Appeal type: Experimental
Decision: Upheld

Summary Reviewer 1 
 
The parent of a five-year-old male enrollee has requested reimbursement for immunoglobulin G 
(IgG) food testing performed on 9/27/21. The Health Insurer has denied this request and 
reported that the services at issue were investigational for the evaluation of the enrollees 
medical condition. The physician reviewer found that the current standard of care for treatment 
of food allergy is avoidance of the food allergen and treatment of anaphylaxis with auto-
injectable epinephrine. However, this standard of care leaves much to be desired given the 
difficulty to maintain this practice, and the possibility of accidental ingestions with consequences. 
While many food allergy treatments, including oral immunotherapy, have been considered 
investigational  by  professional  allergy  societies  and  other  key  stakeholders,  the  Allergenic 
Products Advisory Committee of the Food and Drug Administration (FDA) has voted to support 
approval  of  a  standardized  oral  immunotherapy  (OIT)  product  for  peanut  allergy.    Oral 
immunotherapy refers to feeding an allergic individual an increasing amount of an allergen with 
the goal of increasing the threshold that triggers a reaction. For example, an individual who is 
allergic to peanuts may be given very small amounts of peanut protein that would not trigger a 
reaction. This small amount is gradually increased in the allergists office or a clinical research 
setting over a period of months. The goal of therapy is to raise the threshold that may trigger a 
reaction  and  provide  the  allergic  individual  protection  against  accidental  ingestion  of  the 
allergen. Efficacy in clinical trials has typically been defined by induction of a desensitized state. 
Desensitization refers to the improvement in food challenge outcomes after therapy and relies 
on ongoing exposure to the allergen. Peanut, eggs and milk oral immunotherapy have been 
shown to desensitize approximately 60 to 80% of patients studied. However, there are many 
important questions about oral immunotherapy that require ongoing study. The precise degree 
of protection is a topic of active investigation. The length of treatment and doses used have 
varied in published studies. Therefore, the best dose to give for any particular allergen is 
unknown.  IgG4 testing is not approved for the diagnosis of food allergies. However, per the letter 
dated 2/08/22, the provider noted that the testing was recommended in order to monitor 
therapeutic efficacy of the tolerance induction program, a type of oral immunotherapy. Studies 
have shown the efficacy of environmental allergen immunotherapy not only by their decrease in 
specific IgE but also in their increase in specific IgG4 blocking antibody. Specifically concerning 
foods, Burton and colleagues showed that injection of specific egg IgG4 to mice facilitated 
tolerance to eggs. Therefore, researchers may use specific food IgG4 antibody levels to monitor 
the efficacy of oral immunotherapy. More importantly, recent studies have confirmed not only 
the use of repeat baseline and during treatment skin prick test and serum allergen specific IgE 
(sIgE) but also specific food IgG4 to monitor oral immunotherapy efficacy. Therefore, IgG food 
testing performed on 9/27/21 was likely to have been more beneficial than any available 
standard therapy.