Adrenal androgens versus cortisol for primary aldosteronism subtype determination in adrenal venous sampling

OBJECTIVE

We examined if measurement of adrenal androgens adds to subtype diagnostics of primary aldosteronism (PA) under cosyntropin-stimulated adrenal venous sampling (AVS).

DESIGN

A prospective pre-specified secondary endpoint analysis of 49 patients with confirmed PA, of whom 29 underwent unilateral adrenalectomy with long-term follow-up.

METHODS

Concentrations of androstenedione, dehydroepiandrosterone (DHEA) and dehydroepiandrosterone sulphate (DHEAS) were measured during AVS in addition to aldosterone and cortisol. Subjects with lateralisation index (LI) of ≥4 were treated with unilateral adrenalectomy, and the immunohistochemical subtype was determined with CYP11B2 and CYP11B1 stains. The performance of adrenal androgens was evaluated by receiver operating characteristics (ROC) curve analyses in adrenalectomy and medical therapy groups.

RESULTS

During AVS, the correlations between cortisol and androstenedione, DHEA and DHEAS for LI and selectivity index (SI) were highly significant. The right and left side SIs for androstenedione and DHEA were higher (p < .001) than for cortisol. In ROC analysis, the optimal LI cut-off values for androstenedione, DHEA and DHEAS were 4.2, 4.5 and 4.6, respectively. The performance of these LIs for adrenal androgens did not differ from that of cortisol.

CONCLUSIONS

Under cosyntropin-stimulated AVS, the measurement of androstenedione and DHEA did not improve the cannulation selectivity. The performance of cortisol and adrenal androgens are confirmatory but not superior to cortisol-based results in lateralisation diagnostics of PA.

Plasma protein biomarkers for the detection of pancreatic neuroendocrine tumors and differentiation from small intestinal neuroendocrine tumors

There is an unmet need for novel biomarkers to diagnose and monitor patients with neuroendocrine neoplasms. The EXPLAIN study explores a multi-plasma protein and supervised machine learning strategy to improve the diagnosis of pancreatic neuroendocrine tumors (PanNET) and differentiate them from small intestinal neuroendocrine tumors (SI-NET). At time of diagnosis, blood samples were collected and analyzed from 39 patients with PanNET, 135 with SI-NET (World Health Organization Grade 1-2) and 144 controls. Exclusion criteria were other malignant diseases, chronic inflammatory diseases, reduced kidney or liver function. Prosed Oncology-II (i.e., OLink) was used to measure 92 cancer related plasma proteins. Chromogranin A was analyzed separately. Median age in all groups was 65-67 years and with a similar sex distribution (females: PanNET, 51%; SI-NET, 42%; controls, 42%). Tumor grade (G1/G2): PanNET, 39/61%; SI-NET, 46/54%. Patients with liver metastases: PanNET, 78%; SI-NET, 63%. The classification model of PanNET versus controls provided a sensitivity (SEN) of 0.84, specificity (SPE) 0.98, positive predictive value (PPV) of 0.92 and negative predictive value (NPV) of 0.95, and area under the receiver operating characteristic curve (AUROC) of 0.99; the model for the discrimination of PanNET versus SI-NET providing a SEN 0.61, SPE 0.96, PPV 0.83, NPV 0.90 and AUROC 0.98. These results suggest that a multi-plasma protein strategy can significantly improve diagnostic accuracy of PanNET and SI-NET.

An ARHGAP25 variant links aberrant Rac1 function to early-onset skeletal fragility

Ras homologous guanosine triphosphatases (RhoGTPases) control several cellular functions, including cytoskeletal actin remodeling and cell migration. Their activities are downregulated by GTPase-activating proteins (GAPs). Although RhoGTPases are implicated in bone remodeling and osteoclast and osteoblast function, their significance in human bone health and disease remains elusive. Here, we report defective RhoGTPase regulation as a cause of severe, early-onset, autosomal-dominant skeletal fragility in a three-generation Finnish family. Affected individuals (n = 13) presented with multiple low-energy peripheral and vertebral fractures despite normal bone mineral density (BMD). Bone histomorphometry suggested reduced bone volume, low surface area covered by osteoblasts and osteoclasts, and low bone turnover. Exome sequencing identified a novel heterozygous missense variant c.652G>A (p.G218R) in ARHGAP25, encoding a GAP for Rho-family GTPase Rac1. Variants in the ARHGAP25 5' untranslated region (UTR) also associated with BMD and fracture risk in the general population, across multiple genomewide association study (GWAS) meta-analyses (lead variant rs10048745). ARHGAP25 messenger RNA (mRNA) was expressed in macrophage colony-stimulating factor (M-CSF)-stimulated human monocytes and mouse osteoblasts, indicating a possible role for ARHGAP25 in osteoclast and osteoblast differentiation and activity. Studies on subject-derived osteoclasts from peripheral blood mononuclear cells did not reveal robust defects in mature osteoclast formation or resorptive activity. However, analysis of osteosarcoma cells overexpressing the ARHGAP25 G218R-mutant, combined with structural modeling, confirmed that the mutant protein had decreased GAP-activity against Rac1, resulting in elevated Rac1 activity, increased cell spreading, and membrane ruffling. Our findings indicate that mutated ARHGAP25 causes aberrant Rac1 function and consequently abnormal bone metabolism, highlighting the importance of RhoGAP signaling in bone metabolism in familial forms of skeletal fragility and in the general population, and expanding our understanding of the molecular pathways underlying skeletal fragility. © 2021 The Authors. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research.

Recurrent Metastasized Parathyroid Carcinoma-Long-Term Remission After Combined Treatments With Surgery, Radiotherapy, Cinacalcet, Zoledronic Acid, and Temozolomide

Parathyroid carcinoma is a rare cause of primary hyperparathyroidism with rather poor prognosis. Apart from surgery, no evidence-based treatments exist. A 48-year-old woman presented with weight loss, nausea, constipation, hypercalcemic crisis, and a recurrent neck tumor 5 years after primary surgery of a parathyroid tumor that primarily was classified as an adenoma. Histopathological reevaluation of the original tumor revealed the correct diagnosis to be parathyroid carcinoma (PC). The patient underwent surgery of the recurrent tumor, which was locally invasive with metastatic spread to the mediastinum and neck lymph nodes. Computed tomography demonstrated large lytic bone lesions in both iliac bones including, on the right, a soft tissue mass compatible with bone metastasis. The patient was treated with cinacalcet, repeated zoledronic acid infusions, and temozolomide cycles for 1 year. She underwent two additional neck surgeries for PC and sternotomy for resection of mediastinal metastases. Massive osteolytic lesions in both femoral necks caused imminent fracture risk and therefore both femurs were prophylactically stabilized by intramedullary nail. Serum calcium normalized after the third neck surgery, cinacalcet was discontinued, and parathyroid hormone gradually normalized during continued treatments with temozolomide, adjuvant radiotherapy, and zoledronic acid, with no signs of active disease on imaging and normal biochemistry. The patient remains in remission 17 years after successful combined treatments for recurrent, metastasized PC. The parathyroid tumor tissue demonstrated high O6-methylguanine DNA methyltransferase (MGMT) promoter methylation status, a known predictor of positive temozolomide treatment response in other tumors. In addition, synergistic effects of multiple treatments may have accounted for the favorable response. © 2018 The Authors. JBMR Plus is published by Wiley Periodicals, Inc. on behalf of the American Society for Bone and Mineral Research.