Neonatal pemphigus vulgaris: IgG4 autoantibodies to desmoglein 3 induce skin blisters in newborns

Punctate Pattern and Pemphigus: Is There Any Evidence of Punctate Pattern Among Iranian Patients?

AIM

To examine the prevalence of this novel pattern among Iranian patients with pemphigus and peruse the relationship between the presence of a punctate pattern with clinical severity of disease and histopathological findings.

METHODS

One hundred recently diagnosed patients with pemphigus were enrolled. DIF evaluation and routine light microscopy were performed on their biopsy specimens. Disease severity was determined using the Pemphigus Disease Area Index. Serum samples were collected to measure autoantibody titers using enzyme-linked immunosorbent assay.

RESULTS

All the samples evaluated by DIF showed a continuous linear pattern of intercellular IgG deposition, whereas none of them had a punctate pattern. Despite a significant correlation between the Pemphigus Disease Area Index score and autoantibody values, no association between histopathological findings and disease severity has been found.

CONCLUSION

We could not detect any punctate pattern among Iranian patients with pemphigus. The importance of this pattern in the diagnosis of pemphigus might be different among patients with different ethnic and genetic factors.

Pemphigus and pregnancy. Analysis and summary of case reports over 49 years

Pemphigus is a group of immune-mediated bullous disorders, which often cause fragile blisters and extensive lesions of the skin or mucous membranes, such as in the mouth. This disease could be life-threatening in some cases. During pregnancy, its condition will become more complicated due to the change in the mother’s hormone level and the effect of drug therapy on both the mother and her fetus. Thus, it will be more difficult to identify the clinical manifestations and to establish the treatment plan. In this article, we present a comprehensive review of pemphigus and pregnancy by analyzing 47 cases of pemphigus reported between 1966 and 2014, with diagnosis before or during pregnancy. The aim of this study is to make a comprehensive review of pemphigus and pregnancy, provide organized and reliable information for obstetricians, dermatologists, physicians, and oral medicine specialists.

Maternal antibodies and developing blood-brain barrier

We briefly review the protective role of maternal antibodies during fetal development and at early postnatal stages. We describe antibody delivery to fetuses, particularly in the context of the developing blood-brain barrier (BBB), and present the essential concepts regarding the adult BBB, together with existing information on the prenatal developing BBB. We focus on maternal antibody transfer to the developing brain and the consequences of the presence of pathogenic antibodies at early stages of brain development on subsequent brain dysfunction.

Blistering diseases in neonates

PURPOSE OF REVIEW

Neonatal blistering diseases are rare yet potentially fatal. Therefore, it is crucial for clinicians to know its broad range of differential diagnoses. This review discusses the recent literature on the causes and the most appropriate clinical approach to neonatal blistering diseases.

RECENT FINDINGS

Neonatal infections are the commonest causes for neonatal blistering. On the other hand, autoimmune blistering diseases are extremely rare with the literature limited to case reports and one systematic review only. Inherited genodermatoses are also rare, with recent developments in epidermolysis bullosa classification.

SUMMARY

In conclusion, as neonatal infections are the commonest cause for blistering, any neonate with blistering should have their blister fluid investigated for infection, while an antimicrobial should be initiated early. Autoimmune blistering diseases should be considered in neonates with a maternal history of autoimmune blistering disease. Although pemphigus and bullous pemphigoid have overall good prognoses, linear IgA bullous dermatoses has a poor prognosis and requires aggressive treatment. Inherited genodermatoses should be suspected when there is a family history of genodermatoses or consanguinity. In this case, the clinician should not hesitate to seek dermatology advice, perform a skin biopsy and consider genetic testing.

Non-infectious environmental antigens as a trigger for the initiation of an autoimmune skin disease

Pemphigus represents a group of organ specific autoimmune blistering disorders of the skin mediated by pathogenic autoantibodies with well-defined antigenic targets. While most of these diseases are sporadic, endemic forms of disease do exist. The endemic form of pemphigus foliaceus (also known as fogo selvagem, FS) exhibits epidemiological features that suggest exposure to hematophagous insect bites are a possible precipitating factor of this autoimmune disease, and provides a unique opportunity to study how environmental factors contribute to autoimmune disease development. FS patients and healthy individuals from endemic regions show an autoreactive IgM response that starts in early childhood and becomes restricted to IgG4 autoantibodies in FS patients. In searching for triggering environmental antigens, we have found that IgG4 and IgE autoantibodies from FS patients cross-react with a salivary antigen from sand flies. The presence of these cross-reactive antibodies and antibody genetic analysis confirming that these antibodies evolve from the same naïve B cells provides compelling evidence that this non-infectious environmental antigen could be the initial target of the autoantibody response in FS. Consequently, FS serves as an ideal model to study the impact of environmental antigens in the development of autoimmune disease.

Neonatal Autoimmune Blistering Disease: A Systematic Review

We aimed to better understand the pathogenesis, clinical features, prognosis, and treatment of neonatal autoimmune blistering diseases (AIBDs). We searched Medline, Embase, PubMed, Latin American and Caribbean Health Sciences Literature, and reference lists of identified articles. Inclusion criteria were articles published from 1946 to December 2014 in any language. Exclusion criteria were age greater than 4 weeks and no confirmed AIBD diagnosis. We identified 51 cases of neonatal AIBDs: 34 cases of pemphigus (31 pemphigus vulgaris [PV], 3 pemphigus foliaceus [PF]) and 17 cases of pemphigoid diseases (9 bullous pemphigoid [BP], 5 linear immunoglobulin A bullous dermatosis [LABD], 1 BP and LABD, 1 epidermolysis bullosa acquisita, 1 bullous systemic lupus erythematosus). Pemphigoid diseases had a higher male predominance (male:female ratio 4.6:1) than pemphigus (male:female ratio 1:1.06) (p = 0.004). Pemphigus had a higher proportion presenting at birth (79.4%) than pemphigoid diseases (29.4%) (p = 0.008). The most common sites involved were the trunk (63.0%), followed by the head and neck (60.9%). The mucosal membranes were involved in 32.6% of cases (27.6% in pemphigus, 41.6% in pemphigoid diseases). Only 33.3% used systemic therapy, and 75.5% achieved control within 3 weeks. Most PV, PF, and BP cases, but not LABDs, reported maternal disease. In pemphigus cases, 75.0% of mothers had active disease and 25.0% were in control. Pregnant women with PV, PF, and PG of any severity can passively transfer autoantibodies leading to neonatal AIBD. Pemphigoid diseases are more likely to present after birth and may be more male predominant. The presentation of LABDs may be different from that of all other AIBDs.

Transplacental Transmission of Pemphigus Herpetiformis in the Setting of Maternal Lymphoma

Pemphigus herpetiformis (PH) is characterized by grouped vesicular or papular pruritic lesions with histologic and immunopathologic features of pemphigus. PH can manifest at any age, and paraneoplastic cases have been reported. We describe a healthy boy born with acral crateriform erosions of the hands and feet whose 35-year-old mother had similar lesions. Biopsies from both patients were most consistent with PH. The mother was diagnosed with high-grade B-cell non-Hodgkin lymphoma and began chemotherapy with dexamethasone, and her lesions quickly improved. The infant had no additional lesions after 3 weeks of age and his acral erosions healed. To our knowledge, this is the first report of a diagnosis of PH in an infant and the first case of transplacental transmission of PH. This is also the first report of paraneoplastic PH in lymphoma. This case adds to the growing differential diagnosis of skin disease in postpartum women and their neonates.

Pediatric dermatohistopathology--histopathology of skin diseases in newborns and infants

While neonatal skin physiology has been thoroughly examined using non-invasive techniques in recent years, only few systematic studies and review articles addressing the histopathology of neonatal skin have been published thus far. In most cases, histopathological findings of dermatoses in neonatal skin do not significantly differ from those seen in adult skin. Nevertheless, a comprehensive knowledge of embryonic and fetal skin development as well as the microanatomical structure of neonatal skin can contribute to a better understanding of various dermatoses of infancy. In the first part of this review article, we present the histopathological features of such skin diseases, which, though generally rare, almost exclusively appear during the first weeks of life due to distinctive structural and functional features of neonatal skin. The second part is dedicated to classic dermatoses of infancy and their histopathological features.

Current concepts of immunofluorescence in oral mucocutaneous diseases

Aim:

To study the immunofluorescence pattern and to assess its reliability as a confirmatory diagnostic test in patients with pemphigus, pemphigoid, lichen planus, and lupus erythematosus and also to assess the disease activity by indirect immunofluorscence (IIF) in patients with pemphigus only.

Materials and Methods:

Twenty-six patients were included in the study group, out of which, 6 patients were clinically and histopathologically diagnosed as pemphigus, completely free of active lesions were subjected to IIF only to assess the disease activity and were grouped separately. Based on the clinical and provisional diagnosis, the remaining 20 patients who had active lesions were subjected to direct immunofluorscence (DIF) and IIF and were divided into four groups. Biopsy specimens were taken from the periphery of the lesions and were examined by both conventional light microscopic and DIF methods. Five milliliters of venous blood was collected from each patient and were subjected to IIF.

Results:

Histopathological diagnosis was consistent with direct immunofluorescence study in 15 cases (75%). The various immunofluorescence patterns observed in our study were consistent with those described by various authors in standard textbooks and articles.

Conclusion:

Histopathology remains gold standard for most of the diseases, it is recognized from this study that not all lesions are amenable to definitive histopathological diagnosis thus; DIF can provide a valuable additional criterion in diagnosis.

IgG placental transfer in healthy and pathological pregnancies

Placental transfer of maternal IgG antibodies to the fetus is an important mechanism that provides protection to the infant while his/her humoral response is inefficient. IgG is the only antibody class that significantly crosses the human placenta. This crossing is mediated by FcRn expressed on syncytiotrophoblast cells. There is evidence that IgG transfer depends on the following: (i) maternal levels of total IgG and specific antibodies, (ii) gestational age, (iii) placental integrity, (iv) IgG subclass, and (v) nature of antigen, being more intense for thymus-dependent ones. These features represent the basis for maternal immunization strategies aimed at protecting newborns against neonatal and infantile infectious diseases. In some situations, such as mothers with primary immunodeficiencies, exogenous IgG acquired by intravenous immunoglobulin therapy crosses the placenta in similar patterns to endogenous immunoglobulins and may also protect the offspring from infections in early life. Inversely, harmful autoantibodies may cross the placenta and cause transitory autoimmune disease in the neonate.

A novel concept of Mikulicz's disease as IgG4-related disease

Since Morgan's report in 1953, Mikulicz's disease (MD) has been considered part of primary Sjögren's syndrome (SS). However, MD has a unique presentation, including persistent swelling of the lacrimal and salivary glands, and is characterized by good responsiveness to glucocorticoids, leading to recovery of gland function. Recently, it has been revealed that MD patients show elevated serum immunoglobulin G4 (IgG4) levels and prominent infiltration of IgG4-positive plasmacytes. The complications of MD include autoimmune pancreatitis, retroperitoneal fibrosis, tubulointerstitial nephritis, autoimmune hypophysitis, and Riedel's thyroiditis, all of which show IgG4 involvement in their pathogenesis. Thus, MD is a systemic "IgG4-related disease." In addition, recent analyses have revealed that Küttner's tumor (KT), a chronic sclerosing sialadenitis that presents with asymmetrical firm swelling of the submandibular glands, is also associated with prominent infiltration of IgG4-positive plasmacytes. MD and KT differ from SS and are thought to be singular systemic IgG4-related plasmacytic diseases. Here we discuss the results of recent studies and provide an overview of MD as an IgG4-related disease.

Clinicopathologic similarities between Mikulicz disease and Küttner tumor

PURPOSE

Recent studies have revealed that Mikulicz disease (MD) differs from Sjögren syndrome and is an immunoglobulin G(4) (IgG(4))-related systemic disease. Küttner tumor (KT) is also reported to be an IgG(4)-related disease. In this study, we examined the clinicopathologic and serologic findings in MD (39 patients) and KT (6 patients) and attempted to discern the similarities between MD and KT.

MATERIALS AND METHODS

We diagnosed 39 patients with MD and 6 patients with KT. We analyzed the clinicopathologic and serologic findings (IgG subclasses) in 39 patients with MD and 6 patients with KT. Submandibular and labial salivary gland specimens obtained from patients with MD and KT were stained with anti-IgG(4) antibodies.

RESULTS

The mean IgG(4) concentration (±SD) was 931.1 ± 796.2 mg/dL in patients with MD and 756.2 ± 449.2 mg/dL in patients with KT. Abundant infiltration of IgG(4)-positive plasmacytes into the salivary glands was observed in both patients with MD and patients with KT.

CONCLUSION

The serologic and histopathologic findings in MD and KT are very similar, and these 2 conditions may be IgG(4)-related systemic diseases.

The enigmatic autoimmune response in endemic pemphigus foliaceus

Endemic pemphigus foliaceus, known as Fogo Selvagem (FS) in Brazil, is a disease characterized by subcorneal blisters and IgG4 anti-dermoglein 1 (Dsg1) autoantibodies. Epidemiological studies of FS strongly an environmental etiology. A 15-year surveillance of the Limao Verde Amerindian reservation in Brazil has uncovered information on the transition of the autoimmune response from the pre-clinical stage to disease state. This incubation time may evolve over several years. The serological markers of the pre-clinical state of FS are IgM anti-Dsg1, IgE and non-IgG4 autoantibodies against Dsg1. The disease stage of FS is characterized by the rise of pathogenic IgG4 anti-Dsg1 autoantibodies. In this review, the authors reviewed the literature on the relevance of the humoral autoimmune response of FS as well as the possible environmental triggers of anti-Dsg1 autoantibody formation. Based on epidemiological observations, the authors hypothesize that the pathogenic IgG4 response in FS may be triggered by hematophagous insect bites.

Autoimmune pancreatitis

Autoimmune pancreatitis is becoming a more widely recognized form of pancreatitis that can mimic pancreatic or biliary malignancy. The combination of serological, histological and radiographic findings makes it unique among pancreatic diseases. The presence of autoantibodies, IgG4 and a lymphoplasmacytic infiltrate reflect its autoimmune etiology. The dramatic response to steroids is also a distinguishing feature and differentiates it from other pancreatic diseases.

Structure and function of immunoglobulins

Immunoglobulins are heterodimeric proteins composed of 2 heavy and 2 light chains. They can be separated functionally into variable domains that bind antigens and constant domains that specify effector functions, such as activation of complement or binding to Fc receptors. The variable domains are created by means of a complex series of gene rearrangement events and can then be subjected to somatic hypermutation after exposure to antigen to allow affinity maturation. Each variable domain can be split into 3 regions of sequence variability termed the complementarity-determining regions (CDRs) and 4 regions of relatively constant sequence termed the framework regions. The 3 CDRs of the heavy chain are paired with the 3 CDRs of the light chain to form the antigen-binding site, as classically defined. The constant domains of the heavy chain can be switched to allow altered effector function while maintaining antigen specificity. There are 5 main classes of heavy chain constant domains. Each class defines the IgM, IgG, IgA, IgD, and IgE isotypes. IgG can be split into 4 subclasses, IgG1, IgG2, IgG3, and IgG4, each with its own biologic properties, and IgA can similarly be split into IgA1 and IgA2.

Pemphigus vulgaris in pregnancy: analysis of current data on the management and outcomes

OBJECTIVES

The occurrence of pemphigus vulgaris (PV) during pregnancy is rare. The purpose of this review was to describe management of PV in the mother, and report maternal and perinatal outcomes associated with the disease.

DATA SOURCES

A search of PubMed was conducted using the phrases "pemphigus and pregnancy" and "neonatal pemphigus." The bibliographies of retrieved articles were also searched for relevant reports. Only articles in English and in which the diagnosis of pemphigus had been made on the basis of histology or immunopathology were included.

TABULATION, INTEGRATION, AND RESULTS

In 38 reports, pregnancies from 49 women with PV were described. Among the 40 patients in whom clinical profiles were provided, 33 had active disease and 7 were disease free. Prednisone was used in 37 of 49 (75%) patients with doses ranging from 5 to 300 mg/day (mean 152.5 mg). Concomitant therapies included plasmapheresis, plasma exchange, and dapsone in 1 patient each, and azathioprine in 5. Of the 44 live births, 20 (45%) neonates had PV lesions at birth and 24 (55%) were lesion-free. Five stillbirths were reported. In all neonates, PV lesions resolved within 1 to 4 weeks, either spontaneously or with mild topical corticosteroids treatment. Of the 5 intrauterine deaths, 1 was due to umbilical cord prolapse, 1 attributed to placental dysfunction, and 1 to cytomegalovirus pneumonitis. In the remaining 2, the cause was unknown. One neonate died 2 days after delivery due to meconium aspiration syndrome. Thus the aggregate perinatal mortality rate was 12% (6/49).

CONCLUSIONS

The outcome of pregnancies complicated by pemphigus is generally good, but achieving good outcomes likely depends on the collaborative efforts of the dermatologist and obstetrician. The available data suggest that the rate of perinatal mortality is increased, but these data may be subject to publication bias.

TARGET AUDIENCE

Obstetricians & Gynecologists, Family Physicians.

LEARNING OBJECTIVES

After completion of this educational activity, the participant should be better able to describe appropriate medical therapies for pemphigus vulgaris complicating pregnancy, and plan the management of pregnancies complicated by pemphigus vulgaris.

Clinical activity of pemphigus vulgaris relates to IgE autoantibodies against desmoglein 3

Pemphigus vulgaris (PV) is a severe autoimmune bullous skin disease and is primarily associated with IgG against desmoglein 3 (dsg3), a desmosomal adhesion protein. In light of the recent association of autoreactive T helper (Th) 2 cells with active PV, the present study sought to relate the occurrence of Th2-regulated dsg3-specific autoantibody subtypes, i.e. IgE and IgG4, in 93 well-characterized PV patients. Patients with acute onset PV (n=37) showed the highest concentrations of serum IgE and IgG4 autoantibodies, which were significantly lower in PV patients in remission (n=14). Furthermore, there was a strong correlation between dsg3-reactive IgE and IgG4 in acute onset, but not in chronic active (n=42) or remittent patients. Additionally, intercellular IgE deposits were detected in the epidermis of acute onset PV. Thus, dsg3-specific IgE and IgG4 autoantibodies are related to acute onset disease which provides additional support to the concept that PV is a Th2-driven autoimmune disorder.

Tubulointerstitial nephritis associated with IgG4-related systemic disease

We report three patients with tubulointerstitial nephritis (TIN) with high serum IgG4 concentrations. None of the patients had notable pancreatic lesions when the TIN developed, although one had a history of autoimmune pancreatitis (AIP). Nevertheless, the clinicopathological findings were quite similar to those of AIP. They were all middle-aged to elderly men. Sialadenitis and lymphadenopathy were often evident. Serum total IgG and IgG4 concentrations were elevated and hypocomplementemia was observed. Although antinuclear antibodies were positive, anti-Ro and anti-La antibodies were negative. Renal biopsy showed dense lymphoplasmacytic infiltration with fibrosis in the renal interstitium, and the infiltrated plasma cells had strong immunoreactivity for IgG4. Furthermore, lymphoplasmacytic infiltration and abundant IgG4-positive plasma cells were observed in the salivary glands of a patient. Steroid therapy was effective for TIN in all three patients. The present findings support the recently proposed concept of IgG4-related systemic disease, and suggest that IgG4 is associated not only with AIP but also with other systemic lymphoplasmacytic diseases, including TIN. The conditions responsible for the pathogenesis of TIN need to be considered, irrespective of the presence of AIP.

The relevance of the IgG subclass of autoantibodies for blister induction in autoimmune bullous skin diseases

Autoimmune bullous skin diseases are characterized by autoantibodies and T cells specific to structural proteins maintaining cell-cell and cell-matrix adhesion in the skin. Existing clinical and experimental evidence generally supports a pathogenic role of autoantibodies for blister formation. These autoantibodies belong to several IgG subclasses, which associate with different functional properties and may thus determine the pathogenic potential of IgG antibodies. In pemphigus diseases, binding of IgG to keratinocytes is sufficient to cause intraepidermal blisters without engaging innate immune effectors and IgG4 autoantibodies seem to mainly mediate acantholysis. In contrast, in most subepidermal autoimmune blistering diseases, complement activation and recruitment and activation of leukocytes by autoantibodies are required for blister induction. In these conditions, tissue damage is thought to be mainly mediated by IgG1, but not IgG4 autoantibodies. This review summarizes the current knowledge on the pathogenic relevance of the IgG subclass of autoantibodies for blister formation. Characterization of the pathogenically relevant subclass(es) of autoantibodies not only provides mechanistic insights, but should greatly facilitate the development of improved therapeutic modalities of autoimmune blistering diseases.

How does acantholysis occur in pemphigus vulgaris: a critical review

BACKGROUND

Pemphigus vulgaris is a life-threatening autoimmune blistering disease targeting skin and mucous membranes, characterized by disruption of keratinocytes' adhesion termed acantholysis. Today multiple classes of targets are considered to play a role in the genesis of the acantholysis; of these, the classical pemphigus antigens, desmosomal cadherins (desmoglein 1 and 3) are the best characterized and considered as the most important. Additional antigens include the novel epithelial acetylcholine receptors (alpha9 and pemphaxin). Thus, acantholysis in pemphigus seems to result from a cooperative action of antibodies to different keratinocyte self-antigens, but the mechanisms by which epithelial cleft occurs are not yet clearly understood. In fact, the binding of the autoantibodies to these targets generates a plethora of biological effects due, on one hand, to their direct interference with adhesive function and, on the other, to more complex events involving intracellular pathways that modify proteases activity or calcium metabolism, leading to loss of cell-cell adhesion.

Pathogenic human monoclonal antibody against desmoglein 3

Pemphigus vulgaris (PV) is a potentially fatal autoimmune mucocutaneous disease associated with production of IgG autoantibodies to desmoglein 3 (Dsg3), a 130-kDa epidermal cadherin protein. The binding of pathogenic antibody to Dsg3 on epidermal keratinocytes leads to loss of intercellular adhesion and results in intraepithelial blister formation. Here, we describe a human monoclonal antibody, PVMAB786, a Dsg3-specific IgG4 antibody, from an untreated patient with active PV. The antibody reacts with a 130-kDa protein on keratinocyte cell surfaces and recombinant Dsg3 protein, but not desmoglein 1 protein. PVMAB786 induces acantholysis in normal human skin and mucous membranes and induces a clinical and histological profile similar to human PV when injected into neonatal mice. PVMAB786 will be a valuable tool in identifying the role of Dsg3 in epithelial cell adherence and acantholysis, mechanisms of Dsg3 processing/presentation and V gene and isotype usage in PV pathogenesis.

Neonatal pemphigus vulgaris in an infant born to a mother with pemphigus vulgaris in remission

Neonatal pemphigus vulgaris is a rare autoimmune disease that is caused by transplacental passage of pemphigus vulgaris autoantibodies. The association of maternal pemphigus vulgaris with neonatal disease pemphigus vulgaris has been only rarely reported. We describe an infant with pemphigus vulgaris born to a mother whose disease was in remission.

Serum IgG4 concentrations in pancreatic and biliary diseases

BACKGROUND

Recently, it has been reported that the serum concentration of IgG4, a minor component of IgG subclasses, is increased in autoimmune pancreatitis. However, data regarding IgG4 concentrations in other pancreatic or biliary diseases have been insufficient.

METHODS

Serum IgG4 was measured in 116 patients with pancreatic or biliary diseases (35 autoimmune pancreatitis, 24 chronic pancreatitis except autoimmune pancreatitis, 11 primary sclerosing cholangitis, 23 pancreatic cancer, 3 islet cell tumor, 2 papilla cancer, 15 bile duct cancer, and 3 gallbladder cancer patients). The cut-off concentration of IgG4 was 135 mg/dl.

RESULTS

Increased serum IgG4 was observed in 33 of 35 patients with autoimmune pancreatitis, 0 of 24 with chronic pancreatitis, 4 of 11 with primary sclerosing cholangitis, 0 of 23 with pancreatic cancer, 0 of 3 with islet cell tumor, 0 of 2 with duodenal papilla cancer, 0 of 15 with bile duct cancer and 0 of 3 with gallbladder cancer patients.

CONCLUSIONS

Serum IgG4 was increased in autoimmune pancreatitis and was within normal limits for other pancreatic or biliary diseases except primary sclerosing cholangitis.

Clinical and pathological differences between Mikulicz's disease and Sjögren's syndrome

OBJECTIVE

Mikulicz's disease (MD) has been included within the diagnosis of primary Sjögren's syndrome (SS), but represents a unique condition involving enlargement of the lachrymal and salivary glands and characterized by few autoimmune reactions and good responsiveness to glucocorticoids. We have previously described elevated immunoglobulin (Ig) G4 in the serum of four patients with MD. In this paper, we accumulated more MD cases and undertook clinical and histopathological analysis of these patients to clarify differences between MD and SS.

METHODS

We diagnosed seven patients with MD according to the following criteria: (i) visual confirmation of symmetrical and persistent swelling in more than two lachrymal and major salivary glands; (ii) prominent mononuclear infiltration of lachrymal and salivary glands; and (iii) exclusion of other diseases that present with glandular swelling, such as sarcoidosis and lymphoproliferative disease. We summarized the clinical and serological characteristics (IgG subclasses and IFN-gamma/IL-4 ratio) of seven patients with MD, compared with SS with glandular swelling (SSw) and without glandular swelling (SSo). After steroid administration, we analysed changes in IgG subclasses in MD. Labial salivary gland specimens in MD, SSw and SSo were stained with anti-IgG4 antibodies.

RESULTS

The concentration (+/-s.d.) of IgG4 was 1169.7 +/- 892.2 mg/dl in MD, 24.4 +/- 7.0 mg/dl in SSw (P<0.005) and 82.6 +/- 189.7 mg/dl in SSo (P<0.005). The IFN-gamma/IL-4 ratio was 0.392 +/- 0.083 (0.78 +/- 0.23/2.14 +/- 0.31 IU/pg) in MD, 0.004 +/- 0.002 (0.20 +/- 0.07/57.02 +/- 14.05 IU/pg) in SSw (P<0.05) and 0.012 +/- 0.009 (0.58 +/- 0.86/116.24 +/- 207.65 IU/pg) in SSo (P<0.05). The concentration (+/-s.d.) of IgG4 in MD decreased to 254.0 +/- 50.3 mg/dl (P<0.05) after glucocorticoid treatment. Histopathologically, only MD was associated with prominent infiltration of IgG4-positive plasmacytes into lachrymal and salivary glands.

CONCLUSION

Mikulicz's disease is quite different from SS clinically and histopathologically. MD is suggested to be an IgG4-related systemic disease.