Pembrolizumab-Induced Isolated Adrenocorticotropic Hormone (ACTH) Deficiency.

Pembrolizumab is a programmed death 1 receptor (PD-1) inhibitor. It is used as immunotherapy in various cancers, including metastatic melanoma, non-small cell lung cancer, and, notably, high-risk triple-negative breast cancer. We discuss a case of a 44-year-old female with a past medical history of triple-negative breast cancer who presented with a chief complaint of poor oral intake and fatigue after her fourth cycle of pembrolizumab therapy. The patient was diagnosed with pembrolizumab-induced isolated secondary adrenal insufficiency (AI) and was treated with corticosteroids with improvement in her symptoms. Secondary AI due to pembrolizumab use is a rare yet potentially life-threatening complication. If initial serum cortisol is borderline low, as observed in our patient, repeated testing within shorter intervals should be considered to optimize patient outcomes.

Neurosarcoidosis-Induced Panhypopituitarism.

Sarcoidosis is an inflammatory condition that can impact multiple organs in the body such as the lungs, skin, eyes, and, occasionally, the central nervous system. When sarcoidosis affects the nervous system, it is referred to as neurosarcoidosis and is estimated to occur in approximately 5%-15% of sarcoid patients. When neurosarcoidosis affects the pituitary gland, it can result in panhypopituitarism, which can be life-threatening. A 35-year-old male with a known diagnosis of sarcoidosis by skin biopsies presented to the hospital with altered mental status, hypernatremia, hypotension, and hypothermia. He reported symptoms of polyuria and polydipsia for several weeks before admission. Laboratory workup revealed elevated serum sodium at 167 mmol/L, high serum osmolality at 381 mOsm/kg, and low urine osmolality at 381 mOsm/kg, consistent with diabetes insipidus. Anterior pituitary hormone profile workup revealed low 8 am serum cortisol (1.9 mcg/dL) and inappropriately normal adrenocorticotropic hormone (ACTH) (34 pg/ml), low serum free testosterone (<2.5 ng/dL), low luteinizing hormone (0.7 mIU/ml), low follicular stimulating hormone (< 2.6 mIU/ml), low free T4 at 0.4 ng/dL. and inappropriately normal thyroid-stimulating hormone (TSH) at 2.77 uIU/mL. Serum prolactin was mildly elevated at 86.8 ng/mL. Angiotensin-converting enzyme level was within the normal range at 33 U/L. A diagnosis of panhypopituitarism was made. Brain MRI revealed a 3 cm mass in the suprasellar region involving the hypothalamus and bilateral optic tracts with a mass effect on the anterior third ventricle. No discrete pituitary or stalk lesion was identified. A ventriculostomy tube was placed for developing hydrocephalus. A biopsy of the suprasellar mass revealed non-caseating granuloma, confirming neurosarcoidosis. Treatment was initiated with high-dose IV corticosteroids to manage secondary adrenal insufficiency and neurosarcoidosis. He was also started on IV desmopressin and IV levothyroxine to manage his diabetes insipidus and central hypothyroidism. He was transitioned to oral therapy upon discharge. Panhypopituitarism secondary to neurosarcoidosis is a rare presentation that can occur due to the infiltration of the pituitary gland or the infiltration of the hypothalamus affecting the hypothalamic-pituitary axis. Neurosarcoidosis should be considered a differential when evaluating patients with symptoms consistent with panhypopituitarism. Prompt diagnosis and initiation of corticosteroids and deficient hormones can be lifesaving.

IFT46 gene promoter-driven ciliopathy disease model in zebrafish.

Ciliopathies are human genetic disorders caused by abnormal formation and dysfunction of cellular cilia. Cilia are microtubule-based organelles that project into the extracellular space and transduce molecular and chemical signals from the extracellular environment or neighboring cells. Intraflagellar transport (IFT) proteins are required for the assembly and maintenance of cilia by transporting proteins along the axoneme which consists of complexes A and B. IFT46, a core IFT-B protein complex, is required for cilium formation and maintenance during vertebrate embryonic development. Here, we introduce transgenic zebrafish lines under the control of ciliated cell-specific IFT46 promoter to recapitulate human ciliopathy-like phenotypes. We generated a Tg(IFT46:GAL4-VP16) line to temporo-spatially control the expression of effectors including fluorescent reporters or nitroreductase based on the GAL4/UAS system, which expresses GAL4-VP16 chimeric transcription factors in most ciliated tissues during embryonic development. To analyze the function of IFT46-expressing ciliated cells during zebrafish development, we generated the Tg(IFT46:GAL4-VP16;UAS;nfsb-mCherry) line, a ciliated cell-specific injury model induced by nitroreductase (NTR)/metrodinazole (MTZ). Conditionally, controlled ablation of ciliated cells in transgenic animals exhibited ciliopathy-like phenotypes including cystic kidneys and pericardial and periorbital edema. Altogether, we established a zebrafish NTR/MTZ-mediated ciliated cell injury model that recapitulates ciliopathy-like phenotypes and may be a vertebrate animal model to further investigate the etiology and therapeutic approaches to human ciliopathies.

SIRT1 ubiquitination is regulated by opposing activities of APC/C-Cdh1 and AROS during stress-induced premature senescence.

SIRT1, a member of the mammalian sirtuin family, is a nicotinamide adenosine dinucleotide (NAD)-dependent deacetylase with key roles in aging-related diseases and cellular senescence. However, the mechanism by which SIRT1 protein homeostasis is controlled under senescent conditions remains elusive. Here, we revealed that SIRT1 protein is significantly downregulated due to ubiquitin-mediated proteasomal degradation during stress-induced premature senescence (SIPS) and that SIRT1 physically associates with anaphase-promoting complex/cyclosome (APC/C), a multisubunit E3 ubiquitin ligase. Ubiquitin-dependent SIRT1 degradation is stimulated by the APC/C coactivator Cdh1 and not by the coactivator Cdc20. We found that Cdh1 depletion impaired the SIPS-promoted downregulation of SIRT1 expression and reduced cellular senescence, likely through SIRT1-driven p53 inactivation. In contrast, AROS, a SIRT1 activator, reversed the SIRT1 degradation induced by diverse stressors and antagonized Cdh1 function through competitive interactions with SIRT1. Furthermore, our data indicate opposite roles for Cdh1 and AROS in the epigenetic regulation of the senescence-associated secretory phenotype genes IL-6 and IL-8. Finally, we demonstrated that pinosylvin restores downregulated AROS (and SIRT1) expression levels in bleomycin-induced mouse pulmonary senescent tissue while repressing bleomycin-promoted Cdh1 expression. Overall, our study provides the first evidence of the reciprocal regulation of SIRT1 stability by APC/C-Cdh1 and AROS during stress-induced premature senescence, and our findings suggest pinosylvin as a potential senolytic agent for pulmonary fibrosis.

Euglycemic Diabetic Ketoacidosis Caused by Alcoholic Pancreatitis and Starvation Ketosis.

Starvation ketosis and pancreatitis are uncommon and underrecognized etiologies of euglycemic diabetic ketoacidosis (DKA). Euglycemic DKA is associated commonly with pregnancy, use of insulin en route to the hospital, and use of sodium-glucose cotransporter-2 (SGLT-2) inhibitors. A 58-year-old male with past medical history of type II diabetes mellitus and alcoholism presented with chief complaint of nausea, vomiting, and poor oral intake for several weeks. Despite extensive history of diabetes and no recent SGLT-2 inhibitor use, his labs were consistent with euglycemic DKA. His imaging and clinical history also confirmed alcoholic pancreatitis. The patient was admitted for euglycemic DKA secondary to starvation ketosis and alcoholic pancreatitis. His anion gap and beta-hydroxybutyrate rapidly cleared with initiation of the DKA protocol. This case teaches us that clinicians should consider early initiation of the DKA protocol even in the setting of euglycemia, when a patient presents with high-anion-gap metabolic acidosis, a high beta-hydroxybutyrate level, and a clinical picture of pancreatitis and starvation.

Kikuchi's disease in children: clinical manifestations and imaging features.

Previously published studies on Kikuchi disease (KD) have frequently addressed the computed tomography (CT) findings in the adult population, however, only a few studies have been reported for the pediatric age group. The purpose of this study is to analyze the clinical characteristics and imaging features of KD in children. Fifteen children (2-14 yr) who had a neck CT and pathology diagnosis of KD were included in this study. Clinical features, including the duration of lymphadenopathy and fever, prognosis, and laboratory values, were evaluated. We analyzed the sites, size, and lymph node pattern as seen on their CT scans. The median duration of fever was 10 days. Fourteen patients experienced improvement in their condition, although four of these patients experienced recurrent episodes of KD. All patients had affected cervical nodes at level V. Perinodal infiltrates were observed in the affected cervical nodes in 14 cases (93%), and non-enhancing necrosis was also noted within the affected cervical nodes in 10 cases (63%). In conclusion, the combination of imaging findings in conjunction with clinical findings of KD may help to determine whether or not to perform pathology analysis and follow-up studies.

A large infiltrating fibrous hamartoma of infancy in the abdominal wall with rare associated tuberous sclerosis.

Tuberous sclerosis is a complex autosomal-dominant neurocutaneous syndrome characterized by hamartomatous malformations of fibrous and connective tissues in various organs. Although various histologic types of soft-tissue masses can occur with tuberous sclerosis, we present a unique case of fibrous hamartoma of infancy presenting as large infiltrating cutaneous and subcutaneous masses in the abdominal wall in a 4-year-old boy with tuberous sclerosis. Although the co-occurrence of tuberous sclerosis and fibrous hamartoma of infancy is very rare, it should be considered in the differential diagnosis of subcutaneous soft-tissue masses found in children with tuberous sclerosis.