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R S Labib

Publications and source records attributed to R S Labib.

At least 19 recordsLinked to original sources
PubMed1992

Purification of immunoprecipitated pemphigus foliaceus antigen fragment and its use in radioimmunoassay.

A major difficulty in biochemical studies of the pemphigus foliaceus (PF) antigen is the lack of a method for its quantitative determination. Immunofluorescence blocking and immunoprecipitation methods are semiquantitative and time consuming. Radioimmunoassay (RIA) methods are quantitative but they require pure and stable antigen preparations that have not been available for PF. The present investigation shows the further purification of a previously described preparation of PF antigen fragment obtained from trypsinization media of mouse skin (Con A Frn) and demonstrates its usefulness in a RIA method for quantitation of the antigen. The major contaminants of the 45-kD tryptic fragment of the PF antigen (tf-PF) in immunoprecipitates of the Con A Frn with PF sera were identified as H and L chains of murine IgG and mannose-binding lectins. The IgG contaminants could be removed by avoidance of blood contamination during preparation of the Con A Frn and/or pre-absorption of the Con A Frn with protein A Sepharose. The lectins could be removed by affinity chromatography of the Con A Frn on asialofetuin column and washing the immunoprecipitates with 0.2 M alpha-methyl-mannoside. Using the purified, labeled Con A Frn in RIA, we showed that standard curves could be established and the amounts of PF antigen could be determined in different extracts without the need for electrophoresis, autoradiography, or scanning. This RIA method is rapid and can be easily used to analyze many samples, e.g., chromatographic fractions and extracts made from different tissues.

Animals↗
PubMed1992

Human autoantibodies against desmoplakins in paraneoplastic pemphigus.

Recently, a previously unrecognized autoantibody mediated blistering disease, paraneoplastic pemphigus has been described. Paraneoplastic pemphigus is associated with lymphoid malignancies, thymomas, and poorly differentiated sarcomas. Serum of affected patients contain pathogenic autoantibodies that immunoprecipitate from normal keratinocytes a characteristic complex of four polypeptides with M(r) of 250, 230, 210, and 190 kD. As our preliminary studies indicated that the 250-kD and the 210-kD antigens comigrated with desmoplakins I and II, we investigated the possibility that autoantibodies against the desmoplakins were a component of this autoimmune syndrome. 11 sera from affected patients were tested by indirect immunofluorescence against desmosome containing tissues, immunoprecipitation of metabolically labeled keratinocytes, and Western immunoblotting of desmoplakins I and II that had been purified to homogeneity from pig tongue epithelium. By indirect immunofluorescence, 9 of 11 sera showed strong binding to epithelial and nonepithelial desmosomes, and 2 were weakly reactive. All 11 immunoprecipitated 250- and 210-kD bands of variable intensity that comigrated with bands identified by a murine monoclonal antidesmoplakin antibody, and immunoblotting confirmed binding of the serum autoantibodies to purified desmoplakins. This demonstrates that paraneoplastic pemphigus is the first human autoimmune syndrome in which autoantibodies against the desmoplakins are a prominent component of the humoral autoimmune response.

Animals↗
PubMed1991

The calcium-sensitive epitope of pemphigus foliaceus antigen is present on a murine tryptic fragment and constitutes a major antigenic region for human autoantibodies.

Recent findings indicate that the pemphigus foliaceus (PF) antigen is involved in epidermal cell adhesion and that characteristic PF lesions result from loss of this function as a consequence of autoantibody binding. In the present communication we present data on the epitopes involved in the human autoantibody binding to an immunologically reactive murine tryptic fragment of the PF antigen (tf-PF). Immunoprecipitation experiments showed that 39 PF sera, obtained from North American, Colombian, and Brazilian patients recognized only calcium-sensitive epitope(s) on the tf-PF. Immunofluorescence blocking experiments showed that preincubation with tf-PF completely blocked the immunofluorescence of 80% of the sera when tested on human skin substrate, and 86% of the sera when tested on murine skin substrate. These results show that the calcium-sensitive epitope(s) originally recognized on human PF complex, is (are) present on the murine tf-PF and constitute(s) a major antigenic region for the human PF autoantibodies. They also implicate this region of the PF antigen in the pathogenesis of PF as well as in epidermal cell adhesion.

Animals↗
PubMed1990

Pemphigus foliaceus antigen: characterization of an immunoreactive tryptic fragment from BALB/c mouse epidermis recognized by all patients' sera and major autoantibody subclasses.

The pemphigus foliaceus antigen (PF Ag) is a 160-kDa desmosomal core glycoprotein, desmoglein I. A 50-kDa soluble immunoreactive fragment of the PF Ag was recently prepared from trypsinized cornified cell envelope preparations by papain treatment (R.S. Labib et al. 1989, J. Invest. Dermatol. 93, 272-279). This papain fragment (pf-PF) is associated with upper cell layers of the epidermis and appears to be trypsin resistant in situ. The present work describes the preparation of another fragment by trysinization of the viable lower cells of the epidermis of neonatal BALB/c mice. This tryptic fragment (tf-PF) is a 45-kDa glycoprotein that is partially purified by concanavalin A affinity chromatography of the trypsinization medium. The partially purified tf-PF preparation is capable of completely blocking the indirect immunofluorescence of high titer PF sera. The tf-PF is immunoprecipitated by all PF sera tested (n = 19) and by the two major subclasses of PF autoantibodies, IgG1 and IgG4. Autoantibodies of both the predominant IgG4 and the less prevalent IgG1 subclasses precipitate the same tf-PF as demonstrated by a single compact spot of pI 5.5 by two-dimensional polyacrylamide gel electrophoresis. Chemical and immunological comparison of the tf-PF and pf-PF may explain why the acantholytic lesions of PF appear only in the upper epidermis, despite the presence of the PF Ag throughout all layers of the epidermis. The availability of these two soluble immunoreactive fragments of the PF Ag will be of great value for the further immunochemical characterization of the antigenic epitopes and their role in cell-cell adhesion.

Animals↗
PubMed1990

A soluble and immunoreactive fragment of pemphigus foliaceus antigen released by trypsinization of viable human epidermis.

Pemphigus foliaceus (PF) antigen is a transmembrane desmosomal glycoprotein (desmoglein I), part of which is located on the keratinocyte surface. Previous studies have shown that after trypsinization of viable human epidermis, this antigen is no longer detected on the surface of detached keratinocytes. It was not known, however, if this loss of antigenic activity was due to destruction, internalization, or cleavage of the antigen itself. In the present study we investigated the fate of the PF antigen after trypsinization of viable human skin. By using Concanavalin-A agarose affinity chromatography, we could partially purify an antigenic glycoprotein fraction that was released by trypsinization into the medium. This antigenic fraction was radiolabeled and tested by immunoprecipitation using sera from endemic pemphigus foliaceus or fogo selvagem (FS), non-endemic pemphigus foliaceus (NEPF), pemphigus vulgaris (PV), and bullous pemphigoid (BP) patients, and sera from normal subjects as controls. Immunoprecipitated labeled proteins were analyzed by SDS-PAGE and autoradiography. All FS sera (20 of 20 FS and five of five NEPF) and 46% of the PV sera (six of 13) immunoprecipitated a band of 45-kD molecular weight. Sera from FS patients in prolonged clinical and serological remission (seven of 10), sera from BP patients (five of five), and sera from normal donors (nine of nine) did not precipitate this 45-kD band. This study showed that a fragment of the PF antigen is released by trypsinization of human skin as a soluble immunoreactive glycopeptide of 45-kD molecular weight. Additionally, this procedure has generated sufficient quantities of the PF antigen for further biochemical characterization.

Antigens, Surface↗
PubMed1990

Studies of the relationship of the 230-kD and 180-kD bullous pemphigoid antigens.

In bullous pemphigoid (BP), autoantibodies from most patients recognize a high molecular weight 230-kD epidermal antigen (Ag) by immunoprecipitation. By Western immunoblotting, 50-70% of sera recognize the high molecular weight Ag, but 30-50% recognize a low molecular weight, 180-kD epidermal Ag. We examined the specificities of affinity-purified antibodies against these Ag. Antibodies specific for the 230- and 180-kD Ag were prepared by immunoaffinity against Ag immobilized on nitrocellulose and released by acid glycine. IgG eluted from the 230-kD Ag band retained its specific binding to the 230-kD Ag by immunoblotting, and bound to the epidermal basement membrane zone (BMZ) by indirect immunofluorescence (IF) and to hemidesmosomes by indirect immunoelectron microscopy (EM). IgG affinity purified by the 180-kD Ag band bound only the 180-kD Ag in immunoblotting, with no cross reaction to the 230-kD Ag, bound the epidermal BMZ by indirect IF, and also bound to hemidesmosomes in immuno-EM. IgG specific for the 230-kD Ag in immunoblotting immunoprecipitated only the 230-kD Ag, with no apparent precipitation of the 180-kD Ag. Surprisingly, IgG specific for the 180-kD Ag precipitated both the 180- and the 230-kD Ag in immunoprecipitation, and the 230-kD Ag band was much more intense than the 180-kD Ag band. This study shows that apparent cross-reactivity between these Ag by BP autoantibodies can only be detected in native conditions by immunoprecipitation, and cannot be demonstrated using denatured Ag in immunoblotting. The two proteins appear to be distinct Ag, closely associated in the epidermal hemidesmosome, but the exact relationship of these Ag to each other may not be clarified until complete structural data become available.

Antibodies↗
PubMed1990

Monovalent Fab' immunoglobulin fragments from endemic pemphigus foliaceus autoantibodies reproduce the human disease in neonatal Balb/c mice.

Fogo selvagem (FS) is an autoimmune disease caused by IgG autoantibodies to desmoglein I (DG-I), a desmosomal glycoprotein. We have previously shown that the autoantibodies in these patients are pathogenic and restricted mainly to the IgG4 subclass. The purpose of this study was to determine if the Fc domain or the valence of FS autoantibodies were relevant in the induction of epidermal disease in neonatal mice. IgG4 was prepared from sera of FS patients by anion exchange chromatography, and digested with pepsin to yield F(ab')2 fragments. Monovalent FS Fab' were made by reduction and alkylation of FS F(ab')2. Intact FS IgG4, FS F(ab')2, and FS Fab' fragments were injected into neonatal mice. Intact FS IgG4 and both FS IgG fragments were pathogenic. The disease in the animals was dose dependent, and on the molar basis, FS Fab' fragments were more potent and efficient in producing disease than whole FS IgG. These results suggest: (a) simple binding of FS autoantibodies to DG-I may trigger keratinocyte detachment and epidermal disease; (b) DG-I may represent a keratinocyte cell adhesion molecule; and (c) complement activation and surface cross-linking may not be relevant in keratinocyte detachment.

Animals↗
PubMed1989

The pathogenic effect of IgG4 autoantibodies in endemic pemphigus foliaceus (fogo selvagem).

Endemic pemphigus foliaceus, or fogo selvagem, is an autoimmune blistering skin disease caused by IgG autoantibodies to a desmosome-associated glycoprotein. We studied the IgG subclasses with autoantibody activity in serum from 29 patients with active disease and in the skin lesions of 18 patients by immunofluorescence, using IgG-subclass-specific monoclonal antibodies. The predominant disease autoantibodies present in all patients were of the IgG4 subclass. IgG1 and IgG2 autoantibodies were detected in low titer in the 29 patients: IgG1 in 23 patients and IgG2 in 9. IgG3 autoantibodies were not detected in the serum of any patient. Direct immunofluorescence testing of skin lesions showed a preferential deposition of IgG4 on the keratinocyte surface. The pathogenic effect of IgG4 was demonstrated by the passive transfer of fractions containing IgG4 autoantibodies from the patients to neonatal BALB/c mice. The disease of the patients was reproduced clinically, histologically, and immunologically in these animals. Only IgG4 autoantibodies were detected by direct immunofluorescence, bound to the epidermis in the lesions of the mice, and by immunoelectron microscopy at the keratinocyte surface. IgG4 has previously been reported to be a blocking or protective antibody because it has poor effector functions in vitro, as compared with the other IgG subclasses. The finding that it is the pathogenic autoantibody in fogo selvagem raises the possibility that it may also be important in other autoimmune disease.

Animals↗
PubMed1989

Selective surface radioiodination of keratinocytes in primary culture labels a 59 kD keratin and other surface proteins.

Murine keratinocytes were vectorially labeled in order to identify and characterize surface proteins. Freshly trypsinized keratinocytes were obtained from neonatal BALB/c mice and primary cultures were established. Cells were radiolabeled with iodogen and 125I immediately after harvesting and after 4, 24, 48, and 72 h in culture. Cells were solubilized with 1% sodium dodecyl sulfate (SDS) and reducing agents (total extract), or sequentially extracted with: (a) 1% Triton X-100 (membrane/cytosol fraction); (b) 2 M NaCl (salt fraction); and (c) 1% sodium dodecyl sulfate (SDS; cytoskeleton fraction). Extracts were analyzed by 1- or 2-D polyacrylamide gel electrophoresis (PAGE), followed by autoradiography (AR). The 59 kD acidic murine keratin was identified by immunoblot analysis with monoclonal antibody AE1 and a human polyclonal anti-59 kD keratin autoantibody designated Cascas-42. Total extracts contained up to ten labeled proteins ranging from 10 to 180 kD. Eight of these proteins were present in the membrane/cytosol fraction (10, 12, 18, 30, 38, 41, 66, and 130 kD). Intense labeling of a 59 kD cytoskeletal protein was consistently seen; this protein was identified as the 59 kD acidic murine keratin (Moll's catalogue no. 10) by immunoblot analysis of extracted proteins separated by 1-D and 2-D PAGE. A 180 kD protein had variable solubility characteristics, fractionating with either the cytoskeleton or membrane/cytosol as a function of time. No labeled proteins were detected in the salt extract, and neither actin nor other major cytoskeletal proteins were radiolabeled. These studies demonstrate the cell-surface disposition of at least ten keratinocyte proteins, and suggest that the 59 kD murine acidic keratin has a surface-exposed domain.

Animals↗
PubMed1989

Definition of bullous pemphigoid antibody binding to intracellular and extracellular antigen associated with hemidesmosomes.

Bullous pemphigoid (BP) antibodies are deposited predominantly in the lamina lucida in vivo; however, circulating BP antibodies bind in vitro to the cytoplasmic plaque of basal cell hemidesmosomes. We examined the ability of IgG in nine BP sera to bind to intracellular or extracellular antigen. On skin cryosections, indirect IF showed IgG bound to basement membrane zone (BMZ) and indirect ImmunoEM confirmed intracellular binding on the cytoplasmic plaque of hemidesmosomes. In contrast, when normal skin was exposed to BP serum in organ culture, direct IF showed fainter linear deposition of IgG along the BMZ, and direct ImmunoEM demonstrated extracellular IgG binding in the lamina lucida, predominantly beneath hemidesmosomes. Four of nine sera showed complement fixation on indirect IF samples (IgG bound to intracellular antigen) and three showed complement fixation on direct IF specimens (IgG bound to extracellular antigen). Three of the nine sera contained complement fixing antibodies detectable only in antibody populations specific for intracellular or extracellular antigen. Western immunoblots showed that five of nine sera recognized a 240-kD protein and four of nine recognized a 180-kD protein. There was no correlation between the presence (or absence) of either band and the detection of complement fixing antibodies specific for intracellular or extracellular antigen. BP autoantibodies bind both intracellular and extracellular antigen, and IgG binding exclusively to extracellular antigen that mimics the in vivo situation can be detected by using organ culture. Complement fixation may be restricted to antibodies specific for intracellular or extracellular antigen. These findings underscore the complexity of the autoantibody-antigen system in BP and have implications regarding the proposed pathogenicity of the autoantibodies.

Antigen-Antibody Reactions↗
PubMed1989

Pemphigus foliaceus antigen: characterization of a keratinocyte envelope associated pool and preparation of a soluble immunoreactive fragment.

In both the endemic and sporadic forms of pemphigus foliaceus (PF), antiepidermal autoantibodies against desmoglein I are present. Desmoglein I is a highly insoluble 160-kD transmembrane glycoprotein of the desmosomal core. The detailed immunochemical characterization of the epitope(s) recognized by the PF autoantibodies is hampered by its large molecular weight and the insolubility of desmoglein I in nondenaturing buffers. This study was designed to identify alternative methods that could yield soluble immunoreactive PF antigen (Ag) from normal human epidermis. The presence of PF Ag in human epidermis and in its soluble or insoluble fractions was monitored by indirect immunofluorescence, immunoadsorption of PF sera, and immunoprecipitation of radiolabeled fractions. The PF Ag from trypsin-resistant, radiolabeled cell envelope preparations was cleaved by papain and immunoprecipitated by PF sera. A 50-kD peptide, isoelectric at pH 5.5-5.8, was immunoprecipitated by sera from all patients with endemic PF (n = 15) or idiopathic PF (n = 4), and by two of four pemphigus vulgaris sera, but by no control sera (n = 7). This study shows that a significant fraction of the PF Ag is insoluble, trypsin-resistant, and is associated with the cornified cell envelope fraction, but an Ag fragment can be obtained in a small molecular weight, soluble, and immunoreactive form by papain digestion. This 50-kD papain fragment is more amenable to detailed chemical and immunologic characterization than the native molecule.

Antigens↗
PubMed1989

Ultrastructural studies of acantholysis induced in vivo by passive transfer of IgG from endemic pemphigus foliaceus (Fogo Selvagem).

Intraperitoneal (IP) injections of IgG from patients with Endemic Pemphigus Foliaceus [Fogo Selvagem (FS)] cause acantholysis in BALB/c mice (JID. 85:538, 1985). The dynamic ultrastructural changes of FS IgG-induced acantholysis in mice are the subject of this study. FS IgG was injected IP into neonatal BALB/c mice. Skin and serum was studied at 0, 1, 3, 6, 12, 18, and 24 h post injection by immunofluorescence (IF), electron microscopy (EM), and immuno-EM. Binding of FS IgG in the intercellular spaces (ICS) of the basal cell layer was seen by IF within 1 h and was strongest at 12 h. IgG binding affected the spinous and granular cell layer by 12 h, then faded and remain localized only in the basal cell layer at 24 h. By immuno-EM, IgG binding was diffuse along the keratinocyte surface. Edema of the ICS in the basal cell layer was present at 1 h by EM. At 12 h, there was microvillous formation with intact desmosomes at the tip of the projections. Splitting of desmosomes (forming half desmosomes) and acantholysis primarily affecting the granular cell layer were most prominent between 12 and 24 h. The plaques of the half desmosomes gradually disappeared and tonofilaments retracted into the cytoplasm. Detaching keratinocytes showed vacuolization, swollen mitochondria, and internalization of intact desmosomes and half desmosomes (remnants of split desmosomes). This investigation shows that the ultrastructural changes observed in the epidermis of patients with FS can be duplicated in experimental animals by IP injection of FS IgG. Further, FS IgG may have direct effects on the assembly/disassembly of desmosomes.

Acantholysis↗
PubMed1988

Herpes gestationis autoantibodies recognize a 180-kD human epidermal antigen.

Herpes gestationis (HG) is a putative autoimmune bullous dermatosis of pregnancy which shares many findings with bullous pemphigoid (BP), a disease of the elderly. This study identifies for the first time the antigen detected by HG autoantibodies and compares it with that recognized by BP autoantibodies. Sera from 16 HG and 17 BP patients, and from normal pregnant women were evaluated by immunofluorescent (IF) studies and immunoblotted against human epidermal extracts. 89% of HG sera with circulating antibodies by IF recognized a 180-kD protein by immunoblotting. 71% of BP sera recognized a 240-kD band, but 47% detected a 180-kD protein that comigrated with the antigen detected by HG sera. None of the control sera recognized any specific bands. These findings suggest that the 180-kD epidermal protein may be the antigen detected by the HG factor and they also define immunologic similarities between HG and BP.

Autoantibodies↗
PubMed1987

An autoantibody in pemphigus serum, specific for the 59 kD keratin, selectively binds the surface of keratinocytes: evidence for an extracellular keratin domain.

We have identified a novel IgG antikeratin autoantibody in the serum of a Brazilian pemphigus foliaceus patient (Cascas-42). This antibody is specific for the 59 kD acidic murine keratin and its 56.5 kD human counterpart (Moll's catalogue #10), and is distinct from the pemphigus antibody system. Antikeratin autoantibodies present in the Cascas-42 serum were purified by affinity chromatography with a 59 kD murine keratin-agarose column (IAP-Cascas-42 antibodies). The specificity of the IAP-Cascas-42 antibodies was tested by indirect immunofluorescence and immunoelectron microscopy against epidermal cryosections, trypsin-dissociated keratinocytes, and epidermal cell cultures. The serum was also tested with extracts from unlabeled and surface 125I-labeled keratinocytes (Iodo-Gen method) by immunoblot analysis of one- and two-dimensional polyacrylamide gel electrophoresis. The IAP-Cascas-42 antibodies bind the intercellular spaces of murine epidermis, and the cell surfaces of viable, dissociated murine keratinocytes, as well as murine epidermal cells in culture by immunofluorescence and immunoelectron microscopy. These autoantibodies did not stain cytoplasmic keratins and did not react with parallel human epidermal substrates. The Cascas-42 serum identified the 59 kD murine acidic keratin and its 56.5 kD human counterpart in epidermal extracts by two-dimensional polyacrylamide gel electrophoresis and immunoblot analysis. In addition, surface radioiodination of viable murine keratinocytes selectively labeled the 59 kD keratin suggesting that a domain of this molecule is exposed on the cell surface. The 125I-labeled 59 kD keratin was also recognized by the Cascas-42 serum by immunoblotting and autoradiography. These studies suggest that in murine epidermis, the 59 kD keratin is a transmembrane protein with an extracellular domain recognized by the IAP-Cascas-42 antibodies.

Animals↗
PubMed1986

Defining the role of complement in experimental pemphigus vulgaris in mice.

Parenteral passive transfer of human pemphigus vulgaris IgG (PV IgG) into neonatal mice reproduces the cutaneous disease. We used this model to study the role of complement in the development of acantholysis in three steps. Peptic F(ab')2 fragments were prepared from PV IgG and were injected into seven newborn mice, and all animals developed acantholytic skin blisters without local complement activation, as shown by direct immunofluorescence. These fragments were reduced and alkylated to produce Fab' fragments with equivalent in vitro binding activity. The monovalent fragments were given in an identical fashion to five littermates but failed to produce disease even though they were bound in the epidermis in vivo. Intact PV IgG was injected in 20 genetically C5-deficient neonates (B10-D2-OSN strain) and 20 control neonates (B10-D2-NSN, normal complementemic). Extensive blistering, with a positive Nikolsky sign, was produced in all 40 animals. PV IgG was given to 34 BALB/c neonates that were complement depleted by pretreatment with cobra venom factor (CoF) for 24 hr, and to 38 untreated neonates from the same litters. There was no difference in the disease produced after CoF treatment in animals that received high doses of PV IgG (5 to 15 mg/g/day). In animals receiving 2.5 mg PV IgG/g/day, blister formation was delayed and the final extent of the cutaneous lesions was less in CoF-treated mice (n = 12) than in normal complementemic controls (n = 12, p less than 0.02). These results show that complement activation is not an essential mechanism in PV IgG-induced acantholysis in vivo, but it does have an amplifying effect on the development of cutaneous lesions under certain conditions, and lesions can be induced in vivo by bivalent F(ab')2 fragments of PV IgG, but not by the monovalent Fab' fragments, suggesting that cross-linking of the cell surface antigen is an initiating signal in acantholysis.

Acantholysis↗
PubMed1986

Molecular heterogeneity of the bullous pemphigoid antigens as detected by immunoblotting.

Sera from 28 patients with bullous pemphigoid (BP), four patients with cicatricial pemphigoid (CP), and 24 controls (normal volunteers and patients with pemphigus, systemic lupus erythematosus, or other skin diseases) were tested against extracts of human epidermis by immunoblotting techniques. The extraction buffer included 1% SDS, 5% beta-mercaptoethanol, and six protease inhibitors with various specificities. BP sera from individual patients showed different patterns of reactivity with the same epidermal extract, and each pattern consisted of one or more bands. A total of five bands of 240 kD, 200 kD, 180 kD, 97 kD, and 77 kD reacted with BP sera; the 240-kD band reacted with one CP sera, and none of these bands was detected by the control sera. The 240-kD and 180-kD bands reacted very strongly with some sera and were most frequently observed (43% and 29%, respectively). The 200-kD, 97-kD, and 77-kD bands were less frequently observed (25%, 7%, and 7%, respectively), but when present, their reactions were usually strong. Eleven percent of the BP sera did not react with any bands. Contrary to previous reports, this study shows that BP autoantibodies react with several protein bands, as detected by immunoblotting. We have recently shown by immunoelectron microscopy that BP autoantibodies bind to the basal cell hemidesmosomes. It remains to be determined which of these protein bands represent specific hemidesmosomal proteins and which antibody-antigen interactions are relevant to the pathogenesis of this disease.

Antigen-Antibody Reactions↗
PubMed1986

Elevated thymosin alpha I levels in Brazilian pemphigus foliaceus.

Levels of thymosin alpha I in the sera of 37 patients with Brazilian pemphigus foliaceus (BPF) were measured using a competitive binding radioimmunoassay. The values were compared with 19 patients with other forms of pemphigus, 13 relatives of patients with BPF, 18 patients with other dermatological diseases, and 265 normal controls. We found that 27 (73%) of the patients with BPF had thymosin alpha I serum levels that were at least two standard deviations above the mean for normal individuals. The mean value for patients with BPF was significantly greater than any other groups studied. The thymosin elevation is similar to alterations seen in certain viral diseases and suggests that BPF is aetiopathogenically distinct from the forms of pemphigus.

Adult↗