January 27, 2025

A 40-year-old Hispanic woman has diffuse fatigue and arthritis

By Med-Challenger · 2 minute read

A 40-year-old Hispanic woman has diffuse fatigue and arthritis with morning stiffness of at least 2 hours for the last 2 months. Her primary care doctor gave her 20mg of Prednisone with good benefit; however, her symptoms returned after discontinuing the treatment. She now has diffuse extremity edema, joint pains, fatigue, and difficulty walking.

On examination, her temperature is 100.7°F. She has no skin rashes and has 1+ diffuse upper and 2+ lower extremity edema with inability to lift her legs against gravity. She has some tenderness and swelling over a few PIP joints. Laboratory analysis reveals a normal CBC, albumin of 1.7, AST of 35, ALT of 50, with a total bilirubin of 0.6 (normal) and an INR of 1.1. Urinalysis reveals 2+ RBCs and 2+ protein with a 24 hour collection of 1.3 grams (normal <250mg). Hepatitis A/B/C testing is normal. Anti-Cardiolipin antibodies are abnormal and an Anti-mitochondrial antibody and Anti-smooth muscle antibodies were unremarkable. An Anti-nuclear Antibody is 1:80 (normal <1:40). A lower extremity doppler showed a deep vein thrombosis.

Which of the following would be the best test for the diagnosis and determination of management?

Checking serologies
D-Dimers
Liver biopsy
Muscle biopsy
Kidney biopsy

The correct answer is:

Kidney biopsy

Educational Objective:

Diagnose lupus nephritis.

Key Point:

A kidney biopsy is critical to confirm the diagnosis of lupus nephritis. Biopsy details may guide specific therapy.

Explanation:

The patient most likely has Systemic Lupus Erythematosus. This can be suggested by antiphospholipid syndrome (Anticardiolipin antibody with a DVT), an abnormal ANA, inflammatory arthritis, and nephritis.

A kidney biopsy is critical to determine the best treatment for her condition as the class of nephritis will determine the use of chemotherapeutics. A biopsy will also rule out any other potential causes such a as anti-phospholipid syndrome involvement.

D-Dimer will be elevated with the recent DVT and will not change treatment. Serologies may show an abnormal Anti-Smith or double stranded DNA antibodies, but will not change management.

A liver biopsy will not be helpful as her liver function is normal and there is likely no significant disease in her liver.

Myositis is relatively uncommon and occurs in fewer than 15% of cases and a muscle biopsy, which may be helpful, will not change disease treatment.

References:

Wilson HR, Lightstone L. Manifestations of lupus in the kidney and how to manage them. Nephrol Dial Transplant. 2017 Oct 1;32(10):1614-1616.

Satish S, Deka P, Shetty MS. A clinico-pathological study of lupus nephritis based on the International Society of Nephrology-Renal Pathology Society 2003 classification system. J Lab Physicians. 2017 Jul-Sep;9(3):149-155.

This question appears in Med-Challenger Internal Medicine Exam Review with CME

Try for free and save. Ace your exams and meet your CME/MOC requirements for just $35 a month!

No matter your program, no matter the size, Med-Challenger for Groups and Institutions can better prepare your program or group, fulfill industry requirements, and increase test scores.