Abstract: A method comprising obtaining a substantially cell-free sample of blood plasma or blood serum from a subject with osteoarthritis; and detecting a presence of or measuring a level of novel_miRNA_1 (gucuggcucaggguuggg) (SEQ ID NO: 1), novel_miRNA_2 (ucccuguucgggcgccacu) (SEQ ID NO: 2), novel_miRNA_3 (uguuuagcauccuguagccugc) (SEQ ID NO: 3), and novel_miRNA_4 (uaguggguuaucagaacu) (SEQ ID NO: 4). Also provided are methods where additional miRNAs are detected including novel miRNA 5 (SEQ ID NO: 5), novel miRNA 6 (SEQ ID NO: 6), novel miRNA 7 (SEQ ID NO: 7), novel miRNA 8 (SEQ ID NO: 8), novel miRNA 9 (SEQ ID NO: 9), novel miRNA 10 (SEQ ID NO: 10), novel miRNA 11 (SEQ ID NO: 11), novel miRNA 12 (SEQ ID NO: 12), novel miRNA 13 (SEQ ID NO: 13), hsa-miR-335-3p, hsa-miR-199a-5p, hsa-miR-671-3p, hsa-miR-1260b, hsa-miR-191-3p, hsa-miR-335-5p and/or hsa-miR-543.

Abstract: A method staging of knee osteoarthritis (OA) comprising a) obtaining a substantially cell-free sample of blood plasma or blood serum from a subject with osteoarthritis; b) detecting a presence of or measuring a level of one or more miRNAs selected from hsa-miR-335-3p, hsa-miR-199a-5p, hsa-miR-671-3p, hsa-miR-1260b, hsa-miR-191-3p, hsa-miR-335-5p, hsa-miR-543, novel_miRNA_1 (gucuggcucaggguuggg) (SEQ ID NO: 1), novel_miRNA_2 (ucccuguucgggcgccacu) (SEQ ID NO: 2), novel_miRNA_3 (uguuuagcauccuguagccugc) (SEQ ID NO: 3), and novel_miRNA_4 (uaguggguuaucagaacu) (SEQ ID NO: 4); and c) identifying the subject as likely to have early stage osteoarthritis or late stage osteoarthritis based on the presence of or measured level of the one or more miRNAs. Isolated nucleic acids, primers, probes, panels and kits are also provided.