Abnormal expression of class II MHC antigens in placentae from patients with pemphigoid gestationis: analysis of class II MHC subregion product expression

Maternal-Fetal Interplay in Zika Virus Infection and Adverse Perinatal Outcomes

During pregnancy, the organization of complex tolerance mechanisms occurs to assure non-rejection of the semiallogeneic fetus. Pregnancy is a period of vulnerability to some viral infections, mainly during the first and second trimesters, that may cause congenital damage to the fetus. Recently, Zika virus (ZIKV) infection has gained great notoriety due to the occurrence of congenital ZIKV syndrome, characterized by fetal microcephaly, which results from the ability of ZIKV to infect placental cells and neural precursors in the fetus. Importantly, in addition to the congenital effects, studies have shown that perinatal ZIKV infection causes a number of disorders, including maculopapular rash, conjunctivitis, and arthralgia. In this paper, we contextualize the immunological aspects involved in the maternal-fetal interface and vulnerability to ZIKV infection, especially the alterations resulting in perinatal outcomes. This highlights the need to develop protective maternal vaccine strategies or interventions that are capable of preventing fetal or even neonatal infection.

Antepartum Intravenous Immunoglobulin Therapy in Refractory Pemphigoid Gestationis: Case Report and Literature Review

Background:

Pemphigoid gestationis is an autoimmune blistering disease affecting pregnant women. Treatment often consists of topical corticosteroids, oral antihistamines, and oral prednisone followed by immunosuppressants. Refractory cases in antepartum patients present a particular therapeutic challenge as the majority of second-line agents are contraindicated until the patient has delivered.

Objective:

The following report describes the case of a 34-year-old woman pregnant for the third time at 16 weeks' gestation. Her previous two pregnancies were complicated by pemphigoid gestationis but were successfully managed with oral prednisone and topical agents. During her third pregnancy, the initial lesions were controlled with oral prednisone, but attempts to decrease her dose resulted in disease flare.

Conclusion:

Monthly infusions of intravenous immunoglobulin (40 g intravenously for 3 consecutive days for 120 g total) proved to be successful in reducing the dose of oral prednisone required to maintain disease remission. A healthy baby was delivered at 37.5 weeks.

The hidden maternal-fetal interface: events involving the lymphoid organs in maternal-fetal tolerance

The genetic disparity between the mother and fetus has long enticed immunologists to search for mechanisms of maternal tolerance to fetal antigens. The study of antigen-specific tolerance in murine and human pregnancy has gained new momentum in recent years through the focus on antigen-presenting cells, uterine lymphatics and fetal antigen-specific maternal T cell responses. In mice, we now know that these responses occur within the secondary lymphoid structures as they can be conveniently tracked through the use of defined, often transgenic fetal antigens and maternal T cell receptors. Although the secondary lymphoid organs are sites of both immunization and tolerization to antigens, the immunological processes that occur in response to fetal antigens during the healthy pregnancy must invariably lead to tolerance. The molecular properties of these maternal-fetal tolerogenic interactions are still being unraveled, and are likely to be greatly influenced by tissue-specific microenvironments and the hormonal milieu of pregnancy. In this article, we discuss the events leading to antigen-specific maternal tolerance, including the trafficking of fetal antigens to secondary lymphoid organs, the properties of the antigen-presenting cells that display them to maternal T lymphocytes, and the nature of the ensuing tolerogenic response. Experimental data generated from human biological specimens as well as murine transgenic models are considered.

Clinicopathological features and HLA tissue typing in pemphigoid gestationis patients in Kuwait

Pemphigoid gestationis (PG) is a rare autoimmune disease of pregnancy. We report a series of 22 cases of PG in Kuwait. They constituted 18% of all the autoimmune bullous diseases registered in our centre over a span of 11 years. PG was observed to be the third most common bullous disease in our region. Ninety-five per cent of the patients were of Arab ethnicity. The clinical features observed in our patients were comparable to those reported elsewhere. Systemic steroids (prednisolone 20-60 mg daily) remained the mainstay of treatment to control the active disease and an optimal dose of 20 mg of prednisolone was maintained throughout the pregnancy and immediate postpartum period. We observed a favourable outcome of pregnancies complicated by PG without any associated maternal or foetal morbidity. Kuwaiti patients with PG were observed to have a predominance of HLA-DR3 and DQ2 antigens. No predominance of HLA-DR4 antigen was observed.

Specific dermatoses of pregnancy: an evidence-based systematic review

OBJECTIVE

We conducted an evidence-based systematic analysis of the literature on specific dermatoses of pregnancy.

STUDY DESIGN

The bibliographic databases MEDLINE and EMBASE were screened for studies and reports in all languages about herpes gestationis, pruritic urticarial papules and plaques of pregnancy, pruritic folliculitis of pregnancy, and prurigo of pregnancy from January 1962 to January 2002. As main index terms, including analogs and derivatives, we used the names of specific dermatoses of pregnancy. Intrahepatic cholestasis of pregnancy, not a primary dermatosis, was included herein because this disorder is associated with pregnancy and its secondary skin manifestations must be differentiated from specific dermatoses of pregnancy. Other sources were abstract books of symposia and congresses, theses, textbooks, monographs, reviews, editorials, letters to the editor, free or rapid communications, and the reference lists from all the articles that were retrieved. All articles selected for inclusion in this review were evaluated critically with regard to their impact factor and evidence-based contribution to this field, as measured by their citation index and impact factor of the journal in which they were published. Approximately 39% of articles met the selection criteria.

RESULTS

The clinical features and prognosis of the specific dermatoses of pregnancy have been delineated through a number of retrospective and cohort studies. The molecular biologic and immunogenetic properties of herpes gestationis, pruritic urticarial papules and plaques of pregnancy, and intrahepatic cholestasis of pregnancy have been further clarified. A meta-analysis in this review reveals a higher prevalence of multiple gestation pregnancy (11.7%) among patients with pruritic urticarial papules and plaques of pregnancy. Several investigations have unraveled the fetal complications in intrahepatic cholestasis of pregnancy and herpes gestationis. New treatment modalities in intrahepatic cholestasis of pregnancy (cholestyramine, ursodeoxycholic acid) and herpes gestationis (cyclosporin, intravenous immunoglobulin, and tetracyclines postpartum) have shown promise and warrant further evaluation.

CONCLUSION

During the past few decades, a significant amount of new data has provided new insights into the classification, pathogenesis, treatment, prognosis, and fetal risks that are associated with the specific dermatoses of pregnancy.

Dermatoses of pregnancy

The dermatoses of pregnancy can be classified into the following 3 groups: physiologic skin changes in pregnancy, dermatoses and cutaneous tumors affected by pregnancy, and specific dermatoses of pregnancy. Correct diagnosis and classification are essential for the treatment of these disorders, when necessary. Laboratory investigations are required when the diagnosis remains in question despite a careful history and thorough physical examination. A discussion with the pregnant woman about the nature of her skin condition, and the possible fetal risks associated with it, is imperative.

Focus on primary care: pruritic dermatological conditions in pregnancy

This article reviews the literature that evaluates pruritic urticarial papules and plaques of pregnancy, herpes gestationis, and intrahepatic cholestasis of pregnancy and their impact on the fetus. Using MEDLINE years 1966 to 1999, a literature search was performed using the terms pregnancy, dermatology, pruritic urticarial papules and plaques of pregnancy, herpes gestationis, and intrahepatic cholestasis of pregnancy. References from the selected papers were then reviewed for additional sources. Thirty-seven studies were reviewed. Both original studies and review articles were included in the sources. The results of each study as originally reported are included to provide the reader the finding of each. The available literature reports no risk with pruritic urticarial papules and plaques of pregnancy; however, the current opinion of most was that there is an increased risk with herpes gestationis and intrahepatic papules and plaques of pregnancy. Although much information is known concerning these unique conditions, a consensus regarding their effect on the fetus has yet to be reached. Pregnancies affected by herpes gestationis and cholestasis of pregnancy should be considered high risk until more definitive evidence can be gained.

The specific dermatoses of pregnancy: a re-appraisal

Pregnancy is associated with immunological, endocrine, metabolic and vascular changes that may adversely affect the skin. The specific dermatoses of pregnancy are disease entities almost exclusively related to the pregnancy or the puerperium.

LEARNING OBJECTIVE

At the conclusion of this learning activity, participants should be aware of the main entities of the specific pregnancy dermatoses, their clinical presentations, the main diagnostic criteria and therapeutic options.

Pemphigoid gestationis: a review

Pemphigoid gestationis is a rare autoimmune vesiculobullous skin disease closely related to the pemphigoid group of blistering disorders. It is unique in that it is most frequently associated with pregnancy. Diagnosis is made on the basis of the presence of a subepidermal vesicle on routine histologic examination and of linear deposition of the third component of complement along the basement membrane zone of perilesional skin. Abnormal expression of major histocompatibility complex class II molecules in the placenta may trigger the initiating immunologic event in this organ, which is followed by cross-reactivity with an antigen present in the skin and the characteristic cutaneous signs of the disease. The immunogenetics of this disorder are interesting. A role for the involvement of major histocompatibility complex class II antigens seems likely because of the association with human leukocyte antigens DR3 and DR4. Major histocompatibility complex class III associations have also been observed, as has a high frequency of anti-human leukocyte antigen antibodies. We review the current understanding of the molecular biologic and immunogenetic properties of this disease and discuss treatment and potential impact on the fetus.

Anti-HLA antibodies in pemphigoid gestationis (herpes gestationis)

Pemphigoid gestationis (PG; herpes gestationis) is a rare autoimmune disease associated with pregnancy, currently defined by the presence of complement deposition along the cutaneous basement membrane zone. It is known to be associated with HLA-DR3 and DR4, and an increase in anti-HLA antibodies in those with a history of PG has been reported. We have studied 39 patients with an immunofluorescence-confirmed diagnosis of PG for the presence and specificity of anti-HLA antibodies. Anti-HLA antibodies were found in all 39 patients. Specificity was against class I antigens in 98% (controls 10%; P < 0.001) and class II antigens in 25% (controls 8.5%; P < 0.001). Almost all anti-HLA antibodies were cytotoxic. The universal presence of anti-HLA antibodies in PG suggests that they may develop coincidently with antibasement membrane antibodies, and may reflect a common immunological event.

Murine trophoblast failure and spontaneous abortion

PROBLEM

Infection has been proposed to initiate abortion, and the role of viruses in spontaneous resorption in mice has not been tested.

METHOD

The anti-viral drug ribavirin (1-beta-D-ribofuranosyl-1,2,4-triazole-3-carboxamide) was fed to CBA/J and C3H/HeJ female mice beginning on the morning after mating with DBA/2J males.

RESULTS

Ribavirin treatment increased the rate of abortion (resorption) on day 13.5, and this was associated with retardation of the rate of embryo development and hypoplasia of the trophoblast. There was a reduction in trophoblast-dependent decidua-associated soluble suppressor activity, but there was no maternal mononuclear cell infiltrate of the type reported in association with resorption of semiallogeneic and xenogeneic mouse embryos. This may be due to an immunosuppressive effect of ribavirin. Ribavirin was able to potently suppress proliferation of mouse trophoblast and mastocytoma cell lines in vitro.

CONCLUSIONS

There are several drug-induced murine abortion models that provide useful insights into potential mechanisms underlying spontaneous pregnancy failure, but in the ribavirin mode, a direct impairment of trophoblast development appears to be responsible.

Secondary autoimmune diseases in herpes gestationis (pemphigoid gestationis)

BACKGROUND

Herpes gestationis (HG) is an autoimmune disease of the skin that occurs exclusively in association with pregnancy (or trophoblastic disease). It is associated with the HLA-DR3 and -DR4 antigens that are also associated with several other autoimmune diseases. HG has previously been reported in association with Graves' disease.

OBJECTIVE

Our purpose was to determine the frequency of other autoimmune disease(s) in patients with a history of HG.

METHODS

Seventy-five patients with a history of HG were studied for the frequency of other autoimmune diseases.

RESULTS

We found an increased frequency of Graves' disease in patients with a history of HG. Those with HG have an increased risk for the development of other autoantibodies. There is an increased frequency of autoimmune diseases in the family members of patients with HG.

CONCLUSION

Secondary autoimmune disease in HG is unusual, but does occur. The most frequent is Graves' disease.

Isolated basal keratinocytes express pemphigoid gestationis antigen

Basal keratinocytes were isolated from epidermal cell suspensions prepared by trypsinization of normal human skin. Cells were identified as basal cells by their adherence to collagen and confirmed as basal cells by the presence of pemphigoid antigen. Using an indirect immunofluorescence assay, cells were found to express pemphigoid gestationis-related antigen. Sera from patients with pemphigoid gestationis reacted in one of two immunofluorescence patterns: either polar, in a pattern similar to that observed with bullous pemphigoid serum, or with uniform staining around the cell periphery. Pemphigoid gestationis-related antigen is expressed by isolated basal keratinocytes and is resistant to trypsinization. The heterogeneity of immunofluorescence patterns may correspond to the heterogeneity of antigen recognition by different patients with pemphigoid gestationis.

Fetal risks in herpes gestationis

BACKGROUND

The potential risks to the fetus in herpes gestationis have long been a controversial subject, but because of the rarity of the disease, have only occasionally been studied.

OBJECTIVE

The purpose of this study was to determine the incidence of fetal complications in herpes gestationis.

METHODS

We collected and analyzed the obstetric histories of 74 patients and compared their involved pregnancies with their uninvolved pregnancies.

RESULTS

There was an obvious tendency for premature delivery associated with herpes gestations. A slight tendency toward small-for-gestational-age newborns associated with herpes gestationis was confirmed, but, perhaps surprisingly, no increase in spontaneous abortions or stillbirths was noted. The use of systemic steroids did not appear to influence risk.

CONCLUSION

Herpes gestationis is associated with an increase in prematurity and small-for-gestational-age infants.

Anchoring villi in human placental basal plate: lymphocytes, macrophages and coagulation

We have studied basal plates in 25 normal placentae, ten placentae from primary aborters and six placentae from secondary aborters for leukocyte markers and coagulation components. Anchoring villi contained class II MHC antigen-reactive (HLA-DR, DP and DQ) macrophages and T-lymphocytes of the helper (CD4) phenotype. Antibodies to coagulation components revealed the presence of tissue factor, factor IX and fibrin in and around anchoring villi. Immune cells and coagulation components in anchoring villi were more frequently identified in secondary aborters. These findings provide morphological support for an idea that there is a linkage between the presence of immune cells and coagulation in anchoring villi of the basal plate. Helper T-lymphocytes can activate macrophages which release cytokines that activate coagulation through the extrinsic pathway. We envision this as an expression of maternal allogeneic recognition of extraembryonic tissues in the basal plate.

Concordant expression of tissue factor and class II MHC antigens in human placental endothelium

Villitis of unestablished etiology is a placental lesion frequently associated with high risk pregnancies: it is also found in placentae from normal term pregnancies. The etiology of the lesion is unknown. Vasculitis and thrombosis have been described in villitis areas of placentae from normal and high risk pregnancies. We asked if fetal stem vessel endothelium in villitis lesions expresses MHC class II antigens, and if this is associated with a thrombogenic activity of these vessels. We found that endothelium of fetal stem vessels in villitis areas was usually MHC class II (HLA-DR, DP and DQ) reactive. Reactivity of fetal stem vessel endothelium for MHC class II antigens was associated with the presence of tissue factor reactivity and the absence of thrombomodulin reactivity. These changes on endothelial plasma membranes can promote intravascular coagulation, ischemic necrosis, vasculitis and other histological changes characteristic of villitis.

Antigen-presenting cells in the skin and placenta in pemphigoid gestationis

In pemphigoid gestationis (PG), one of the major initiating events is the aberrant expression of the class II molecules of the major histocompatibility complex in the placenta. We used a panel of 13 monoclonal antibodies to investigate the phenotype of the MHC class II positive antigen-presenting cells (APC) in the skin and placenta in PG. In the skin, the APC show reactivity with a variety of macrophage markers and the CDI marker of Langerhans cells. By contrast, the MHC class II positive cells in the placenta showed no reactivity with macrophage or Langerhans cell markers, but were the cytokeratin-positive trophoblast or vimentin-positive stromal cells.

Allogeneic recognition and rejection reactions in the placenta

One of the major questions in medicine is how human extraembryonic tissues escape rejection by maternal immune responses, because these tissues are allogeneic and should stimulate allogeneic recognition and rejection reactions. Evidence for maternal allogeneic recognition of extraembryonic tissues in chorionic villi, basal plate, and spiral arteries is presented. Extraembryonic membranes seem always to stimulate maternal allogeneic recognition and rejection reactions, and abnormal pregnancies appear to be associated with a simple quantitative increase of the same placental immunopathological lesions found in normal pregnancies.

Immunopathology of the placenta in pemphigoid gestationis and linear IgA disease

We have investigated the immunopathology of the placenta in bullous diseases by studying the deposition of immune complexes and expression of MHC class II subregion products by immunohistological methods. Placentae from seven patients with pemphigoid gestationis (PG) and two patients with linear IgA disease were studied. In PG immune complexes containing IgGI and C3 were identified in six cases. In linear IgA disease IgAI containing immune complexes were found in both cases. Placentae from patients with PG showed aberrant expression of MHC Class II products. This was not seen in the placentae from patients with linear IgA disease. In PG there was incoordinate expression of the subregion products, DP and DR being more extensively and consistently expressed than DQ. These results and previous immunogenetic studies suggest that PG may be unique among organ specific autoimmune disease, the autoantibodies forming during an allogenic response rather than target cells behaving as antigen presenting cells.