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

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.