Introduction: Preeclampsia is a major cause of maternal morbidity and mortality, complicating 2-8% of pregnancies world-wide. The exact mechanism which causes preeclampsia is unknown, however it has been suggested that infections may play a role in a subset of cases. CagA positive Helicobacter pylori, is one infection potentially linked to preeclampsia onset. This pilot study aimed to use precision, epitope-based CagA serology to further investigate the link between CagA positive H. pylori infection and preeclampsia development.
Methods: The pilot cohort consisted of 31 samples, 15 cases and 16 matched controls. This cohort was selected from a larger cohort consisting of women who gave birth in the Swedish region of Kronoberg between 2016 – 2019, who were diagnosed with preeclampsia. Each diagnosed preeclampsia case had been matched with normal pregnancies as a control.
Samples were screened for anti-CagA peptide antibody responses using peptide array analysis; with each sample tested for IgG responses against 228 different 15-mer peptides spanning overlapping regions across the CagA protein. The results were validated using an IgG anti-peptide ELISA.
Results: There was a significant association between anti-CagA IgG responses of the preeclampsia cases compared to controls. Peptide array IgG screening against all 228 tested peptides revealed five out of 15 cases with an anti-CagA antibody-response significantly higher than the controls, indicating that approximately 30% of the preeclampsia cases were associated with infection by CagA H. pylori. Further IgG anti-peptide ELISA testing of five individual peptides of interest identified two peptides, which were strongly associated to preeclampsia in 20% of disease cases.
Conclusions: This pilot study found that a subset of women developing preeclampsia have high levels of certain anti-CagA IgG antibodies preceding the disease. This demonstrates the promise of using peptide-specific antibodies for CagA H. pylori diagnostics, particularly as a screening tool for risk of preeclampsia development.