Purpose: (1) To see the effectiveness of applying the criteria laid down by the American college of Rheumatology in the diagnosis of giant cell arteritis (GCA). (2) To quantify the role of temporal artery biopsy (TAB) in diagnosing GCA using the Greenwich grading system.
Methods: A retrospective case notes review of consecutive patients undergoing TAB over 6 years, from 1995 to 2000, in a UK hospital eye unit was done. The American college of Rheumatology 1990 criteria for diagnosis of GCA were applied. A detailed analysis of age of onset, mode of presentation, laboratory findings and histology was done for all the patients. In an attempt to quantify the clinical value of TAB in patients with clinically suspected GCA, the Greenwich grading system was used. The role of TAB was graded as essential, important, helpful, unnecessary, and adverse effect.
Results: Out of the 53 patients who underwent TAB, 13 were found to have positive TAB, while 40 had negative biopsies. On application of the American College of Rheumatology criteria, 36 patients fulfilled the criteria required to make a diagnosis of GCA. Temporal headache, ESR>50 mm/h and temporal artery tenderness were found to occur more often in patients with positive biopsy.
Conclusion: (1) The American College of Rheumatology criteria provide a framework in which the clinician can continually assess the need for TAB. (2) The Greenwich grading system, as applied in evaluating the role of TAB in the management of GCA, demonstrated the clinical usefulness of this invasive procedure in the majority of cases. It identified the patient groups that benefit the most from a TAB.