Lupus Nephritis Masquerading as Preeclampsia: A Treatment Dilemma

Introduction: Systemic Lupus Erythematosus (SLE) increases pregnancy related maternal and fetal risk when compared to healthy women. Active disease has been associated with poorer pregnancy outcomes. Differentiating between active lupus nephritis (LN) and preeclampsia is a diagnostic challenge making management difficult. Case Description: A 21-year-old female was diagnosed with SLE, eight months prior to presentation. She had been on Cellcept which was discontinued at conception. She was admitted at 22 weeks of gestation with abdominal pain, nausea and vomiting. Vital signs were significant for BP of 166/110 mmHg. Physical examination revealed malar rash, mid epigastric tenderness but no peripheral edema. Laboratory data was significant for hemoglobin 9.2 g/dl, platelet count 83 K/uL, Creatinine (Cr) 1.17 mg/dl (baseline 0.6), serum albumin 3.2 g/dl and normal liver enzymes. Urinalysis revealed RBC > 100/hpf, WBC 100/hpf, 3 + proteinuria. A 24-hour urine protein/creatinine ratio was 2.6 g. Serologic work up revealed elevated antinuclear antibody (ANA) titer 1: 1280 and low complement C4 level. Serum Uric acid level was normal. Antineutrophil cytoplasmic antibodies (ANCA), anti-double stranded DNA (dsDNA), anti-Glomerular Basement Membrane Antibody (Anti-GBM), HIV, hepatitis panel, Antibody to SSA-Ro and SSB-were negative. She was initiated on therapy for a LN flare with hydroxychloroquine and prednisone. However, she had clinical and laboratory deterioration with large pleural effusion, pulmonary edema, worsening liver and kidney function and anemia requiring packed RBC transfusions. A kidney biopsy could not be safely done. A suspicion of preeclampsia was entertained and a 24-hour urine calcium collection was 14 mg/d confirming the diagnosis. She was treated with betamethasone, magnesium sulfate and underwent an urgent cesarian section. Subsequently, her renal function and hematologic parameters improved. A subsequent renal biopsy showed mesangial proliferative lupus nephritis class II for which she received Cellcept therapy. Discussion: Active LN can mask the presentation of preeclampsia making diagnosis challenging due to the similarity of symptoms and laboratory features. A renal biopsy can clarify these differences; however, it is usually avoided during pregnancy. A high index of suspicion can help clarify this diagnostic and treatment dilemma which can otherwise be life threatening.