The interleukin-1 gene test (IL-1 gene test; interleukin test 1) is a method for determining an individual’s genetic periodontitis risk. The IL-1 gene polymorphism is considered a proinflammatory (inflammation-promoting) risk factor. Patients whose genome shows a positive IL-1 genotype are more susceptible to the development of periodontitis (inflammation of the periodontium) and show stronger inflammatory reactions if periodontopathogenic bacteria are present in the environment of the oral cavity. If the genetic test is positive, the result helps the treating dentist, especially for long-term therapy planning. Chronic periodontitis is associated if the genetic code on chromosome 2 has allele 2 of the IL-1A polymorphism or allele 2 of the IL-1B polymorphism. If even both gene loci carry allele 2, this results in a greatly increased release of interleukin-1 from monocytes (belong to the white blood cell group; cells of the immune system and precursors of macrophages/eating cells) when they have surface contact with Gram-negative bacteria. Patients are referred to as IL-1 genotype positive. The cytokine IL-1, interleukin-1, is produced only in the inflammatory state and has a proinflammatory (inflammation-promoting) effect. It is used for communication between immune defense cells and causes the formation of prostaglandins (PGE2; prostaglandin E2) in the body. These in turn promote bone resorption. At the same time, the periodontal ligament cells that connect the tooth to the alveolus (tooth socket) are damaged. IL-1 inhibits collagen synthesis while promoting the production of collagenase (enzyme for collagen degradation). Likewise, it has a stimulatory effect on osteoclasts (bone-degrading cells). An inappropriately high production and release of interleukin-1 can trigger a variety of different symptoms (arthritis/joint inflammation, exanthema/skin rash, fever, conjunctivitis/conjunctivitis, serositis/inflammation of a serous skin (e. g. as peritonitis/peritonitis, pleurisy/peritonitis, pericarditis/pericarditis), and hearing loss) and “inflammatory diseases” (ankylosing spondylitis/Morbus Bechterew, type 2 diabetes mellitus, familial middle fever, gout, Behçet’s disease/rheumatoid disease, Still’s disease (form of rheumatoid arthritis occurring in children), plasmocytoma (multiple myeloma; cancer of the bone marrow), Schnitzler syndrome (combination of chronic urticaria/hives, a monoclonal IgM gammopathy and arthralgias/joint pain; main criteria: IgM monoclonal gammopathy and recurrent urticarial vasculitis; in addition, two of the following secondary criteria should be met recurrent fever, bone changes, leukocytosis or elevated CRP, evidence of a neutrophilic infiltrate in the skin biopsy (tissue sampling from the skin) of urticaria), sicca syndrome/dry eyes, synovitis (synovitis), systolic heart failure/heart failure). Interleukin-1 can be detected in sulcus fluid (fluid from gingival pockets) and periodontal tissues. The more interleukin-1 is present, the stronger the body’s immune response to the causative germs and the more rapidly the bone is broken down in the course of periodontitis. Based on genetic predisposition, it is therefore possible that patients with a high number of periodontopathogenic bacteria (germs that cause periodontitis) and heavy plaque colonization may well have slower bone resorption than patients with little plaque, good oral hygiene technique and an IL-1 gene polymorphism present. They are interleukin high-responders and have a higher risk of developing severe periodontitis due to high interleukin production. Before any further diagnostics, a detailed clinical examination and diagnosis must first be performed. If clinical and radiographic damage to the periodontium is present, in combination with the assessment of existing risk factors such as:
- Smoking
- Diabetes mellitus
- Stress
- Immunodeficiency
- Positive IL-1 genotype
- Other limitations of general health
Develop a long-term treatment plan and thus curb the progression (progression) of periodontitis.
Indications (areas of application)
In principle, the IL-1 gene test can be used in the context of individual risk analysis even in the case of incipient periodontal disease in order to make the most accurate possible prognosis about the further course of the disease. Its use, on the other hand, is particularly useful, for example, in the case of
- Juvenile periodontitis (in adolescents).
- Aggressive periodontitis
- Therapy-resistant periodontitis with progressive attachment loss (progressive destruction of the periodontium).
- Advanced severe chronic periodontitis.
- Periodontally diseased relatives of patients who tested IL-1 genotype positive.
- Patients who are already at increased risk of periodontitis due to smoking; if they are ICL-1 genotype positive, their periodontitis risk increases almost 8-fold
- Before implant restoration
Contraindications
Since the procedure is non-invasive (does not penetrate the body), there are no contraindications.
The procedure
To have the genetic test performed, the dentist takes a buccal mucosa sample using a swab that contains enough cellular material for laboratory analysis. The result is not a snapshot of the current IL-1 concentration, but provides an indication of the patient’s immune response to bacteria, or the propensity and ability to produce interleukin for inflammation. It has lifelong validity. About 30 percent of Caucasians (synonymous with Europeans and fair-skinned people) will test positive. If the test result confirms an IL-1 genotype, the therapeutic goal is to reduce the biofilm (the plaque, the dental plaque) and the periodontopathogenic bacteria (germs that damage the periodontium) living in it. This is because their presence and contact with cells of the immune defense system leads to the release of interleukins that promote bone resorption.
Benefit
The test result provides you and your dentist with important information about the expected progression (progression) of the disease. If a positive IL-1 genotype results, this means intensive and close-meshed therapy and follow-up measures that you should be prepared for throughout your life in order to maintain your dental health. After all, only the combination of dental treatment and consistent oral hygiene at home can permanently reduce pathogenic germs and bring periodontitis to a halt.
