CeliacStrip kit is a test based on the reverse hybridization principle and allows the identification of the main HLA haplotypes associated with Celiac disease. And specifically, the test detects the presence or absence of the ones that encode HLA-DQ2 and HLA-DQ8.
Susceptibility to gluten sensitivity is to some extent genetically predetermined. Its hereditary nature is manifested through an increase in prevalence amongst family members (10-15%) and a concordance of 80% between homozygous twins. A series of genes located in the Major Histocompatibility Complex (MCH) gene region have been shown to contribute towards this genetic predisposition. In fact, it is estimated that this complex contributes 40% to the genetic susceptibility to Celiac disease, and that the isolated contribution of other possible genes is minimal.
Nowadays, despite all medical advances, Celiac condition remains as a highly underdiagnosed disease due to its multisystemic nature and to its lack of specificity of its clinical manifestations.
CeliacStrip test evaluates the patient’s genetic predisposition to develop Celiac disease. It detects all the alleles related to Celiac condition, allowing to know if the patient is a carrier or not of any of the risk haplotypes.
All the alleles and haplotypes related to Celiac disease in only one test
Grouped alleles for a better interpretation of the results
Automated reading with scanner available
Possibility to automate the hybridization process
An approach to celiac biomarkers given by Dr. Fabiola Fabiano, Clinical and laboratory immunologist and celiac disease specialist.
The recorder webinar is available on demand. If you missed it, feel free to request it!
The most important thing in a Celiac disease result is the presence or absence of the DQ2 or DQ8 complete haplotypes. The presence of the alleles by itself is not indicative of Celiac condition.
It is not important for the patient, but it gives information about the genetic transmission in the family. If the patient has a DQ2 cis, one of the parents has an increased risk of developing Celiac disease. It can be taken into account, so that the person “at risk” of developing the disease can be controlled by a doctor.
We cannot know if the alleles are in homocygosity. We just can say that it is in heterozygosity if 2 alleles of the same type (DQA1, or DQB1, or DRB1) are present.
There are very important in the kit, but not for reporting. It is recommended to inform using only the terms “presence” or “absence” of DQ2 (cis or trans) or DQ8.
Serological and molecular tests look for different markers of Celiac Disease (CD), so they are used in different situations. The serological tests, as ELISA or rapid tests, look for the presence of the antibodies generated after the exposition to gluten, in patient with symptoms: a positive result may indicate that the patient is suffering Celiac disease (CD). It has to be confirmed by a duodenal biopsy. However, the genetic tests look for the presence of the genes that indicate a predisposition to suffer CD: a positive test only indicates that the patient has the likelihood of suffering CD. About 30% of the population is positive to those tests, but only 5% will suffer from CD. Thus, the genetic tests are used to exclude the possibility of having CD, eliminating the need to repeat serology, and to study the family members of CD sufferers. Thus, individuals presenting genetic markers can be more closely monitored for the development of symptoms.
A child with a negative result in a genetic test does not need further evaluations. A child with a positive result for genetic test can be monitorised looking for symptoms, specially if there are members of his family suffering from Celiac condition.
Genetic tests are useful to discard Celiac disease, but not for its confirmation. If a genetic neonatal screening is performed, these are the possible results and the actions to be taken: in the case of obtaining a negative result (around 80%), gluten could be introduced in the diet as usual and no monitoring should be needed. In the case of obtaining a positive result (around 20%), gluten would be also introduced in the diet and the patient should be monitorised, in case some symptoms may arise. It is estimated that, of this 20%, only 5% would develop symptoms, which may not even develop until adulthood. In no case should gluten be eliminated from the diet without presenting symptoms or positive results in other diagnostic tests (serology, biopsy). Therefore, neonatal screening for genetic markers would not be recommended, except perhaps in the case of patients with a history of several family members with CD, in order to follow up more closely when introducing gluten. The ESPGHAN recommendation is to perform early detection of Celiac disease based on symptom monitoring, performing the necessary diagnostic tests, and to apply screening only in risk groups (relatives of patients with Celiac disease up to 2nd degree, Down, Turner, Williams and other syndromes, anaemia, infertility, osteoporosis, short stature of unclear cause and autoimmune diseases).
The test allows to discard Celiac disease if there are no positive markers, although the current symptoms and complementary tests, if any, should be taken into account. On the contrary, if the test shows positive results, this should be complemented with a serology and a biopsy. See previous answer.
The relative risk indicated refers to the entire world population. In different populations, one haplotype may be more frequent than another, but the risk they confer is the same. Thus, among indigenous people in Latin America, the most frequent haplotype is DQ8, which confers a high risk of Celiac disease.