Pustular Lichenoid Eruptions Induced by Immune Checkpoint Inhibitors: Two Case Reports and a Review of the Literature.

Immune checkpoint inhibitors (ICIs) have become the standard treatment for many types of cancer. After several years of using these therapies, many adverse events related to ICIs have been observed. Dermatologic toxicities such as nonspecific morbilliform rash, vitiligo, Stevens-Johnson syndrome/toxic epidermal necrolysis, and more rarely, lichenoid eruptions have been described in the literature. We report 2 cases of pustular lichenoid eruptions, 1 in a patient with nonsmall cell lung carcinoma and 1 in a patient with metastatic melanoma, induced by pembrolizumab and nivolumab, respectively. The 2 patients were treated with topical corticosteroids, and complete healing of lesions was slowly obtained. Due to the severity of the cutaneous eruptions, pembrolizumab and nivolumab were discontinued. We identified 6 cases of pustular lichenoid eruptions induced by ICIs in the published literature and in the French Pharmacovigilance Database and reviewed their main clinical features and courses.

NOX1 and NOX2: Two enzymes that promote endothelial-to-mesenchymal transition induced by melanoma conditioned media.

Tumor microenvironment plays an important role in melanoma progression. Recent studies reported endothelial cells (EC) are involved in endothelial-to-mesenchymal transition (EndMT). During this phenotypic switch, EC progressively lose their endothelial markers and acquire mesenchymal properties. Depending on their concentration, reactive oxygen species (ROS) can control tumor growth. In EC, ROS are mainly produced by NAPDH oxidases (NOX) such as NOX1 and NOX2. The aim of the present study was to determine the role of these enzymes in EndMT induced by conditioned media (CM) from SK-MEL 28 melanoma cells. The capacity of CM to induce EndMT in HUVEC after 24 h, 48 h or 72 h has been evaluated by following endothelial HUVECs proliferation, migration and their capacity to form capillary on ECMgel®. Furthermore, EndMT was confirmed by western blot and flow cytometry. To determine the role of NOX in EndMT, specific NOX1 and/or NOX2 inhibitors has been tested. TGF-ß2 + /- IL-1ß was used as positive control. ROS production was determined through DCFDA assay. An altered endothelial phenotype was found in CM-treated HUVECs. This phenotypic modification was correlated with a decrease in both capillary formation on ECMgel® and cell proliferation and an increase in cell migration. Exposure to CM for 48 h significantly enhanced intracellular HUVECs ROS production and this increase was prevented by the dual pharmacological inhibition of NOX1 and NOX2. Furthermore, inhibition of NOX1/2 also leads to a partial reversion of CM-induced EndMT. These data confirmed the role of NOX1 and NOX2 in EndMT induced by melanoma cancer cell secretome.

Carpal Tunnel Syndrome: A New Adverse Effect of Immune Checkpoint Inhibitors, 11 Cases.

This study aims at reporting 11 cases of carpal tunnel syndrome (CTS) occurring in patients on immunotherapy. The increasing use of immune checkpoint inhibitors in oncodermatology is associated with the appearance of immunologic adverse effects linked to nonspecific stimulation of the immune system. CTS has not been reported in this context. A retrospective multicenter review was performed on CTSs occurring on immunotherapy and confirmed with electroneuromyography. Data were collated from patients' files. Most of the time, CTS was severe, bilateral, with a motor deficit and confirmed axonal damage on electroneuromyography. In 4 cases, it was associated with rheumatological adverse effects (arthralgia/inflammatory synovitis). The most effective treatment appeared to be general corticosteroid therapy, even at low doses (<15 mg/d), or surgery. An imputability of the CTS of these patients to immunotherapy was considered due to the unusual intensity of the symptoms and the absence of other predisposing factors (diabetes and dysthyroidism well-controlled). Its combination with other immunologic adverse effects and the efficacy of general corticosteroid therapy suggests an immunologic origin. CTS is probably an immunologic adverse effect of immunotherapy. It is often severe or misleading in presentation and affects quality of life. The recognition of this adverse effect should make it possible to provide patients with appropriate care.