Classical polyarteritis nodosa and microscopic polyangiitis--a clinicopathologic study.

OBJECTIVE

To describe the clinical spectrum, laboratory features, histopathological findings and treatment outcome in patients with classical polyarteritis nodosa (PAN) and microscopic polyangiitis (MPA).

MATERIAL AND METHODS

Patients with PAN and MPA seen at a large teaching hospital in north India over a period of five years (1994-99) were included in the present study.

RESULTS

We encountered five patients with PAN and six patients with MPA during the study period. Of the five patients with PAN, two had systemic disease while three had limited PAN. The patients with limited PAN included two with cutaneous PAN and one with PAN confined to the nerves. Constitutional symptoms, musculoskeletal complaints, peripheral neuropathy and skin lesions dominated the clinical picture. Fifty percent of the MPA patients presented as pulmonary renal syndrome. All the patients with PAN were HBsAg and ANCA negative and had normal urinalysis findings. In contrast, all patients with MPA demonstrated an active urine sediment and 83.3% were pANCA positive. Some of the rare features encountered by us were the presence of antiphospholipid syndrome and extensive interstitial lung disease in MPA, and spontaneous recovery in one patient with systemic PAN. Treatment outcome was better in PAN as compared with MPA.

CONCLUSIONS

The clinical spectrum of PAN and MPA is quite varied. A good outcome is possible with the use of corticosteroids and cyclophosphamide.