Exploration of Allograft Humoral Rejection in Chronic Histiocytic Intervillositis

Condition(s) studied

Investigational drug(s) / intervention(s)

Biological collection: up to 25 mL of blood collection for the adults and saliva collection for the minor at inclusion, and placenta collection at childbirth

Study summary

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.

Eligibility

Primary outcome measure(s)

• Proportion of patients diagnosed with CHI, defined by the concomitant presence of the 3 criteria required to evoke humoral alloimmune rejection for this pathology — up to 6 months
  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.

Trial sites (1)

More Assistance Publique - Hôpitaux de Paris trials in France

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