Serum cathepsin B and D levels in pregnancy in Ngoerah Hospital: a cross sectional study

Objective: Cathepsins are lysosomal proteases involved in extracellular matrix remodeling, angiogenesis, and immune regulation. Evidence on serum cathepsin B (Cat B) and cathepsin D (Cat D) levels during pregnancy remains limited and inconsistent, particularly in the Balinese population. This study compared serum Cat B and Cat D levels across pregnancy trimesters and in nonpregnant women. Methods: This analytical cross-sectional study included 96 women, with 24 participants in each group: first trimester, second trimester, third trimester, and nonpregnant controls. Serum Cat B and Cat D levels were measured using enzyme-linked immunosorbent assay. Data were analyzed using one-way analysis of variance or the Kruskal-Wallis test, followed by post hoc analysis. Results: Baseline characteristics were comparable across groups. Serum Cat B levels were significantly higher in pregnant women than in nonpregnant controls (P=0.002). Post hoc analysis confirmed significantly higher Cat B levels in all trimesters than in nonpregnant women, with no significant differences among trimesters. Cat D levels were not normally distributed (P<0.001). Median Cat D levels were highest in the third trimester (P<0.001), whereas no significant differences were observed among the other three groups. Conclusion: Cat B levels were elevated throughout pregnancy without trimester-specific variation, whereas Cat D levels increased markedly in the third trimester. The trimester-related patterns observed in this study are consistent with previous findings; however, absolute Cat B and Cat D levels differed across populations. Further studies are warranted to clarify the mechanistic and endocrine associations of these biomarkers during pregnancy.