The ESR is elevated. Leukocytosis is present. Anemia may be profound. Antinuclear antibodies and LE cells are absent. Diagnosis Wegener's granulomatosis is diagnosed by characteristic clinical, serologic, and pathologic findings.
Renal biopsy determines the extent of renal involvement.
Open pulmonary biopsy of a solid or cavitating lesion sometimes leads to diagnosis. Clusters of densely packed atypical cells may be found in the sputum of patients with pulmonary involvement. Polyarteritis nodosa is ruled out by biopsy of skin lesions and by pathologic localization of vascular lesions. Characteristic blood cultures and changing cardiac murmurs are present in subacute bacterial endocarditis. In SLE, antinuclear antibodies and LE cells are present in the serum, and the serum complement level is depressed.