Objective: Interferon (IFN) signaling, and excessive apoptosis have a well-established role in systemic lupus erythematosus (SLE) pathogenesis. Long non-coding RNA (lncRNA) growth arrest-specific transcript 5 (GAS5) has been linked to excessive apoptosis and upregulation of IFN genes. We aimed to investigate the expression of IFN-stimulated genes in SLE patients compared to healthy controls, and to assess their association with lncRNA GAS5 and clinical characteristics of SLE. Methods: The study included 30 SLE patients and 20 controls. IFN-stimulatory genes (interferon-induced protein 44-like [IFI44L] gene, MX dynamin like GTPase 1 [MX1], IFN-induced protein with tetratricopeptide repeats 1 [IFIT1]) and GAS5 expression levels in plasma were estimated by quantitative real-time polymerase chain reaction. IFN signature score was calculated. Results: IFIT1 gene expression and IFN signature score were significantly higher in SLE patients compared to controls (p<0.001, p<0.001, respectively). LncRNA GAS5 positively correlated with IFIT1 expression (p<0.001) and IFN signature score (p=0.005).No significant associations were found between IFN gene expression or IFN signature score and disease activity (Systemic Lupus Erythematosus Disease Activity Index 2000, SLEDAI-2K) or organ damage (Systemic Lupus International Collaborating Clinics/ American College of Rheumatology Damage Index, SDI). IFI44L expression was significantly higher in SLE patients with secondary antiphospholipid syndrome (p=0.040). Conclusion IFN signature is a potential biomarker for SLE diagnosis, but it can’t be relied on for the assessment of activity or damage. The correlation between lncRNA GAS5 and IFN-related gene expression suggests a possible role for GAS5 in the IFN pathway in SLE.

PURPOSE: Recent studies have suggested that decreased serum potassium level may contribute to various metabolic disorders in adult patients including nonalcoholic fatty liver disease (NAFLD). We aimed to study the correlation between serum potassium levels and the histologic severity of NAFLD in children. METHODS: Pediatric patients with biopsy-proven NAFLD were included in this study. Demographic, clinical, and histopathological data were obtained. Multivariable logistic regression analysis was used to assess whether potassium levels are associated with the presence of nonalcoholic steatohepatitis (NASH) or fibrosis after adjusting for possible confounders. A p-value <0.05 was considered statistically significant. RESULTS: Among 125 biopsies, 49.6% (62) had evidence of NASH while 66.4% (83) had some degree of fibrosis (stage 1-3). Mean serum potassium was significantly lower in NASH group as compared to non-NASH group (4.4+/-0.42 mmoL/L vs. 4.8+/-0.21, p<0.001). Higher potassium level had negative correlation with presence of steatosis, ballooning, lobular inflammation, fibrosis and NAFLD activity score (p<0.05). On multivariable analysis and after adjusting for the metabolic syndrome and insulin resistance, higher potassium level was significantly associated with lower likelihood of having a histological diagnosis of NASH on biopsy (odds ratio [OR], 0.12; 95% confidence interval [95% CI], 0.05-0.28; p<0.001). Similarly, the likelihood of having fibrosis decreases by 76% for every 0.5 mmoL/L increase in potassium (OR ,0.24; 95% CI, 0.11-0.54; p<0.001). CONCLUSION: Our study shows an inverse relationship between serum potassium levels and the presence of aggressive disease (NASH and fibrosis) in children with NAFLD.
Adult ; Biopsy ; Child* ; Diagnosis ; Fatty Liver* ; Fibrosis ; Humans ; Inflammation ; Insulin Resistance ; Logistic Models ; Pediatrics ; Potassium*