Clinical Everolimus Experience in Pediatric Renal Transplant Patients

mTORC1 links pathology in experimental models of Still's disease and macrophage activation syndrome

Still's disease is a severe inflammatory syndrome characterized by fever, skin rash and arthritis affecting children and adults. Patients with Still's disease may also develop macrophage activation syndrome, a potentially fatal complication of immune dysregulation resulting in cytokine storm. Here we show that mTORC1 (mechanistic target of rapamycin complex 1) underpins the pathology of Still's disease and macrophage activation syndrome. Single-cell RNA sequencing in a murine model of Still's disease shows preferential activation of mTORC1 in monocytes; both mTOR inhibition and monocyte depletion attenuate disease severity. Transcriptomic data from patients with Still's disease suggest decreased expression of the mTORC1 inhibitors TSC1/TSC2 and an mTORC1 gene signature that strongly correlates with disease activity and treatment response. Unrestricted activation of mTORC1 by Tsc2 deletion in mice is sufficient to trigger a Still's disease-like syndrome, including both inflammatory arthritis and macrophage activation syndrome with hemophagocytosis, a cellular manifestation that is reproduced in human monocytes by CRISPR/Cas-mediated deletion of TSC2. Consistent with this observation, hemophagocytic histiocytes from patients with macrophage activation syndrome display prominent mTORC1 activity. Our study suggests a mechanistic link of mTORC1 to inflammation that connects the pathogenesis of Still's disease and macrophage activation syndrome.

Everolimus-related unilateral abdominal lymphedema in a renal cancer patient: A case report

RATIONALE

Unilateral manifestation of lymphedema during everolimus therapy has been described only rarely, mostly in transplant recipients.

PATIENT CONCERNS

We report the first case of a patient who developed unilateral abdominal lymphedema, during a short period of everolimus treatment for renal cancer.

DIAGNOSIS

The abdominal asymmetry occurred only on the right side of the abdomen, neither ultrasound nor CT scan detected ascites but showed enlargement of the abdominal wall. The Naranjo Adverse Drug Reaction Probability scale was evaluated, in this case, a score of 6 indicated a probable adverse reaction to everolimus.

INTERVENTIONS

Discontinuation of everolimus therapy led to immediate alleviation and reduction of the lymphedema, with worsening once again after initiating retreatment with everolimus at a reduced dose.

OUTCOMES

The patient's lymphedema recovered after discontinuation of everolimus.

LESSONS

This rare case demonstrates the importance of the selection of mammalian target of rapamycin inhibitors using caution, especially for patients with a high risk of developing lymphedema.