Bone pain that responds to calcium channel blockers. A retrospective and prospective study of transplant recipients.
A severe episodic bone pain syndrome of unknown cause was first described in renal transplant recipients in France and associated with the use of cyclosporine. We have retrospectively and prospectively evaluated this pain syndrome in our transplant patients. This pain is bilateral, of acute onset and episodic, primarily involving the knees and/or ankles. It usually occurs at night or with recumbency, and is often relieved with elevation or walking. Physical examination of the affected areas is unrevealing. Kidney, liver, pancreas, heart, lung and combined organ transplant recipients on cyclosporine were available from the University of Washington Transplant Services and were retrospectively evaluated by chart review (n = 351) or prospective clinical evaluation (n = 38) for evidence of this clinical syndrome. In the retrospective chart review, 19.1% of patients had episodes of bone pain. The highest prevalence occurred in renal transplant recipients (27.7%). The bone pain syndrome was documented in the charts of 14 patients who subsequently developed significant osteonecrosis. Prospectively, 21 of 22 patients with the bone pain syndrome experienced complete relief of this pain upon treatment with calcium channel blockers (95.4% response rate). The pathophysiology of this bone pain syndrome is unknown, although its response to the vasodilatory effects of calcium channel blockers suggests a vascular etiology.