PO:19:279 | Predictors of proteinuria, amyloidosis and kidney failure in familial Mediterranean fever: data from the International AIDA Network Registry

Jessica Sbalchiero¹, Antonio Vitale¹, Valeria Caggiano¹, Abdurrahman Tufan², Ezgi Batu³, Gaafar Ragab⁴, Seza Ozen³, Jurgen Sota¹, Carla Gaggiano¹, Ali Sahin⁵, Petros Sfikakis⁶, Francesca Li Gobbi⁷, Giacomo Emmi⁸, Jose Rodriguez⁹, Piero Ruscitti¹⁰, Paolo Sfriso¹¹, Ewa Szewczyk¹², Giuseppe Lopalco¹³, Alberto Balistreri¹⁴, Claudia Fabiani¹⁵, Bruno Frediani¹, Luca Cantarini¹ | ¹Department of Medical Sciences, Surgery and Neurosciences, University of Siena, Siena, Italy; ²Department of Internal Medicine, Division of Rheumatology, Gazi University Hospital Ankara, Turkey; ³Division of Pediatric Rheumatology, Department of Pediatrics, Hacettepe University School of Medicine Ankara, Turkey; ⁴Internal Medicine Department, Rheumatology and Clinical Immunology Unit, Faculty of Medicine, Cairo University Giza, Egypt; ⁵Division of Rheumatology, Department of Internal Medicine, Sivas Cumhuriyet University Medical Faculty Sivas, Turkey; ⁶Joint Academic Rheumatology Program, Medical School, National and Kapodistrian University of Athens Athens, Greece; ⁷Rheumatology Unit, Hospital S. Giovanni di Dio, Azienda USL-Toscana Centro Florence, Italy; ⁸Clinical Medicine and Rheumatology Unit, Cattinara University Hospital Trieste, Italy; ⁹Department of Autoimmune Diseases, Institut Investigacions Biomediques August Pi I Sunyer, University of Barcelona Barcelona Spain; ¹⁰Rheumatology Unit, Department of Biotechnological and Applied Clinical Sciences, University of L'Aquila, L'Aquila, Italy; ¹¹Rheumatology Unit, Department of Medicine, University of Padua Padua, Italy; ¹²7Department of Internal Medicine, Pneumonology, Allergology, Clinical Immunology and Rare Diseases, Military Institute o Warsaw, Poland; ¹³Department of Precision and Regenerative Medicine and Ionian Area DiMePRe-J Policlinic Hospital, University of Bari Bari, Italy; ¹⁴Bioengineering and Biomedical Data Science Lab, Department of Medical Biotechnologies, University of Siena Siena, Italy; ¹⁵Ophthalmology Unit, Department of Medicine, Surgery and Neurosciences, University of Siena Siena, Italy

Objectives. Proteinuria, amyloidosis and kidney failure are the main long-term renal complications of FMF. This study assesses their risk factors, independent of ethnicity or residence.

Methods. Patients’ data were drawn from the International AIDA Network registry for monogenic autoinflammatory diseases.

Results. A total of 598 FMF patients were enrolled, with 80 having proteinuria, 61 amyloidosis and 25 kidney failure. At multivariate regression analysis, proteinuria was associated with out-of-flares thrombocytosis (odds ratio [OR]: 4.78, 95% CI: 1.54–14.8, P ¼ 0.007), increased out-offlares ESR (OR: 2.7, 95% CI: 1.3–5.6, P ¼ 0.008), homozygous M694V mutation (OR: 2.27, 95% CI: 1.1–4.66, P ¼ 0.025) and heterozygous M694V mutation (OR: 0.29, 95% CI: 0.09–0.86, P ¼ 0.026); amyloidosis was associated with the disease duration (OR: 1.034, 95% CI: 1.004–1.065, P ¼ 0.027), during-flares anaemia (OR: 2.9, 95% CI: 1.18–7.19, P ¼ 0.021), out-of-flares leucocytosis (OR: 7.47, 95% CI: 1.6–34.7,P ¼ 0.01), increased out-of-flares ESR (OR: 3.6, 95% CI: 1.48–8.81, P ¼ 0.005) and heterozygous M694V mutation (OR: 0.18, 95% CI: 0.035–0.9, P ¼ 0.04); kidney failure was associated with the age at diagnosis (OR: 1.04, 95% CI: 1.0003–1.19, P ¼ 0.048), the disease duration in years (OR: 1.07, 95% CI: 1.02–1.12, P ¼ 0.005), attack frequency per year (OR: 1.04, 95% CI: 1.007–1.076, P ¼ 0.019), anaemia out-of-flares (OR:4.7, 95% CI: 1.004–22.1, P ¼ 0.049) and out-of-flares leucocytosis (OR: 25.8, 95% CI: 2.75–242, P ¼ 0.004). The intraclass correlation coefficient related to ethnicity and country of residence was 6.7% and 6.8% for amyloidosis, respectively, and 0% for proteinuria and kidney failure.

Conclusions. FMF patients with older age at diagnosis, longer disease duration, anaemia, leucocytosis, thrombocytosis, elevated ESR and homozygous M694V mutation are at higher risk of kidney complications