Clues to the aetiology and pathogenesis of herpes gestationis

Subepithelial autoimmune blistering dermatoses: Clinical features and diagnosis

Subepithelial autoimmune blistering dermatoses are a group of rare skin disorders that are characterized by the disruption of the dermal-epidermal junction through the action of autoantibodies. The third article in this continuing medical education series explores the background, epidemiology, clinical features, and diagnostic criteria of each of the major subepithelial autoimmune blistering dermatoses, including bullous pemphigoid, pemphigoid gestationis, lichen planus pemphigoides, mucous membrane pemphigoid, linear IgA bullous dermatosis, and dermatitis herpetiformis.

Subepidermal autoimmune bullous diseases: overview, epidemiology, and associations

Subepidermal autoimmune bullous diseases of the skin and mucosae comprise a large group of chronic diseases, including bullous pemphigoid, pemphigoid gestationis, mucous membrane pemphigoid, linear IgA bullous dermatosis, epidermolysis bullosa acquisita, and anti-p200 pemphigoid. These diseases are characterized by an antibody response toward structural components of the basement membrane zone, resulting in subepidermal blistering. The epidemiological features of these diseases vary substantially in different regions of the world. Observational studies investigating comorbidities and associations among patients with these diseases are inconsistent and sometimes inconclusive. This review provides a brief overview regarding each one of the subepidermal autoimmune bullous diseases. In addition, it summarizes the most recent understanding of the epidemiological features and associations of this group of organ-specific autoimmune diseases.

Autoimmune Subepidermal Bullous Diseases of the Skin and Mucosae: Clinical Features, Diagnosis, and Management

Autoimmune subepidermal blistering diseases of the skin and mucosae constitute a large group of sometimes devastating diseases, encompassing bullous pemphigoid, gestational pemphigoid, mucous membrane pemphigoid, epidermolysis bullosa acquisita, and anti-p200 pemphigoid. Their clinical presentation is polymorphic. These autoimmune blistering diseases are associated with autoantibodies that target distinct components of the basement membrane zone of stratified epithelia. These autoantigens represent structural proteins important for maintenance of dermo-epidermal integrity. Bullous pemphigoid (BP) is the most common subepidermal autoimmune blistering disease of the skin and mucosae. Although the disease typically presents with a generalized blistering eruption associated with itch, atypical variants with either localized bullous lesions or "non-bullous" presentations are observed in approximately 20% of patients. A peculiar form of BP typically associated with pregnancy is pemphigoid gestationis. In anti-p200 pemphigoid, patients present with tense blisters on erythematosus or normal skin resembling BP, with a predilection for acral surfaces. These patients have antibodies targeting the 200-kDa basement membrane protein. Epidermolysis bullosa is a rare autoimmune blistering disease associated with autoantibodies against type VII collagen that can have several phenotypes including a classical form mimicking dystrophic epidermolysis bullosa, an inflammatory presentation mimicking BP, or mucous membrane pemphigoid-like lesions. Mucous membrane pemphigoid (MMP) is the term agreed upon by international consensus for an autoimmune blistering disorder, which affects one or more mucous membrane and may involve the skin. The condition involves a number of different autoantigens in the basement membrane zone. It may result in severe complications from scarring, such as blindness and strictures. Diagnosis of these diseases relies on direct immunofluorescence microscopy studies and immunoserological assays. Management of affected patients is often challenging. We will here review the clinical and immunopathological features as well as the pathophysiology of this group of organ-specific autoimmune diseases. Finally, we will discuss the diagnostic approach and the principles of management in clinical practice.

Pemphigoid gestationis: current perspectives

Many skin diseases can occur in pregnant women. However, a few pruritic dermatological conditions are unique to pregnancy, including pemphigoid gestationis (PG). As PG is associated with severe morbidity for pregnant women and carries fetal risks, it is important for the clinician to quickly recognize this disease and refer it for dermatological evaluation and treatment. Herein, we review the pathogenesis, clinical characteristics, and management of PG.

Dermatoses of pregnancy: Nomenclature, misnomers, and myths

The most recent reclassification of dermatoses of pregnancy includes polymorphic eruption of pregnancy, atopic eruption of pregnancy, and pemphigoid gestationis; intrahepatic cholestasis of pregnancy, strictly not a dermatosis, was included in specific dermatoses of pregnancy for working purposes. Another dermatosis, pustular psoriasis of pregnancy, could be included for similar reasons. The nomenclature of these pregnancy-specific eruptions has been revised several times, generating potential confusion among practitioners. Clouding the picture further are misnomers that have been used to describe dermatoses of pregnancy. In addition, several cutaneous conditions that are associated with, but not specific to, pregnancy, have been misunderstood, which has resulted in certain myths among patients and physicians. In this contribution, we describe how the nomenclature of each dermatosis of pregnancy has evolved to fit the current classification scheme. We then identify several misnomers that have generated confusion within the scheme. Finally, we debunk several myths that have developed around cutaneous conditions outside of this scheme, in both mother and newborn.

Blistering disease: insight from the hemidesmosome and other components of the dermal-epidermal junction

The hemidesmosome is a specialized transmembrane complex that mediates the binding of epithelial cells to the underlying basement membrane. In the skin, this multiprotein structure can be regarded as the chief adhesion unit at the site of the dermal-epidermal junction. Focal adhesions are additional specialized attachment structures located between hemidesmosomes. The integrity of the skin relies on well-assembled and functional hemidesmosomes and focal adhesions (also known as integrin adhesomes). However, if these adhesion structures are impaired, e.g., as a result of circulating autoantibodies or inherited genetic mutations, the mechanical strength of the skin is compromised, leading to blistering and/or tissue inflammation. A particular clinical presentation emerges subject to the molecule that is targeted. None of these junctional complexes are simply compounds of adhesion molecules; they also play a significant role in signalling pathways involved in the differentiation and migration of epithelial cells such as during wound healing and in tumour invasion. We summarize current knowledge about hereditary and acquired blistering diseases emerging from pathologies of the hemidesmosome and its neighbouring proteins as components of the dermal-epidermal junction.

Pemphigoid gestationis in a third trimester pregnancy

Pemphigoid gestationis (PG) is a rare vesiculobullous dermatosis of pregnancy. It is commonly seen in second or third trimester. The diagnosis is frequently made with direct immunofluorescence studies of perilesional skin. Prompt recognition and appropriate management may reduce morbidity of this disease. Herein we present a case of pemphigoid gestationis occurring in a 33-year-old primigravida woman with symptoms of generalized pruritus.

Gestational pemphigoid

Gestational pemphigoid (pemphigoid gestationis, PG) is a rare autoimmune skin disorder occurring characteristically during pregnancy. Autoantibodies against placental BP180 (also known as BPAG2 or collagen XVII) cause damage to the skin basement membrane, resulting in severe itching and blistering rash over the body and the extremities. The diagnosis of PG is confirmed by immunofluorescence analysis of a skin biopsy, while serum levels of pemphigoid antigen BP180 antibody can be used to assess disease activity. PG with mild symptoms can be treated with topical corticosteroids, while oral corticosteroids are the mainstay in treatment of severe PG. PG usually flares up at the time of delivery, and resolves spontaneously shortly after. However, relapses in subsequent pregnancies are common. As PG has been linked to the risk of prematurity and fetal growth restriction, prenatal monitoring jointly by a dermatologist and an obstetrician is recommended. Mothers should also be informed of the potential risk of re-activation of the disease in subsequent pregnancies and during hormonal contraception.

Postpartum pemphigoid gestationis

Pemphigoid gestationis (PG) or herpes gestationis is a rare autoimmune subepidermal blistering disorder associated with pregnancy. The condition typically develops during the second or third trimester of pregnancy, but has been rarely reported in the first trimester and postpartum period. Here, we report a case of PG that presented for the first time in the postpartum period, associated with a low birth weight baby.

Autoimmune bullous diseases associations

The presence of one autoimmune disorder helps lead to the discovery of other autoimmune conditions. It is thought that diseases in which autoimmunity is a feature tend to be associated together more often than one can ascribe to chance. A variety of diseases have been implicated in the onset of intraepidermal and subepidermal autoimmune diseases. The presence of one autoimmune disease should alert the physician to watch for a second immunologic disorder. A list of autoimmune bullous diseases associations includes autoimmune bullous diseases, pemphigus, pemphigoid, epidermolysis bullosa acquisita, dermatitis herpetiformis (Duhring), linear immunoglobulin A disease, and multiple autoimmune syndrome.

Autoimmune blistering diseases in children

Autoimmune blistering disorders comprise a series of conditions in which autoantibodies target components of the skin and mucous membranes, leading to blister and bullae formation. Most conditions in the spectrum of autoimmune blistering disorders are uncommonly seen in the pediatric population, even the most common ones, such as chronic bullous disease of childhood and dermatitis herpetiformis; however, they often come into the differential diagnosis of other more common pediatric entities. In addition, prompt recognition and treatment avoids unnecessary morbidity and improves ultimate outcome.

A case of gestational diabetes arising following treatment with glucocorticosteroids for pemphigoid gestationis

A case of pemphigoid gestationis, a rare autoimmune disease unique to pregnancy, is described. To control the skin lesions systemic corticosteroids were required. The patient developed gestational diabetes mellitus. The pregnancy continued to 37 weeks and a live male infant was delivered. There was no evidence of macroscopic changes in the placenta. The skin lesions resolved in the postpartum period.

Pemphigoid gestationis: clinical and laboratory evaluation

INTRODUCTION

Pemphigoid gestationis, also known as herpes gestationis, is a rare autoimmune blistering disease associated with pregnancy. It usually occurs during the second or third trimester, but it may be present at any stage of pregnancy or the puerperium. The clinical, histologic, and immunopathological features of pemphigoid gestationis are similar to those of the pemphigoid group of disorders.

METHODS

We hereby report seven patients who were diagnosed with pemphigoid gestationis and followed at the Autoimmune Blistering Disease Clinic in the Department of Dermatology of the University of Sao Paulo Medical School between 1996 and 2008.

DISCUSSION

Demographic and clinical findings, such as median age, sites of involvement, and gestational age of onset or C3 of our patients, coincide with those described in previous reports. The majority of patients (85%) exhibited complement C(3) and immunoglobulin G (IgG) deposition along the basement membrane zone (BMZ) on immunofluorescence. Herpes gestationis factor (HG) factor was postitive in four out of six patients (67%), and three out of five patients recognized the bullous pemphigoid recombinant antigen (BP180) by ELISA.

CONCLUSION

This study revealed a good outcome of the newborns from pemphigoid gestationis affected mothers, based on the absence of pemphigoid gestationis cutaneous lesions, mean birth weight, and normal Apgar scores and gestational age at birth.

A case of chronic herpes gestationis: persistent disease or conversion to bullous pemphigoid?

We report the case of a 38-year-old woman with herpes gestationis (HG) persistent for 26 months postpartum with typical erythematous-edematous grouped lesions associated with vesicles, blisters, and scaled crusts on most parts of her body. Despite high doses of oral prednisolone, azathioprine, and dapsone, and a trial of 5 plasmaphereses, the disease has persisted to date. Histopathologic examination of lesional skin showed subepidermal blisters, focal basal cell necrosis, and a dermal inflammatory infiltrate including many eosinophils. Direct immunofluorescence showed linear C3 staining in the basement membrane zone and the complement fixation test demonstrated circulating antibasement membrane zone antibodies at a low titer (1:80). HLA typing demonstrated an A2, A24, B35, B52, DR4,5, DR13,15, DRW52,53 phenotype. We present this case as chronic persistent HG and discuss the differential diagnosis between chronic persistent HG and HG evolving to bullous pemphigoid, together with a careful examination of similar cases reported in literature.

The role of T lymphocytes and cytokines in the pathogenesis of pemphigoid gestationis

BACKGROUND

Pemphigoid gestationis (PG), also known as herpes gestationis, is a rare autoantibody-mediated bullous disease, usually associated with pregnancy and the postpartum period. However, infiltrating cells have recently been suggested to also contribute to the pathogenesis of cutaneous lesions.

OBJECTIVES

To evaluate the immunophenotype of T cells infiltrating the PG lesional skin and their prevalent cutaneous cytokine expression, as well as the presence and distribution of mast cells, eosinophils and neutrophils. Methods We performed an immunohistochemical study with a large panel of monoclonal antibodies to CD3, CD4, CD8, HLA-DR, CD25, myeloperoxidase, tryptase, eosinophil cationic protein EG2, human interleukin (IL)-2, -4, -5, -8, interferon (IFN)-gamma, and granulocyte-macrophage colony-stimulating factor using the alkaline phosphatase-antialkaline phosphatase procedure on lesional skin of seven patients with PG. Skin from four subjects with pruritic urticarial papules and plaques of pregnancy and three additional healthy donors were used as controls.

RESULTS

The findings indicate that there is a T-cell population with a prevalent T-helper (Th) 2 phenotype in the lesional skin of PG subjects. We also found a number of eosinophils and neutrophils with clear signs of activation.

CONCLUSIONS

These data suggest that an inflammatory infiltrate is involved in the production of PG bullous lesions. In particular, we assume that the Th2 cells might be implicated in the very early stages of autoimmune response and may exercise a broad influence in blister formation in this disease.

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.

Successful treatment with doxycycline and nicotinamide of two cases of persistent pemphigoid gestationis

Pemphigoid gestationis (PG) is a rare dermal-epidermal autoimmune bullous disease of pregnancy and postpartum, which relapses more seriously and earlier during following pregnancies. PG also occurs in association with trophoblastic tumours or oral contraceptive treatment. The term 'persistent PG' represents the cases where active disease persists for months to many years after delivery. Four cases of persistent PG have been reported to date in the literature. So far, systemic cortico-steroids have been the main PG therapy and the use of cyclophosphamide, dapsone, pyridoxine, methotrexate, plasmapheresis or ritodrine has also been reported, with contradictory results. In this paper are described two patients with persistent PG who were successfully treated with doxycycline (200 mg/day) and nicotinamide (500 mg/day), a treatment that was demonstrated to be safe and efficacious in bullous pemphigoid.

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.

Clinical features and management of 87 patients with pemphigoid gestationis

Pemphigoid gestationis is a rare vesiculo-bullous disorder of pregnancy. In this review we summarize the clinical data on 142 pregnancies in 87 patients complicated by pemphigoid gestationis. Our aim is to provide a comprehensive clinical overview of this disease.

The time course of the change in antibody titres in herpes gestationis

The time course of the change in antibody titres was examined postpartum after treatment in two patients with herpes gestationis. The first patient, a 29-year-old woman seen first in the 32nd week of her first pregnancy, had an exudative erythema, and developed an itchy erythema with small tense vesicles on the trunk and legs after delivery in the 40th week of pregnancy. The second patient, a 28-year-old woman seen first in the 28th week of her first pregnancy, had an itchy exudative erythema, small tense vesicles and crusts on the legs. After a Caesarean section in the 40th week of pregnancy performed because of cardiac complications in the fetus, the skin lesions extended to the trunk and extremities. Direct immunofluorescence revealed linear depositions of IgG and C3 at the basement membrane zone (BMZ) and indirect immunofluorescence was positive at the epidermal side of the BMZ in 1 mol/L NaCl-split skin in both cases. In patient 1, prednisolone, 20 mg/day, administered 4 months after delivery, gave rapid improvement (within 1 week) of the skin lesions; in patient 2, minocycline, 200 mg/day, administered 2 weeks after delivery, gave improvement within 2 weeks. Immunoblotting against epidermal extracts revealed the presence of antibodies directed to the 180 kDa bullous pemphigoid antigen in both sera. Indirect immunofluorescence and immunoblot were positive for at least 2 months in patient 1 and for 5 months in patient 2 after disappearance of the skin lesions.

Dermatoses of pregnancy

Several reported dermatoses of pregnancy have not survived the scrutiny of time and thus including them in current classification schemes does not serve any useful purpose. This review resolves issues in the existing conflicting literature.

[Neurologic manifestations in a child of a mother with gestational herpes]

BACKGROUND

Herpes gestationis in the neonate is usually associated with an increased risk of premature birth and/or low birth weight for gestational age (GA) and sometimes skin lesions. Neurologic manifestations are nos described in these babies.

CASE REPORT

A boy was born at 35 weeks of GA from a mother who developed skin eruption typical of herpes gestationis. His weight was 2320 g and his height was 46 cm. He had transient respiratory distress syndrome and was given antibiotics due to suspected group B streptococcus infection. He developed on day 3 skin vesiculous eruption which disappeared within 3 days and neurologic manifestations: hypertonia and hyperkinesis, abnormal EEG. The CSF was normal. The manifestations spontaneously disappeared within 5 days. The herpes gestationis factor was present in both mother and infant.

CONCLUSION

A relationship between the maternal herpes gestationis and neonatal neurologic manifestations is possible; there was no other known causes for the transient neurological disease.

Pemphigoid gestationis--response to chemical oophorectomy with goserelin

A 46-year-old caucasian female presented in January 1991 with a 17-year history of severe pemphigoid gestationis. She had been on systemic steroids for 10 years since her last pregnancy in 1981 and required doses of 20-80 mg prednisolone daily to control her disease. A chemical oophorectomy was induced using a new luteinizing hormone releasing hormone (LHRH) analogue known as goserelin. A complete remission occurred within 6 months of initiating this treatment and the systemic steroids were discontinued.

Pemphigus gestationis (herpes gestationis): a case report

Pemphigus gestationis is a rare disease, probably of immunologic origin, that causes the placenta to absorb immunoglobulins and deposit them in its basement membrane. The resulting placental insufficiency leads to increased morbidity and mortality among the offspring of such patients. A case of pemphigus gestationis is presented, and the importance of early diagnosis is discussed.

Herpes gestationis

Herpes gestationis is a rare, self limited bullous disease of pregnancy and the post-partum period with a presumed autoimmune basis. It is characterized clinically by pruritic, urticarial and vesiculobullous lesions, histologically by subepidermal vesicle formation, and immunopathologically by deposition of immunoreactants along the basement membrane zone. These features are shared by bullous pemphigoid which suggests that herpes gestationis may be a related entity. Immunoblotting studies have shown that herpes gestationis sera recognize a 180 kD epidermal antigen; in comparison, bullous pemphigoid sera most often detect a 220-240 kD antigen, but a significant number also recognize a 180 kD epidermal antigen, suggesting immunological similarities between these two diseases. Etiology and pathophysiology are not established, but an immunological basis is implicated by the frequent finding of C3 along the basement membrane zone of perilesional skin, the presence of herpes gestationis factor, increased incidence of HLA-DR3 and HLA-DR4, and association with other putative autoimmune diseases. Treatment usually consists of systemic corticosteroids.

Severe polymorphic eruption of pregnancy occurring in twin pregnancies

We describe three women pregnant with twins who developed severely symptomatic polymorphic eruption of pregnancy. In all of these women oral prednisolone treatment was indicated and administered to two of them with resulting remission. Both these women breast fed their twins and relapsed in the puerperium requiring further systemic steroid therapy. The third woman was cured by early elective delivery. It has not been previously suggested that the severity of polymorphic eruption is related to multiple pregnancy and this possibility is discussed. The safety of oral prednisolone in pregnancy and during lactation is also reviewed.

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.