Assembling the evidence…
functional binding immunoassay methods serve as reliable alternates for conventional chromogenic method to quantitate fC1-INH in human plasma samples with a better dynamic range of detection and ease of use
parallel selected-sample comparisons support broad alternativeness, but representative diagnostic and external validation are absent
FXIIa-binding method gave better sensitivity, specificity, and correlation to the chromogenic method as a diagnostic method to distinguish HAE samples from healthy controls
Table 2 and the Discussion identify chromogenic testing, not FXIIa binding, as having the best specificity
profiles obtained from different fC1-INH methods matched for individual HAE subjects
parallel longitudinal profiles agree directionally, though pooled correlations ignore repeated measurements within 15 subjects
Derived from the full evaluation — not a separate score.
Strengths
Chromogenic, C1s-binding, and FXIIa-binding methods were applied in parallel to the same healthy-control, HAE, and longitudinal pharmacodynamic samples, enabling direct comparison rather than cross-study inference.
↳ Methods §2.1; Results §§3.1–3.4
The longitudinal arm used 17 timepoints from 15 consented participants in a Phase III crossover study, testing assay behaviour across a broad post-dose concentration range.
↳ Methods §2.1; Results §§3.3–3.4; Figures 3–4
The paper relates its findings to prior chromogenic and binding-assay studies and explicitly states that its selected cases may not represent patients with equivocal laboratory values.
↳ Introduction; Discussion, paragraphs 2–3
Limitations
Results §3.2 reports 48 chromogenic HAE samples and one false negative, but the corresponding sensitivity in Table 2 is not mathematically consistent; other stated event counts and percentages also lack reconciliation. These discrepancies directly weaken the assay-ranking claims.
↳ Results §3.2; Figure 2; Table 2
Figure 4 correlates 255 samples drawn from only 15 subjects, without accounting for within-subject dependence. The reported p-values therefore overstate the effective precision of the longitudinal correlation analysis.
↳ Results §3.4; Figure 4
Cutoffs were selected and evaluated using commercial controls and trial participants already required to have diagnosed HAE and reduced fC1-INH. The paper acknowledges that this selected population may not represent equivocal diagnostic cases.
↳ Methods §2.1; Results §3.2; Discussion, paragraph 3
The matched three-assay design and use of both baseline and longitudinal clinical samples make the comparison practically informative. Its contribution remains incremental because each assay was already established, and diagnostic cutoffs were evaluated in commercial controls and selected confirmed HAE cases. The diagnostic ranking is weakened by inconsistencies among the denominators, event counts, and percentages in Results §3.2 and Table 2, including the claim of better FXIIa specificity. Figure 4 also treats 255 observations from 15 subjects as a pooled correlation without modelling within-subject dependence, limiting the precision of the concordance evidence.
Nabu’s assessment, alongside the field’s view.
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Sound3.1
Confidence mediumThe contribution is a same-sample comparison of three established fC1-INH assays across diagnostic and longitudinal pharmacodynamic settings. It addresses a practical assay-selection question but introduces no new diagnostic principle and remains incremental.
We conducted a parallel head-to-head comparison of methods using clinical samples collected at multiple timepoints
The assay procedures, calibration ranges, and parallel sampling design are sufficiently described, but the ROC denominators and percentages do not reconcile. Pearson correlations pool 255 repeated observations from 15 subjects without accounting for within-subject dependence.
255 samples from a total of fifteen HAE subjects
The manuscript follows a clear sequence from assay description through ROC and longitudinal comparisons. Reporting is reduced because the Abstract claims superior FXIIa specificity while Table 2 and the Discussion identify the chromogenic assay as having the best specificity.
chromogenic assay had the best specificity
The discussion engages directly relevant assay studies and the WAO/EAACI guideline, and it acknowledges that selected confirmed cases may not represent equivocal patients. Implications for cross-laboratory reproducibility and independent implementation receive limited treatment.
HAE patient population was highly selected
Concerns4 of 4 checks
The diagnostic-performance reporting contains unresolved inconsistencies among sample denominators, error counts, and sensitivity percentages. These discrepancies bear directly on the comparison of assay performance, although they do not invalidate the broader finding that all three assays separate the selected groups well.
Patient consent and company involvement are visible, but the supplied text does not state ethics-committee approval for the secondary analysis and does not clearly characterise the disclosed corporate relationships as potential competing interests.
Flags: 1 declared / 5 total
15 of 15 checkable references verified
15 references in manuscript
No retraction notice found in Retraction Watch.
Sources: Retraction Watch ✓
Where this paper’s evidence sits on the path from initial observation to real-world use.
The assays were applied to consented samples from a Phase III crossover trial, providing evidence beyond an artificial laboratory panel. Readiness remains pre-deployment because diagnostic performance was not independently validated in a representative intended-use population.
leftover pharmacokinetic/pharmacodynamic samples from fifteen HAE patients
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