Validation by quantitative real-time polymerase chain reaction (qRT-PCR)

The peripheral blood samples of 11 HSP/HSPN children and 3 age-matched healthy children were enrolled from the Children’s Hospital, Zhejiang University School of Medicine (Hangzhou, China) between August 2021 and November 2021. HSP was diagnosed according to the criteria outlined by the Society of Pediatrics, Chinese Medical Association in 2013 (32). HSPN was diagnosed as the presence of either hematuria and/or proteinuria during the first 6 months of HSP (33). None of the patients had complications or had taken any immunosuppressants prior to this study. The clinical characteristics of the children are presented in Table S1. The research was approved by the Ethics Committee of the Children’s Hospital, Zhejiang University School of Medicine (No. 2022-IRB-015). Informed consent was taken from all the participants’ guardians, and the study was conducted in accordance with the Declaration of Helsinki (as revised in 2013). The total RNA of these samples was extracted using the RNA Extraction Kit (Omega, Guangzhou, China). Reverse transcription was conducted using PrimeScript RT Master Mix Kit (Takara, Dalian, China). The expression of lncRNAs was assessed using the TB Green Premix Ex Taq Kit (Takara, Dalian, China) in accordance with the manufacturer’s instructions. Primers used in this study are listed in Table S2. The relative expression of lncRNAs was calculated using the 2^−ΔΔCt method, with glyceraldehyde-3-phosphate dehydrogenase (GAPDH) as the reference. Two-sided unpaired Student’s t-test was applied to compare the difference in lncRNA expression levels between the peripheral blood samples of 11 HSP/HSPN children and 3 age-matched healthy children. The corresponding results were visualized using R package “ggplot2”.