A pregnant patient and was found to have chronic histiocytic intervillositis of unknown etiology (CHI), which was successfully managed and treated, according to a case report recently published in Frontiers in Immunology.
Both chronic histiocytic intervillositis and fetal and neonatal alloimmune thrombocytopenia (FNAIT) involve maternal immune attacks on fetal antigens, are often linked to recurrent pregnancy loss and include inflammation at the placental barrier. CHI is a general placental inflammation, while FNAIT is a specific platelet-focused alloimmune condition, with studies showing significant overlap and shared immune pathways.
Despite a 37-year-old having previously had a normal first pregnancy and delivery, her next six successive pregnancies ended in fetal loss. Karyotype on the couple and in-depth multidisciplinary assessments showed no evidence of what could explain her repeated pregnancy losses.
Prior to plans for a new pregnancy, further investigations were conducted. Much of these investigations were normal. HlA-typing of the couple showed numerous IgG anti-HLA antibodies; four showed specificity against paternal class I HLA antibodies.
“Since the patient had never received transfusions, the alloimmunization was likely due to exposure to paternal-derived fetal HLA antigens during previous pregnancies,” the authors of the report opined.
The patient’s physicians think that immunization may have taken place during her first pregnancy with her first partner (with all 6 subsequent miscarriages being with another partner). It was likely that the patient developed high affinity anti-HLA antibodies that corresponded to the 80N eplet (especially 76VRN and 76ESN eplets).
Read more about FNAIT testing and diagnosis
Complement-dependent cytotoxicity and flow cytometry demonstrated positivity for complement-binding anti-HLA antibodies (class I). Histology of the first 3 pregnancies revealed diffuse, high-grade intervillositis, with mononuclear inflammatory cells and fibrin deposition in the intervillous space.
All these investigations and others led physicians to believe that an anti-rejection treatment regimen was appropriate, including intravenous immunoglobulin, methylprednisolone and tacrolimus. The baby was safely delivered via cesarean section.
“These cases contribute to the growing evidence that alloimmunity may be central to the pathogenesis of CIUE and suggest that therapies targeting antibody-mediated immune responses could offer new perspectives for patients with recurrent pregnancy losses linked to this condition,” the authors of the report wrote.
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