MicroRNA expression in antiphospholipid syndrome: a systematic review and microRNA target genes analysis.

INTRODUCTION Antiphospholipid antibodies (aPL) are autoantibodies that attack phospholipid through anti-beta 2-glycoprotein 1. The actions of aPL are associated with events leading to thrombosis and morbidity in pregnancy. Antiphospholipid syndrome (APS) is diagnosed when a patient is persistently positive for aPL and also has recognised clinical manifestations such as recurrent pregnancy losses, arterial or venous thrombosis and in a catastrophic case, can result in death. Unfortunately, the pathogenesis of APS is still not well established. Recently, microRNA expressed in many types of diseased tissues were claimed to be involved in the pathological progression of diseases and has become a useful biomarker to indicate diseases, including APS. OBJECTIVE This systematic review aims to search for research papers that are focussing on microRNA expression profiles in APS. METHOD Three search engines (Ebcohost, ProQuest and Ovid) were used to identify papers related to expression of specific microRNA in antiphospholipid syndrome. RESULTS AND DISCUSSION A total of 357 papers were found and screened, out of which only one study fulfilled the requirement. In this particular study blood samples from APS patients were tested. The microRNAs found to be related to APS were miR-19b and miR-20a. No data was found on specific microRNA being expressed in obstetric antiphospholipid syndrome. Analysis on the microRNA target genes revealed that most genes targeted by miR-19b and miR-20a involve in TGF-Beta Signalling and VEGF, hypoxia and angiogenesis pathways. CONCLUSION In view of the limited data on the expressions of microRNA in APS we recommend further research into this field. Characterization of microRNA profile in blood as well as in placenta tissue of patients with APS could be useful in identifying microRNAs involved in obstetric APS.