Clinical Spectrum and Outcome of Kidney Involvement in Non-Langerhans Histiocytosis

The aim of this study was to describe the clinical features and treatment responses of Rosai-Dorfman disease (RDD) and Erdheim-Chester disease (ECD) with kidney involvement.

We retrospectively analyzed patients with RDD and ECD with kidney involvement from 2005 to 2023, evaluating kidney function changes, as well as computed tomography (CT), and metabolic responses.

The study included 4 patients with RDD and 44 with ECD, with median ages of 58 and 51 years, respectively. Patients with RDD lacked kidney symptoms, whereas 27.3% of patients with ECD exhibited lower extremity edema. The median estimated glomerular filtration rate (eGFR) was 80.5 (63-125) in RDD and 100 (22-133) ml/min per 1.73 m² in ECD. All patients with RDD had renal masses; 68.2% of ECD cases showed perirenal infiltration. Two patients with RDD received steroids (1 postnephrectomy), and 2 received lenalidomide and dexamethasone (RD) therapy. One patient with RDD (25%) showed eGFR improvement, and 3 (75%) had CT and positron emission tomography (PET)-CT responses. Of 34 patients with ECD, 26 were treated with interferon-alpha, 5 with BRAF inhibitor, and 3 with cytarabine. The rates of eGFR improvement, CT response, and PET-CT response were 14.7%, 5.9%, and 52.9%, respectively. Median follow-up was 27.0 months for RDD and 53.0 months for ECD. The 5-year overall survival was 66.7% for RDD and 81.8% for ECD. The median progression-free survival was 18.3 months for RDD and 59.4 months for ECD.

We described details of kidney involvement characteristics and treatment responses in RDD and ECD, highlighting the typical renal mass in RDD and perirenal soft tissue in ECD. Patients with ECD may experience irreversible kidney dysfunction, indicating the critical need for early diagnosis and timely treatment.