Weight loss, weakness and proteinuria

A 65-year-old woman presents to a doctor for the first time in 25 years, with a history of weight loss and weakness.

On examination, she is hypertensive and her extremities demonstrate pitting edema.

Urinalysis shows proteinuria. An abdominal fat pad tissue biopsy reveals deposits of amyloid, while further immunochemical staining demonstrates serum amyloid A proteins.

Which of the following conditions is most likely to be part of this patient’s past medical history?

  1. Diabetes mellitus
  2. Charcot arthropathy
  3. Multiple myeloma
  4. Rheumatoid arthritis

The answer is below the imge.

Image credit: @ReginaldoCastro

Answer: Rheumatoid arthritis

This patient’s findings are suggestive of amyloid A (inflammatory) amyloidosis secondary to rheumatoid arthritis.

The chronic inflammation in rheumatoid arthritis can lead to an overproduction of the acute-phase reactant serum amyloid A, which deposits in tissues and causes dysfunction.

The condition most commonly manifests in the kidneys as nephrotic syndrome, but liver, spleen, and cardiac involvement have also been reported.

Other chronic inflammatory conditions also associated with amyloid A (inflammatory) amyloidosis include inflammatory bowel disease, chronic infections like osteomyelitis, and familial Mediterranean fever.

By contrast, primary amyloidosis has a similar pathophysiology, but with a different protein—AL amyloid.

You can see more images like this at Figure1.