prolactin (PRL). In contrast, GH-producing adenomas which express all of corticotropin-releasing factor (CRF), urocorin1 (Ucn1) and urocortin3 (Ucn3) have not been reported. A 39-year-old woman was admitted for evaluation of the pituitary tumor. The diagnosis of acromegaly was confirmed by elevated serum GH and IGF-I levels, and the absence of GH suppression by oral glucose tolerance test. ACTH response to desmopressin (DDAVP) was observed (plasma ACTH levels increased from 13.9 to 50.4 pg/ml at 90 min). Although it is known that ACTH response to DDAVP is considerably useful for the diagnosis of ACTH-dependent Cushing's syndrome, the diagnosis of Cushing's disease was not supported by the criteria. The patient underwent transsphenoidal resection of the pituitary tumor. Immunohistological examination confirmed a GH- and PRL-producing adenoma, whereas ACTH was negative. ACTH response to DDAVP disappeared after tumor removal. To determine the cause of preoperative ACTH response to DDAVP, we examined expression of CRF family peptides and vasopressin V1b receptor in the pituitary adenoma by immunohistochemistry. Immunohistochemistry revealed positive immunostaining for CRF, Ucn1, Ucn3 and vasopressin V1b receptor in the adenoma. These observations raised the possibility that DDAVP caused an ACTH response, perhaps via the paracrine effects of tumor-derived CRF and Ucn1. When ACTH response to DDAVP is observed in patients with pituitary tumor, not only the direct effect of DDAVP on ACTH secretion, but also a possible involvement of CRF and/or urocortins expressed in the pituitary adenoma, should be considered.