SURAL NERVE BIOPSY IN VASCULITIC NEUROPATHIES - MORPHOMETRIC ANALYSISOF THE CALIBER OF INVOLVED VESSELS

We performed histologic and morphometric analyses of the sural nerve i n 13 patients with vasculitic neuropathies. The ratio of vessels with vasculitis, the caliber of involved vessels, and pathologic changes of myelinated fibers were evaluated. In patients with polyarteritis nodo sa (PN), rheumatoid arthritis (RA), and systemic lupus erythematosus ( SLE), marked vasculitis with inflammatory cell infiltration and occlus ion were observed in epineurial arteries greater than 100 mu m in diam eter, and mild vasculitic changes were noted in arterioles 40 to 100 m u m in diameter. In vessels less than 40 mu m, mild vasculitis with pe rivascular cuffing was noted in patients with RA and SLE, but not in P N. In a patient with microscopic PN, mild inflammatory cell infiltrati on was encountered around small vessels at diameters less than 40 mu m as well as those greater than 100 mu m. In a patient with nonsystemic vasculitic neuropathy, vasculitic changes were identified only in ves sels less than 40 mu m. In patients with Churg-Strauss syndrome (CSS), there were no distinct findings of vasculitis in any biopsy material. In conclusion, morphometric analyses of the caliber of involved vesse ls may be useful in the differential diagnosis and classification of u nderlying vasculitic neuropathies.