Plasma microRNA Levels and Some Cytokines Expression in Patients With Primary Immune Thrombocytopenic Purpura (ITP)

In recent years the critical role of miRNAs has been established in many diseases, including autoimmune disorders. Immune thrombocytopenic purpura (ITP) is a predominant autoimmune disease, in which aberrant expression of miRNAs has been observed, suggesting that miRNAs are involved in its development (Jafarzadeh et al., 2021). Studies have also shown that cell-free miRNAs in circulation are stable and that such miRNAs may be exploited as novel disease markers (Etheridge et al.,2011) and ( van Rooij et al., 2008).

MicroRNAs (miRNAs) are endogenous small RNAs, usually 18-25 nucleotides in length. These non-coding RNAs regulate gene expression by several mechanisms, such as repressing protein translation and altering mRNA stability (Ambros, 2008. Bartel,2004). In humans, >2,000 miRNAs have been discovered. The functional significance of the majority of the identified miRNAs has yet to be fully elucidated. Studies have shown that miRNAs play important roles in hematopoietic differentiation, e. g. megakaryocytopoiesis. (Garzon et al., 2008) and erythropoiesis ( Masaki et al., 2007 )and (Bruchovaetal., 2007), and in hematological malignancies (Rossi et al.,2010) and (Visone et al.,2009). More recently, miRNAs have also been implicated in cellular immune responses that contribute to ITP (Jernas et al., 2013) and (McKenzie etal., 2013). It was found that 23 differentially expressed miRNAs in ITP (14 up-regulated and 9 down-regulated) Altered miRNA expression may occur in specific diseases and at specific disease stages (Martin et al., 2012) Also, Recent studies have demonstrated that Th17, which is characterized for its production of IL-17, is elevated in ITP patients (Hu et al., 2012) and (Huber et al., 2007). IL-17 belongs to the IL-17 cytokine family. Increased IL-17 expression has been observed in various autoimmune diseases, such as rheumatoid arthritis (RA) ( Roeleveld et al., 2013) and systemic lupus erythematosus (SLE) (Ballantine et al., 2014). This evidence suggests that IL-17 may be associated with autoimmune diseases.