Prognostic factors for adult-onset Still disease: a retrospective analysis of 90 patients in China

Background Adult-onset Still disease (AOSD) is a systemic auto-inflammatory disorder that can be divided into monocyclic, polycyclic and chronic arthritis subtypes based on the clinical course. Since the prognoses of the three patterns of AOSD are substantially different, it is important to identify clinical indices that can be used to differentiate them. Objectives To investigate the clinical features of the three patterns of AOSD in order to determine possible prognostic factors. Materials & Methods Clinical records of inpatients admitted with a probable diagnosis of AOSD to the Second Xiangya Hospital of Central South University between 2009 and 2019 were retrospectively studied. Ninety patients were divided into a monocyclic group, a polycyclic group and a chronic arthritis group. Results The average age at onset was 39.01 ± 13.04 years, and female to male ratio was 3.3. Elevated white blood cell (WBC) count, even beyond 15 × 10 9 /L, and increased serum level of interleukin-6 (IL-6) >5.3 pg/mL (upper limit of normal value) were associated with the recurrence of AOSD, while the presence of rash and increased level of alanine aminotransferase (ALT) and/or aspartate aminotransferase (AST) were more commonly seen in the monocyclic group. Conclusion Our results indicate that gender, presence of rash, WBC count, serum level of IL-6, and ALT and/or AST are promising prognostic factors for AOSD. However, larger cohorts are needed to validate these factors due to the limitations of the retrospective study design and relatively small sample size.