{"id":1573,"date":"2025-08-20T10:40:19","date_gmt":"2025-08-20T10:40:19","guid":{"rendered":"https:\/\/www.yorktest.com\/us\/?page_id=1573"},"modified":"2025-10-22T08:39:29","modified_gmt":"2025-10-22T08:39:29","slug":"what-is-igg","status":"publish","type":"page","link":"https:\/\/www.yorktest.com\/us\/what-is-igg\/","title":{"rendered":"What is the difference between IgG and IgG4?"},"content":{"rendered":"\n\n\n<section class=\"pt-6 pb-6 lg:pt-8 lg:pb-8 \" id=\"\" data-section=\"breadcrumbs\">\n    <div class=\"container\">\n        <div class=\"flex\">\n            <nav aria-label=\"breadcrumbs\" class=\"rank-math-breadcrumb\"><p><span class=\"last\">Home<\/span><\/p><\/nav>\n        <\/div>\n    <\/div>\n<\/section>\n\n\n\n\n<section class=\"pt-0 pb-10 lg:pt-0 lg:pb-10 \" id=\"\" data-block=\"heading-and-text\">\n    <div class=\"container\">\n        <div class=\"flex flex-col gap-6\">\n                            <h1 class=\"text-5xl lg:text-[70px] leading-[1.2]\">\n                    What is IgG?\n                <\/h1>\n            \n                            <div class=\"wysiwyg\">\n                    <p>IgG is a fancy word for testing the reaction to proteins in foods. This simple blood test is used as a measurement strategy of food-specific IgG antibodies for identifying foods to which a person may be sensitive.<\/p>\n<p>This type of testing is now considered mainstream as many choose to use this approach as a starting point for an elimination diet.<\/p>\n\n                <\/div>\n                    <\/div>\n    <\/div>\n<\/section>\n\n\n\n\n\n\n<section class=\"two-column-image-video-and-text overflow-x-hidden bg-white pt-10 pb-10 lg:pt-20 lg:pb-20 \" id=\"\" data-block=\"two-column-image-video-and-text\">\n    <div class=\"container\">\n        <div class=\"grid grid-cols-3 sm:grid-cols-6 lg:grid-cols-12 gap-6 lg:gap-10\">\n            <div class=\"col-span-3 sm:col-span-6 flex flex-col justify-center gap-6 order-2  lg:order-2   lg:col-start-7   items-center \">\n                \n                                    <h2 class=\" text-xl lg:text-3xl  leading-[1.2] text-yt-bright-teal  text-center \">\n                        Antibodies are major components of the immune system\n                    <\/h2>\n                \n                                    <div class=\"wysiwyg text-yt-black  text-center \">\n                        <p>Immunoglobulin (IgG) is a type of antibody. Antibodies are major components of the immune system. In normal human blood IgG1 is the most prevalent making up 60-70% of the total IgG, followed by IgG2 (20-30%) and IgG3 (5-8%). IgG4 only consists of 1-4% of the food-specific IgG antibodies present.<\/p>\n\n                    <\/div>\n                \n                \n                            <\/div>\n\n            <div class=\"col-span-3 sm:col-span-6 order-1  lg:col-span-5   \">\n                                    <div class=\"rounded-2xl overflow-hidden   sm:w-1\/2 lg:w-full lg:h-[400px] xl:h-[450px]   mx-auto \">\n                        <img decoding=\"async\"\n                            src=\"https:\/\/www.yorktest.com\/app\/uploads\/sites\/3\/2025\/08\/whats-the-difference-IgG-2-600x6-1.png\"\n                            srcset=\"https:\/\/www.yorktest.com\/app\/uploads\/sites\/3\/2025\/08\/whats-the-difference-IgG-2-600x6-1-300x300.png 300w, https:\/\/www.yorktest.com\/app\/uploads\/sites\/3\/2025\/08\/whats-the-difference-IgG-2-600x6-1.png 768w, https:\/\/www.yorktest.com\/app\/uploads\/sites\/3\/2025\/08\/whats-the-difference-IgG-2-600x6-1.png 1024w\"\n                            sizes=\"auto, (max-width: 640px) 100vw, (max-width: 1024px) 50vw, 450px\"\n                            alt=\"\"\n                            loading=\"lazy\"\n                            width=\"600\"\n                            height=\"600\"\n                            class=\"w-full h-full object-cover object-center sm:object-top lg:object-center\"\n                            title=\"whats-the-difference-IgG-2-600x6 (1)\"\n                        >\n                    <\/div>\n                \n                            <\/div>\n        <\/div>\n    <\/div>\n<\/section>\n\n\n\n\n\n\n<section class=\"two-column-image-video-and-text overflow-x-hidden bg-white pt-10 pb-10 lg:pt-20 lg:pb-20 \" id=\"\" data-block=\"two-column-image-video-and-text\">\n    <div class=\"container\">\n        <div class=\"grid grid-cols-3 sm:grid-cols-6 lg:grid-cols-12 gap-6 lg:gap-10\">\n            <div class=\"col-span-3 sm:col-span-6 flex flex-col justify-center gap-6 order-2  lg:order-1    items-center \">\n                \n                                    <h2 class=\" text-xl lg:text-3xl  leading-[1.2] text-yt-bright-teal  text-center \">\n                        Why do some tests only measure IgG4?\n                    <\/h2>\n                \n                                    <div class=\"wysiwyg text-yt-black  text-center \">\n                        <p>There are different types of food-specific IgG antibodies that can be measured; IgG1, IgG2, IgG3 and IgG4. yorktest measure all four subtypes of food-specific IgG and we therefore describe our IgG testing as food-specific IgG (1-4) testing. We cover all bases to give you your individual food fingerprint.<\/p>\n\n                    <\/div>\n                \n                \n                            <\/div>\n\n            <div class=\"col-span-3 sm:col-span-6 order-1  lg:col-span-5   lg:col-start-8  \">\n                                    <div class=\"rounded-2xl overflow-hidden   sm:w-1\/2 lg:w-full lg:h-[400px] xl:h-[450px]   mx-auto \">\n                        <img decoding=\"async\"\n                            src=\"https:\/\/www.yorktest.com\/app\/uploads\/sites\/3\/2025\/08\/whats-the-difference-IgG-3-600x6-2.png\"\n                            srcset=\"https:\/\/www.yorktest.com\/app\/uploads\/sites\/3\/2025\/08\/whats-the-difference-IgG-3-600x6-2-300x300.png 300w, https:\/\/www.yorktest.com\/app\/uploads\/sites\/3\/2025\/08\/whats-the-difference-IgG-3-600x6-2.png 768w, https:\/\/www.yorktest.com\/app\/uploads\/sites\/3\/2025\/08\/whats-the-difference-IgG-3-600x6-2.png 1024w\"\n                            sizes=\"auto, (max-width: 640px) 100vw, (max-width: 1024px) 50vw, 450px\"\n                            alt=\"\"\n                            loading=\"lazy\"\n                            width=\"600\"\n                            height=\"600\"\n                            class=\"w-full h-full object-cover object-center sm:object-top lg:object-center\"\n                            title=\"whats-the-difference-IgG-3-600x6 (2)\"\n                        >\n                    <\/div>\n                \n                            <\/div>\n        <\/div>\n    <\/div>\n<\/section>\n\n\n\n\n\n\n<section class=\"two-column-image-video-and-text overflow-x-hidden bg-white pt-10 pb-10 lg:pt-20 lg:pb-20 \" id=\"\" data-block=\"two-column-image-video-and-text\">\n    <div class=\"container\">\n        <div class=\"grid grid-cols-3 sm:grid-cols-6 lg:grid-cols-12 gap-6 lg:gap-10\">\n            <div class=\"col-span-3 sm:col-span-6 flex flex-col justify-center gap-6 order-2  lg:order-1    items-center \">\n                                    <h2 class=\" text-base text-yt-mid-grey uppercase tracking-widest   text-center \">\n                        Clinical evidence\n                    <\/h2>\n                \n                                    <h2 class=\" text-xl lg:text-3xl  leading-[1.2] text-yt-bright-teal  text-center \">\n                        How accurate is a test for IgG4 only?\n                    <\/h2>\n                \n                                    <div class=\"wysiwyg text-yt-black  text-center \">\n                        <p>There is a complex relationship between the four IgG subtypes. Meaningful results can only be determined by testing for all four subtypes together.<\/p>\n<p>IgG1, IgG2 and IgG3 are all capable of causing inflammation which could contribute to symptoms. IgG4 antibodies are only present in low levels and its presence does not relate directly to inflammatory reactions.<\/p>\n<p>Therefore, testing only for IgG4 antibodies in foods severely limits the accuracy of pinpointing those ingredients that are causing significant reactions and could be contributing to your symptoms.<\/p>\n<p>The substantive YorkTest clinical evidence base for food-specific IgG guided elimination diet supports this approach and recognizes the fundamental importance of measuring IgG1-4 (total food-specific IgG) and not just IgG4 alone.<\/p>\n\n                    <\/div>\n                \n                \n                            <\/div>\n\n            <div class=\"col-span-3 sm:col-span-6 order-1  lg:col-span-5   lg:col-start-8  \">\n                                    <div class=\"rounded-2xl overflow-hidden   sm:w-1\/2 lg:w-full lg:h-[400px] xl:h-[450px]   mx-auto \">\n                        <img decoding=\"async\"\n                            src=\"https:\/\/www.yorktest.com\/app\/uploads\/sites\/3\/2025\/10\/whats-the-difference-IgG-4-600x600-1.png\"\n                            srcset=\"https:\/\/www.yorktest.com\/app\/uploads\/sites\/3\/2025\/10\/whats-the-difference-IgG-4-600x600-1-300x300.png 300w, https:\/\/www.yorktest.com\/app\/uploads\/sites\/3\/2025\/10\/whats-the-difference-IgG-4-600x600-1.png 768w, https:\/\/www.yorktest.com\/app\/uploads\/sites\/3\/2025\/10\/whats-the-difference-IgG-4-600x600-1.png 1024w\"\n                            sizes=\"auto, (max-width: 640px) 100vw, (max-width: 1024px) 50vw, 450px\"\n                            alt=\"\"\n                            loading=\"lazy\"\n                            width=\"600\"\n                            height=\"600\"\n                            class=\"w-full h-full object-cover object-center sm:object-top lg:object-center\"\n                            title=\"whats-the-difference-IgG-4-600x600\"\n                        >\n                    <\/div>\n                \n                            <\/div>\n        <\/div>\n    <\/div>\n<\/section>\n\n\n\n\n\n\n<section class=\"two-column-image-video-and-text overflow-x-hidden bg-white pt-10 pb-10 lg:pt-20 lg:pb-20 \" id=\"\" data-block=\"two-column-image-video-and-text\">\n    <div class=\"container\">\n        <div class=\"grid grid-cols-3 sm:grid-cols-6 lg:grid-cols-12 gap-6 lg:gap-10\">\n            <div class=\"col-span-3 sm:col-span-6 flex flex-col justify-center gap-6 order-2  lg:order-1    items-center \">\n                                    <h2 class=\" text-base text-yt-mid-grey uppercase tracking-widest   text-center \">\n                        Our range of tests\n                    <\/h2>\n                \n                                    <h2 class=\" text-xl lg:text-3xl  leading-[1.2] text-yt-bright-teal  text-center \">\n                        Which test is right for you?\n                    <\/h2>\n                \n                                    <div class=\"wysiwyg text-yt-black  text-center \">\n                        <p>Did you know that the average person who has positive food-specific IgG (1-4) triggers reacts to four to five food and drink ingredients?<\/p>\n<p>We have a range of tests that could help you uncover what ingredients work for and against your body. If you are unsure what test to take our customer care team is on hand to guide you to the right test.<\/p>\n\n                    <\/div>\n                \n                \n                            <\/div>\n\n            <div class=\"col-span-3 sm:col-span-6 order-1  lg:col-span-5   lg:col-start-8  \">\n                                    <div class=\"rounded-2xl overflow-hidden   sm:w-1\/2 lg:w-full lg:h-[400px] xl:h-[450px]   mx-auto \">\n                        <img decoding=\"async\"\n                            src=\"https:\/\/www.yorktest.com\/app\/uploads\/sites\/3\/2025\/08\/whats-the-difference-igg-5-600x6-1.png\"\n                            srcset=\"https:\/\/www.yorktest.com\/app\/uploads\/sites\/3\/2025\/08\/whats-the-difference-igg-5-600x6-1-300x300.png 300w, https:\/\/www.yorktest.com\/app\/uploads\/sites\/3\/2025\/08\/whats-the-difference-igg-5-600x6-1.png 768w, https:\/\/www.yorktest.com\/app\/uploads\/sites\/3\/2025\/08\/whats-the-difference-igg-5-600x6-1.png 1024w\"\n                            sizes=\"auto, (max-width: 640px) 100vw, (max-width: 1024px) 50vw, 450px\"\n                            alt=\"\"\n                            loading=\"lazy\"\n                            width=\"600\"\n                            height=\"600\"\n                            class=\"w-full h-full object-cover object-center sm:object-top lg:object-center\"\n                            title=\"whats-the-difference-igg-5-600x6 (1)\"\n                        >\n                    <\/div>\n                \n                            <\/div>\n        <\/div>\n    <\/div>\n<\/section>\n\n\n\n\n<section class=\"pt-6 pb-6 lg:pt-10 lg:pb-10 \" id=\"\" data-block=\"trustpilot\">\n    <div class=\"container\">\n        <div class=\"trustpilot-widget min-h-[28px]\" data-locale=\"en-GB\" data-template-id=\"5419b732fbfb950b10de65e5\" data-businessunit-id=\"600997d2b8f14c0001173a4f\" data-style-height=\"28px\" data-style-width=\"100%\" data-theme=\"light\">\n            <a href=\"https:\/\/uk.trustpilot.com\/review\/www.yorktest.com\" target=\"_blank\" rel=\"noopener\">Trustpilot<\/a>\n        <\/div>\n    <\/div>\n<\/section>","protected":false},"excerpt":{"rendered":"","protected":false},"author":1,"featured_media":0,"parent":0,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"_acf_changed":false,"footnotes":""},"class_list":["post-1573","page","type-page","status-publish","hentry"],"acf":[],"_links":{"self":[{"href":"https:\/\/www.yorktest.com\/us\/wp-json\/wp\/v2\/pages\/1573","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.yorktest.com\/us\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/www.yorktest.com\/us\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/www.yorktest.com\/us\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.yorktest.com\/us\/wp-json\/wp\/v2\/comments?post=1573"}],"version-history":[{"count":3,"href":"https:\/\/www.yorktest.com\/us\/wp-json\/wp\/v2\/pages\/1573\/revisions"}],"predecessor-version":[{"id":86587,"href":"https:\/\/www.yorktest.com\/us\/wp-json\/wp\/v2\/pages\/1573\/revisions\/86587"}],"wp:attachment":[{"href":"https:\/\/www.yorktest.com\/us\/wp-json\/wp\/v2\/media?parent=1573"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}