Question
An 85-year-old male patient with a history of familial hypocalciuric hypercalcemia presents to the office complaining of left knee pain. He has had these episodes before, which manifest in either knee and are usually self-limiting. The physical evaluation shows redness, warmth, and swelling of the left knee. The synovial fluid analysis shows positively birefringent crystals. Which of the following laboratory findings is associated with the most likely pathology?
| A. |
Hypernatremia
|
| B. |
Hyperuricemia
|
| C. |
Elevated erythrocyte sedimentation rate (ESR)
|
| D. |
Hypocalcemia
|
Show Answer
|
Correct Answer � C
Explanation
|
|
Answer C) Elevated erythrocyte sedimentation rate (ESR)
-
As this is a classic case of Psuedo-Gout, secondary to inflammation – Elevated ESR will be seen in the patient
-
Calcium pyrophosphate in the joint causes inflammation. This condition used to be called pseudogout.
-
The ESR is often elevated during acute attacks.
-
Uric acid may be elevated in patients with gout.
-
Multiple diseases have been associated with calcium pyrophosphate deposition disease, including hyperparathyroidism, familial hypocalciuric hypercalcemia, and hemochromatosis in addition to other laboratory findings such as hypomagnesemia or hypophosphatemia.
Evaluation
-
Synovial fluid aspiration
-
Serum uric acid levels are not helpful (30% of patients with gout attack have normal levels)
-
ESR may be elevated
-
no bacteria on Gram Stain
-
Pseudogout: XR of joint space may have radiolucent calcium pyrophosphate formation
