Soluble (pro)renin receptor (s(P)RR) levels in women carrying Aboriginal and/or Torres Strait Islander babies; the Gomeroi Gaaynggal study.

Objective: To determine the levels of soluble (pro)renin receptor (s(P)RR) in women carrying Aboriginal and/or Torres Strait Islander (First Nations) babies and investigate whether s(P)RR levels change in women who have complicated pregnancies.

Study Design: Cross-sectional analysis of data (2010-2018). Data/samples were from the Gomeroi Gaaynggal Study, a longitudinal cohort study based on Gomeroi/Kamilaroi lands (Tamworth), NSW, Australia. Third trimester samples (blood/urine) were collected from pregnant women carrying a First Nations baby (N = 188).

Methods/main Outcome Measures: Plasma s(P)RR and markers of kidney function (plasma: creatinine, urea and cystatin C; urinary: creatinine, protein, albumin, angiotensinogen, nephrin and Na/K) were measured by enzyme-linked immunosorbent assay or standardised pathology procedures as needed.

Results: Soluble (P)RR was detected in plasma of women in the cohort (median: 19.86 ng/mL; IQR: 12.52-26.8). Soluble (P)RR levels correlated positively with maternal plasma creatinine (P = 0.0001) and gestational age in the third trimester (P = 0.002). Levels of s(P)RR tended to positively correlate with urinary protein/creatinine (P = 0.04) and nephrin/creatinine (P = 0.03). Soluble (P)RR levels tended to be higher in women who birthed prematurely (P = 0.06). Soluble (P)RR levels did not change with other pregnancy complications or outcomes (preeclampsia, GDM or small or large for gestational age birth).

Conclusions: Soluble (P)RR is present in the plasma of pregnant women carrying First Nations babies and is correlated with known urinary biomarkers of renal function. Increased maternal s(P)RR levels may be associated with increased risk of preterm birth.