Abstract: PUB219
Navigating Diagnostic Complexities: Membranous Nephropathy in a Patient with Rheumatoid Arthritis and Systemic Lupus Erythematosus
Session Information
Category: Glomerular Diseases
- 1402 Glomerular Diseases: Clinical, Outcomes, and Therapeutics
Authors
- Dhayalan, Dhayanithi, Adventist Health Central Valley Network, Hanford, California, United States
- Adapa, Sreedhar R., Adventist Health Central Valley Network, Hanford, California, United States
- Annam, Swetha, Adventist Health Central Valley Network, Hanford, California, United States
- Rajendran, Abinaya, Pondicherry Institute of Medical Sciences, Puducherry, PY, India
Introduction
Systemic Lupus Erythematosus (SLE) is well known for its renal involvement, presenting as lupus nephritis. Rheumatoid arthritis (RA), a chronic autoimmune inflammatory arthropathy, is less commonly associated with glomerular disease. However, secondary renal involvement may arise due to chronic inflammation, amyloidosis, or drug-induced nephrotoxicity. The coexistence of SLE and RA—referred to in rare instances as “rhupus syndrome”—has been documented, though renal manifestations in such overlap syndromes remain poorly understood. We present a case of membranous nephropathy in a patient with concurrent SLE and RA, highlighting the diagnostic complexity and therapeutic challenges posed by overlapping autoimmune disorders affecting the kidney
Case Description
40-year-old female with pmh of rheumatoid arthritis (RA) presented to the renal clinic for management of CKD 2. She was on methotrexate and hydroxychloroquine (HCQ) for RA. The patient exhibited new onset nephrotic range proteinuria (Pr/Cr 6.5), prompting a renal biopsy. Serological workup revelaed + ANA, + Rheumatoid factor and elevated dsDNA levels. The biopsy tissue was insufficient for light microscopy. Most of the tissue were medullary and IM did not reveal “full house “ pattern of enhancement. Ultrastructural evaluation revealed GBM remodeling suggestive of membranous nephropathy, but with predominantly chronic features and without significant "active" or "recent" subepithelial immune complex deposits, so the diagnosis was inconclusive. Given inconclusive biopsy results but worsening proteinuria, decision was made to treat the condition as lupus nephritis. Patient was started on MMF and steroids along with RAAS blockade for proteinuria control. Follow-up showed significant improvement in her Pr/cr to less than 0.4. Her renal function remained stable
Discussion
This case highlights the importance of longitudinal monitoring in patients with autoimmune disease and nephrotic-range proteinuria, even when renal biopsy is inconclusive. Early diagnosis and timely initiation of immunosuppressive therapy were critical in this patient’s outcome, as supported by KDIGO guidelines, which emphasize integrating histologic findings with evolving clinical data