Question

Infants are least allergic to which of one of the following formulas?

• A. Soy milk based formula
• B. Partially hydrolyzed formula
• C. Extensively hydrolyzed formula
• D. Amino acid based formula

Hint:

Hypoallergenic Infant Formulas:
ZERO Allergenicity (Least Allergic) = AMINO ACID BASED FORMULA (Elemental free amino acids).
Next best = Extensively Hydrolyzed Formula (eHF).

Answer 1

The Correct Option is D

Step 1: Understanding the Concept:
Pediatric hypoallergenic nutrition and Cow's Milk Protein Allergy (CMPA): elemental amino acid-based formulas (AAF) contain 100% synthetic free amino acids devoid of intact peptide conformational or linear epitopes, providing zero allergic reactivity.
Key Formula or Approach:
\[ \text{Allergenicity Spectrum: Whole Cow's Milk } \gg \text{Partially Hydrolyzed} > \text{Extensively Hydrolyzed (eHF)} > \mathbf{Amino \text{ } Acid \text{ } Formula (AAF, 0\% \text{ Antigenic})} \]

Step 2: Detailed Explanation:
In pediatric infant nutrition and management of Cow's Milk Protein Allergy (CMPA):
1. Amino Acid Based Formula (Elemental Formula AAF) (D): Formulated using 100% synthetic free, monomeric amino acids with no peptide chains. Because it contains zero antigenic protein epitopes to cross-link IgE receptors on mast cells, infants with severe anaphylactic cow's milk and soy allergies are least allergic (100% non-allergenic) to amino acid formulas.
2. Extensively Hydrolyzed Formula (eHF): Oligopeptides ($< 1.5 - 3.0\text{ kDa}$); tolerated by $\approx 90\%$ of allergic infants, but can cause reactions in highly sensitized infants.
3. Partially Hydrolyzed Formula (pHF): Large peptides; not hypoallergenic.
4. Soy-based Formula: Up to $10 - 15\%$ cross-reactivity with CMPA.

Step 3: Final Answer:
Hence, infants are least allergic to Amino acid based formula, matching option (D).