Chronic histiocytic intervillositis (CHI) is a rare condition with an incidence of 5 in 10,000 pregnancies. This rare condition is associated with placental inflammatory lesions leading to severe and recurrent obstetrical complications: intrauterine growth retardation (IUGR), fetal death in utero and miscarriage. The pathophysiological mechanisms of CHI are poorly understood, while the empirical treatments prescribed to prevent recurrence are cumbersome and of poor efficacy. Recent findings suggest that an alloimmune response may play a role. In a recent work, the investigators have demonstrated the role of maternal alloantibodies directed against fetal HLA antigens in two patients followed for recurrent IUGR associated with CHI. Their work suggests that a humoral alloimmune response directed against fetal HLA antigens mimics an allograft rejection process. The investigators propose to extend the preliminary results obtained in these patients to provide new insights into the pathophysiological mechanisms of CHI, and eventually to predict the risks of fetal loss.
Study Type
INTERVENTIONAL
Allocation
NON_RANDOMIZED
Purpose
BASIC_SCIENCE
Masking
NONE
Enrollment
200
up to 25 mL of blood collection for the adults and saliva collection for the minor at inclusion, and placenta collection at childbirth
Antoine Béclère Hospital
Clamart, France
RECRUITINGProportion of patients diagnosed with CHI, defined by the concomitant presence of the 3 criteria required to evoke humoral alloimmune rejection for this pathology
Proportion of patients diagnosed with CHI, defined by the concomitant presence of the 3 criteria required to evoke humoral alloimmune rejection for this pathology, namely CD68+ infiltrate, AND C4d deposits on the trophoblastic villi AND the presence of at least one FSA (fetus-specific antibody, directed against fetal HLA antigens in the maternal blood) with an elevated level, defined by a Mean Fluorescence Intensity (MFI) \> 10,000). This proportion of patients observed in CHI carriers will be compared to the proportion of patients with the concomitant presence of the same 3 criteria observed in the other two control groups.
Time frame: up to 6 months
To measure the FSA levels by Mean Fluorescence Intensity for the different obstetrical complications: intrauterine growth retardation (IUGR), fetal death in utero and abortion for IUGR.
Time frame: up to 6 months
to measure the correlation between fetus-specific antibody level by Mean Fluorescence Intensity and the severity and/or precocity of obstetrical complications
Time frame: up to 6 months
measure of semi-quantitative graduation of C4d in placenta compared to percentage of villositis
Time frame: up to 6 months
measure of semi-quantitative graduation of CD68+ infiltrate in placenta compared to surface and number of involved villositis
Time frame: up to 6 months
To measure the expression of HLA class I and II molecules by placental villi by ß2-microglobulin and HLA-DR labelling
Time frame: up to 6 months
Epitope analysis with algorithm developped by laboratoire HLA de St Louis (Pr JL Taupin)
Epitope analysis with algorithm developped by laboratoire HLA de St Louis (Pr JL Taupin) to determine whether an antibody response against a limited number of epitopes present during a first pregnancy that resulted in a healthy child can explain immunization against both paternal alleles
Time frame: up to 6 months
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