Predicting development of ipilimumab-induced hypophysitis: utility of T4 and TSH index but not TSH.

PURPOSE: Ipilimumab, a monoclonal antibody inhibiting CLTA-4, is an established treatment in metastatic melanoma, either alone or in combination with nivolumab, and results in immune mediated adverse events, including endocrinopathy. Hypophysitis is one of the most common endocrine abnormalities. An early recognition of hypophysitis may prevent life threatening consequences of hypopituitarism; therefore, biomarkers to predict which patients will develop hypophysitis would have clinical utility. Recent studies suggested that a decline in TSH may serve as an early marker of IH. This study was aimed at assessing the utility of thyroid function tests in predicting development of hypophysitis. METHODS: A retrospective cohort study was performed for all patients (n = 308) treated with ipilimumab either as a monotherapy or in combination with nivolumab for advanced melanoma at the Royal Marsden Hospital from 2010 to 2016. Thyroid function tests, other pituitary function tests and Pituitary MRIs were used to identify those with hypophysitis. RESULTS AND CONCLUSIONS: Ipilimumab-induced hypophysitis (IH) was diagnosed in 25 patients (8.15%). A decline in TSH was observed in hypophysitis cohort during the first three cycles but it did not reach statistical significance (P = 0.053). A significant fall in FT4 (P < 0.001), TSH index (P < 0.001) and standardised TSH index (P < 0.001) prior to cycles 3 and 4 in hypophysitis cohort was observed. TSH is not useful in predicting development of IH. FT4, TSH index and standardised TSH index may be valuable but a high index of clinical suspicion remains paramount in early detection of hypophysitis.

Thyroid abnormalities following the use of cytotoxic T-lymphocyte antigen-4 and programmed death receptor protein-1 inhibitors in the treatment of melanoma.

CONTEXT: Checkpoint inhibitors are emerging as important cancer therapies but are associated with a high rate of immune side effects, including endocrinopathy. OBJECTIVE: To determine the burden of thyroid dysfunction in patients with melanoma treated with immune checkpoint inhibitors and describe the clinical course. DESIGN AND PATIENTS: Consecutive patients with melanoma treated with either ipilimumab, nivolumab, pembrolizumab or the combination of ipilimumab and nivolumab were identified. Baseline thyroid function tests were used to exclude those with pre-existing thyroid abnormalities, and thyroid function tests during treatment used to identify those with thyroid dysfunction. RESULTS: Rates of overt thyroid dysfunction were in keeping with the published phase 3 trials. Hypothyroidism occurred in 13·0% treated with a programmed death receptor-1 (PD-1) inhibitor and 22·2% with a combination of PD-1 inhibitor and ipilimumab. Transient subclinical hyperthyroidism was observed in 13·0% treated with a PD-1 inhibitor, 15·9% following a PD-1 inhibitor, and 22·2% following combination treatment with investigations suggesting a thyroiditic mechanism rather than Graves' disease, and a high frequency of subsequent hypothyroidism. Any thyroid abnormality occurred in 23·0% following ipilimumab, 39·1% following a PD-1 inhibitor and 50% following combination treatment. Abnormal thyroid function was more common in female patients. CONCLUSION: Thyroid dysfunction occurs commonly in patients with melanoma treated with immune checkpoint inhibitors, with rates, including subclinical dysfunction, occurring in up to 50%.

The role of arterial stimulation and simultaneous venous sampling in addition to cross-sectional imaging for localisation of biochemically proven insulinoma.

Insulinomas, although rare, cause considerable morbidity but are frequently amenable to surgical cure. Laparoscopic surgery can now be considered if the tumour is localised pre-operatively, but the optimal imaging approach has not been determined. The objective of this study was to evaluate the ability of different imaging investigations, including CT, MRI, endoscopic ultrasound, octreotide scintigraphy and arterial stimulation with simultaneous venous sampling (ASVS), to localise insulinomas. All patients with biochemically proven insulinoma at our institution underwent ASVS along with other imaging investigations as part of their routine investigation. The results of these investigations were compared with histological findings. Twenty-eight patients with biochemically proven insulinoma confirmed by histology were identified. Ultimately ASVS localised a lesion in all patients. Seventeen patients (61%) had laparoscopic surgery. Tumor-detection rates for other imaging investigations included 43.5% of cases using CT, 71% using MRI, 86% using endoscopic ultrasound and 33% using octreotide scintigraphy. In four patients, the ASVS was the only test to correctly localise the lesion. ASVS should be considered routinely before surgery to ensure accurate localisation of insulinomas.

Conditionally immortalized white preadipocytes: a novel adipocyte model.

This study describes a novel approach to generate conditionally immortalized preadipocyte cell lines from white adipose tissue (IMWAT) that can be induced to differentiate into white adipocytes even after expansion in culture. Such adipocytes express markers of white fat such as peroxisome proliferator-activated receptor gamma and aP2 but not brown fat markers, have an intact insulin signaling pathway, and express proinflammatory cytokines. They can be readily transduced with adenoviral vectors, allowing them to be used to investigate the consequences of the depletion of specific adipocyte factors using short hairpin RNA. This approach has been used to study the effect of reduced expression of the nuclear receptor corepressor receptor interacting protein 140 (RIP140), a regulator of adipocyte function. The depletion of RIP140 results in changes in metabolic gene expression that resemble those in adipose tissue of the RIP140 null mouse. Thus, IMWAT cells provide a novel model for adipocytes that are derived from preadipocytes rather than fibroblasts and provide an alternative system to primary preadipocytes for the investigation of adipocyte function.