Chronic histiocytic intervillositis in three consecutive pregnancies in a single patient: Differing clinical results and pathology according to treatment used

Effect of Anti-TNF Biologic Exposure During Pregnancy on Villitis of Unknown Etiology Diagnoses in Patients with Autoimmune Disease

Tumor necrosis factor-α (TNF-α) antagonists are highly effective in controlling autoimmune diseases. This has led to speculation that they might also be useful in treating inflammatory placental conditions, such as chronic villitis of unknown etiology (VUE). VUE affects 10-15% of term placentas and is associated with recurrent fetal growth restriction (FGR) and pregnancy loss. We aimed to evaluate outcomes in patients with autoimmune diseases with and without anti-TNF-α biologic exposure during gestation. This retrospective cohort study compared pregnant women with autoimmune disease taking anti-TNF-α biologics (n = 89) to pregnant women with autoimmune disease but not taking a biologic (n = 53). We extracted data on all patients meeting our inclusion criteria over a 20-year period. Our primary outcome was the diagnosis of VUE by histology. Our secondary outcomes were maternal and neonatal complications such as preeclampsia, FGR, and neonatal intensive care admission. Kruskal-Wallis and chi-squared tests were performed as appropriate for statistical analysis. Maternal characteristics were comparable between groups, and there was no increase in adverse pregnancy outcomes based on anti-TNF-α treatment. Exposure to anti-TNF-α therapy had no significant effect on the incidence of VUE or other obstetric complications. Within the cohort exposed to anti-TNF-α biologics during pregnancy, the rate of VUE was 9.3%, which is comparable to the reported general population risk. Our data support the safety profile of biologic use in pregnancy.

Chronic Inflammatory Placental Disorders Associated With Recurrent Adverse Pregnancy Outcome

Chronic inflammatory placental disorders are a group of rare but devastating gestational syndromes associated with adverse pregnancy outcome. This review focuses on three related conditions: villitis of unknown etiology (VUE), chronic histiocytic intervillositis (CHI) and massive perivillous fibrin deposition (MPFD). The hallmark of these disorders is infiltration of the placental architecture by maternal immune cells and disruption of the intervillous space, where gas exchange between the mother and fetus occurs. Currently, they can only be detected through histopathological examination of the placenta after a pregnancy has ended. All three are associated with a significant risk of recurrence in subsequent pregnancies. Villitis of unknown etiology is characterised by a destructive infiltrate of maternal CD8+ T lymphocytes invading into the chorionic villi, combined with activation of fetal villous macrophages. The diagnosis can only be made when an infectious aetiology has been excluded. VUE becomes more common as pregnancy progresses and is frequently seen with normal pregnancy outcome. However, severe early-onset villitis is usually associated with fetal growth restriction and recurrent pregnancy loss. Chronic histiocytic intervillositis is characterised by excessive accumulation of maternal CD68+ histiocytes in the intervillous space. It is associated with a wide spectrum of adverse pregnancy outcomes including high rates of first-trimester miscarriage, severe fetal growth restriction and late intrauterine fetal death. Intervillous histiocytes can also accumulate due to infection, including SARS-CoV-2, although this infection-induced intervillositis does not appear to recur. As with VUE, the diagnosis of CHI requires exclusion of an infectious cause. Women with recurrent CHI and their families are predisposed to autoimmune diseases, suggesting CHI may have an alloimmune pathology. This observation has driven attempts to prevent CHI with a wide range of maternal immunosuppression. Massive perivillous fibrin deposition is diagnosed when >25% of the intervillous space is occupied by fibrin, and is associated with fetal growth restriction and late intrauterine fetal death. Although not an inflammatory disorder per se, MPFD is frequently seen in association with both VUE and CHI. This review summarises current understanding of the prevalence, diagnostic features, clinical consequences, immune pathology and potential prophylaxis against recurrence in these three chronic inflammatory placental syndromes.

Chronic histiocytic intervillositis (CHI): current treatments and perinatal outcomes, a systematic review and a meta-analysis

BACKGROUND

Chronic histiocytic intervillositis (CHI) is a rare placental lesion with a high recurrence rate and poor perinatal outcomes. There are currently limited guidelines regarding the diagnosis of this condition in the index pregnancy and treatment where recurrence is suspected.

OBJECTIVE

The primary objective of this systematic review and meta-analysis was to determine the perinatal outcomes of pregnancies affected by chronic histiocytic intervillositis and to what extent they can be improved with treatment. The secondary objective was to assess the relationship between CHI lesion severity and pregnancy loss.

METHODS

A systematic search of Ovid Embase, Web of Science, Science Direct, PubMed, Ovid Medline, Google Scholar and CINAHL was carried out. Case reports, cohort, case-control and randomised controlled trials (RCT) detailing the perinatal outcomes of CHI pregnancies, both treated and untreated, were included.

RESULTS

No RCTs were identified. However, in a review population of 659 pregnancies, with additional 7 in case reports, CHI treatments included aspirin, prednisone, prednisolone, low molecular weight heparin (LMWH), hydroxychloroquine and adalimumab. A descriptive synthesis of data found mixed results for treatments in relation to live birth, miscarriage and fetal growth restriction outcomes. Furthermore, quantitative synthesis of 38 pregnancies revealed a non-significant improvement in live birth rate with CHI targeted treatment (OR 1.79 [95% CI 0.33-9.61] (p=0.50), while meta-analysis of CHI severity in line with pregnancy loss, in a sample of 231 pregnancies, revealed lower odds of pregnancy loss with less severe lesions (OR: 0.17 [0.03-0.80], p=0.03).

CONCLUSIONS

This systematic review and meta-analysis reinforce notions surrounding the insufficient evidence for CHI treatment. It also strengthens previous hypotheses detailing the positive association between CHI lesion severity and odds of pregnancy loss. Aspirin, LMWH, prednisolone, hydroxychloroquine and adalimumab are candidates with varying levels of weak to moderate evidence supporting their use. Further prospective research is required to obtain robust evidence pertaining to treatment safety and efficacy and optimal drug regimes.

SYSTEMATIC REVIEW REGISTRATION

[website], identifier CRD42021237604.

Immunomodulatory Therapy Reduces the Severity of Placental Lesions in Chronic Histiocytic Intervillositis

Chronic histiocytic intervillositis (CHI) is a rare, but highly recurrent inflammatory placental lesion wherein maternal macrophages infiltrate the intervillous space. Pregnancies with CHI are at high risk of fetal growth restriction, miscarriage or stillbirth. Presently, the diagnosis can only be made after histopathological examination of the placenta. Given its proposed immunological etiology, current treatments include aspirin, heparin, and immunomodulatory agents. However, the rationale for these medications is largely based upon small case series and reports as there is a lack of larger studies investigating treatment efficacy. Therefore, this study sought to determine whether inclusion of immunomodulatory medications was effective at reducing the severity of lesions and improving pregnancy outcomes in subsequent pregnancies. Thirty-three women with a history of CHI in at least one pregnancy (index case) were identified retrospectively through medical records. Twenty-eight participants presented with a first subsequent pregnancy and a further 11 with a second subsequent pregnancy at a specialist clinic for pregnancy after loss. Data on maternal demographics, medical history, medication, pregnancy outcome, and placental pathology was collected and compared between pregnancies. Twenty-seven (69%) subsequent pregnancies were treated with at least one or both of prednisolone and hydroxychloroquine. Inclusion of at least one immunomodulatory agent in treatment regimen resulted in an almost 25% increase in overall livebirth rate (61.5 vs. 86.2%). In women treated with immunomodulatory medication a greater proportion of placentas had reduced severity of lesions compared to those treated without (86.7 vs. 33.3%, respectively). A reduction in CHI severity was associated with a 62.3% improvement in livebirth rate compared to those where severity remained unchanged in relation to the index case. These data provide preliminary evidence that the use of immunomodulatory medication in the management of CHI improves histopathological lesions and the chance of livebirth in subsequent pregnancies. Due to CHI's rarity and ethical and feasibility issues, randomized controlled trials in affected women are challenging to conduct. As a result, collaboration between centers is required in future to increase study sample sizes and elucidate the mechanisms of hydroxychloroquine and prednisolone in reducing pathology.

Hypertensive disease, preterm birth, fetal growth restriction and chronic inflammatory disorders of the placenta: experiences in a single institution with a standardized protocol of investigation

PURPOSE

Chronic inflammatory disorders of the placenta, in particular villitis of unknown etiology (VUE), chronic deciduitis (CD), chronic chorioamnionitis (CC), chronic histiocytic intervillositis (CHI), and eosinophilic/T-cell chorionic vasculitis (ETCV) can exclusively be diagnosed histologically. Using a standardized procedure for submission and pathological-anatomical examination of placentas in a single perinatal care center, we analyzed the association of chronic placental lesions to perinatal complications.

METHODS

We reviewed all singleton placentas and miscarriages that were examined histologically over a period of ten years after having implemented a standardized protocol for placental submission in our hospital. Cases with chronic inflammatory lesions were identified, and clinical data were analyzed and compared with a focus on preterm birth, hypertensive disorders, and fetal growth restriction and/or fetal demise.

RESULTS

In 174 placentas, at least one of the chronic inflammatory entities was diagnosed. CD was the most frequent disorder (n = 95), and had strong associations with preterm birth (47.3% of all cases with CD) and intrauterine fetal demise. VUE (n = 74) was exclusively diagnosed in the third trimester. This disorder was associated with a birth weight below the 10th percentile (45% of the cases) and hypertensive disease in pregnancy. Miscarriage and intrauterine fetal demise were associated with CHI (in 66.7% of cases, n = 18).

CONCLUSIONS

Chronic inflammatory disorders are frequently observed and contribute to major obstetric and perinatal complications. Further studies are needed to get a better picture of the connection between adverse obstetric outcomes and chronic inflammation to aid in the better counseling of patients.

Chronic histiocytic intervillositis (CHI): an under-recognised condition with potential serious sequelae in pregnancy

Chronic histiocytic intervillositis (CHI) is a rare placental disorder associated with adverse pregnancy outcomes and high recurrence rates in subsequent pregnancies. We discuss a case of CHI diagnosed incidentally in a young primigravida who presented with a first trimester miscarriage. CHI is usually diagnosed after an adverse pregnancy outcome by microscopic placental histopathology. Currently, CHI is a poorly understood condition by clinicians in many aspects, including its aetiology and subsequent management of patients in their future pregnancies. This is due to the lack of awareness and underdiagnosis of CHI among general pathologists and obstetricians. The authors would like to highlight this interesting case to encourage more research on CHI to understand its pathophysiology and optimal management better. Clinicians should also focus on providing holistic care to this group of patients by considering the impact of adverse pregnancy outcomes on their emotional well-being.

Chronic histiocytic intervillositis: A breakdown in immune tolerance comparable to allograft rejection?

Chronic histiocytic intervillositis (CHI) is a pregnancy disorder characterized by infiltration of maternal macrophages into the intervillous space of the human placenta, often with accompanying perivillous fibrin deposition. CHI is associated strongly with foetal growth restriction and increased risk of miscarriage and stillbirth. Although rare, affecting 6 in every 10 000 pregnancies beyond 12 weeks' gestation, the rate of recurrence is high at 25%-100%. To date, diagnosis of CHI can only be made post-delivery upon examination of the placenta due to a lack of diagnostic biomarkers, and criteria vary across publications. No treatment options have shown proven efficacy, and CHI remains a serious obstetric conundrum. Although its underlying aetiology is unclear, due to the presence of maternal macrophages and the reported increased incidence in women with autoimmune disease, CHI is hypothesized to be an inappropriate immune response to the semi-allogeneic foetus. Given this lack of understanding, treatment approaches remain experimental with limited rationale. However, there is recent evidence that immunosuppression and antithrombotic therapies may be effective in preventing recurrence of associated adverse pregnancy outcomes. With similarities noted between the pathological features of CHI and acute rejection of solid organ transplants, further investigation of this hypothesis may provide a basis for tackling CHI and other immune-related placental conditions. This review will explore parallels between CHI and allograft rejection and identify areas requiring further confirmation and exploitation of this comparison.

Maternal-Fetal Inflammation in the Placenta and the Developmental Origins of Health and Disease

Events in fetal life impact long-term health outcomes. The placenta is the first organ to form and is the site of juxtaposition between the maternal and fetal circulations. Most diseases of pregnancy are caused by, impact, or are reflected in the placenta. The purpose of this review is to describe the main inflammatory processes in the placenta, discuss their immunology, and relate their short- and long-term disease associations. Acute placental inflammation (API), including maternal and fetal inflammatory responses corresponds to the clinical diagnosis of chorioamnionitis and is associated with respiratory and neurodevelopmental diseases. The chronic placental inflammatory pathologies (CPI), include chronic villitis of unknown etiology, chronic deciduitis, chronic chorionitis, eosinophilic T-cell vasculitis, and chronic histiocytic intervillositis. These diseases are less-well studied, but have complex immunology and show mechanistic impacts on the fetal immune system. Overall, much work remains to be done in describing the long-term impacts of placental inflammation on offspring health.

Chronic Intervillositis of Unknown Etiology (CIUE): Prevalence, patterns and reproductive outcomes at a tertiary referral institution

INTRODUCTION

the objective of this study was to evaluate the incidence of Chronic Intervillositis of Unknown Etiology (CIUE) at our institution and to report on the pregnancy outcomes based on severity of lesions.

METHODS

retrospective cohort study including 29 889 perinatal specimens from 27 968 patients. The pathology database at our institution was queried for the keywords "intervillositis" and "CIUE" between February 2006 and April 2019. Histology was re-examined using a standardized diagnostic criterion to confirm diagnosis. Cases in which diagnosis was confirmed were categorized as low grade (5-49% intervillous space involvement) or high grade (≥50% involvement). Interventions and pregnancy outcomes were recorded.

RESULTS

The overall prevalence of CIUE is 0.17% (47 of 27 968 patients), with significantly higher prevalence in 1st trimester products of conception compared with 2nd and 3rd trimester specimens (0.38% vs 0.09%; p < 0.0001). A total of 97 specimens were initially diagnosed with chronic intervillositis. 56 out of 97 (57.7%) specimens met our diagnostic criteria for CIUE on review. Pregnancies with confirmed CIUE had significantly higher rates of pregnancy loss compared with pregnancies with chronic intervillositis not meeting our study criteria for CIUE (94% vs 71%; p = 0.003). Pregnancy loss between low grade (42.9%; 24 out of 56 cases of CIUE) and high grade (57.1%; 32 out of 56 cases) CIUE were not significantly different.

DISCUSSION

CIUE prevalence is low at 0.17%, but it is associated with pregnancy loss, particularly in the first trimester. High grade disease may be associated with worse pregnancy outcomes than low grade disease.

Complement receptor-associated CD163+/CD18+/CD11c+/CD206-/CD209- expression profile in chronic histiocytic intervillositis of the placenta

INTRODUCTION

Chronic histiocytic intervillositis of unknown etiology (CIUE) is a non-infectious, most probably immunologic placenta lesion. CIUE is associated with recurrent miscarriage, intrauterine growth restriction and stillbirth. Among the pathologic-anatomic defined placental lesions this entity displays the highest risk of recurrence in following pregnancies (about 67-100%). The histiocytic cells accumulate in the placental blood space but do not infiltrate into the villi or decidua. Sparsely known is the expression profile of these intervillous cells regarding histiocytic markers.

METHODS

We analysed 5-22 markers by immunohistochemistry in a total of 41 placenta samples and evaluated decidual, villous and intervillous histiocytic cells.

RESULTS

In CIUE, intervillous CD163⁺ histiocytes over-express CD11c/CD18 and down-regulate CD206/CD209, while CD163⁺ decidual and Hofbauer cells show low CD11c/CD18 and higher CD206/CD209 protein expressions.

DISCUSSION

CD163 expression indicates a M2-like polarisation. CD11c and CD18 form the complement receptor 4 which could be related to a complement mediated trigger for aberrant cell accumulation in CIUE.