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Biomedical subjects

H Hintner

Publications and source records attributed to H Hintner.

At least 37 records · Page 2Linked to original sources

[Hereditary angioedema in the German-speaking region].

A multicentre, retrospective study of hereditary deficiency of C1-esterase inhibitor (C1-INH) function, a deficiency which clinically manifests as hereditary angioedema (HAE), was performed in six centres in Germany, Austria and Switzerland. 242 individuals were registered with proven functional or quantitative deficiency of C1-INH who belonged to kindered with disease manifestation in 2 to 6 generations. Considering the total population in the three countries and the number of registered individuals, a frequency of the deficiency of 0.02 x 10(-4) was calculated. As this epidemiological study involved only 6 centres, a 10 to 100 times higher frequency of C1-INH deficiency is estimated to be a more realistic value. Out of the 242 registered individuals 110 were evaluated for type and location of clinical manifestation of the deficiency, the laboratory data and the therapy outcome. 86 (78.2%) of the patients belonged to the "common type" and 24 (21.8%) to the "variant type" of HAE. In 53.9% of the cases first manifestation of the disease was before the age of 20 years. In only 3.9% of the patient population did the disease begin after 40 years of age. A mean time lag of 5,3 years was observed, between the first manifestation and correct diagnosis. Initial diagnosis was correct in only 31.8% of the cases of which dermatologists provided 51.7%. False diagnoses include urticaria (41.3%), allergy (20%), acute abdomen (18.7%), angina (8%), rheumatoid disease (5.3%) and intracranial haemorrhage, CNS tumour, epilepsy, migraine (5.3%). The distribution pattern of HAE resembled that of intolerance reactions and pseudoallergies. Urticarial lesions were not associated with C1-INH deficiency. 24% of the patients had at least one episode of laryngeal edema. 40% of patients were unable to identify a trigger of edema formation. The others indicated as triggers trauma, hormonal changes, mental stress, insect stings and in a few cases food and drugs. Menstruation and oral contraceptives aggravated or made disease manifestations more frequent. In contrast, during pregnancy in many cases clinical manifestations improved and delivery posed no problems. The possibility of HAO is very much suggested by the tailure of edema to respond to classical anti-allergic therapy. Therapy of choice of acute attacks is C1-INH concentrate. No side reactions, antibody formation or virus transmission have been observed. For long term prophylaxis danazol, an attenuated androgen, or tranexamic acid, a protease inhibitor, was chosen. The daily dose of danazol should be kept as low as possible because of its anabolic, anti-estrogenic, anti-gestagenic, and anti-gonadotropic effects. Indeed, adverse reactions were observed in 41.7% of patients receiving danazol. Frequencies of adverse reactions were twice as common in women as in men. Adverse reactions were dose dependent and reversible except for one woman with irreversible deepening of her voice. Measuring C1r is a effective way to assess C1-INH function and monitor therapy.

Adolescent↗

A deletion mutation in COL17A1 in five Austrian families with generalized atrophic benign epidermolysis bullosa represents propagation of an ancestral allele.

Patients with generalized atrophic benign epidermolysis bullosa, a usually nonlethal form of junctional epidermolysis bullosa, have generalized blistering, nail dystrophy, patchy alopecia, and dental abnormalities. Skin fragility in most cases is due to mutations in the gene encoding type XVII collagen (COL17A1). Recently, we reported five Austrian families with generalized atrophic benign epidermolysis bullosa who share the same COL17A1 mutation. Affected individuals in three families are homozygous for 4003delTC, whereas those in two others are compound heterozygotes. To determine if the occurrence of 4003delTC in these unrelated families signifies propagation of an ancestral allele or a mutational hot spot, haplotypes were determined for polymorphisms both within and flanking COL17A1. Five intragenic polymorphisms were chosen based on their informativeness. One of these, not previously reported, was 2988 A or C that introduces a new restriction site for Eco0109 I. All the 4003delTC alleles showed the same haplotype for these five polymorphic markers. Fourteen microsatellite polymorphisms were selected based on their high heterozygosity and their location within 10q23-q25 near COL17A1. Three families shared microsatellite polymorphisms covering at most 19 cM, whereas the others shared smaller regions consistent with cross-over events during passage of this mutation through several generations. These results indicate that 4003delTC occurs on a single ancestral allele.

Alleles↗

Cycloheximide facilitates the identification of aberrant transcripts resulting from a novel splice-site mutation in COL17A1 in a patient with generalized atrophic benign epidermolysis bullosa.

Patients with generalized atrophic benign epidermolysis bullosa often show decreased expression of type XVII collagen, a transmembrane hemidesmosomal protein encoded by COL17A1. This report documents a novel splice-site mutation in COL17A1 in a patient with generalized atrophic benign epidermolysis bullosa, and applies a new methodology to define and characterize the resulting mRNA splice variants. Mutational analysis of COL17A1 identified a maternally inherited G-to-T transversion at the -1 position of exon 32. This acceptor splice-site mutation led to the formation of aberrant transcripts present at extremely low levels. Based on our recent finding that cycloheximide stabilized mutant COL17A1 transcripts in keratinocytes homozygous for a frameshift mutation, the effects of the splice-site mutation on splicing of COL17A1 transcripts were determined using reverse transcriptase polymerase chain reaction of total RNA from keratinocytes incubated for 2.5 h in the presence or absence of 10 microg cycloheximide per ml. Using this approach, an abnormally spliced transcript was identified that contains an extra 264 bases upstream from exon 32, resulting in a premature termination codon 27 bp downstream from the cryptic splice site. Three other splice variants, including one derived from the skipping of exon 32, were also identified. These results indicate the usefulness of cycloheximide treatment in evaluating the abnormal processing of mRNA due to splice-site mutations, because: (i) aberrant splicing often generates a premature termination codon, (ii) transcripts with premature termination codons can occur at low or undetectable levels due to nonsense-mediated mRNA decay, and (iii) the levels of these transcripts can be increased by cycloheximide.

Adult↗

Intravenous immunoglobulin treatment in therapy-resistant epidermolysis bullosa acquisita.

Epidermolysis bullosa acquisita is an uncommon autoimmune bullous disease of the skin and mucous membranes. It is chronic, disabling, and difficult to treat. We describe a case of severe epidermolysis bullosa acquisita of 7 years' duration that had been treated with azathioprine, corticosteroids, chlorambucil, plasma exchanges, cyclophosphamide, cyclosporine, and colchicine without any lasting effect. Seven cycles of treatment were administered with immunoglobulin given intravenously at a low dose, 40 mg/kg body weight daily for 5 days. The patient was free of disease for 10 months after the initiation of therapy. We suggest that low-dose regimens of immunoglobulins may be as effective in this disease as the high-dose regimens suggested in the literature, and at much lower cost.

Adult↗

Premature termination codons are present on both alleles of the bullous pemphigoid antigen 2/type XVII collagen gene in five Austrian families with generalized atrophic benign epidermolysis bullosa.

Patients with generalized atrophic benign epidermolysis bullosa (GABEB), an inherited subepidermal blistering disease, often have no immunologically detectable bullous pemphigoid antigen 2 (BPAG2) in their epidermal basement membrane. Recently, we analyzed the BPAG2 gene (GenBank no. M91669) in an Austrian family with GABEB and identified a homozygous deletion mutation, 4003delTC, that results in a downstream premature termination codon (PTC). This mutation has now been identified in additional descendants, suggesting transmission of this mutant allele through at least six generations. Screening of four other Austrian GABEB families revealed that affected members were homozygous for 4003delTC in two cases and heterozygous in two others. In the latter, mutational analysis identified two novel nonsense mutations, Q1403X and G803X, that were confirmed by restriction endonuclease digestions. Thus, PTCs on both alleles of BPAG2 are present in all of these GABEB families. Immunoprecipitation and northern blot studies of cultured keratinocytes from homozygous GABEB patients show that 4003delTC results in undetectable levels of BPAG2 protein and mRNA-findings consistent with the process of nonsense-mediated mRNA decay. Incubating keratinocytes with cycloheximide increased BPAG2 mRNA to a level detectable by northern analysis. When the latter was used in reverse transcription-PCR studies, the mutation was demonstrated, suggesting that cycloheximide may allow mutational analysis in cases where low transcript levels have previously thwarted RT-PCR studies. These findings account for the absence of BPAG2 in GABEB patients and attest to the importance of this protein in adhesion of epidermis to epidermal basement membrane.

Alleles↗

Generalized atrophic benign epidermolysis bullosa.

Junctional EB was once considered a uniformly fetal autosomal recessive skin disease. One of the first and best characterized forms of generalized JEB that has a more favorable prognosis was GABEB. Since its initial description in 1976, many additional cases have been compiled, all sharing the features of chronic blistering from birth, nail dystrophy, hair loss, and abnormal teeth. In addition, some patients have large melanocytic nevi that form at sites of prior blisters. The first clues as to the protein defective in these patients was provided by immunofluorescence microscopy studies, which showed absent or decreased expression of type XVII collagen in these patient's epidermal BM. This protein was a promising candidate because it is located in the ultrastructural plane where blisters from in patients with GABEB. It is also the same hemidesmosomal protein against which antibodies are directed in patients with autoimmune blistering diseases: bullous, gestational, and cicatricial pemphigoid. The demonstration of decreased expression of type XVII collagen in patients with GABEB pointed the way to a crucial distinction that could not be based on clinical and histologic findings--that of discriminating infants with GABEB from those with the lethal Herlitz variant of JEB. These two diseases may be differentiated because decreased expression of type XVII collagen is found exclusively in GABEB, whereas decreased expression of laminin 5 is most likely associated with Herlitz JEB. The molecular basis of GABEB has been determined. The immunofluorescence microscopy studies mentioned above directed mutation studies to the COL17A1 gene. Several mutations in COL17A1 have been described in patients with GABEB, almost all of which result in a PTC. As a consequence of the PTC, mutant COL17A1 transcripts are rapidly degraded by nonsense-mediated mRNA decay, blocking production of type XVII collagen from the mutant allele. Heterozygous carriers of the mutation are thus rendered untouched by the mutation. In the homozygous state, however, this results in the absence of this vital adhesion protein, leading to chronic blistering and skin fragility observed in these patients. These studies also significantly increase our knowledge about the normal functions of type XVII collagen. The fact that patients deficient in type XVII collagen have fragile skin attests to the role of this protein in the adhesion of basal keratinocytes to epidermal BM. The severity of GABEB, however, is much less than that observed in patients with a complete deficiency of laminin 5, suggesting that type XVII collagen functions cooperatively with other hemidesmosomal proteins in promoting adhesion. Studies using GABEB keratinocytes will help characterize these kinds of interactions. The ultimate prospect of mutation analysis in these patients is the hope of correcting their genetic defect and curing their disease. Until then, the physician plays an important role in making the diagnosis, providing general supportive skin care, advising avoidance of trauma, treating infections, and supporting the patient's psychosocial development. Further studies of patients with GABEB will lead to new therapeutic approaches, as well as reveal additional complex functions of type XVII collagen not only in skin, but also in hair, teeth, and nails.

Collagen↗

A homozygous deletion mutation in the gene encoding the 180-kDa bullous pemphigoid antigen (BPAG2) in a family with generalized atrophic benign epidermolysis bullosa.

The 180-kDa bullous pemphigoid antigen (BPAG2) is a candidate gene/protein for mutations in some forms of junctional epidermolysis bullosa. In this study, we searched for mutations in BPAG2 in a large Austrian pedigree with generalized atrophic benign epidermolysis bullosa, a distinct nonlethal form of junctional epidermolysis bullosa, using polymerase chain reaction amplification of genomic DNA, heteroduplex analysis of the polymerase chain reaction products, and direct nucleotide sequencing. We identified a homozygous 2-bp deletion within the coding region of BPAG2 in the affected individuals. This mutation results in a frameshift and downstream stop codons on both alleles, predicting an absence of functional protein. These findings illustrate the molecular basis of the skin fragility in this family and attest to the importance of the 180-kDa bullous pemphigoid antigen in the attachment of the epidermis to the underlying dermoepidermal basement membrane.

Autoantigens↗

Immunoglobulin A (IgA) deposits in lesional skin of a patient with blepharochalasis.

We describe a 21-year-old male patient with blepharochalasis, a form of localized acquired cutis laxa. He had a 13-year history of recurrent swelling attacks of the eyelids of unknown origin leading to periocular localized cutis laxa. Histology of lesional skin confirmed almost complete loss of elastic fibres in the reticular and papillary dermis. Immunofluorescence and immunoelectron microscopy studies showed abundant immunoglobulin A (IgA) deposits around the remaining elastic fibres. Control skin of the forearm was negative. These findings support the hypothesis that immunopathogenetic mechanisms may contribute to the elastolytic process of blepharochalasis.

Adult↗

Diminished expression of the extracellular domain of bullous pemphigoid antigen 2 (BPAG2) in the epidermal basement membrane of patients with generalized atrophic benign epidermolysis bullosa.

Generalized atrophic benign epidermolysis bullosa (GABEB) is a nonlethal form of junctional epidermolysis bullosa characterized by generalized skin and mucosal blisters that heal with atrophy; other features include alopecia, nail dystrophy, large melanocytic nevi, and autosomal recessive inheritance. The specific aim of this study was to identify an abnormality in epidermal basement membrane adhesion molecules in well characterized GABEB patients that would explain why these subjects' epidermis separates from their epidermal basement membrane. Cryostat sections of nonlesional skin from 8 GABEB patients in 5 different families as well as skin from normal volunteers (controls) were studied by indirect immunofluorescence microscopy using rabbit antiserum directed against a BPAG1 fusion protein or monoclonal antibodies directed against the extracellular domain of BPAG2 (HD18 and 233), epiligrin (P1E1), laminin 5 (GB3), types IV and VII collagen, or integrin subunits alpha 2, alpha 3, beta 1, alpha 6, or beta 4. In these studies, monoclonal antibodies HD18 and 233 showed no reactivity and diminished reactivity, respectively, to the epidermal BM of all GABEB patients. Interestingly, in one patient, the absent or diminished reactivities of monoclonal anti-BPAG2 antibodies were limited to well demarcated portions of an otherwise intact epidermal basement membrane. Moreover, BPAG1, epiligrin, laminin 5, types IV and VII collagen, and all integrin subunits under study were expressed in the same manner in both GABEB and normal human skin. These findings identify an abnormality in the extracellular domain of BPAG2 in the skin of GABEB patients. BPAG2 (type XVII collagen) is a transmembrane, hemidesmosome-associated molecule whose extracellular domain resides at the exact level where blisters develop in the skin of patients with GABEB.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

Hereditary complete deficiency of the fourth component of complement: effects on the kidney.

Hereditary complete C4 deficiency has until now been detected in 18 patients. A disturbed clearance of immune complexes probably predisposes these individuals to systemic lupus erythematosus and other immune complex diseases. Renal involvement of hereditary complete C4 deficiency is described in seven patients from three families. Three patients of one family suffered from SLE and a severe mesangial and endocapillary proliferative glomerulonephritis which required immunosuppressive treatment. In two patients from a second family a mild focal and segmental mesangioproliferative glomerulonephritis was present which, except for an episode of acute renal failure in one patient, did not cause serious clinical problems. One additional child died without renal involvement. The patient from a third family developed Henoch-Schoenlein purpura, mesangioproliferative glomerulonephritis with segmental scarring and terminal renal failure. Immunofluorescence studies showed deposition of immunoglobulins and complement C3 in the glomeruli. Severity of renal disease is probably determined by activation of the alternative pathway of complement in the kidney.

Adolescent↗

Life history of cutaneous vascular lesions in Sneddon's syndrome.

Sneddon's syndrome is a potentially fatal arterio-occlusive disorder characterized by generalized livedo racemosa and cerebrovascular lesions. Skin biopsies often fail to yield diagnostic arterial lesions. In the present series, affected vessels were found in skin biopsies from 12 of 15 patients with Sneddon's syndrome. Selection of the correct biopsy site (seemingly uninvolved skin at the center of a livedo racemosa area), adequate biopsy size (1 to 2 cm), and serial sections are essential for the detection of relevant vascular pathology. Only small to medium-sized arteries of the dermis-subcutis boundary were found to be involved. Lesions follow a distinct course. The initial stage displays partial detachment of endothelial cells, adhesion of mononuclear cells interspersed with fibrin ("endothelitis"), a marked edema of the surrounding connective tissue with numerous dilated capillaries, and a predominantly lymphohistiocytic infiltrate with polymorphonuclear leukocytes. In the early phase a sponge-like plug is formed from mononuclear cells, fibrin, and red blood cells, leading to partial to complete obstruction. A perivascular inflammatory infiltrate, devoid of polymorphonuclear leukocytes, is located around affected arteries; in the adventitia of the occluded vessel, a very regular corona of dilated capillaries appears that is continuous with more peripheral dilated and branching vessels. Organization of the occluding plug ensues in the intermediate stage by "subendothelial cell proliferation," most likely due to immigrating smooth muscle cells. In the final stage, the occluding artery undergoes fibrosis, shrinkage, and atrophy.

Adult↗

[Typing of infiltration cells in primary, localized, nodular, cutaneous amyloidosis].

Amyloid tumours in two patients with primary localized nodular cutaneous amyloidosis contained very dense infiltrates consisting mainly of plasma cells and lymphocytes. In one case IgM was detected on many cells of the infiltrate, while in the other IgA was found in morphologically apparently normal plasma cells. Immunohistochemical investigations did not reveal any immunoglobulin light chain restriction in either of the tumours. Numerous cells expressed B cell markers, such as CD20 or CD38. Rearrangement studies on material from the amyloid tumour of one of the patients confirmed the monoclonality of plasma cells. This observation indicates that the nodules of primary localized nodular cutaneous amyloidosis indeed represent an extramedullary plasmocytoma, which consists of amyloid-producing plasma cells. Of special interest was the unexpectedly high proportion of cells expressing T cell markers (CD3, CD5, CD4 greater than CD8) in the amyloid nodules of both patients. After excluding co-expression of B and T cell markers on identical cells by immunohistochemical studies on serial sections and also after molecular biological studies, we assume that this is a separate T cell population that may have a regulatory effect on the production of amyloid.

Aged↗

Acquired perforating dermatosis. Transepidermal elimination of DNA material and possible role of leukocytes in pathogenesis.

A patient had acquired perforating dermatosis and suffered from renal disease, diabetes mellitus, and lupus vulgaris. Histologic and immunohistochemical studies revealed that the bulk of the coarse granular basophilic material being extruded by transepidermal elimination was of nuclear origin obviously derived from polymorphonuclear leukocytes that were particularly abundant in an early, nonperforated lesion. At the lower boundary of the material being eliminated transepidermally, leukocytes were seen to accumulate, to undergo pyknosis and karyorrhexis, and to transform into nuclear debris. As a minor component, the material contained collagen fibers with altered staining qualities and, in an early lesion, elastic fibers. We speculate that accumulation, disintegration, and enzyme release from polymorphonuclear leukocytes may represent an important, hitherto disregarded driving force in transepidermal elimination. Lysosomal enzymes may later be responsible for the alteration of staining properties in collagen fibers, the degradation of elastic fibers, and for opening up the transepidermal route by impairing intercellular keratinocyte cohesion.

Aged↗

Tissue vitronectin in normal adult human dermis is non-covalently bound to elastic tissue.

Vitronectin is a multifunctional human plasma glycoprotein that is also found in constant association with elastic tissue fibers in normal adults. We have investigated the nature of the association of vitronectin with elastic tissue, and compared it to that of other elastic fiber-associated proteins, namely fibrillin and amyloid P component. Samples of normal human dermis were incubated with a variety of extraction agents, including high molar salt solution, non-ionic detergent (Nonidet P-40), the reducing agents dithiothreitol or 2-mercaptoethanol, and the chaotropic agents sodium dodecyl sulfate or guanidine hydrochloride. Vitronectin purified from serum typically migrates as two bands of 75 and 65 kD. By contrast, immunoblotting studies of residual dermal material after extraction with the various agents revealed only lower molecular weight (58, 50, 42, 35, and 27 kD) anti-vitronectin reactive bands. Although these bands may represent degradation products of vitronectin generated as a result of the extraction procedure, we cannot exclude the possibility that tissue vitronectin is distinct from plasma vitronectin. Anti-vitronectin reactive polypeptides co-migrating with the 58-, 50-, and 42-kD bands were solubilized following extraction with sodium dodecyl sulfate or guanidine hydrochloride, but not with the other extraction agents. Immunofluorescence studies using residual dermal material after extraction with guanidine hydrochloride demonstrated a marked reduction in elastic fiber staining intensity with anti-vitronectin and anti-amyloid P component, but not with anti-fibrillin. Thus the majority, if not all of dermal vitronectin, is, like amyloid P component, non-covalently associated with, and not an integral constituent of, elastic fibers.

Blood Proteins↗

Gene rearrangement studies in the diagnosis of primary systemic and nodular primary localized cutaneous amyloidosis.

Difficulties may arise in the diagnosis of patients with clinical features suggestive of plasma cell dyscrasia-related amyloidosis (amyloidosis L), but without evidence of a paraprotein. We have employed gene rearrangement methodology to demonstrate the clonality of bone marrow cells not only in a patient with myeloma-associated systemic amyloidosis, but also in a patient with "primary" systemic amyloidosis without overt myeloma or a detectable paraprotein. Furthermore, we have shown the clonality of the amyloid-producing plasma cells within a skin nodule of a patient with primary localized cutaneous amyloidosis; by contrast, clonal rearrangement was not detected in bone marrow cells from this patient. This finding provides definitive proof that organ-limited nodular primary localized cutaneous amyloid deposits arise in relation to cutaneous plasmacytomas. Gene rearrangement studies may enable early diagnosis and initiation of treatment in patients with systemic amyloidosis L, as well as their differentiation from patients with organ-limited nodular cutaneous amyloidosis, who do not require aggressive therapy.

Aged↗