ANCA-Associated Systemic Vasculitis Presenting With Hypertrophic Spinal Pachymeningitis: A Report of 2 Cases and Review of Literature

Reports of hypertrophic pachymeningitis associated with myeloperoxidase-antineutrophil cytoplasmic antibody (MPO-ANCA) localized exclusively in the spine were quite rare. Two cases of ANCA-associated systemic vasculitis (AASV) presenting with hypertrophic spinal pachymeningitis (HSP) causing low back pain and numbness are described. Two patients showed prominent systemic and local inflammatory reactions manifested as fever, elevated levels of erythrocyte sedimentation rate and C-reactive protein, and markedly increased levels of total protein of cerebrospinal fluid. The gadolinium (Gd)-enhanced T1-weighted magnetic resonance imaging scan of spinal cord demonstrated diffuse spinal dura matter thickening. Additionally, simple microscopic hematuria was found in 1 case suggestive of renal involvement and the other 1 complicated with interstitial lung disease. Then, a diagnosis of HSP secondary to AASV was made. Combination therapy of corticosteroids and cyclophosphamide produced a rapid improvement in the clinical symptoms and laboratory parameters. Followed up for 6 months, 1 case relapsed when the dosage of prednisone was tapered to 10 mg daily. Since the patient refused rituximab-based regimen, an immunosuppressive triple-therapy (corticosteroid, cyclophosphamide, and azathioprine) was initiated and brought control of the disease during the subsequent 6 months of follow-up. HSP is a relatively rare form of central nervous system involvement of AASV. Early recognition and intervention are of great significance since the pathogenesis of HSP starts with an inflammatory and fibrosing process.