Hypertrophic pachymeningitis in ANCA-associated vasculitis: a cross-sectional and multi-institutional study in Japan (J-CANVAS)

Primary angiitis of the CNS and ANCA-associated vasculitis: from pathology to treatment

Vasculitis of the central nervous system can be a localized process, such as primary angiitis of the central nervous system (PACNS), or systemic vasculitis, such as ANCA-associated vasculitis (AAV). Since both conditions share neurological manifestations, the following review will discuss the neurological aspects of both. This review aims to provide a comprehensive comparison of the pathogenesis, clinical manifestation and assessment, diagnostic workup, and treatment protocol for both PACNS and AAV with central nervous system involvement. To provide a comprehensive comparison and update, a literature review was conducted using PubMed and Ovid databases (Embase and Medline). Then, the references were retrieved, screened, and selected according to the inclusion and exclusion criteria. PACNS and AAV share similarities in clinical presentation and neurological symptoms, especially in terms of headache, focal deficits, and cognitive impairment. Additionally, both conditions may exhibit similarities in laboratory and radiological findings, making brain biopsy the gold standard for differentiation between the two conditions. Moreover, the treatment protocols for PACNS and AAV are nearly identical. Comparing PACNS and AAV with CNS involvement highlights the similarities in clinical presentation, radiological findings, and treatment protocols between the two conditions. Further research should focus on establishing a practical diagnostic protocol.

Clinical characteristics of hypertrophic cranial pachymeningitis in granulomatosis with polyangiitis: a retrospective single-center study in China

BACKGROUND

Hypertrophic cranial pachymeningitis (HCP) is uncommon but a poorly understood complication of granulomatosis with polyangiitis (GPA).

OBJECTIVES

We conducted this retrospective study to elucidate the clinical characteristics and factors independently associated with granulomatosis with polyangiitis (GPA) complicated by hypertrophic cranial pachymeningitis (HCP) in China.

METHODS

We collected the medical records of 78 patients diagnosed with GPA who were admitted to the inpatient department of Peking Union Medical College Hospital between January 2003 and September 2021. Clinical features, laboratory and radiological findings, and Birmingham Vasculitis Activity Scores (excluding meningitis score) were recorded. A binary logistic regression analysis was performed to analyze factors independently associated with GPA-related HCP.

RESULTS

Headache (100%) and cranial nerve palsy (61.5%) were common manifestations of HCP. Compared to 52 GPA patients without HCP, 26 patients with HCP required more time from initial symptoms to diagnosis, with a lower ratio of pulmonary and renal involvement, a higher ratio of myeloperoxidase-antineutrophil cytoplasmic antibody (MPO-ANCA) positivity, conductive or sensorineural hearing loss, mastoiditis, and decreased vision or sudden visual loss. Binary logistic regression analysis indicated that proteinase 3-antineutrophil cytoplasmic antibody (PR3-ANCA) negativity (OR 10.698, p = 0.001), conductive or sensorineural hearing loss (OR 10.855, p = 0.005), and decreased vision or sudden visual loss (OR 8.647, p = 0.015) were significantly associated with GPA-related HCP. Of the 26 patients, 18 received methylprednisolone pulse treatment, and 18 received intrathecal injections of dexamethasone and methotrexate.

CONCLUSIONS

HCP was a severe manifestation of GPA in our study. Independent factors associated with the occurrence of HCP in patients with GPA included PR3-ANCA negativity, conductive or sensorineural hearing loss, and decreased vision or sudden visual loss. Furthermore, GPA-related HCP was associated with higher disease activity, requiring more intensive treatments.

Quantitative evaluation of the thickened dura mater impacting clinical signs in immune-mediated hypertrophic pachymeningitis

OBJECTIVE

This study evaluated the volume of thickened dura mater lesions and their impact on clinical findings in immune-mediated hypertrophic pachymeningitis (HP).

METHODS

The volume of contrast-enhanced dura mater on magnetic resonance imaging was evaluated using the imaging feature quantification system in 19 patients with immune-mediated HP, including 12 with antineutrophil cytoplasmic antibody-related, 4 with IgG4-related, and 3 with idiopathic HP, as well as 10 with multiple sclerosis (MS) as controls. The implications of HP volume on neurological manifestations and cerebrospinal fluid (CSF) laboratory markers were statistically analyzed in patients with immune-mediated HP.

RESULTS

The volumes of the contrast-enhanced dura mater in the convexity, cranial fossa, and tentorium cerebelli were significantly higher in patients with immune-mediated HP than in those with MS. Among patients with immune-mediated HP, those with cranial nerve (CN) VIII neuropathy had a significantly higher volume of the contrast-enhanced dura mater in the cranial fossa than those without CN VIII neuropathy. The volume of the contrast-enhanced dura mater in the tentorium cerebelli was positively correlated with CSF protein levels.

CONCLUSION

Quantification of the thickened dura mater is useful for elucidating the relationship with the clinical findings in immune-mediated HP. Thickened dura mater lesions in the cranial fossa may be implicated in the development of CN VIII neuropathy. The enlargement of HP lesions in the tentorium cerebelli can increase CSF protein levels.

Rituximab for treatment of pachymeningitis in granulomatosis with polyangiitis

Pachymeningitis is a rare manifestation of granulomatosis with polyangiitis (GPA), and there is a paucity of literature regarding the efficiency of rituximab (RTX) in such cases. We present a woman in her early 50s with GPA who initially responded adequately to conventional therapy. However, the treatment course was complicated by pulmonary cryptococcosis. The patient later developed non-infectious pachymeningitis, which failed to respond to steroids and methotrexate. However, using RTX upfront led to good clinical response and radiological resolution.

Spinal Hypertrophic Pachymeningitis in Antineutrophilic Cytoplasmic Antibody-Negative Vasculitis: A Case Report

Hypertrophic pachymeningitis (HPM) is a rare but extremely debilitating disease. It is even rarer for HPM to be seen in association with antineutrophil cytoplasmic antibody (ANCA)-negative vasculitis. In this case, we are presenting HPM that was diagnosed in a 28-year-old female patient who presented with worsening back pain. Imaging revealed dural-based enhancing masses affecting the thoracic spinal cord with compression. Infectious etiologies were ruled out and a total of three biopsies failed to show any evidence of granulomatous inflammation, malignancy, or evidence of immunoglobulin G4-related disease. ANCA was negative on repeated testing. The patient was managed with repeated short courses of steroids that resulted in symptomatic control as well as radiological stability of the disease. This is an extremely rare case of atypical presentation of spinal HPM that is likely associated with granulomatous and polyangiitis without other manifestations of the disease except for nasal septal perforation. This case is a supplement to a limited body of knowledge and established cases of HPM in ANCA-negative, ANCA-associated vasculitis.

Hypertrophic pachymeningitis in ANCA-associated vasculitis: Clinical and immunopathological features and insights

Hypertrophic pachymeningitis (HP) is an inflammatory disorder characterized by intracranial and spinal thickened dura mater, leading to several neurological manifestations including headaches, cranial neuropathies, seizures, and sensorimotor disorders. Antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) is a crucial disease that is implicated in the development of immune-mediated HP. HP is observed throughout the clinical course of AAV, and 3%-4% of patients with AAV experience HP as the initial clinical episode. However, patients with ANCA-related HP are unclassifiable in the classification criteria of AAV when HP is the only manifestation, suggesting that ANCA-related HP can be identified as a central nervous system-limited type of AAV. Among patients with AAV, those who develop HP have predominantly been classified as having granulomatosis with polyangiitis (GPA). Myeloperoxidase-ANCA positivity has been more frequently demonstrated than proteinase 3-ANCA positivity in patients with ANCA-related HP. The ear, nose, and throat manifestations, such as otitis media, sinusitis, and mastoiditis, as well as mucous membranes/eyes manifestations including sudden visual loss, are robustly associated with HP in AAV. The histology of thickened dura mater tissues includes fibrotic changes and infiltration of several immunocompetent cells, but the typical findings of GPA, such as granulomatous inflammation with necrotizing vasculitis, are not observed in all patients with ANCA-related HP. Corticosteroids are the first-line therapy for ANCA-related HP, while the concomitant use of immunosuppressive agents including cyclophosphamide, methotrexate, and mycophenolate mofetil, is an ideal strategy for achieving remission. Rituximab is a useful agent in refractory ANCA-related HP.