Objective: To investigate morphometrically the relationship between the degree of inflammatory reaction and arterial cross-sectional dimensions in giant cell arteritis (GCA).
Methods: The media and intima of cross-sectioned inflamed arteries from GCA patients were outlined. The media circumference and the media and intima cross-sectional areas were measured. The two segments in every biopsy displaying the least and most widespread media inflammation were compared, using a paired Student's t-test. Moreover, paired comparisons were made of the intima area in inflamed and noninflamed sectors in single cross-sections.
Results: The segment in each biopsy showing the most widespread media inflammation had the largest circumference and volume of media and intima; the intima cross-sectional area increased disproportionately. The intima was thickest in inflamed sectors in single cross-sections.
Conclusion: The close spatial correlation between inflammatory media infiltration and the marked intimal expansion supports the contention that promoting factors produced by inflammatory cells play a pathogenetic role in GCA.