Diagnostic delays in AAV vary by subtype and disease features
EGPA tied to longest time to diagnosis; severe cases identified sooner
Written by |
The time it takes to diagnose ANCA-associated vasculitis (AAV) may be influenced by disease type, organ involvement, and the medical specialties consulted, according to a single-center study in Germany.
The longest median time to diagnosis was seen in people with eosinophilic granulomatosis with polyangiitis (EGPA), the rarest type of AAV, while those with more active disease, higher levels of inflammatory markers, and kidney involvement at presentation tended to be diagnosed sooner.
“These findings underline the persisting challenge of recognizing AAV in its early stages, despite advances in classification criteria and diagnostic tools,” the researchers wrote. “Earlier recognition of AAV across specialties may reduce diagnostic delay and prevent organ damage.”
The study, “The diagnostic pathway and time to diagnosis in ANCA-associated vasculitis: a retrospective study at a tertiary rheumatology center,” was published in Clinical Rheumatology.
AAV is a rare disease that can affect multiple organs
AAV is a group of rare autoimmune conditions marked by inflammation and damage to small blood vessels. It can affect any organ, but most commonly involves the upper airways, the lungs, and the kidneys.
There are three recognized types — granulomatosis with polyangiitis (GPA), microscopic polyangiitis (MPA), and EGPA — based on clinical manifestations, specific features on tissue analysis, and presence and type of ANCA, self-reactive antibodies found in most AAV cases that are thought to drive the disease process.
Because the disease presents so differently from patient to patient, diagnosis is often delayed. Earlier diagnosis may help limit the risk of permanent organ damage.
Prior studies have identified several factors that contribute to delayed diagnosis in AAV, including lengthy referral times to specialized care, initial misdiagnosis, limited awareness of the disease’s early signs, and non-specific symptoms.
“Health care systems differ substantially regarding referral pathways and access to specialist care,” the researchers wrote. “There are no data from Germany (one of the most populous countries in Europe) systematically evaluating the time to diagnosis, referring structures, and involved medical specialties in patients with AAV.”
Study examines diagnostic pathways in patients with AAV
To address this gap, researchers at Ruhr University Bochum in Germany reviewed medical records from 216 people diagnosed with AAV between 2014 and 2024 at a specialized center.
Among them, more than half were diagnosed with GPA (59.3%), followed by MPA (32.4%), and EGPA (8.3%). Women made up 51% of GPA cases, 67% of MPA cases, and 78% of EGPA cases. The average age at diagnosis was 56 years in GPA, 64 years in MPA, and 60 years in EGPA.
At diagnosis, blood tests showed elevated levels of C-reactive protein (CRP), a common marker of inflammation, across all subtypes.
Disease activity was measured using the Birmingham Vasculitis Activity Score (BVAS), which ranges from zero to 63, with higher scores indicating more active disease. Mean BVAS scores at diagnosis were in the low-to-moderate range: nine for GPA, seven for MPA, and eight for EGPA.
The time from first symptoms to confirmed diagnosis differed across AAV types. The longest median time to diagnosis was seen in EGPA, at 454.5 days (about 15 months), compared with 153 days (about five months) in MPA and 120 days (about four months) in GPA. A statistical analysis confirmed that the delay in EGPA patients was significantly longer than in patients with the other two types.
In addition, among EGPA patients whose first symptoms were asthma and nasal polyps (growths on the lining of the nose), the estimated median time to diagnosis was even longer, at 625 days (little over 1.5 years).
Referral patterns vary across AAV subtypes
GPA and MPA patients were most often referred by general practitioners, specialists in internal medicine (internists), and autoimmune disease specialists (rheumatologists). In comparison, EGPA patients were more commonly referred by lung disease specialists (pulmonologists) and heart disease specialists. Before receiving their diagnosis, patients saw an average of 2.66 specialists, with EGPA patients seeing the most, at an average of 3.44.
Statistical analyses adjusted for age and sex showed that kidney involvement at presentation was significantly associated with a shorter time to diagnosis, along with referral by internists. In contrast, prior consultations with skin disease specialists (dermatologists), rheumatologists, and pulmonologists were significantly associated with longer diagnostic delays, likely reflecting more complex or less typical disease presentations.
Also, higher BVAS scores and elevated CRP levels were each significantly associated with faster diagnosis, “indicating that higher disease activity facilitated an earlier diagnosis,” the team wrote.
“Our study provides valuable insights into the diagnostic process of AAV within a tertiary rheumatology setting,” the researchers wrote. “Identifying clinical and structural factors associated with delayed diagnosis is essential for developing targeted educational, diagnostic, and organizational strategies aimed at facilitating earlier recognition and improving patient outcomes.”
