Exosomal miRNAs may help diagnose Kawasaki disease
Exosomal microRNAs (miRNAs) in the serum are potential diagnostic biomarkers for Kawasaki disease (KD), a new study shows.
The study involved frozen blood samples from 79 KD patients who did not undergo intravenous immunoglobulin (IVIG) injection and of 29 patients who received IVIG injections. Fresh samples from 30 KD patients prior to IVIG, two epstein-barr virus (EBV) patients, two adenovirus (ADV) patients and 30 healthy controls were also collected.
Exosomes were isolated using the ExoQuick precipitation. Proteins and miRNAs were characterized using Western blotting and microarray analysis, respectively. Quantitative real-time polymerase chain reaction (qRT-PCR) was used to verify the microarray.
Microarray analysis found that miR-1260a, miR-4701-5p, miR-885-5p, miR-328 and miR-197-3p were present in high amounts in patients with KD but were undetectable in healthy controls and patients that were treated with IVIG.
However, when these biomarkers were validated in a larger cohort of 60 samples (20 KD patients, 20 controls, 20 IVIG-treated) using qRT-PCR, the difference between KD patients and controls lost significance (p>0.01 for most biomarkers).
Only the miRNA pair miR-1246/miR-4436b-5p had significantly different expressions between KD patients and controls (p<0.01), and between KD patients and IVIG-treated patients (p<0.01). Additionally, its expression between controls and ADV patients was not significantly different (p>0.01), making it a good potential biomarker for KD.
The miRNA pair miR-197-3p/miR-671-5p showed the opposite trend. Its expression between KD patients and healthy controls, and between KD patients and IVIG-treated patients was not significantly different, while its expression between controls and ADV patients was. This implies that it may help differentiate ADV infection from KD.