Disease activity in EGPA at diagnosis is 'chameleon-like' and cannot be captured by specific immunological signatures, requiring multidimensional assessment integrating laboratory parameters with clinical scores including ANAs, eosinophil counts, NLRs, and BVASs.
Median eosinophil counts at EGPA diagnosis were 685 cells/µL in this cohort of 38 patients.
ANCA positivity was found in only 5 of 38 EGPA patients at diagnosis.
Antinuclear antibodies (ANAs) were positive in 20 of 38 EGPA patients, representing just over half the cohort.
ANA-positive EGPA patients showed higher disease activity scores with elevated general, nervous system, and ENT BVAS domain scores.
The neutrophil-to-lymphocyte ratio (NLR) median was 2.29 at EGPA diagnosis.
Inflammatory markers ESR and CRP showed median values of 24 mm/h and 1.99 mg/L respectively at EGPA diagnosis.
EGPA at diagnosis is described as 'chameleon-like' and requires multidimensional assessment integrating laboratory parameters with clinical scores for early recognition.
This research examined the laboratory and clinical features of 38 patients with eosinophilic granulomatosis with polyangiitis (EGPA), a rare inflammatory blood vessel disease, at the time of their diagnosis. EGPA is notoriously difficult to identify early because its symptoms can look like many other conditions. The study found that only 5 of the 38 patients tested positive for ANCA antibodies (which are commonly associated with vasculitis diseases), while more than half — 20 patients — tested positive for antinuclear antibodies (ANAs), which are more often linked to autoimmune diseases like lupus. This suggests that the disease presents with an unusual and mixed immunological picture that does not fit neatly into standard diagnostic categories. The research found that patients who were ANA-positive tended to have lower eosinophil counts (a type of white blood cell elevated in EGPA) but showed higher levels of inflammation markers (ESR and CRP) and higher disease activity scores (BVAS), particularly in domains related to general symptoms, the nervous system, and ear-nose-throat (ENT) features. This suggests that ANA-positive EGPA patients may present with a distinct clinical pattern that is more inflammatory and less eosinophil-driven at the time of diagnosis. The authors concluded that EGPA at diagnosis behaves like a 'chameleon' — it cannot be identified through any single laboratory test or immunological marker alone. This research suggests that clinicians should use a combination of tools including eosinophil counts, the neutrophil-to-lymphocyte ratio (NLR), ANA testing, and clinical disease activity scoring (BVAS) together to raise suspicion for EGPA and refer patients to specialized centers early. The unexpected frequency of ANA positivity in this cohort points to its potential usefulness as part of a broader diagnostic approach for this rare and complex condition.
Brunetto S, Dimasi F, Maiolo C, Zumbo E, Buta F, Gangemi S, et al.. (2026). EGPA at Diagnosis: A Comprehensive Single-Center Profile of Laboratory Findings and Clinical Evidence.. International journal of molecular sciences. https://doi.org/10.3390/ijms27167116