Braga, Quecchia, Perotta, Timpini, Maccarinelli, Di Tommaso, Di Gioacchino 2013 — SNAS nosologic framework and diet regimen for diagnosis
This Int J Immunopathol Pharmacol study from the Spedali Civili Brescia and University G. d’Annunzio Chieti SNAS-research groups is the canonical reference for the SNAS nosologic framework and the development of the BraMa-Ni diet as a diagnostic tool. 145 patients with suspected SNAS underwent oral nickel challenge for definitive diagnosis, and the BraMa-Ni structured low-nickel diet (~50 µg Ni/day, nutritionally balanced) was compared against the conventional forbidden-foods-list approach for sensitivity and specificity. The BraMa-Ni diet substantially outperformed the forbidden-food-list approach: 94.4 percent sensitivity and 93.3 percent specificity, versus 51.1 percent / 44.2 percent for the simpler list. The paper consolidates SNAS as a well-defined clinical entity with rigorous diagnostic criteria.
Key numbers
| Diagnostic approach | Sensitivity | Specificity |
|---|---|---|
| BraMa-Ni structured low-nickel diet (~50 µg Ni/day) | 94.4 percent | 93.3 percent |
| Conventional forbidden-foods list | 51.1 percent | 44.2 percent |
The BraMa-Ni diet is approximately 50 µg Ni/day (vs typical Western intake 150-350 µg/day), is nutritionally balanced, and serves both diagnostic and therapeutic functions.
Methods (brief)
145-patient cross-sectional study with suspected SNAS by history and prior benefit from Ni dietary restriction. All underwent standardized oral nickel challenge for definitive diagnosis. Each followed either BraMa-Ni structured diet or conventional forbidden-foods list. Sensitivity and specificity computed against the oral-challenge gold standard.
Implications
- Certification: Establishes SNAS as a well-defined clinical entity affecting approximately 20 percent of nickel-ACD patients and provides the validated diagnostic tool (BraMa-Ni diet). HMTc Ni-threshold rationale for vulnerable populations should reference SNAS prevalence and the BraMa-Ni framework when discussing dietary Ni intake at the population level.
- Microbiome / immunology: Both Th1 and Th2 pathways implicated; IL-5 most significantly elevated cytokine within 24 hours of oral challenge. Intestinal mucosa CD4+CD45RO+ infiltration documented.
- Courses: Foundational reference for SNAS diagnostic criteria.