Serum heat shock protein 70 in preeclampsia and normal pregnancy: A systematic review and meta-analysis

BACKGROUND: Preeclampsia, a severe complication of human pregnancy is one of the main causes of maternal, fetal, and neonatal morbidity and mortality with unclear pathogenesis. Heat shock protein 70 (HSP70) is one of the factors that can mediate cytoprotective, antiapoptotic, and immune regulatory effects. OBJECTIVE: This meta-analysis was performed with aim to evaluate HSP70 in preeclampsia and normal pregnancy. MATERIALS AND METHODS: The original publications reporting the serum HSP70 levels in preeclampsia and normal pregnancies published before November 2015 were identified by searching PubMed Central, Scopus, and ISI Web of Knowledge databases by two researchers, separately. The keywords were” preeclampsia” and “HSP70” or “Heat shock protein 70” Statistical analyses were performed using STATA software (version 11). RESULTS: Out of 127 studies, seven eligible case-control studies were identified which consists of 350 preeclampsia and 429 normal pregnancies. Our pooled analysis of data from 7 studies which met the inclusion criteria, provides evidence that there is a significant association between HSP70 and preeclampsia. Cochran's test results showed the heterogeneity of the studies (p<0.001) and the I2 index was 91%. The standardized mean differences (SMD) based on a random effect model with trim and fill method was 0.92 (95% CI: 0.33-1.51); also there was a significant association between HSP70 and preeclampsia (Z=3.07, p=0.002). CONCLUSION: The results showed that serum HSP70 concentration was significantly higher in preeclamptic patients than the control group. Therefore HSP70 may be identified as a diagnostic factor.