Significance of decreased serum interleukin-10 levels in the progression of cerebral infarction

Anti-inflammatory cytokine and its serological detection may have an important role in the process of cardiovascular and cerebrovascular diseases. We investigated whether serum interleukin-10 (IL-10) is associated with cerebral infarction or not in the general population. Identified comprehensive searching was performed covering PubMed, EMBASE, Web of Science, Cochrane Library, CISCOM, CINAHL, Google Scholar, China BioMedicine, and China National Knowledge Infrastructure databases. Two reviewers extracted data and assessed studies independently. Information was extracted separately and classed into Asians and Caucasians. Summary standardized mean differences (SMDs) with 95 % confidence intervals (CI) were used with the utilization of Z test. Nine studies ranged from 2003 to 2014 were collected for meta-analysis. Results identified a negative association between serum IL-10 levels and cerebral infarction (SMD = 1.80, 95 % CI 0.79–2.81, P < 0.001). Country-subgroup analysis showed that low IL-10 level may be the main risk factor for cerebral infarction in India (SMD = 1.44, 95 % CI 1.13–1.75, P < 0.001) and Croatia (SMD = 2.96, 95 % CI 2.48–3.44, P < 0.001). In the ethnicity-stratified subgroup analysis, serum IL-10 levels were negatively correlated with cerebral infarction in Asians (SMD = 2.52, 95 % CI 0.47–4.57, P = 0.016), while not in Caucasians (P > 0.05). The lower serum IL-10 concentration was significantly associated with an increased likelihood of cerebral infarction in this meta-analysis. More prospective studies should be conducted to provide stronger evidence justifying the use of IL-10 as new biomarker to identify a predisposition toward cerebral infarction.