Unveiling the Diagnostic and Prognostic Value of Inflammatory Cytokines in Preeclampsia: A Review of Ιnterleukins IL-15, IL-16, IL-17 and IL-35

Background: Preeclampsia (PE) is a multicomplex disorder occurring during pregnancy, characterized by the onset of hypertension and proteinuria, or hypertension accompanied by organ dysfunction (such as impaired liver function, renal insufficiency, pulmonary edema, or cerebral and visual impairment), with or without proteinuria in the latter half of pregnancy or postpartum. It impacts around 5% of all pregnancies, resulting in considerable fetal and maternal mortality and morbidity. A properly regulated inflammatory response is crucial for achieving a successful pregnancy; nevertheless, an excessive reaction appears to contribute to the onset of this syndrome. This review sought to investigate the role and correlation of interleukins (IL)-15, IL-16, IL-17, and IL-35 in the pathogenesis of PE, along with the prospective application of biomarkers in predicting and monitoring this illness. Methods: A thorough investigation was performed in the PubMed/Medline, Scopus, and Google Scholar electronic databases up to September 2025, employing the terms PE, Pregnancy, IL-15, IL-16, IL-17, IL-35, Inflammatory Response, and Cytokines. Women at the time of diagnosis were matched with normotensive counterparts of similar gestational age. Results: A total of 30 full-text articles were obtained following a thorough assessment. The majority of the published data showed that women with preeclampsia have significantly higher levels of IL-15 and IL-17 in their plasma compared to normotensive women, whereas IL-35 levels were mainly decreased, respectively. Moreover, IL-16 levels were elevated across all the studies, primarily correlating with condition severity. Conclusions: Collectively, IL-15, IL-16, IL-17, and IL-35 are markedly linked to the immunopathology of preeclampsia, with elevated maternal serum levels corresponding with the presence and severity of the disease. These cytokines demonstrate potential as biomarkers for diagnosis, prognosis, and disease surveillance. Future study, including the examination of cytokine profiles in placental and amniotic fluid, as well as additional intriguing cytokines, is essential to clarify their prognostic importance and mechanistic roles.