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Review of: The Evolution of Food Immune Reactivity Testing: Why IgG Antibody for Food May Not be Reproducible From One Lab to Another
Alternative Therapies, Vol. 23, Supplement 1, Aristo Vojdani, PhD., MSc, CLS
This Review Written by Dr. James M. Blum
Article Abstract (as written by Dr. Aristo Vojdani)
“The gold standard for identifying food reactions is the elimination-provocation diet. Embarking on this long, tedious journey takes an expert practitioner and a completely dedicated patient, with a whole lot of patience from both. In the contemporary fast lane, microwave, “give me a pill” popping, I-want-satisfaction-now society, many clinicians have turned to laboratory assessments for quick answers to food reactivity. From the introduction of cytotoxic testing for food allergies in 1947 until today, food reactivity testing has evolved and branched out; it has been both pseudo-improved and scientifically improved. With multiple available options for methodology, specimen types, and clinical lab, how is a clinician expected to find the one that fits the requirements of a particular practice? How, indeed, when one self-promoting paper supports a particular methodology, while another criticizes it? In this article, with the benefit of his years of training and experience as a research scientist and test development expert, the author, who is trained in both microbiology and immunology, discusses the history of food testing, analyzes the criticisms of it, reviews the scientific literature, and tours the methodologies.”
Review by Dr. Blum
Dr. Vojdani summarizes the much-published criticisms of food testing into three categories, which are (1) reproducibility within a given lab and correlation from lab-to-lab, (2) clinical outcomes of using IgG for identifying reactive foods, and (3) the role that the actual food antigens play in testing for food sensitivities. Each is summarized.
Item 1: Reproducibility and Lab-to-Lab Variability
As stated in laboratory testing guidelines, “If a test is not reproducible, it is considered invalid”. [NEW] Reproducibility is generally done by split sampling, where a blood sample from a single individual (taken at the same time) is split and submitted under two different names, and the results compared. Federal regulations state that split samples be within a variance of 20% in order to achieve an acceptable passing grade. Vojdani reviewed a 1998 study by Jones et al where blood from a subject was split three ways and sent to three different labs. Two of the three labs reported variances that ranged from 49%-73%. He did not detail the labs methodologies but because the samples were frozen, it would have excluded life-blood testing.
Ten years later, Simpson et al published a comparison of live-blood cytotoxic vs. IgG ELISA methodologies. Vojdani summarized that comparing different methods was like “comparing apples to sausages”. The reported variances for the IgG labs were 82 and 95%. He points out that some food antigens have enzymes that may confound the results, reacting in such a way as to produce a false positive result. However, in a split sample to the same lab, two identical false-positives would constitute an identical result. We don’t know due to the data presented if that occurred.
Vojdani next discusses Lab Developed Tests, which is extremely common and leads to difficulty in comparing one lab to another. The key point in these scenarios is the source and preparation of the antigens. [NEW] Using pharmaceutical-grade food antigens is clearly the gold standard, because physicians demand FDA-approved antigen preparations as they are placed on the body during scratch testing. [NEW] Only a handful of labs use them due to the dramatically increased cost factor and some foods are not available as pharmaceutical-grade.
Item 2: Clinical Value or Usefulness of IgG Results
Vojdani summarizes the situation in the following quoted manner: “The argument that IgG antibodies are an indication of exposure to antigens or a failure in immune tolerance has been made and repeated many times. This notion is based on the virus model, where levels of IgG are indicative of past exposure and high levels of IgG are indicative of super-immune protection. [NEW] It is well recognized that IgG these molecules bind pathogens which results in agglutination and opsonization, the binding of the pathogen outer shell and coating, which signals phagocytic WBC to digest these pathogenic cells. IgG also activates the complement system, and binds and neutralizes certain toxins. There are many examples of IgG in eliminating various viral particles, including the seminal work done on dengue fever.
According to Vojdani, a trained and experienced immunologist, “contemporary immunologists have not applied this concept to other antigen reactivities, but many authors appear to be stuck in the virus model.”
Generally, IgG antibodies against tissues can help diagnose diseases. Antibodies against agents (like H. pylori toxins) confirm the presence of this bacteria, making the diagnosis of an active infection more likely. Examples of disease and specific tissue involvement include:
Patients have been shown to have high levels of anti-prothrombin IgG who are being screened for systemic lupus, where standard testing was negative. Osteoarthritis and rheumatoid arthritis can be differentiated by the presence of fibulin IgG in biopsy-confirmed celiac individuals, IgG antibodies to endomysial cells, thyroid peroxidase, glutamic acid decarboxylase, insulin, and islet cells are elevated, but results fall into the normal range, following a two-month gluten-free diet
Vojdani points out that IgG antibodies against food antigens have documented clinical significance. Example disease conditions that were successfully treated with the elimination of reactive foods identified by IgG food testing include:
It is worth mentioning that in the past three years, there are a dozen new journal articles demonstrating the clinical usefulness of creating elimination diets using IgG for food sensitivities in different disease categories. Each of these are available and will be summarized for your reading pleasure.
My work over the past fifteen years has produced an array of individuals who have been helped by adhering to an elimination of reactive foods for a period of at least 10-12 weeks. These conditions include:
Case histories and evaluations for these are listed on our website.
Item 3: Antigen Involvement:
The crux of the issue for food sensitivity testing is to identify food antigen-antibody complexes. These complexes depend on the quality of the antigen. Highly purified food antigens are crucial for reliable reporting.
It has been suggested by Goldstein et al that some false-positives are a result of contamination by microbes and environmental toxins. Vojdani points out that the ratio of proteins from foods compared to proteins from microbes are in the range of 1,000 to 10,000 to 1. He argues that It is unlikely that this ratio would allow a positive result in the ELISA system because of the requirement of the antigen-antibody reaction. [NEW] Moreover, chemical toxins are hapten molecules and incapable of producing an immune complex by themselves. Haptens are small molecules that can elicit an immune response but only when bound to a large carrier molecule, such as a protein. Examples include aniline and urushiol, one of the active compounds found in poison ivy. In food testing, haptens would need to bind to food proteins to form an active immune molecule, but the tiny proportions would make false-positives unlikely.
[NEW] However, labs that use non-pharmaceutical-grade food antigens have the issue that these preparations themselves may contain substrates that react with the enzymes in their ELISA or live-cell assay systems. In these cases, it is possible to see false-positives and more importantly, false-negatives.
[NEW] A much more important problem arises if these substrates and impure antigens prevent the appropriate immune complex from forming, thus resulting in a false-negative. False-positives are inconvenient and unwanted but do not detract from reducing systemic inflammation. However, not knowing that a food is reactive and thus possibly continuing to eat it, which is causing inflammation, could be very crucial because they could result in poorer clinical outcomes. There are certainly logistical challenges from eliminating a food that was identified improperly as a false-positive, especially if it involves a major food item, such as wheat or a meat choice, but there are usually many alternative to choose from so most clients can manage. The misses that come from false-negatives could derail the effort if it involves a highly reactive or a common food item. It is unlikely that if the ELISA kits use highly purified food antigens specified as ‘pharmaceutical grade’, that either false-positives or false-negatives would be a problem.
Live-Cell Testing Platforms
[NEW through-out] The principle of live-cell testing involves phagocytosis changes. Populations of various WBC will change their morphology and size in response to interactions with food proteins prior to dumping their bullets (mediators). Live-cell testing relies on observing these size changes and reporting a grading of the severity of the cellular response. According to Vojdani, three labs use this approach (ALCAT, MRT, and LRA) and the first two have developed their own analyzers to record these responses. A number of problems arise that include the pH of the food extracts and the timing of events. Phagocytosis occurs over a specific framework but may differ from antigen-to-antigen and severity of the reaction. It appears that the live-cell systems have a difficult time matching the real-time cellular responses with the assays. The major challenges fall within the scope of the analyzers and the assay wells that contain the food and where the reactions occur. If the analyzer starts at well one and there are many wells, then the timing will be very different by the time the analyzer gets to well 20, 30, or 40. It is very possible that optimal reactions are missed, leading too poor reproducibility. Since there are a number of different lymphocytes involved, it would stand to reason that there would be different times required for various antigens. These are difficult to control. Live-cell testing requires whole fresh blood, whereas IgG testing only requires plasma and is very stable for several months. Fresh blood can be damaged by temperature variations (hot or cold) so samples coming during winter months in the north or from many places in the summer months may be disrupted and yield improper results. Whole, fresh blood is only viable for several days and therefore can’t be retested with confidence compared to IgG, which can be retested following freezing of the serum or plasma.
Vojdani continues to point out the weaknesses involved in live-cell assays for food sensitivities and fills in these gaps for promoting the usefulness of IgG assays.
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