Case Presentation: 63y old female with history of CHF, HTN, and hypothyroidism presented from primary care physician’s office for lab abnormalities. Review of systems was positive for decreased urine output, fatigue, and sinus congestion. Vitals were within normal limits and physical exam was non-contributary. Lab workup was significant for hypokalemia (2.9) and elevated Cr (4.0). During hospital stay, she rapidly developed decompensated heart failure and atrial fibrillation and was medically managed with cardiology input. Additionally, her EF was 30% and she was noted to have severe mitral regurgitation. Worsening generalized edema, 3+ proteinuria, persistently elevated creatinine, and echogenic appearance of kidneys warranted further nephrology and autoimmune workup. She continued to decline significantly with unresolving dyspnea and non-response to diuretics. Kidney biopsy revealed focal segmental glomerulosclerosis with collapsing features, tubulo-reticular inclusion bodies, and non-specific immunofluorescence. Other workup revealed she was HIV negative, +ANA, +anti-histone Ab, +ds-DNA Ab, -ANCA, -anti-GBM Ab. Failure of response to immunosuppressive therapy, lack of improvement in urine output, and development of signs/symptoms of uremia eventually lead to initiation of hemodialysis.
Discussion: Systemic Lupus Erythematosus (SLE) is an autoimmune disease characterized by production of antinuclear antibodies and other autoantibodies that affect multiple organ systems. Lupus nephritis results in various clinical manifestations including laboratory abnormalities, nephritic and/or nephrotic syndrome, and kidney failure. The wide range of presenting symptoms warrant a high level of suspicion for diagnosis and to decrease delay in treatment. The patient above was diagnosed with SLE and found to have segmental to global glomerulosclerosis with collapsing like features and focal reactive cresent/pseudocresent formation concerning for the collapsing variant of focal segmental glomerulosclerosis (FSGS). Additionally, there was a lack of any specific patterns of immunoflorescence on electron microscopy. The patient’s pathology was concerning for lupus podocytopathy (LP) with FSGS, an uncommon pathology not typically associated with SLE (Hanaoka). LP with FSGS typically presents with acute kidney injury less responsive to glucocorticoid treatment and more prone to relapse with glucocorticoid maintenance treatment alone. One study notes that collapsing FSGS has worse 1 year and 3 year renal survival compared to other variants with recommendations for combined glucocorticoid treatment plus immunosuppressive agents to decrease relapse rates. Because even partial remission in severe LN is associated with significantly better patient and renal survival compared to no remission, adjusting clinical practice has relevant and far reaching consequences for the practitioner and patient (Chen).
Conclusions: The non-specific presentation and initial lab abnormalities of lupus nephritis warrant a high level of clinical suspicion especially in a case of unresolving acute kidney injury. Furthermore, in a rare variant such as lupus FSGS with collapsing glomeruli, a delay in diagnosis can have significant outcome implications for the patient’s rapidly progressing disease state. The distinct features of lupus podocytopathy and the prognostic value in differentiating different types of FSGS warrant a revised pathological classification of lupus nephritis.