Early-stage chronic obstructive pulmonary disease identification marker and application thereof in diagnostic kit

The invention relates to the technical field of gene engineering, and particularly discloses an early-stage chronic obstructive pulmonary disease identification marker and application thereof in a diagnostic kit.The early-stage chronic obstructive pulmonary disease identification marker is obtained by collecting a large amount of chronic obstructive pulmonary disease patient human serum, extracting exosome RNA and establishing an RNA difference database of different levels of chronic obstructive pulmonary diseases through next-generation sequencing; the expression of miRNA1255a in an early patient-derived exosome is abnormal, so that the early chronic obstructive pulmonary disease identification marker is screened out, and the marker is miRNA1255a in a serum-derived exosome; according to biological function analysis after sequencing, in numerous target genes of the miRNA1255a, gene metalloproteinase tissue inhibition factors TIMP-2 and CD36 related to protease-resistant counterbalance of protease participate