Early changes of the heat-shock protein 60 to 70 ratio as prediction of miscarriage in pregnancy

To study the balance of circulating heat shock protein (HSP)60 and HSP70 in pre-term delivery.

A two-stage approach was used. At first stage, we run retrospective analysis of prospective collected clinical data, and at a second stage, we studied an animal model of pre-term delivery (PTD). Blood samples were collected for prenatal screening in 3629 women. Samples from 23 women with miscarriage before gestational week 21 and 53 well-matched comparators for age, body mass index, parity, and previous miscarriage with full-term pregnancy were depicted. Women with risk factors were excluded. HSP60 and HSP70 were measured by an enzyme immunosorbent assay. PTD was induced after injection of low dose of bacterial lipopolysaccharide; mice were killed for the measurement of HSP60 and HSP70 in blood and tissues. The study endpoint was the association of the HSP60 to HSP70 ratio to miscarriage.

A ratio >6 could distinguish between women who will miscarry from women with term pregnancies with sensitivity 60%, specificity 81.8%, positive predictive value 81.8%, and negative predictive value 60% (OR: 6.750, P = 0.025). Mice of the LPS-group PTD had this ratio significantly increased in maternal serum, placentas, and embryos compared to the sham-operation group. Gene expression of hsp60/70 remained in tissues unaltered.

A HSP60/HSP70 ratio equal to or more than 6 until gestational week 12 is accompanied with great likelihood for miscarriage. A similar ratio applies in an animal model of PTD induced by low-dose LPS.