MicroRNA expression levels in lung recipients: correlations with clinical and laboratory data

Objective: to evaluate the expression levels of miRNA (miR-27, miR-101, miR-142, miR-339 and miR-424) and its relationship with clinical and laboratory parameters in lung transplant recipients. Materials and methods. The study included 57 lung recipients aged 10 to 74 years (35 ± 15), including six children (9%) – four boys 10, 12, 13 and 17 years and girls 13 and 14 years old – and 51 adult recipients, including 30 men (62.5%). The control group was made up of 14 healthy individuals that were not significantly different by gender and age. Expression levels of the microRNAs studied in blood plasma were determined via quantitative polymerase chain reaction (PCR). Correlations of miRNA expression levels with complete blood count and biochemical blood test indicators were analyzed. Results. Patients with end-stage chronic respiratory failure (potential lung recipients) were found to have significantly higher expression levels of miR-27, miR-101 and miR-339 in plasma than the healthy individuals (p = 0.02, p = 0.03 and p = 0.01, respectively). The expression level of miR-339 correlated with the age of potential lung recipients (p = 0.04). It was a negative correlation (r = –0.46). The expression levels of the other four miRNAs were age independent. The average expression level of miR-424 in lung recipients in the long-term period after lung transplant was higher than in waitlisted patients (p = 0.03). Analysis of the relationship between miRNA expression levels and external respiration function in the long-term post-transplant period showed that miR-142 expression level (r = 0.61; p = 0.04) positively correlates with the Tiffeneau-Pinelli index. This strong correlation, which exceeds 85%, indicates the presence of restrictive lung diseases. A year and more after transplantation, it was found that in the recipients, there were close positive correlations between miR-27, miR-142, miR-424 expression levels and blood leukocyte concentration, as well as between the miR-142 expression level and the sCD40L concentration during this period. Conclusion. A comparative study of the expression level of miRNAs (miR-27, miR-101, miR-142, miR-339 and miR-424) in the blood plasma of patients suffering from end-stage chronic lung diseases of various origin and in lung recipients enables us to conclude that further studies of the miRNA panels are needed in order to assess their effectiveness as potential molecular and genetic markers of post-transplant complications