CMS RAST Type Tests Form

Effective Date

08/03/2023

Last Reviewed

07/25/2023

Original Document

  Reference



Background for this Policy

Summary Of Evidence

N/A

Analysis of Evidence

N/A

Abstract:

Radioallergosorbent test (RAST), fluoroallergosorbent test (FAST), and multiple antigen simultaneous tests are in vitro techniques for determining whether a patient's serum contains IgE antibodies against specific allergens of clinical importance. As with any allergy testing, the need for such tests is based on the findings during a complete history and physical examination of the patient.

The multiple antigen simultaneous testing technique is similar to the RAST/FAST techniques in that it depends upon the existence of allergic antibodies in the blood of the patient being tested. With the multiple antigen simultaneous test system, several antigens may be used to test for specific IgE simultaneously.

ELISA (enzyme-linked immunosorbent assay) is another in vitro method of allergy testing for specific IgE antibodies against allergens. This method is also a variation of RAST.

Limitations:

The following tests are considered to be not medically necessary and will be denied.

  • ELISA/Act qualitative antibody testing
    This testing is used to determine in vitro reaction to various foods and relies on lymphocyte blastogenesis in response to certain food antigens.
  • LMRA (Lymphocyte Mitogen Response Assays) by ELISA/Act
  • IgG ELISA, indirect method 
  • Qualitative multi-allergen screen 
    This is a non-specific test that does not identify a specific antigen.
  • IgG and IgG subclass antibody tests for food allergy do not have clinical relevance, are not validated, lack sufficient quality control, and should not be performed.