Intestinal Dysbiosis

Immunobilan Test (Test Code: IM01)

The Immunobilan test is an antibody screening assay for IgA and IgM which recognize the surface proteins of intestinal pathogens. In a healthy individual, these bacteria are only found in very low quantities in the gut. Therefore, we would not expect to find high titers of these antibodies in serum. All Immunobilan bacteria are strictly associated with the gut, with the exception of Klebsiella, which is also associated with respiratory and urinary tract infections.

Intestinal Dysbiosis

IgA (immunoglobulin A) are typically found in secretions of digestive, respiratory and genitourinary systems. However, they can be found in the bloodstream if large quantities are produced. This is the case for bacterial overgrowth of the small intestine. In addition, if large quantities are produced, bacterial toxins are reabsorbed into the bloodstream. This causes immune activation; in such a state herpes virus reactivation is often seen. Typically, these patients do not have depressed NK cell function, unless it is accompanied by PKR activation, in which case we seen less positives for Mycoplasma infections.

Leaky Gut

IgM (immunoglobulin M) serve as the B-cell surface receptor for antigen attachment and are secreted in the early stages of plasma-response. This occurs in the blood, in contrast to IgA, which are secreted. If we find high titers of IgM for all or most of the intestinal bacteria, this indicates bacterial proteins made their way into the blood stream (leaky gut). This most likely occurs in the first 30 cm of the colon, which has a much higher permeability/less selectivity than the small intestine. Further down the colon there is limited oxygen; and the type of bacteria we test for are aerobes. Therefore, it is likely that the IgM’s for intestinal bacteria in the blood coincide with increased permeability and in turn, continually activate the immune system.

Patients with IgM’s in the blood (Gram (-) bacteria) have a reaction to lippopolysaccarides (LPS), which increases NFkB, iNOS and COX-2 and the overall inflammatory condition. Often TNF-a is also increased in this group. Because NO is increased, NK function is decreased and an increase of opportunistic infections such as mycoplasma infection is often observed.

Method
Fluorescent ELISA

Result
Semiquantitative. The results for this analysis are presented as positive or negative and a relative value compared to a control value.

Results and Interpretation

Results are semiquantitative, positive /negative, with normal reference range. The results of this test should be used in addition to all other relevant clinical data before making a diagnosis and/or a recommendation for treatment. Ranges are subject to change dependent on future data. This test was developed and its performance characteristics verified by REDLABS U.S.A.

Inflammatory Bowel Disease (Crohn’s and Ulcerative Colitis)

Inflammatory bowel disease (IBD) is believed to be the result of inappropriate and ongoing activation of the mucosal immune system in response to the presence of normal, but perhaps excessive, luminal flora. This deviant response is most likely made possible by defects in both the mucosal immune system and the barrier function of the intestinal epithelium.

Genetic Factors

Clinical studies suggest genetic factors may predispose and individual for developing Crohn’s disease. These factors include familial clustering of inflammatory bowel disease, rare association of IBD with uncommon genetic disorders and population prevalence of Crohn’s disease. Several studies show that immediate relatives of an individual with IBD are 4 to 20 times more likely either have or develop the disease when compared against the general population (Tysk, Lindberg et al. 1988; Orholm, Munkholm et al. 1991). In addition, identical twins are substantially more likely to both develop Crohn’s disease than paternal twins (Tysk, Lindberg et al. 1988). The identification of an exact genetic mutation has been elusive and several studies believed to have identified a genetic marker had not been reproducible (Satsangi, Welsh et al. 1996; Cariappa, Sands et al. 1998; Negoro, Kinouchi et al. 1999). However, genome-wide screening methods have produced some promising results; for instance, DNA screening of families with multiple affect members revealed a genetic linkage to chromosome 16 among those with Crohn’s disease but not ulcerative colitis (Hugot, Laurent-Puig et al. 1996). Mapping of chromosome 16 has identified a gene partly responsible which is expressed in macrophages and codes for a protein that may serve as a pattern-recognition receptor for bacterial lipopolysaccarides, possibly regulating NF-kB (Hugot, Chamaillard et al. 2001; Ogura, Bonen et al. 2001).

Therapeutic Options for Ulcerative Colitis and Crohn’s Disease

In that Crohn’s disease is dominated by Th-1 activation and ulcerative colitis is dominated by Th-2 activation a Th-1/Th-2 profile maybe a useful diagnostic tool in delineating between the two (Podolsky 2002). In addition, bacterial antigens that penetrate the mucosal barrier and activate the Th-1 response will elicit a humoral response that can be detected by screening for bacterial surface protein specific IgM’s (Immunobilan test).

The Immune Response and Inflammation

The over-all result of the immune reaction associated with IBD is activation of mucosal immune responses. It is not clear if this activation is due to a fundamental shortcoming of the immune system or because of perpetual stimulation resulting from a breach of the epithelial mucosal barrier (Mashimo, Wu et al. 1996; Schmitz, Barmeyer et al. 1999). However, significant advancement has been achieved in regard to understanding which immune system components are involved. It is widely accepted that the predominant cell-mediated component associated with Crohn’s disease are CD4+ lymphocytes with a Th-1 phenotype typified by the production of INF-g and IL-2. In contrasts to this, ulcerative colitis is predominated by CD4+ of the Th-2 phenotype which are characterized by the secretion of TNF-b and IL-5 but not IL-4 (Fuss, Neurath et al. 1996).

Diagnosis and Treatment

Prior to a developing a logical treatment strategy, a accurate diagnosis must be made. This may involve clinical history, physical findings, endoscopic, radiological and histological findings as well as accurate diagnostic laboratory tests.