P-027 A CASE OF PSEUDOGOUT ATTACK AFTER ZOLEDRONIC ACID TREATMENT IN PRIMARY HYPERPARATHYROIDISM

Abstract Introduction Calcium pyrophosphate dihydrate (CPPD) deposition in the joints is an inflammatory arthropathy known as pseudogout (PG). Rare cases of pseudogout associated with bisphosphonate therapy have been reported in the literature. Here, we present a patient with primary hyperparathyroidism (PHP) who developed pseudogout in the elbow joint following bisphosphonate use. Clinical Case A 65-year-old female patient was evaluated due to hypercalcemia and diagnosed with primary hyperparathyroidism. No pathological focus was detected in ultrasonography and scintigraphy. Because of persistently high calcium levels and osteoporosis on bone densitometry, intravenous zoledronic acid (ZA) was administered. Three days after ZA treatment, the patient developed nausea and diffuse body pain. Laboratory evaluation revealed elevated creatinine levels, and she was admitted to the hospital with a preliminary diagnosis of acute kidney injury (AKI). On the third day of hospitalization, she developed pain, swelling, limited motion, and increased temperature in the right elbow. Since septic arthritis could not be excluded after orthopedic consultation, joint irrigation was performed. However, her complaints persisted, and joint culture revealed no bacterial growth. The patient was then evaluated by rheumatology, and pseudogout was considered. Systemic steroid therapy was initiated, leading to significant improvement in her symptoms. Conclusion Although bisphosphonates such as zoledronic acid (ZA) have an important role in the treatment of osteoporosis, potential complications should be kept in mind. In this case, the patient’s PHP, age, significant hypercalcemia at admission, and the rapid decrease in calcium levels after ZA treatment were predisposing factors for a PG attack. Pseudogout following ZA treatment is a rare complication reported in the literature.Table 1:Laboratory Parameters Before ZA, During AKI, and After Treatment