The Proteinuria Puzzle of Pregnancy: Membranous Nephropathy Unmasked

Introduction: The evaluation of proteinuria in pregnancy can be a challenge. While proteinuria is commonly associated with conditions like pre-eclampsia during pregnancy, it is important to recognize that there can be other underlying causes as well. Membranous nephropathy is one such cause. Case Description: In this case, a 23-year-old female G5P1031 with a family history of IgA nephropathy presented at 36 weeks of gestation due to oligohydramnios. On admission, she displayed elevated blood pressure (146/82 mmHg) accompanied by headaches, along with facial and leg swelling persisting for several months. Further investigation revealed significant proteinuria, indicating nephrotic syndrome. Tests showed a notably high urine protein to creatinine ratio 11 mg/mg. Diagnosis of pre-eclampsia with severe features was made, necessitating induced labor. Post-delivery, the patient continued to exhibit nephrotic-range proteinuria. Serum albumin level was low 2.5 g/dL, prompting additional tests that revealed elevated phospholipase A2 receptor (PLA2R) level 17 RU/mL with uptrend to 47 RU/mL. Subsequent kidney biopsy showed positive staining for PLA2R in the glomerular deposits (see figure 1), confirming the diagnosis of primary membranous glomerulopathy. Treatment commenced with ACE inhibitor, leading to favorable response characterized by decreasing PLA2R levels to <2 RU/mL and improved proteinuria. Discussion: This case underscores the intricate relationship between pregnancy-related complications such as pre-eclampsia and underlying renal conditions like primary membranous nephropathy. Effective management requires a comprehensive approach addressing both maternal and fetal health considerations.Figure 1: Immunohistochemistry for PLA2R