Heinz Kofler

Mouse Variable-Region Gene Families: Complexity, Polymorphism and Use in non-Autoimmune Responses

During B-cell ontogeny, functional immunoglobulin (Ig) genes are generated by somatic juxtaposition of gene segments separated in the germline and termed variable (V), diversity (D, heavy chain only) and joining (J) gene segments (reviewed in (Tonegawa 1983, Alt et al. 1986)). V genes encode all residues of the first and second complementarity-determining region (CDR) of both heavy (H) and light (L) chains as well as part of the L chain CDR-3, and hence contribute the majority of antigen contact residues (Kabat et al. 1991). In human and murine systems, a considerable number of highly polymorphic VH and VL gene segments exist in the germline and, for practical reasons, have been classified into V-gene families and V-region protein groups. The complexity of V-gene families, their chromosomal organization and degree of polymorphism, and their usage in various responses has been studied in great detail. In an attempt to better understand autoimmune diseases, the present volume addresses the expression of these V genes and V-gene families in response to self antigens. This chapter introduces Ig genetics in the mouse, summarizes current Vgene and V-region protein classifications, reviews the complexity, chromosomal organization and polymorphism of the V-gene repertoire, and discusses V-gene usage in different B-cell repertoires and in response to complex foreign antigens to allow comparisons with V-gene usage in autoantibodies described throughout this volume. Lambda L chains are not included since they make up only a few percent of total mouse serum Ig and are rarely found in autoantibodies. Furthermore, the large body of data on V-gene usage in hapten responses will

Leg ulcers associated with long-term hydroxyurea therapy☆☆☆★

Hydroxyurea is commonly used in the treatment of various hematologic disorders, e.g., chronic myelogenous leukemia (CML), polycythemia vera, and occasionally, at lower doses, for severe psoriasis vulgaris. Cutaneous side effects such as alopecia, diffuse hyperpigmentation, poikiloderma, atrophy of the skin, or nail changes occur, especially with long-term treatment. Painful leg ulcers in association with hydroxyurea have only rarely been reported. We describe 2 patients who developed spontaneous painful leg ulcers during long-term hydroxyurea therapy for a myeloproliferative disorder; these ulcers healed only after hydroxyurea was withdrawn.

Eczema-like, erythematous, infiltrated plaques: A common side effect of subcutaneous heparin therapy

Erythematous, infiltrated plaques appear to be a common but neglected cutaneous reaction to heparin. Erythematous, infiltrated plaques are unrelated to heparin necrosis and sometimes closely mimic contact dermatitis. We report 15 patients (14 women and 1 man, the first to be reported in the literature) in whom erythematous, infiltrated plaques developed 3 to 21 days after commencement of subcutaneous heparin therapy. The clinical appearance, routine histopathologic and immunohistopathologic findings, and results of various skin tests provided circumstantial evidence for the presence of a delayed hypersensitivity reaction. Subcutaneous provocation tests proved superior to intracutaneous or epicutaneous tests for the diagnosis of erythematous, infiltrated plaques. Erythematous, infiltrated plaques were caused by heparin constituents in all female patients, whereas chlorocresol was implicated as the cause in the only man.

SPINA BIFIDA AS AN INDEPENDENT RISK FACTOR FOR SENSITIZATION TO LATEX

PURPOSE Patients with spina bifida are at a high risk for having an immediate type allergy to latex products. The number of surgical interventions, atopy and catheterization are well known responsible factors, whereas the condition of spina bifida per se has not been established as an independent risk factor. MATERIALS AND METHODS A total of 131 patients with a shunted hydrocephalus (48 with spina bifida and 83 of other origin) were investigated for sensitization to latex by skin prick tests and determination of specific IgE. We hypothesized that the diagnosis of spina bifida will increase the risk for latex sensitization while considering potential confounding factors. Thus, we performed a multiple logistic regression analysis to determine independent risk factors. RESULTS Whereas 56.3% (27/48) of children with spina bifida proved sensitized against latex, this result was the case in only 16.9% (14/83) with another cause of hydrocephalus (p <0.001). The mean number of surgical interventions was 6.2 for patients with no latex sensitization and 9.3 for those with sensitization (p = 0.02). Of patient sensitized to latex 43.9% had a history of atopy compared to 15.5% of those not sensitized (p = 0.02). Sensitized and nonsensitized patients were comparable regarding gender and catheterization. In a multiple logistic regression analysis the cause of the hydrocephalus (odds ratio 6.76 for spina bifida), atopy (odds ratio 3.37) and the number of surgical interventions (odds ratio 1.14 per operation) were identified as independent risk factors. CONCLUSIONS The increased risk of latex sensitization in patients with spina bifida seems to be disease associated. Possible explanations for this finding may be genetic, antigen mediated, early latex exposure and immunological reasons.

Expression of class II-MHC antigens in the dermis of patients with progressive systemic sclerosis.

Expression of class II major histocompatibility complex (MHC) antigens on normally negative cell types may convert them into effective antigen-presenting cells. It was therefore of special interest to elucidate whether the main cell populations involved in progressive systemic sclerosis (PSS) express class II antigens on their surfaces and participate in the initiation and/or perpetuation of a cellular immune response in the connective tissue. Immunofluorescence studies on frozen skin sections of scleroderma patients using double-staining techniques revealed a pronounced dermal mononuclear cellular infiltrate with signs of activation manifested by expression of MHC class II antigens in the acute phase of the disease. Most endothelial cells of the papillary and deeper dermal vessels were class II-positive as seen in other inflammatory dermatoses. Moreover, class II antigen-positive fibroblasts were found, especially in the deeper dermis within infiltrated areas around blood vessels. MHC class II molecules were also detected in higher density and on increased numbers of perivascular dermal dendrocytes. On all cell types, HLA-DP was much less frequently expressed than HLA-DR, but more frequent than HLA-DQ. However, in the chronic phase of the disease, with reduced inflammation and increasing sclerosis, MHC class II antigen expression on dermal fibroblasts was again diminished or even absent, as seen in normal and non-PSS inflammatory control biopsies and clinically unaffected skin of scleroderma patients in the acute inflammatory disease stage. Our data speak against a primary expression of class II molecules on PSS-fibroblasts. It seems more likely that Ia-antigens on fibroblasts and an increase of MHC class II positive dermal dendrocytes are induced in an early stage of the disease, i.e., after the influx of the mononuclear infiltrate, most probably by mediators released from these cells. Since an enhanced transcription rate of collagen genes in fibroblasts surrounded by infiltrating cells has been described, this early expression of class II MHC antigens does not seem to play a central role in the induction phase, but rather, may be important in the perpetuation of fibrotic processes in scleroderma.

Mechanism of allergic cross-reactions--III. cDNA cloning and variable-region sequence analysis of two IgE antibodies specific for trinitrophenyl.

As a first step toward defining the molecular interactions between ligands and the IgE antigen-combining site, we report here the cDNA cloning and variable (V) region nucleic acid sequences of the heavy (H) and light (L) chains of 2 monoclonal mouse IgE antibodies to trinitrophenyl (ATCC-TIB142 = IGELa2 and ATCC-TIB141 = IGELb4). In all instances, full-length cDNA clones were obtained to facilitate future expression studies. The H chains were encoded by VH genes from the VH3660 and J558 gene families in context with DQ52 and DSP2.2 diversity (D) mini genes, and JH3 and JH4 joining (J) gene segments, respectively. Vk8/Jk2 and Vk1/Jk5 rearrangements encoded the respective L chain V-regions. Both antibodies exhibited considerable conservation of complementarity determining region (CDR) sequences, which will facilitate template-based computer modeling of the three-dimensional structures of complexes formed between various ligands and these antibodies. From sequence comparison between the dinitrophenyl (DNP)-binding myeloma protein MOPC-315 and these IgE antibodies likely candidates for hapten-contact residues within the binding sites of IGELa2 and IGELb4 have been suggested.

Development of an enzyme-linked immunosorbent assay for the detection of autoantibodies against thyroglobulin in chickens

This paper describes the development of an enzyme immunoassay (EIA) for the detection of autoantibodies against thyroglobulin in an avian system. In this system EIA offers an efficient and alternative approach to already established methods such as double diffusion in gel, passive haemagglutination, indirect immunofluorescence and radioimmunoassay. The optimization of the different incubation steps is described and the expression of results of observed antibody activity is discussed.

Histamine 50-Skin-Prick Test: A Tool to Diagnose Histamine Intolerance

Background. Histamine intolerance results from an imbalance between histamine intake and degradation. In healthy persons, dietary histamine can be sufficiently metabolized by amine oxidases, whereas persons with low amine oxidase activity are at risk of histamine toxicity. Diamine oxidase (DAO) is the key enzyme in degradation. Histamine elicits a wide range of effects. Histamine intolerance displays symptoms, such as rhinitis, headache, gastrointestinal symptoms, palpitations, urticaria and pruritus. Objective. Diagnosis of histamine intolerance until now is based on case history; neither a validated questionnaire nor a routine test is available. It was the aim of this trial to evaluate the usefullness of a prick-test for the diagnosis of histamine intolerance. Methods. Prick-testing with 1% histamine solution and wheal size-measurement to assess the relation between the wheal in prick-test, read after 20 to 50 minutes, as sign of slowed histamine degradation as well as history and symptoms of histamine intolerance. Results. Besides a pretest with 17 patients with HIT we investigated 156 persons (81 with HIT, 75 controls): 64 out of 81 with histamine intolerance(HIT), but only 14 out of 75 persons from the control-group presented with a histamine wheal ≥3 mm after 50 minutes (P < .0001). Conclusion and Clinical Relevance. Histamine-50 skin-prickt-test offers a simple tool with relevance.

Immunofluorescence studies on the codistribution immune deposits and complement in the thyroid glands of obese strain (OS) chickens

This study demonstrates immune complexes in thyroid glands of Obese strain (OS) chickens, that consist of thyroglobulin (Tg) and antibodies to Tg. In IIF tests it was shown that these complexes fix complement with an age-dependent increase from 12% in 19-day-old embryos up to 100% in 6-week-old animals. This finding and the observation that the deposition of complement-binding immune complexes precede cellular infiltration of the thyroid gland and correlate with the serum titer of Tg-Ab (as one parameter of the disease) points towards a role as one initial effector mechanism for the development of spontaneous autoimmune thyroiditis (SAT).

Lack of Association between Atopy and the lle181Leu Variant of the Beta-Subunit of the High-Affinity Immunoglobulin E Receptor

A previous study has reported a strong association of a variant (Ile181Leu) of the beta-subunit of the high-affinity IgE receptor (Fc epsilon RI-beta) with allergic asthma bronchiale in a random patient sample. Based on their results the authors concluded that Fc epsilon RI-beta may be the maternally inherited, atopy-causing locus. We have investigated 40 unrelated atopic patients, 30 with allergic asthma and 10 with atopic dermatitis or allergic rhinoconjunctivitis along with some of their relatives for the presence of Ile181Leu by nucleic acid sequence analysis and/or hybridization with mutation-specific oligonucleotide probes. None of the probands showed this mutation suggesting that its association with atopy may be restricted to certain populations or occur at lower frequency than reported.