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H H Pas

Publications and source records attributed to H H Pas.

At least 19 recordsLinked to original sources
PubMed2005

Inflammatory epidermolysis bullosa acquisita with coexistent IgA antibodies to plectin.

We present a case of inflammatory epidermolysis bullosa acquisita (EBA) with IgA antibodies to plectin. Analysis of lesional skin biopsies by electron microscopy revealed the split level to be in the sublamina densa zone, corresponding to the diagnosis of EBA. Direct immunofluorescence of perilesional skin demonstrated u-serrated depositions of IgG and IgA that under immunoelectron microscopy were shown to be located in the sublamina densa. In contrast, indirect immunofluorescence on salt-split skin revealed circulating IgA antibodies that stained the roof rather than the floor of the blister. Immunoblotting showed these serum antibodies to be directed to the cytoplasmic hemidesmosomal antigen plectin. The antiplectin specificity of these antibodies was confirmed by 'knockout' immunofluorescence analysis; the serum IgA did not bind to skin sections of a patient with plectin-deficient epidermolysis bullosa. To our knowledge, this case demonstrates for the first time the existence of IgA antibodies against plectin.

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PubMed2004

A very mild form of non-Herlitz junctional epidermolysis bullosa: BP180 rescue by outsplicing of mutated exon 30 coding for the COL15 domain.

Mutations in the gene COL17A1 cause non-Herlitz junctional epidermolysis bullosa. Here, we describe a patient who, despite two heterozygous mutations in COL17A1, has an extremely mild form of the disease missing most of the characteristic clinical features. DNA analysis revealed a frame-shift mutation 3432delT and a nonsense mutation 2356C-->T (Q751X). cDNA analysis showed that the deleterious effect of the latter mutation was skirted by deleting the premature termination codon containing exon 30. In this way, the reading frame was restored, resulting in a 36 nucleotides shorter mRNA transcript. Immunoblot analysis showed expression of the 180-kDa bullous pemphigoid antigen (BP180) with a slightly higher SDS-PAGE mobility, in line with the deletion of 12 amino acids from the COL15 domain. Immunofluorescence of skin sections showed diminished, but correctly localised expression of BP180, and this, in concert with the mild clinical phenotype, suggests that this COL15 mutated BP180 is still partly functional.

Autoantigens↗
PubMed2004

U-serrated immunodeposition pattern differentiates type VII collagen targeting bullous diseases from other subepidermal bullous autoimmune diseases.

BACKGROUND: Epidermolysis bullosa acquisita (EBA) can be differentiated from other subepidermal bullous diseases by sophisticated techniques such as immunoelectron microscopy, salt-split skin antigen mapping, fluorescence overlay antigen mapping, immunoblot and enzyme-linked immunosorbent assay. OBJECTIVES: To determine whether the diagnosis can also be made by routine direct immunofluorescence microscopy. METHODS: We studied frozen skin biopsies from 157 patients with various subepidermal immunobullous diseases. RESULTS: We found three distinct 'linear' fluorescence patterns at the basement membrane zone: true linear, n-serrated and u-serrated. The true linear pattern, often seen in conjunction with either the n- or the u-serrated pattern, was found in any subepidermal immunobullous disease with nongranular depositions. In bullous pemphigoid, mucous membrane pemphigoid, antiepiligrin cicatricial pemphigoid, p200 pemphigoid and linear IgA disease the n-serrated pattern was found, corresponding with depositions located in hemidesmosomes, lamina lucida or lamina densa. However, in EBA and bullous systemic lupus erythematosus the u-serrated staining pattern was seen, corresponding with the ultralocalization of type VII collagen in the sublamina densa zone. The diagnosis of EBA with IgG or IgA autoantibodies directed against type VII collagen was confirmed by immunoelectron microscopy, salt-split skin antigen mapping, fluorescence overlay antigen mapping or immunoblotting. CONCLUSIONS: Using this pattern recognition by direct immunofluorescence microscopy we discovered several cases of EBA which would otherwise have been erroneously diagnosed as a form of pemphigoid or linear IgA disease.

Basement Membrane↗
PubMed2004

Features of epidermolysis bullosa simplex due to mutations in the ectodomain of type XVII collagen.

BACKGROUND: Mutations in COL17A1, coding for type XVII collagen, cause junctional epidermolysis bullosa with an ultrastructural plane of cleavage through the lamina lucida of the epidermal basement membrane. OBJECTIVES: To identify the COL17A1 mutations in a child with reduced type XVII collagen expression and intraepidermal blister formation. PATIENT AND METHODS: Protein expression and level of tissue separation were studied by immunofluorescence and electron microscopy. The mutations were identified by analysing the patient's DNA and mRNA. RESULTS: Immunofluorescence microscopy performed on nonlesional skin demonstrated absence of the type XVII collagen endodomain and presence, although reduced, of the shed ectodomain. Electron microscopy showed that the plane of cleavage was through the basal cells, not through the lamina lucida. Two heterozygous mutations were identified in COL17A1: a new 3'-acceptor splice-site mutation in intron 21 (1877-2A-->C), and a deletion in exon 48 (3432delT). The splice-site mutation in intron 21 results in alternative transcripts of which two are in-frame, with deletions of the first nine codons of exon 22 and the entire exon 22, respectively. By Western blot analysis, a type XVII collagen molecule was detected that was slightly smaller than normal. CONCLUSIONS: Occasionally mutations in the COL17A1 gene may result in split levels suggesting epidermolysis bullosa simplex rather than junctional epidermolysis bullosa.

Autoantigens↗
PubMed2002

Contact allergens in shoe leather among patients with foot eczema.

Some patients with relapsing foot eczema and a shoe leather allergy, who fail to show positive results with standard series and shoe wear screening tray patch testing, do not respond to the use of hypoallergenic shoe leather. We assume that relevant allergens are present in hypoallergenic shoe leather. We described an experiment to demonstrate the presence of these allergens. Alcoholic extracts were made of green, black and undyed hypoallergenic shoe leather, and the extracts were fractioned by paper chromatography. The resulting chromatograms were cut into 16 equal paper disks and patch tests were performed with extracts and the paper chromatography fractions. Positive reactions were seen to all extracts and to fractions of all types of leather. From analysis of the pattern of positive patch tests we concluded that leather-related allergens (e.g. tanning agent) and dyes were present in hypoallergenic shoe leather. In these cases, alternatives to shoe leather should be sought, for instance wooden or plastic shoes.

Dermatitis, Allergic Contact↗
PubMed2001

Paraneoplastic pemphigus as the initial presentation of chronic lymphocytic leukemia.

The case history of a 61-year-old male patient is described, who presented with severe stomatitis, conjunctivitis and leukocytosis. The diagnosis chronic lymphocytic leukemia (CLL) stage A (0) was made, for which no treatment was necessary. Progression of stomatitis and conjunctivitis and erythosquamous skin lesions with bullae and vesiculae formation developed. Under the diagnosis of bullous pemphigoid the patient was treated with corticosteroids. The histologic and immunofluorescence examination of a skin biopsy was compatible with this diagnosis, and antibodies to skin could not be detected in a first serum sample. Pseudomonas was cultured from all lesions, the corticosteroids were stopped and antibiotic treatment was started, without clear effect. Because of progression of skin lesions and debilitation, the patient finally declined all treatment and died five weeks after admission. Post-mortem examination showed enlarged lymphnodes in the cervical, aortal en iliacal areas, with histology confirming the diagnosis of CLL. Indirect immunofluorescence with the second serum sample showed auto-antibodies in high titer directed against the intercellular epithelial substance. Immunoblot studies showed binding with the classic target antigens in paraneoplastic pemphigus. Re-examination of the histologic skin specimen and the result of direct immunofluorescence were in retrospect compatible with the diagnosis of paraneoplastic pemphigus.

Adrenal Cortex Hormones↗
PubMed2001

Truncated typeXVII collagen expression in a patient with non-herlitz junctional epidermolysis bullosa caused by a homozygous splice-site mutation.

SUMMARY: Type XVII collagen (180-kDa bullous pemphigoid antigen) is a structural component of hemidesmosomes. Mutations in the type XVII collagen gene (COL17A1) have been established to be the molecular basis of non-Herlitz junctional epidermolysis bullosa (JEB-nH), an inherited skin blistering disorder. Here we report for the first time truncated type XVII collagen expression, caused by homozygosity for a COL17A1 donor splice-site mutation (4261+1 g --> c), which was identified by PCR amplification on genomic DNA. By RT-PCR and sequencing of cDNA derived from mRNA from the patient's cultured keratinocytes, we provide evidence of cryptic splicing and exon skipping, most abundantly of exon 52. JEB-nH patients with COL17A1 splice-site mutations resulting in an exon skip often have no immunologically detectable type XVII collagen. However, in our patient with the generalized atrophic benign epidermolysis bullosa subtype, a small amount of type XVII collagen was detectable in the skin, and immunoblotting of cultured keratinocytes revealed that the 180-kDa protein was 10 kDa shorter. We hypothesize that the function of this truncated type XVII collagen polypeptide, which is expressed at low levels, is impaired, explaining the JEB-nH phenotype.

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PubMed2001

Linear IgA bullous dermatosis in a patient with renal cell carcinoma.

Linear IgA bullous dermatosis (LABD) is an autoimmune subepidermal bullous disease with heterogeneous clinical manifestations, characterized by linear deposition of IgA along the epidermal basement membrane zone. We report a patient with a metastasized renal cell carcinoma who developed an extensive blistering eruption. The lesions showed immunopathological findings characteristic of LABD. The patient showed a fair response to prednisolone and dapsone. Treatment to control the LABD was no longer required when interferon-alfa was started as palliative therapy for the metastasized renal cell carcinoma. The association of LABD and malignancies has been documented before and is not due to mere chance alone.

Autoimmune Diseases↗
PubMed2001

False-negative results in immunoblot assay of serum IgA antibodies reactive with the 180-kDa bullous pemphigoid antigen: the importance of primary incubation temperature.

BACKGROUND: Different subepidermal autoimmune blistering skin disorders are characterized by linear deposition of IgA, sometimes accompanied by linear IgG, along the epidermal basement membrane zone. Identification of the targeted autoantigen is usually attempted by immunoblotting. Although immunoblotting works well for human IgG, the method is less successful for IgA and often no or only faint signals are obtained. OBJECTIVES: To improve the method of immunoblotting for diagnosis of IgA-mediated bullous dermatoses. METHODS: Eleven sera, selected from patients with linear deposition of IgA along the epidermal basement membrane zone in vivo, were tested by immunoblotting for antigen specificity using different primary incubation temperatures. RESULTS: No reliable information regarding IgA antigen specificity was obtained when the primary incubation was undertaken at room temperature. In 10 of 11 sera, IgA bound to the 180-kDa bullous pemphigoid antigen (BP180) when the primary incubation temperature was increased to 37 degrees C. CONCLUSIONS: Primary incubation at room temperature may result in false-negative results in the IgA-BP180 immunoblot assay.

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PubMed2000

Inflammatory variant of epidermolysis bullosa acquisita with IgG autoantibodies against type VII collagen and laminin alpha3.

BACKGROUND: The inflammatory variant of epidermolysis bullosa acquisita (EBA) may clinically closely resemble bullous or cicatricial pemphigoid. Patients with inflammatory EBA have IgG autoantibodies against type VII collagen. Patients with anti-epiligrin cicatricial pemphigoid have IgG autoantibodies against laminin 5. OBSERVATION: We describe a patient with inflammatory EBA exhibiting nonscarring oral and vaginal involvement. Indirect immunofluorescence using skin substrate lacking an epidermal basement membrane molecule, direct immunoelectron microscopy, immunoblot, and immunoprecipitation studies revealed the simultaneous presence of circulating IgG autoantibodies against type VII collagen and laminin alpha3. A final diagnosis of EBA was based on the sublamina densa level of blister formation. CONCLUSION: This case illustrates the clinical and immunological overlap between EBA and anti-epiligrin cicatricial pemphigoid, a unique finding that may have developed as a consequence of epitope spreading.

Autoantibodies↗
PubMed2000

Paraneoplastic pemphigus caused by an epithelioid leiomyosarcoma and associated with fatal respiratory failure.

A patient is described who initially presented with pemphigus vulgaris, limited to the oral cavity, and weight loss. Although the various laboratory studies pointed to the diagnosis of paraneoplastic pemphigus (PNP), the underlying neoplasm was not detected until 6 months later, when the patient developed shortness of breath and routine physical examination on admission revealed an abdominal mass, which eventually was proven to be an epithelioid leiomyosarcoma. In spite of radical excision of the tumour and intensive treatment of the dyspnoea, the patient died of respiratory failure 19 months after the PNP had been diagnosed. Early diagnosis of PNP is stressed to possibly prevent fatal pulmonary involvement.

Abdominal Neoplasms↗
PubMed2000

Two type XVII collagen (BP180) mRNA transcripts in human keratinocytes: a long and a short form.

We have analysed BP180 mRNA expression in normal human keratinocytes. Here we report the presence in normal keratinocytes of two COL17A1 transcripts which differ by 0.6 kb in length. Both mRNAs hybridized on Northern blot with probes directed to sequences encoding intracellular and extracellular fragments of BP180. By BLAST homology search alignments we extended the 3' untranslated region (3'UTR) of the known BP180 mRNA sequence by 877 bases to completion. Three of 20 cDNAs identified by BLAST searches contained a 610 bp deletion in this new 3'UTR sequence. Northern blot analysis with a probe complementary to this deleted sequence showed binding only to the larger mRNA. The deletion of 610 nucleotides in the smaller mRNA was verified by reverse transcription-PCR and sequencing. Genomic PCR showed the new sequence to be an extension of exon 56 of the COL17A1 gene which suggests that the second mRNA is generated by differential splicing. In normal keratinocytes the level of the smaller transcript was 5-15% of that of the larger transcript whereas in a squamous cell carcinoma cell line this ratio was reversed, the smaller mRNA being three times more abundant than the larger mRNA. The biological significance of this newly identified transcript in protein synthesis and tissue expression or in cell differentiation, proliferation or adhesion is as yet unknown.

Autoantigens↗
PubMed1999

Type XVII collagen (BP180) and LAD-1 are present as separate trimeric complexes.

This study characterized the high molecular mass BP180 complex that is observed when unheated sodium dodecyl sulfate extracts of human skin or keratinocytes are subjected to sodium dodecyl sulfate-polyacrylamide gel electrophoresis and immunoblotting. In heated extracts BP180 is present as a monomer with a molecular weight of 180 kDa, in unheated extracts BP180 runs at a molecular weight position over 500 kDa. By preincubating the unheated extracts at temperatures between 31 degrees C and 40 degrees C, the high molecular weight complex could be "melted" down to monomeric BP180. Under the conditions employed the T1/2 of the dissociation process was between 35 degrees C and 36 degrees C. The temperature resistance of the high molecular weight complex was used to analyze its molecular composition by performing two-dimensional electrophoresis with a "low-temperature" first dimension step and a "high-temperature" second dimension step. Silver staining and immunoblotting of the two-dimensional gels revealed the high molecular weight complex to be composed of solely BP180, indicating that the complex is the nondissociated homotrimeric form of BP180. The 120 kDa linear IgA dermatosis antigen (LAD-1) is an collagenous anchoring filament protein with homology to the extracellular collagenous part of BP180. Two-dimensional immunoblotting showed that LAD-1, as BP180, is also present as a high molecular mass complex and does not form mixed complexes with BP180.

Autoantigens↗
PubMed1998

Paraneoplastic pemphigus as the presenting symptom of a lymphoma of the tongue.

A patient is described who initially presented with an acrovesicular eczema which subsequently developed into erythema multiforme with histopathological features of bullous pemphigoid. Although the various laboratory studies pointed to the diagnosis of paraneoplastic pemphigus (PNP), the underlying neoplasm was not detected until 6 months later, when the biopsies of an oral lesion showed the presence of an underlying non-Hodgkin lymphoma.

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