ClinicalTrials.gov
ClinicalTrials.gov Menu

Genotyping of Human Platelet Alloantigens : Non-invasive Prenatal Diagnosis

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details.
ClinicalTrials.gov Identifier: NCT02899598
Recruitment Status : Active, not recruiting
First Posted : September 14, 2016
Last Update Posted : September 14, 2016
Sponsor:
Information provided by (Responsible Party):
Assistance Publique Hopitaux De Marseille

Brief Summary:

Neonatal thrombocytopenia isoimmunization maternal-fetal is related to maternal immunization against fetal platelet antigens with paternal origin not present in the mother. It is considered the equivalent of hemolytic disease of the newborn. The incidence of this disease is about 1 in 800-1000 births. The most severe forms associated petechiae, purpura or cephalhematoma at birth with a major risk of cerebral hemorrhages (20% to 25% of cases) can cause the death of the child (15%) or severe neurological troubles (15-30%) Biologic diagnosis requires the detection of anti-platelet antibodies with maternal determination of platelet phenotypes and genotypes of the two parents.

The objective of this work is to develop specific molecular tools to fetal platelet genotyping from maternal blood. We are particularly interested to antigens HPA-1, HPA-5 , HPA-3 and HPA-4. We evaluate the sensitivity and specificity of this test by comparing these results with those obtained from an invasive sampling of amniotic fluid.

This is a prospective study to assess the technical and diagnostic performance of a new molecular method noninvasive prenatal diagnosis of platelet genotyping.


Condition or disease Intervention/treatment Phase
Neonatal Thrombocytopenia Isoimmunization Maternal-fetal Biological: Extra blood draw samples Biological: extra amniotic fluid samples Not Applicable

Detailed Description:

Neonatal thrombocytopenia isoimmunization maternal-fetal is related to maternal immunization against fetal platelet antigens with paternal origin not present in the mother. It is considered the equivalent of hemolytic disease of the newborn. The incidence of this disease is about 1 in 800-1000 births. The most severe forms associated petechiae, purpura or cephalhematoma at birth with a major risk of cerebral hemorrhages (20% to 25% of cases) can cause the death of the child (15%) or severe neurological troubles (15-30%) Biologic diagnosis requires the detection of anti-platelet antibodies with maternal determination of platelet phenotypes and genotypes of the two parents. When it is diagnosed, genetic counseling to the couple for a future pregnancy is necessary because the risk of recurrence is important and severity increases with the number of pregnancies. The risk depends on the nature of paternal antigens, homozygous or heterozygous. In case of heterozygosity, prenatal diagnosis is based on fetal platelet genotyping by an invasive procedure (amniocentesis or chorionic villus sampling) associated with a risk of fetal loss. The alloantibodies responsible for fetal damage are directed against platelet alloantigens: this is HPA system (human platelet alloantigen). 24 alloantigens have been described and 12 of them have a biallelic polymorphism (a: the most frequent allele and b the rare allele) divided into 6 groups (HPA-1, 2, 3, 4, 5, and 15). The genotype-phenotype correlations were performed for 22 of the 24 alloantigens and show that the antigenic polymorphism results from the presence of a SNP (single nucleotide polymorphism-).

In 1997, Lo et al showed the presence of 3-6% of fetal DNA in maternal blood. This discovery led to the development of methods of non-invasive prenatal diagnosis: 1/ the determination of fetal Rhesus 2/ fetal sex by real-time quantitative PCR.

The objective of this work is to develop specific molecular tools to fetal platelet genotyping from maternal blood. We are particularly interested to antigens HPA-1, HPA-5 , HPA-3 and HPA-4. We evaluate the sensitivity and specificity of this test by comparing these results with those obtained from an invasive sampling of amniotic fluid.

This is a prospective study to assess the technical and diagnostic performance of a new molecular method noninvasive prenatal diagnosis of platelet genotyping.


Study Type : Interventional  (Clinical Trial)
Actual Enrollment : 48 participants
Intervention Model: Single Group Assignment
Masking: None (Open Label)
Primary Purpose: Diagnostic
Study Start Date : July 2013
Actual Primary Completion Date : July 2016
Estimated Study Completion Date : July 2017

Resource links provided by the National Library of Medicine

MedlinePlus related topics: Prenatal Testing

Arm Intervention/treatment
Experimental: Pregnant women Biological: Extra blood draw samples
Biological: extra amniotic fluid samples



Primary Outcome Measures :
  1. number of Fetomaternal platelet incompatibilities detected [ Time Frame: 30 months ]


Information from the National Library of Medicine

Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the contacts provided below. For general information, Learn About Clinical Studies.


Ages Eligible for Study:   18 Years and older   (Adult, Older Adult)
Sexes Eligible for Study:   Female
Accepts Healthy Volunteers:   No
Criteria

Inclusion Criteria:

  • patients with known risk of platelet alloimmunization
  • patients for whom suspicion of fetal cerebral hemorrhage has been advanced on ultrasound or fetal MRI signs

Exclusion Criteria:

  • Twin pregnancy or triple

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT02899598


Locations
France
Assistance Publique Hôpitaux de Marseille
Marseille, France, 13005
Sponsors and Collaborators
Assistance Publique Hopitaux De Marseille
Investigators
Study Director: Urielle Desalbres Assistance Publique Hôpitaux de Marseille

Responsible Party: Assistance Publique Hopitaux De Marseille
ClinicalTrials.gov Identifier: NCT02899598     History of Changes
Other Study ID Numbers: 2012-55
First Posted: September 14, 2016    Key Record Dates
Last Update Posted: September 14, 2016
Last Verified: September 2016
Individual Participant Data (IPD) Sharing Statement:
Plan to Share IPD: No

Additional relevant MeSH terms:
Thrombocytopenia
Thrombocytopenia, Neonatal Alloimmune
Blood Platelet Disorders
Hematologic Diseases
Infant, Newborn, Diseases