Study on the Association of Mitochondrial DNA Copy Number with the Severity of Preeclampsia

Author(s): Shafinaz Mehzabin, Nayer Islam, Sumona Parvin, Mohammad Mahbub Elahi, Sharmin Hussain, Mallika Kar Pinkee

Background: Preeclampsia (PE) is a pregnancy-related multisystem disease that affects 2-8% of pregnancies globally with immense maternal and perinatal morbidity and mortality. The present study aimed to investigate the association between maternal peripheral blood mitochondrial DNA copy number (mtDNA-CN) and the severity of PE in a Bangladeshi population.

Methods: This case-control study enrolled 51 PE cases and 51 normotensive pregnant controls in Bangabandhu Sheikh Mujib Medical University, Dhaka. PE was identified using systolic blood pressure ≥140 mmHg and/or diastolic blood pressure ≥90 mmHg accompanied by proteinuria and organ involvement. Blood samples were measured by a quantitative polymerase chain reaction to estimate mtDNA-CN from the ratio of ND1 and HGB genes. Categorical and continuous variables were compared using chi-square tests and unpaired t-tests, respectively.

Results: PE cases had statistically elevated mtDNA-CN compared to controls, with rising levels from controls (44.67±3.56) to mild PE (75.22±22.92) to severe PE (85.21±12.80) (p=0.007). The most optimal cut-off value of mtDNA-CN was determined to be >45, which had a sensitivity of 68.6% and (-specificity was 58.8% for PE detection. Females with mtDNA-CN >45 had approximately three times higher odds for PE (OR=3.1, 95% CI: 1.4-7.0, p=0.005). Overall accuracy was 63.7% (95% CI: 53.6-73.0%).

Conclusion: This study shows a significant correlation between increased maternal peripheral blood mtDNA-CN and PE, with values rising progressively according to the severity of the disease. These results point to mtDNA-CN as a potential biomarker for PE risk stratification and underscore the enteropathogenic role of mitochondrial dysfunctions in PE.