A 32-year-old woman with systemic lupus erythematosus comes to the office for a follow-up visit. The patient was diagnosed with lupus 3 years ago during evaluation of a skin rash and joint pain, and her symptoms have been well controlled with hydroxychloroquine. She takes no other medications, has no other medical conditions, and does not use tobacco, alcohol, or illicit drugs. Blood pressure is 150/90 mm Hg and was normal during previous office visits. Temperature is 37.2 C (99 F) , pulse is 78/min, and respirations are 14/min. There is a faint malar rash but no mucosal ulcers, joint tenderness, or swelling. The lungs are clear on auscultation and heart sounds are normal with no murmur, rub, or gallop. The abdomen is soft and nontender with no hepatosplenomegaly. There is mild pitting edema of the bilateral lower extremities. Neurologic examination shows no abnormalities. Laboratory results are as follows:
The patient's serum chemistry and urinalysis were within normal limits 2 months ago. Renal ultrasonography shows normal-sized kidneys with no hydronephrosis.
Item 1 of 2
Which of the following is the best next step in management of this patient?

Question

A 32-year-old woman with systemic lupus erythematosus comes to the office for a follow-up visit. The patient was diagnosed with lupus 3 years ago during evaluation of a skin rash and joint pain, and her symptoms have been well controlled with hydroxychloroquine. She takes no other medications, has no other medical conditions, and does not use tobacco, alcohol, or illicit drugs. Blood pressure is 150/90 mm Hg and was normal during previous office visits. Temperature is 37.2 C (99 F) , pulse is 78/min, and respirations are 14/min. There is a faint malar rash but no mucosal ulcers, joint tenderness, or swelling. The lungs are clear on auscultation and heart sounds are normal with no murmur, rub, or gallop. The abdomen is soft and nontender with no hepatosplenomegaly. There is mild pitting edema of the bilateral lower extremities. Neurologic examination shows no abnormalities. Laboratory results are as follows:

The patient's serum chemistry and urinalysis were within normal limits 2 months ago. Renal ultrasonography shows normal-sized kidneys with no hydronephrosis.
Item 1 of 2
Which of the following is the best next step in management of this patient?

Quizplus · Accepted Answer

Explanation: 11ec2b69_c0a0_b2b3_8f63_3967e8c719f1_MD0005_00 The presence of lower extremity edema, renal dysfunction, proteinuria, and urinalysis with active sediment (eg, hematuria, red blood cell casts) in a patient with systemic lupus erythematosus raises concern for lupus nephritis. Lupus nephritis is categorized into 6 classes based on pathologic findings on biopsy. Therapy is guided by disease classification; therefore, renal biopsy is indicated prior to treatment in all patients with evidence of marked proteinuria (>500 mg/day), active urinary sediment (eg, persistent hematuria, dysmorphic red blood cells, casts), or declining renal function. Classes I and II are typically mild and often do not require therapy unless the disease progresses. Classes III and IV require immunosuppression with glucocorticoids (eg, methylprednisolone, prednisone) and cyclophosphamide or mycophenolate mofetil (Choices D and E). Class V (membranous) may require immunosuppression if proliferative lesions or nephrotic syndrome is present. Class VI is an advanced sclerosing disease, and immunosuppression is not recommended. Prompt diagnosis is critical for patients with lupus nephritis. Urgent renal biopsy is indicated in patients with rapidly declining renal function or new nephrotic syndrome and should be performed prior to immunosuppression to maximize yield and to aid in appropriately tailoring therapy. (Choice A) Renal dysfunction can be caused by prolonged, uncontrolled hypertension, but it is typically insidious in onset and would not be expected to cause active urinary sediment. If lupus nephritis is suspected, a period of observation without diagnosis and intervention could lead to irreversible damage as immunosuppression may be necessary. (Choice B) Hydroxychloroquine is typically well tolerated and not associated with renal dysfunction; common side effects include rash and gastrointestinal upset. Hydroxychloroquine-related acute interstitial nephritis is rare and is associated with a predominance of white blood cell casts. Educational objective: A kidney biopsy is indicated prior to treatment initiation to guide therapy in all patients with systemic lupus erythematosus with significant renal involvement (ie, proteinuria, active urinary sediment, declining renal function).

A 32-Year-Old Woman with Systemic Lupus Erythematosus Comes to the Office