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

Zenei Arihara,Naoko Iwata,Takashi Watanabe,Naoko Inoshita,Shozo Yamada,Kazuhiro Takahashi,Ryota Sato,Satsuki Niitsuma,Haruki Fujisawa,Yoshihisa Sugimura,Atsushi Suzuki,Kanako Sakurai

doi:10.1038/s41598-022-08552-y

Abstract

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.

Highlights

Central diabetes insipidus (CDI) is a rare condition, with a reported prevalence of approximately 7–10 per 100,000 inhabitants[1]
Anti-vasopressin-cell antibodies have been detected in patients with idiopathic CDI; these antibodies have been detected in DI of other etiologies, including Langerhans cell histiocytosis and germinomas, and cannot be considered a reliable marker of autoimmune-mediated C DI26,27
Anterior pituitary function was evaluated by the basal levels and/or responses of adrenocorticotropic hormone (ACTH), thyroid stimulating hormone (TSH)/ prolactin (PRL), growth hormone (GH) and luteinizing hormone (LH)/ follicle stimulating hormone (FSH) to corticotropin-releasing hormone (CRH), thyrotropin-releasing hormone (TRH), growth hormone-releasing hormone (GRH)/growth hormone-releasing peptide-2 (GHRP-2) and gonadotropin-releasing hormone (GnRH), respectively

Summary

Introduction

Central diabetes insipidus (CDI) is a rare condition, with a reported prevalence of approximately 7–10 per 100,000 inhabitants[1]. Anti-vasopressin-cell antibodies have been detected in patients with idiopathic CDI; these antibodies have been detected in DI of other etiologies, including Langerhans cell histiocytosis and germinomas, and cannot be considered a reliable marker of autoimmune-mediated C DI26,27. In cases with a biopsy-proven diagnosis, the presence of anti-rabphilin-3A antibodies showed a sensitivity of 100% in diagnosing LINH in 4 of 4 patients with LINH, and a specificity of 100% in distinguishing sellar/suprasellar masses (34 patients including 18 CDI patients) that were difficult to differentiate from LINH in clinical p ractice[28]. We evaluated anti-rabphlin-3A antibodies in consecutive CDI patients from a single referral center, in which the staff skillful in diagnosis and treatment of CDI was enrolled. This is the first case series to evaluate the presence of anti-rabphilin-3A antibodies in consecutive patients with CDI

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