[Clinical characteristics and follow-up of 60 patients with recent diagnosis of giant cell arteritis, NEWTON study]. / Caractéristiques et profils évolutifs des patients avec un diagnostic récent d'artérite à cellules géantes, étude NEWTON.

INTRODUCTION: The management of giant cell arteritis (GCA) has evolved with the arrival of tocilizumab (TCZ) and the use of PET/CT. Our objective is to describe the characteristics and followup of patients with recent diagnosis of GCA in current care. PATIENTS AND METHODS: The NEWTON cohort is a monocentric retrospective cohort based on data collected from 60 GCA patients diagnosed between 2017 and 2022 according to the ACR/EULAR 2022 criteria. RESULTS: The median age at diagnosis was 73 [68.75; 81] years old. At diagnosis, the main manifestations were unusual temporal headaches in 48 (80 %) and an inflammatory syndrome in 50 (83 %) patients. Temporal artery biopsy confirmed the diagnosis in 49/58 (84 %) patients. Doppler of the temporal arteries found a halo in 12/23 (52 %) patients. The PET/CT found hypermetabolism in 19/43 (44 %) patients. Prednisone was stopped in 17.5 [12.75; 24.25] months. During follow-up, 22 (37 %) patients received TCZ. At least one complication of corticosteroid therapy was observed in 22 (37 %) patients. After a median follow-up of 24 [12; 42] months, 25 (42 %) patients relapsed. At the end of the follow-up, 29 (48.3 %) patients were weaned from corticosteroid therapy and 15 (25 %) were on TCZ. CONCLUSION: Despite the increasing use of TCZ in the therapeutic arsenal and of the PET/CT in the imaging tools of GCA patients, relapses and complications of corticosteroid therapy remain frequent, observed in more than a third of patients.

Alemtuzumab-induced immune-mediated thrombotic thrombocytopenic purpura: A newly described drug-related autoimmune disease.

Immune-mediated thrombotic thrombocytopenic purpura (iTTP) is a rare and life-threatening disease that may result from drug exposure. We report a case of iTTP occurring in a 39-year-old patient, 45 months following introduction of the anti-CD52 lymphoid cell depleting monoclonal antibody alemtuzumab, to treat a relapsing-remitting multiple sclerosis. Treatment consisted in plasma exchange, corticosteroids and caplacizumab, allowing clinical remission 3 months after the diagnosis, attested by the absence of thrombocytopenia and recovery of ADAMTS-13 activity. As other autoimmune disorders, iTTP may occur following alemtuzumab. This diagnosis should be suspected in patients with features of thrombotic microangiopathy following this treatment.