PO:19:281 | Mitochondrial dysfunction in Still’s disease: a preliminary analysis of mtDNA copy number and TFAM expression

Ludovica Manisera¹, Francesca Giansanti², Andrea Latini³, Francesca Lotito⁴, Serena Colafrancesco⁵, Angelica Gattamelata⁶, Fabrizio Conti⁷, Cinzia Ciccacci⁸, Roberta Priori⁹ | ^1|6|7|9La Sapienza, Roma; ^2|3|4|8Unicamillus, Roma; ⁵Humanitas, Milano, Italy

Background. Still’s disease (SD) is hypothesized to arise from the interaction between environmental and genetic factors that trigger an inappropriate activation of the innate immune system, leading to excessive production of proinflammatory cytokines. Oxidative stress—one of the main sources of DNA damage—plays a crucial role in several inflammatory disorders. Mitochondrial DNA (mtDNA) is particularly vulnerable to oxidative injury caused by reactive oxygen species (ROS), which are physiologically generated during mitochondrial respiration. The mitochondrial DNA copy number (mtDNA-CN) serves as a biomarker of mitochondrial function, and its maintenance depends on several nuclear-encoded genes, including the mitochondrial transcription factor A (TFAM). However, the role of oxidative stress and mitochondrial dysfunction in AOSD remains poorly understood.

Objective: To compare mtDNA-CN and TFAM gene expression in patients with SD and healthy controls (CTRLs).

Materials and Methods: Peripheral blood samples were collected for DNA and RNA extraction. mtDNA-CN and TFAM mRNA expression levels were quantified using quantitative PCR (qPCR). Statistical comparisons between groups were performed using ANOVA tests.

Results: A total of 27 patients fulfilling Yamaguchi criteria for AOSD and 35 healthy CTRLs were enrolled. SD patients showed a significantly lower mtDNA-CN compared with CTRLs (p = 0.006). Conversely, TFAM mRNA expression was significantly higher in SD patients than in CTRLs (p = 0.02). A negative correlation between.....