A report of 4 cases of myeloperoxidase antineutrophil cytoplasmic antibody associated hypertrophic pachymeningitis with literature review

Abstract

Objective To investigate the clinical features of myeloperoxidase antineutrophil cytoplasmic antibody (MPO-ANCA) associated hypertrophic pachymeningitis (HP). Methods Clinical data of 4 casesdiagnosed with MPO-ANCA vasculitis complicated with HP in our hospital were analyzed retrospectively and the related literaturewere reviewed. Results Four male patients with an age range from 44 to 66 years were diagnosed with ANCA-associated HP. The main clinical manifestations included headache and with- various degree ofmultiple cranial paralysis. During active phase of the disease, all patients showed perinu- clear(p)-ANCA positive, elevated levels of inflammatory biomarkers and titers of MPO-ANCA, whereas renal function, cytoplasmic (c)-ANCA and protease 3 (PR3)-ANCA were negative. Contrast-enhanced cranial ma- gnetic resonance imaging (MRI) scan showed obviously thickened dura mater and sinusitis or mass in paranasal sinus. Four patients were sensitive to glucocorticoid. Three patients had a relapse during glucocorti- coid tapering and were undercontrol when the dosage of glucocorticoid was increased and immunosuppressive agents were added. Levels of inflammatory biomarkers, titers of MPO-ANCA and p-ANCA recovered to normal, and the dural thickness on MRI was reduced in the remission stage. Conclusion MPO-ANCA associated HP is a type of central nervous system involvement in ANCA associated vasculitis (AAV). It involves the upper respiratory tract more frequently, and less frequently progresses to systemic AAV. This should be taken into consideration when middle-aged and elderly patients presented with headache and multiple cranial neuropathies. Enhanced MRI is the preferred examination for diagnosis, and dural biopsy should be done when necessary. Key words: Myeloperoxidase; Antineutrophil cytoplasmic antibody; Pachymeningitis, hypertrophic; Granuloma; Vasulitis