Proposed Revised Criteria for the Diagnosis of CLIPPERS (P6.110)

OBJECTIVE: The aim of this study is to propose revised criteria for the diagnosis of chronic lymphocytic inflammation with pontine perivascular enhancement responsive to steroids (CLIPPERS). BACKGROUND: CLIPPERS is a rare inflammatory disorder of unknown origin defined by 1) subacute brainstem signs and symptoms; 2) punctate and curvilinear enhancing lesions predominantly involving the pons on MR; 3) prompt steroid sensitivity; 4) absence of alternative diagnosis, and 5) perivascular lympho-histiocytic infiltrates when the brain biopsy is performed. However, since its first description in 2010, multiple sclerosis, primary arteritis of the CNS, primary CNS lymphoma and lymphomatoid granulomatosis could fulfil, at least initially, all the CLIPPERS criteria (i.e. including histological). METHODS: In our previously reported French study, including 12 patients, CLIPPERS had a relapsing-remitting course in absence of immunosuppressive therapy. Relapses fitted always the four first criteria and occurred only when steroid dosage was below 20 mg/day. Therefore we propose to add this sixth criterion into the CLIPPERS definition, in order to evaluate its ability to distinguish CLIPPERS from its related diseases. RESULTS: Among a total of 22 patients fulfilling the first diagnostic criteria set for CLIPPERS, 5 progressed to a well-defined diseases: multiple sclerosis (n=1), primary arteritis of the CNS (n=1), primary CNS lymphoma (n=2), and lymphomatoid granulomatosis (n=1). Except in the patient having lymphomatoid granulomatosis, a brain biopsy was performed during the first attack and fitted the fifth criterion. The 5 patients (follow: 2 years) did not fit the sixth criterion in contrast to the 17 other CLIPPERS cases. CONCLUSIONS: CLIPPERS has to be considered as a new disorder and not a pre stage of well-defined diseases. Adding this sixth criterion led to distinguish CLIPPERS from other related diseases, mimicking CLIPPERS. Disclosure: Dr. Taieb has nothing to disclose. Dr. Allou has nothing to disclose. Dr. Limousin has nothing to disclose. Dr. Rousselot has nothing to disclose. Dr. Arquizan has nothing to disclose. Dr. Rigau has nothing to disclose. Dr. Pantesco has nothing to disclose. Dr. Ouallet has nothing to disclose. Dr. Labauge has nothing to disclose.