Imaging findings in patients with axial spondyloarthritis presenting with 1 recurrent fever attacks: data from the International AIDA Network Spondyloarthritis 2 registry

Nunzia Di Meglio^1,2*Cristian Sica^1,2Antonio Vitale^2,3Valeria Caggiano^2,3Armando Perrella^1,2Vito Di Martino^1,2Margherita Di Stefano¹Mauro Fratarcangeli¹Giulio Bagnacci¹Piero Ruscitti⁴Paola Cipriani⁵Azadeh Shariat Panahi⁴Samar Tharwat^6,7Hanan M Elberashi⁶Esraa E Othman⁸Alessandro Conforti⁹Linda Lucchetti¹⁰Fabrizio Varini¹¹Jurgen Sota^2,3Guillermo Arturo Guaracha-Basañez¹²Perla Ayumi Kawakami-Campos¹³Eduardo Martin-Nares¹²Maissa Thabet¹⁴Ben Yahia Wissal¹⁴Şükran Erten¹⁵Mehmet Akif Eksin¹⁶Bahar Özdemir Ulusoy¹⁶Patrizia Barone¹⁷Santi Papa¹⁷Andrea Giugno¹⁷Stefano Gentileschi^2,3Carla Gaggiano^2,3Simona Buonanno^2,3Soad Hashad¹⁸Halah Etayari¹⁸Abdurrahman Tufan¹⁹Gaafar Ragab^20,21Ewa Barbara Wiesik-Szewczyk²²José Hernández-Rodríguez^23,24Alberto Balistreri^2,25Andrea Hinojosa-Azaola¹²Claudia Fabiani^2,26Bruno Frediani^2,3Luca Cantarini^2,3Maria Antonietta Mazzei^1,2*

• ¹Unit of Diagnostic Imaging, Department of Medical, Surgical and Neuro Sciences and of Radiological Sciences, University of Siena, Azienda Ospedaliero-Universitaria Senese, Siena, Italy
• ²Azienda Ospedaliero-Universitaria Senese [European Reference Network (ERN) for Rare Immunodeficiency, Autoinflammatory and Autoimmune Diseases (RITA) Center], Siena, Italy
• ³Department of Medical Sciences, Surgery and Neurosciences, Research Center of Systemic Autoinflammatory Diseases and Behçet’s Disease Clinic, University of Siena, Siena, Italy
• ⁴Rheumatology Unit, Department of Biotechnological and Applied Clinical Sciences, University of L’Aquila, L'Aquila, Italy
• ⁵Rheumatology Unit, Department of Biotechnological and Applied Clinical Sciences, University of L’Aquila,, L'Aquila, Italy
• ⁶Rheumatology and Immunology Unit, Internal Medicine Department, Mansoura University, Mansoura, Egypt
• ⁷Department of Internal Medicine, Faculty of Medicine, Horus University, New Damietta, Egypt
• ⁸Rheumatology and Immunology Unit, Internal Medicine Department, Mansoura University, Mansoura, Italy
• ⁹General Medicine Unit, San Paolo di Civitavecchia Hospital, Civitavecchia, Italy
• ¹⁰Hospital Pharmacy Unit, San Paolo di Civitavecchia Hospital, Civitavecchia, Italy
• ¹¹Laboratory of experimental oceanology marine ecology. Departement of ecological and biological sciences (DEB), University of Tuscia, Civitavecchia, Italy
• ¹²Department of Immunology and Rheumatology, Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, Mexico City, Mexico
• ¹³Department of Ophthalmology, Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, Mexico City, Mexico
• ¹⁴Internal Medicine Department, Farhat Hached University Hospital, Faculty of Medicine of Sousse, University of Sousse, Sousse, Tunisia
• ¹⁵Department of Rheumatology, Faculty of Medicine Ankara City Hospital, Ankara Yıldırım Beyazıt, University, Ankara, Türkiye
• ¹⁶Clinic of Rheumatology , Ankara Gaziler Physical Therapy and Rehabilitation Training and Research Hospital, Ankara, Türkiye
• ¹⁷Pediatric Rheumatology Unit, Department of Integrated Maternal-Child and Reproduction Activity AOU Policlinico-San Marco, Catania, Italy
• ¹⁸Rheumatology Department, Tripoli Children’s Hospital, Omar Almukthar Street, Tripoli, Libya
• ¹⁹Department of Internal Medicine, Division of Rheumatology, Gazi University Hospital, Ankara, Türkiye
• ²⁰Rheumatology and Clinical Immunology Unit, Internal Medicine Department, Faculty of Medicine, Cairo University, Giza, Egypt
• ²¹Faculty of Medicine, Newgiza University, 6th of October City, Egypt
• ²²Department of Internal Medicine, Pneumonology, Allergology, Clinical Immunology, and Rare Diseases. Military Institute of Medicine, National Research Institute, Warsaw, Poland
• ²³Clinical Unit of Autoinflammatory Diseases, Department of Autoimmune Diseases, Institut d’Investigacions Biomèdiques August Pi I Sunyer (IDIBAPS), Hospital Clínic of Barcelona, Barcelona, Spain
• ²⁴[European Reference Network (ERN) for Rare Immunodeficiency, Autoinflammatory and Autoimmune Diseases (RITA) Center], University of Barcelona, Barcelona, Spain
• ²⁵Bioengineering and Biomedical Data Science Lab, Department of Medical Biotechnologies, University of Siena, Siena, Italy
• ²⁶Ophthalmology Unit, Department of Medicine, Surgery and Neurosciences, University of Siena, Siena, Italy

Spondyloarthritis (SpA) is a group of immuno-mediated diseases likely caused by a complex interaction between autoimmune and autoinflammatory immunological mechanisms, where a febrile clinical presentation can be an early manifestation. This retrospective study aims to assess the prevalence of inflammatory involvement of the sacroiliac joints (SIJs), pelvis, and lumbosacral spine in patients with axial-SpA and recurrent febrile presentation. MR examinations of 57 patients fulfilling the axial-SpA according to ASAS criteria and presenting with febrile symptoms were evaluated, compared to 30 patients with axial-SpA and no febrile symptoms. 20/57 patients in the axial-SpA group with recurrent fevers underwent a US examination of the SIJs. Structural damage and inflammatory alterations of the SIJs were highly prevalent in both groups. In patients with febrile syndrome, bone marrow edema (78.9%) and erosions (85.9%) were the most prevalent findings in the SIJs; SPARCC score was significantly higher in patients with typical axial-SpA onset (BME:20.1±12.28 vs. 6.15±3.21; erosions:22.16±8.13 vs. 6.60±3.08; p=0.01). Among pelvic enthesitis, enthesitis of the pubic symphysis showed a significant difference in prevalence (p<0.001). Significant differences were found for the prevalence of vertebral body corner sclerosis (p=0.01), zygapophyseal capsulitis (p=0.005), and interspinous enthesitis (p=0.006). No significant correlation was found between ultrasound findings and MR inflammatory changes (p>0.05). SIJs and spinal inflammatory alterations and pelvis enthesitis were highly prevalent in axial-SpA patients with and without recurrent fever. Enthesitis of the pubic symphysis, vertebral body corner sclerosis, zygapophyseal capsulitis, and interspinous enthesitis showed a significant difference in frequency between axial-SpA patients with and without fever attacks.