Eye, Ear Symptoms Common in AAV Patients With Rare Condition
Hypertrophic pachymeningitis seen in nearly 5% of 663 adults, often with GPA
Symptoms affecting the eyes and ears are significantly more common in adults with ANCA-associated vasculitis (AAV) who developed hypertrophic pachymeningitis (HP), a rare condition marked by brain inflammation, a study from Japan reported.
Notably, sudden vision or hearing loss was found in AAV patients with HP, suggesting that eye and ear involvement may be implicated in hypertrophic pachymeningitis.
Researchers also noted a significantly higher prevalence of granulomatosis with polyangiitis (GPA), an AAV subtype, in patients with HP compared with those without this condition.
Findings were detailed in the study, “Hypertrophic pachymeningitis in ANCA-associated vasculitis: a cross-sectional and multi-institutional study in Japan (J-CANVAS),” published in the journal Arthritis Research & Therapy.
AAV, a group of autoimmune diseases marked by inflammation and damage to small and medium-sized blood vessels, mainly affects the kidneys and lungs. But in some cases, AAV symptoms are also found in the central nervous system (CNS), composed by the brain and spinal cord.
HP is a rare AAV-related condition of the CNS characterized by inflammation and thickening of the dura, the protective outer layer of the brain, and/or spinal cord inflammation. Due to its rarity, information regarding the occurrence and clinical characteristics of HP in AAV patients is limited.
Hypertrophic pachymeningitis in 10.6% of 141 adults with GPA
To investigate HP in a large group of AAV patients, scientists at the Shinshu University School of Medicine, in Nagano, examined data covering 663 adults enrolled in the Japan Collaborative Registry of ANCA-Associated Vasculitis (J-CANVAS).
Among them, 141 were diagnosed with GPA and 324 with microscopic polyangiitis (MPA), the two most common types of AAV. Eosinophilic granulomatosis with polyangiitis (EGPA), another form of AAV, was identified in 126 participants.
HP was observed in 30 (4.52%) individuals, 15 GPA patients (10.6%) and 15 MPA patients (4.6%), showing that “the prevalence of GPA was significantly higher in patients with HP than in those without HP,” the scientists noted.
HP occurred in 20 out of 558 (3.58%) newly diagnosed patients and in 10 out of 105 (9.52%) patients with relapsed AAV, “which was a significantly higher frequency than that in newly diagnosed AAV.”
Blood tests found higher levels of the two AAV-associated antibodies, MPO-ANCA and PR3-ANCA, and lower numbers of white blood cells and immune lymphocyte cells in patients with HP. According to standard clinical tests, kidney impairment was significantly more frequent in those without HP.
Based on the Birmingham Vasculitis Activity Scores (BVAS), the occurrence and severity of symptoms affecting the mucous membrane of the eyes, and the ears, nose, and throat (ENT), was significantly higher in patients with HP, as were rates of “sudden visual loss” and “conductive hearing loss.” Conversely, skin and kidney manifestations were significantly lower in the HP group.
“These results suggest that mucous membrane/eye and ENT manifestations may be implicated in the development of HP,” the scientists wrote.
HP was associated with a 5.99-times higher incidence of mucous membrane/eye involvement and a 1.48-times higher incidence of ENT symptoms, analyses showed. HP also significantly associated with BVAS scores for membrane/eye and ENT symptoms, as well as sudden visual loss (20.9-times higher) and conductive hearing loss (11.6-times higher).
The occurrence and severity of nervous system symptoms also were significantly higher in the overall population of patients with HP and in newly diagnosed individuals.
AAV patients with HP experienced significantly more headaches and cranial nerve palsy — a lack of nerve function that can cause weakness or paralysis. Spinal cord lesions occurred significantly more often in those with HP, and meningitis, an inflammation of the membranes covering the brain and spinal cord, also was more frequent in those with HP who had AAV relapses.
Conversely, damage to at least two separate nerve areas, a condition called mononeuritis multiplex, was less often seen in HP patients, considering the overall population of AAV individuals and the subgroup of those newly diagnosed with AAV.
“We expect that the accumulation of significant results determining clinical characteristics can be useful for predicting HP development in AAV,” the scientists wrote. “However, this study was performed using limited clinical information despite the first attempt at a multi-institutional survey.”
Further study, “by analyzing more detailed information from a larger number of patients, is required to elucidate the pathogenesis of HP in AAV,” they added.