- Design
- Retrospective single-centre cohort, blinded adjudication
- Population
- 22 patients with CPA, 57 visit-pairs
- Primary outcome
- Association of IgG change with clinico-radiological worsening
- Effect
- AUC 0.84; ratio of geometric means 1.84 (0.97–3.48); 1.45-fold rise: sens 36%, spec 98%
A retrospective single-centre study in Chest (21 September) examined 22 patients with chronic pulmonary aspergillosis (CPA), with 57 pairs of visits at least three months apart. A blinded panel judged each interval as stable/improved or worsening on clinical and CT grounds, and anti-Aspergillus IgG change was normalised to three months.
IgG rose more during worsening intervals (median ratio 1.28 vs 0.84). After accounting for repeated measures in the same patients, the difference was of borderline significance (ratio 1.84, 95% CI 0.97–3.48). A rise of 1.45-fold over three months had 97.7% specificity but only 36.4% sensitivity; a 1.10-fold rise had 72.7% sensitivity and 83.7% specificity.
This is too small to set thresholds. But it supports using serial IgG as one prompt for earlier CT review, not as a reassurance when it is stable. CPA after tuberculosis is common in India, where CT access for frequent monitoring can be limited.
- Measure anti-Aspergillus IgG on the same assay at each follow-up
- Treat a marked rise as a reason to bring forward CT and sputum studies
- Do not let a stable IgG override clinical or radiological worsening
- Consider CPA in patients with cavities after treated tuberculosis
Why it matters
Monitoring CPA relies on expensive, infrequent imaging; a cheap blood marker could help decide when to scan.
Don't overread it
With 22 patients at one centre, the thresholds are exploratory and need external validation.
The statistics, in plain English
High specificity with low sensitivity means a big rise usually signals trouble, but most worsening episodes do not show one. The cluster-adjusted interval crosses 1, so the overall association is not firmly established in this small sample.
Read the rest in the app
You have read your two free briefings this month. The app carries all 27 specialties, every morning, free — and this finding is waiting in it.
Scan to keep reading on your phone. No account needed to start.
Tomorrow morning, before your first patient
One edition a day for pulmonology, written by the desk, every claim tied to its paper. Six minutes.
Get the app — free