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D F Mutasim

Publications and source records attributed to D F Mutasim.

48 records · Page 3Linked to original sources
PubMed1987

Linear immunofluorescence staining of the cutaneous basement membrane zone produced by pemphigoid antibodies: the result of hemidesmosome staining.

Bullous pemphigoid autoantibodies bind the basement membrane zone of stratified squamous epithelium in a linear pattern, as shown by indirect immunofluorescence; however, other patterns of staining, such as tubular (with convolutions), cytoplasmic, and membranous, have been noted. Recently, by using indirect immunoelectron microscopy, we have shown that bullous pemphigoid antibodies bind specifically to hemidesmosomes. The purpose of this investigation was to correlate the various patterns of basement membrane zone staining by bullous pemphigoid antibodies by immunofluorescence and to correlate these patterns with the ultrastructural findings. We employed adult human skin, neonatal human foreskin, neonatal mouse skin, and rabbit cornea as substrates for electron microscopy and indirect immunofluorescence using bullous pemphigoid serum. For indirect immunofluorescence, cryosections were obtained at vertical, oblique, and horizontal planes with respect to the basement membrane zone. We show that the immunofluorescence band of basement membrane zone staining results from the coalescence of fluorescence from individual hemidesmosomes. We also show that the pattern of basement membrane zone staining depends on the ultrastructural morphology of the basement membrane zone in each tissue and on the angle of sectioning.

Animals↗
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↗
PubMed1987

Bullous pemphigoid autoantibodies are markers of corneal epithelial hemidesmosomes.

Sera from patients with bullous pemphigoid (BP) contain autoantibodies that bind to the BP antigen, which is a component of the epithelial-stromal junction of the cornea. Previous studies, employing direct immunoelectron microscopy (IEM) on perilesional skin of patients have localized the BP antigen to the lamina lucida. On this basis, studies of corneal epithelial-stromal adhesion and wound healing have employed BP antigen as a marker of the lamina lucida of the corneal basement membrane zone (BMZ). The authors used indirect IEM with BP autoantibodies on frozen sections of cornea and found that the majority of the BP antigen is intracellular and is closely associated with the corneal epithelial hemidesmosome. Only a small amount of BP antigen appears to be extracellular, limited to the portion of the lamina lucida directly beneath individual hemidesmosomes. When rabbit corneal epithelium is extracted and analyzed by Western immunoblotting, BP autoantibodies recognize two polypeptides of molecular weights of 240 and 180 kilodaltons, which comigrate with BP antigens extracted from epidermis. BP autoantibodies are a specific marker of corneal epithelial hemidesmosomes and can be used as a probe to identify and study the role of hemidesmosomes in epithelial-stromal adhesion.

Animals↗
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

Human pemphigus autoantibodies are pathogenic to squamous epithelium.

In 1957, Witbesky et al. put forward several criteria that ideally should be fulfilled in order to prove the pathogenic role of an autoantibody in a putative autoimmune disease. There can now be very little doubt of the autoimmune nature of this disease and of the primary role of autoantibodies in its pathogenesis. The evidence that supports the concept that pemphigus autoantibodies are of primary pathogenic importance in the disease is as follows: IgG class autoantibodies can be found both circulating in the serum and bound to the epithelial cell surfaces in and around lesions in patients with pemphigus. These autoantibodies, purified from the serum of pemphigus patients, can induce acantholytic lesions typical of pemphigus both in experimental animals (neonatal mice) and in human and murine epidermal cell cultures. These autoantibodies react with a specific antigen of the epidermal cell. This purified antigen has been used to immunize rabbits and the resulting antibodies are capable of inducing pemphigus-like lesions in neonatal mice.

Acantholysis↗
PubMed1985

A pool of bullous pemphigoid antigen(s) is intracellular and associated with the basal cell cytoskeleton-hemidesmosome complex.

Bullous pemphigoid (BP) antibodies are known to react with an antigen of the basement membrane zone (BMZ) of squamous epithelia and produce, by the indirect immunofluorescence technique, linear fluorescence at the BMZ. Direct and indirect immunoelectron microscopy (IEM) have demonstrated BP antigen to be within the lamina lucida, in close association with the basal cell membrane. Trypsin-dissociated epidermal basal cells bind BP antibodies in a polar distribution, presumably because the BP antigen is restricted to the dermal pole of the basal cell membrane. In this study we have utilized newborn BALB/c mouse skin to obtain both dissociated basal cells (by trypsinization) and epidermal sheets (by dithiothreitol treatment). We show that viable basal cells, which are impermeable to IgG molecules, do not react with BP antibodies. When the basal cell plasma membrane is disrupted by cytospin centrifugation, air drying, freezing and thawing, or hypotonic lysis, or permeated by nonionic detergents (saponin), cells become reactive with BP antibodies. Basal cell cytoskeletons, prepared by sequential treatment with Triton X-100, deoxyribonuclease, and 2 M NaCl continue to react with BP antibodies. Similarly, viable epidermal sheets fail to bind BP antibodies. When epidermal sheets are treated with nonionic detergents, water, or freezing and thawing prior to incubation with BP antibodies, linear BMZ fluorescence is observed. IEM study of saponin-treated basal cells shows the immunoreactants to be localized on intracytoplasmic vacuoles which represent internalized hemidesmosomes. IEM of permeated epidermal sheets shows the immunoreactants as aggregates on the inner surface of the dermal pole of the basal cell membrane. These observations suggest that the BP antigen is intracellular and is in close association with the basal cell cytoskeleton and hemidesmosomes.

Animals↗
PubMed1985

The use of human pemphigoid autoantibodies to study the fate of epidermal basal cell hemidesmosomes after trypsin dissociation.

It is known that during trypsinization of the skin, the epidermis is first separated from the dermis and individual keratinocytes are dissociated by disruption of the epidermal intercellular spaces. The desmosomal unit is separated at the level of the intercellular space and the split desmosomes are internalized in plasma membrane-limited vesicles; however the fate of the hemidesmosome under such conditions has not been studied. We have recently shown (Mutasim et al: J Invest Dermatol 84:47-53, 1985) that autoantibodies from the sera of patients with bullous pemphigoid bind in vitro to hemidesmosomes but not to desmosomes providing a highly specific marker for these organelles. Utilizing these autoantibodies, we studied the fate of the hemidesmosome during trypsin dissociation of epidermal basal cells derived from the skin of neonatal BALB/c mice. During trypsinization, portions of the dermal face of the plasma membrane which include hemidesmosomes formed pits which pinched off to produce vesicles that moved toward the nucleus. This was accompanied by retraction of the tonofilaments away from the cell periphery. The mechanism of this internalization process is not yet known, but may involve contractile elements of the cytoskeleton. The highly specific binding of bullous pemphigoid autoantibodies to the hemidesmosome may prove helpful in future biochemical and immunocytochemical studies of this organelle.

Animals↗
PubMed1984

Graft-versus-host disease in a patient with acute lymphoblastic lymphoma.

A young man with acute lymphoblastic lymphoma on chemotherapy developed acute graft-versus-host disease following nonirradiated blood transfusions during a period of pancytopenia. The importance of the cutaneous manifestations, in particular the histopathologic changes, in facilitating an early diagnosis of the disease are stressed. The question of irradiating blood transfusions for immunosuppressed patients with malignancies is discussed.

Adult↗
PubMed1983

Graft-versus-host disease in lymphoblastic lymphoma following blood transfusions.

The case of a 20-year-old man with lymphoblastic lymphoma in leukemic phase succumbing to acute graft-versus-host disease (GVHD) following intensive chemotherapy and blood transfusions is described. Such a documented association has rarely been reported in the literature. The issue of irradiating blood components prior to transfusion in patients with suspected cell-mediated immunodeficiency receiving intensive chemotherapy is raised and discussed.

Adult↗
PubMedDate not supplied

Milia en plaque of the eyelids in childhood: case report and review of the literature.

Milia en plaque is a rare type of primary milia. Most of the reported cases have occurred around the ears in adults. We report milia en plaque in a 10-year-old girl who presented with symmetrical erythematous plaques studded with milia on the eyelids. Histopathology revealed milia surrounded by a dense lymphocytic infiltrate. Administration of minocycline and manual expression of the milia successfully treated this condition.

Biopsy↗
PubMedDate not supplied

Linear IgA disease with clinical and immunopathological features of epidermolysis bullosa acquisita.

A 10-year-old boy had a 3-month history of urticarial plaques and vesicles. Histologic and immunofluorescence testing confirmed the diagnosis of linear IgA disease. Immunoelectron microscopy revealed IgA deposits in the sublamina densa area similar to those seen in epidermolysis bullosa acquisita. Milia developed after resolution of the lesions, similar to lesions of epidermolysis bullosa acquisita.

Basement Membrane↗