Retinol (vitamin A) and retinol-binding protein levels are decreased in ankylosing spondylitis: clinical and genetic analysis.
Bibliographic record
Abstract
OBJECTIVE: Retinol (vitamin A) plays an important role in bone structure and function. Treatment with retinoids has been associated with bone abnormalities mimicking spondyloarthropathy and diffuse idiopathic skeletal hyperostosis. To determine whether retinol concentrations are altered in patients with ankylosing spondylitis (AS), we examined serum retinol levels in patients with AS and healthy controls. METHODS: Retinol was assessed using mass spectrometry, and retinol-binding protein levels were assessed by ELISA. Retinol levels were correlated with clinical disease activity indices. The CYP26 gene, which plays a key role in retinol metabolism, was examined to define any single-nucleotide polymorphisms (SNP) associations with AS. RESULTS: Retinol levels were significantly lower in the AS cohort than in controls (mean 2.39 +/- 0.88 micromol/l for AS, 3.34 +/- 1.01 micromol/l for controls; p < 0.0001). Retinol-binding protein levels were also lower in AS than controls (AS 4.65 +/- 2.10 microg/l; controls 7.48 +/- 4.87 microg/l; p < 0.001). Serum retinol levels did not correlate with indices of disease activity defined serologically (C-reactive protein, erythrocyte sedimentation rate) or clinically (Bath AS Disease Activity Index, Bath AS Functional Index). Genetic analysis showed that an exonic CYP26C1 SNP (rs11187265) is not associated with AS. CONCLUSION: The hallmark of AS is neo-ossification. AS is associated with abnormal serum levels of retinol, a biochemical factor linked to pathological hyperostosis. Further genetic studies are warranted into the genetic basis of the retinol-AS relationship.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.001 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.001 | 0.000 |
| Insufficient payload (model declined to judge) | 0.002 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".