Detection of serum major histocompatibility complex I (HLA-1) and β2-microglobulin (β2M) in pre-eclampsia using isobaric tags for relative and absolute quantitation (iTRAQ).

Objective: The purpose of this preliminary investigation into the pathogenesis of pre-eclampsia was to screen the differential proteins in the serum of pregnant women with normal pregnancy and early-onset pre-eclampsia using isobaric tags for relative and absolute quantitation (iTRAQ), so as to identify serum biomarkers for the early diagnosis of pre-eclampsia.

Methods: We examined the peripheral serum of 58 normal pregnant women and 42 pregnant women with early-onset pre-eclampsia using iTRAQ; the differentially expressed proteins were screened for bioinformatics analysis; and the expression of candidate proteins human leukocyte antigen-1 (HLA-1) and β2-microglobulin (β2M) in placental tissues was detected using western blot.

Results: We identified a total of 63 differential proteins in the serum of patients from the normal control group and the pre-eclampsia group, and this included 24 up-regulated proteins and 39 down-regulated proteins. The western blot results of placental tissue showed reduced HLA-1 expression (1.12 ± 0.23) in the placenta in the pre-eclampsia group as compared with the normal control group (1.34 ± 0.22). Consistent with the results observed in the serum, β2M in the placenta in the pre-eclampsia group was significantly elevated (1.05 ± 0.47) in comparison with the normal group (0.75 ± 0.33) (P < 0.05).

Conclusion: In this study, we found that iTRAQ technology was useful for identifying differentially expressed proteins in the peripheral serum of pregnant women with pre-eclampsia, and that HLA-1 and β2M, which may be involved in the occurrence of pre-eclampsia, show promise as predictive markers of pre-eclampsia.