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H Kellner

Publications and source records attributed to H Kellner.

At least 55 records · Page 3Linked to original sources
PubMed1997

False-negative serological HLA-B27 typing results may be due to altered antigenic epitopes and can be detected by polymerase chain reaction.

Serological typing with the microlymphocytotoxicity test (MLCT) and flow cytometry (FC) using HLA-B27 antisera is commonly used for the determination of HLA-B27. However, in some patients tested more than once, negative results have turned out to be positive at following investigations. We retested by polymerase chain reaction (PCR) samples from 20 randomly selected patients with reactive arthritis or Reiter's syndrome who had now been followed for 20 yr. Ten of the patients were originally tested to be HLA-B27 positive and 10 HLA-B27 negative by the MLCT. All 10 serologically HLA-B27 positive individuals were also positive in the PCR. However, 2/10 patients interpreted as being HLA-B27 negative were positive by PCR. At this time, the same two patients were also positive in the routine MLCT and FC using four different monoclonal antibodies against HLA-B27. PCR is superior to serological techniques to determine HLA-B27 positivity unequivocally, since it is based on the detection of HLA-B27 gene sequences.

Aged↗
PubMed1997

Routine molecular genotyping of HLA-B27 in spondyloarthropathies overcomes the obstacles of serological typing and reveals an increased B *2702 frequency in ankylosing spondylitis.

OBJECTIVE: To evaluate the reproducibility and reliability of polymerase chain reaction (PCR) in HLA-B27 typing compared to the conventionally used microlymphocytotoxicity test (MLCT). To determine the HLA-B27 subtype frequencies (B*2701-B*2709) in patients with HLA-B27 associated disease and healthy persons using sequence specific oligonucleotides (SSO). METHODS: 398 consecutive patients were HLA-B27 typed by MLCT and PCR. Subtyping by SSO was performed in 142 patients with HLA-B27 associated disease [ankylosing spondylitis (AS) n = 38, reactive arthritis 44, undifferentiated spondyloarthropathy (uSpA) 45, psoriatic arthritis 15] and 125 healthy HLA-B27 controls. RESULTS: MLCT identified 61 HLA-B27 positive patients (15.3%); PCR identified 78 positive patients (19.6%). MLCT gave false negative results for 8 patients (2.0%) and false positives for a further 7 (1.8%). Only subtypes B*2702 and B*2705 were present in patients and controls. Overall frequencies of B*2702 in patients and controls were 14.1 and 9.6%, respectively. The B*2702 frequency was significantly (pcorr. < 0.04) higher in AS (23.7%) and lower in uSpA (6.7%) patients. CONCLUSION: HLA-B27 typing by PCR is reliable and reproducible and therefore recommended for routine typing. It overcomes the obstacles of serological typing, i.e., equivocal results and cross-reactivity. In addition, subtype frequencies (B*2702 and B*2705) are equally distributed among patients and controls, although subtype B*2702 seems to be more frequent in AS and less so in uSpA.

Amino Acid Sequence↗
PubMed1996

A patient-derived cytotoxic T-lymphocyte clone and two peptide-dependent monoclonal antibodies recognize HLA-B27-peptide complexes with low stringency for peptide sequences.

HLA-B27 molecules expressed on the T2 mutant cell line do not have peptides. Such empty HLA-B27 molecules were not recognized by an HLA-B27-restricted cytotoxic T-lymphocyte (CTL) clone (auto-1) derived from synovial fluid. To test for peptide dependency of the clone, B27-T2 cells were incubated with a panel of 48 different peptides. This lack of stringency was compared with that of a peptide-dependent monoclonal antibody, B27.M2. Positive B27.M2 reactivity resulted when the B27-T2 cells were incubated with two peptides: RRKAMFEDI and RRMGPPVGHR, derived from Chlamydia HSP60 and human ribonucleoprotein, respectively. Because of the limited availability of CTL versus monoclonal antibody, the specificity of B27.M2 was studied in greater detail. The importance of the HLA-B27 heavy chain in antibody recognition of class I-peptide complexes was demonstrated by site-directed mutagenesis. The stringency of the peptide residues was tested by making analogs of each of the nine residues in RRKAMFEDI, creating a panel of 180 analogs. Although stringency was highest for the sixth position, as many as six different amino acids provided positive reactivity. These results indicate that immune recognition of HLA-B27-peptide complexes might have rather low stringency for the peptide sequences. In theory, then, pathogen-derived peptides which induce autoimmunity by generating autoreactive CTL might not share much sequence similarity with the responsible self peptides.

Amino Acid Sequence↗
PubMed1996

[Reversible esophageal dysfunction as a side effect of levodopa].

We are reporting the case of a 94-year-old male patient with a 10-year history of Parkinson's disease, who was admitted to our hospital with acute obstruction of esophageal passage. Esophageal obstruction was refractory to endoscopic intervention. However, discontinuation of the pre-existing levodopa medication led to its resolution within hours. While dysphagia is commonly encountered in patients with Parkinson's disease, the observed succession of drug discontinuation and resolution of obstruction in this case suggests an as yet rarely described side effect of levodopa. This potential side effect should be included in the differential diagnosis of dysphagia in Parkinson's disease, especially in the case of older patients, who may exhibit an increased rate of intestinal absorption of levodopa.

Aged↗
PubMed1996

[Value of ultrasound in diagnosis of acute appendicitis].

Acute appendicitis is one of the most frequent causes of an acute abdomen. The clinical diagnosis is based on the case history and the physical examination which plays a major role in clinical diagnosis. However, in some cases the typical clinical symptoms are equivocal or misleading. Without using the opportunities of diagnostic imaging the accuracy of preoperative appendix diagnosis ranged between 70 and 78%. Consequently the rate of unnecessary laporotomies ranged between 22 and 28%. Since 1986, 13 studies including more than 5,000 patients have been published showing a sensitivity of 85% and a specificity of 96% if the sonographic examination was performed by an experienced examiner. The rate of negative laparotomies could be decreased to 7%, and possible differential diagnoses could be either confirmed or ruled out by using ultrasound technique. Based on the current literature, real-time sonography plays a major part in the diagnosis of acute appendicitis.

Abdomen, Acute↗
PubMed1995

Preliminary assessment of a fieldwork education alternative: the fieldwork centers approach.

OBJECTIVE: In response to an acute shortage of clinical fieldwork placement opportunities, faculty members of the Department of Occupational Therapy at Tel Aviv University in Israel formulated the Fieldwork Centers Approach (FCA) as an alternative approach to fieldwork education. Under the FCA, groups of two to eight students were assigned to one facility. The number of participating supervisors, who shared all supervision activities, ranged from two to six. Supervision approaches included both one-to-one and group supervision. This article presents the results of an evaluation of the FCA by the first group of students who participated in it. METHOD: Twenty-five students were surveyed twice, once after they completed their Level I fieldwork and again after they completed their Level II fieldwork. RESULTS: Upon completion of Level I fieldwork, 26% of the students indicated that they perceived advantages in the FCA; this percentage rose to 74% upon their completion of Level II fieldwork. No significant differences were found between the students' fieldwork level and their preference for the FCA vs. a strictly one-to-one, supervisor-student approach. Of the five learning experiences unique to the FCA, four, which received high ratings, represented specific learning experiences and one, which received low ratings, represented a psychological learning experience. CONCLUSION: Results indicate that the FCA is a promising approach to fieldwork education. Overall, student evaluations made upon completion of Level II fieldwork were more positive than those made upon completion of Level I fieldwork. Additional research is needed to determine the reasons for this shift in students' evaluations.

Curriculum↗
PubMed1994

The effect of mutant beta 2-microglobulins on the conformation of HLA-B27 detected by antibody and by CTL.

The arthritis-predisposing HLA-B27 consists of a heavy chain, a small peptide, and the monomorphic beta 2-microglobulin (beta 2-m). CTLs and a mAb, Ye-2, which recognize the complex with specificities both for the heavy chain and for the peptide, are available. The beta 2-m is in noncovalent association with the heavy chain at multiple points and is exchangeable with free beta 2-m outside of the complex. The purpose of our experiments was to test whether mutant beta 2-m capable of modulating HLA-B27 activity could be created. Eighteen recombinant mutants of the human beta 2-m were experimentally generated. In 14 of these, mutations were at or near residues that are either contact residues or interface residues with the heavy chain. Relative to the parent beta 2-m, two-thirds of the mutants showed reduced ability to exchange into HLA-B27 complexes. However, at least four of them induced more than 80% decrease in Ye-2 Ab reactivity. Two mutants were able to induce a minor decrease in susceptibility to lysis by four CTL clones. One of the CTL clones was autoreactive. Two of the CTL clones were specific for HLA-B27 cells experimentally infected with arthritis-causing Yersinia enterocolitica. These results indicate that certain beta 2-m residues play an indirect role in peptide presentation, although they are not directly associated with the peptide residues.

Amino Acid Sequence↗
PubMed1994

A monoclonal antibody that recognizes HLA-B27 in the context of peptides.

The T2 mutant cell line is unable to load peptides into the MHC class I Ags inside the cells. These "empty" MHC class I Ags are not expressed on the cell surface unless the cells are cultured at low temperatures. Expression will occur at 37 degrees C only in the presence of peptides that bind to and stabilize the class I Ags. T2 cells transfected with the B*2705 gene were tested with a panel of anti-HLA-B27 mAb. Two of the antibodies, ME1 and KS3, reacted with the "empty" HLA-B27 expressed at low culture temperatures. Three antibodies, B27.M1, B27.M2, and Ye-2, were unreactive with these "empty" HLA-B27. The cells were then incubated with a panel of HLA-B27-binding peptides. One of the antibodies, Ye-2, became reactive when the cells were incubated with a peptide derived from HIV gp120 and to a less degree with a peptide derived from histone H3.3. Mouse L cells transfected with the B*2705 and the human beta 2m genes also reacted very poorly with B27.M1, B27.M2, and Ye-2. Those two peptides were also able to induce high increase in Ye-2 reactivity. Alternately, increase in Ye-2 reactivity was also observed when the L cells were incubated with IFN-gamma or TNF-alpha. These experiments indicate that the Ye-2 anti-HLA-B27 mAb recognizes HLA-B27 in the context of certain residing peptides either added exogenously or expressed endogenously. The B27.M1 and B27.M2 antibodies might share similar characteristics.

Amino Acid Sequence↗
PubMed1994

The pathogenesis of HLA-B27 associated arthritis: lessons from the B27 crystal.

The most remarkable association between a major histocompatibility complex antigen and disease susceptibility--HLA-B27 and seronegative spondyloarthropathies, particularly ankylosing spondylitis--was discovered 20 years ago. During the two intervening decades advances in basic immunology and molecular biology have not only revealed the biosynthesis and structure of HLA-B27 but also given clues to the basic function of this molecule, the presentation of allele-specific peptides to CD8+ cytotoxic T cells. The recently reported three-dimensional structure of HLA-B27 and the identification of self-peptides bound to this major histocompatibility complex class I antigen can be viewed as a landmark in the understanding of the pathogenic role of HLA-B27. Based on crystallographic evidence, a peptide-binding motif can be postulated that should allow identification of HLA-B27 complexed peptides which may trigger an immune reaction causing arthritis.

Amino Acid Sequence↗
PubMed1994

Seronegative spondylarthropathies in HIV-infected patients: further evidence of uncommon clinical features.

Reiter's syndrome and reactive arthritis in individuals with human immunodeficiency virus (HIV) infection are characterized by severe and persistent arthritis, intense enthesopathy, and poor response to treatment. These uncommon clinical features suggest a direct role of HIV in the pathogenesis of seronegative spondylarthropathies. We report on widely differing clinical features in two HIV-infected patients with undifferentiated seronegative spondylarthropathy or reactive arthritis. Both patients were HLA-B27-positive. The first patient presented with heel swelling and dactylitis ("sausage" toes). Subsequently he developed polyarticular erosive arthritis. The clinical course was complicated by fulminant ulcerative colitis leading to hemicolectomy. After hemicolectomy, a temporary resolution of arthritis occurred. In the second patient, heel swelling and polyarticular arthritis occurred 2 months after Shigella dysentery. After 3 years of continuing joint inflammation, he presented with a Jaccoud-like arthropathy. In a cohort of 700 HIV-infected patients receiving continuous care in our department, these were the only patients with seronegative spondylarthropathy observed between 1984 and 1992.

Adult↗
PubMed1994

Serum antibodies from patients with ankylosing spondylitis and Reiter's syndrome are reactive with HLA-B27 cells transfected with the Mycobacterium tuberculosis hsp60 gene.

HLA-B27-related arthritis is probably mediated by an immune response against HLA-B27 complexed with peptides derived from proteins of arthritis-causing bacteria. Immunogenic proteins with a high degree of homology among bacteria, such as in the hsp60 family, are likely candidates. To create such complexes experimentally, we transfected an HLA-B27 cell line with the Mycobacterium tuberculosis hsp60 gene. Because of previous observations that HLA-B27-peptide complexes can be distinguished by antibodies, we tested the transfected cell line with a panel of sera from 24 HLA-B27+ arthritis patients. Significant antibodies were detected in at least eight of the sera. Several cell lines and peptides were used as negative controls to ensure that the antibody reactivity was specific to HLA-B27-peptide complexes. A panel of nine peptides derived from the sequence of the Mycobacterium hsp60 were synthesized and tested. At least three were identified as being responsible for the serological activities.

Amino Acid Sequence↗
PubMed1994

[3D-ultrasound of soft tissues and joints].

Sonography has become a reliable diagnostic method in musculo-skeletal diseases. It allows a simple and noninvasive examination of joints and soft tissues. Especially in rheumatic diseases meaningful findings can be obtained. In the present study first results of three-dimensional (3D) sonography of the musculo-skeletal system are reported. The method was first validated by examining healthy test persons and criteria for regular findings were defined. In the second part of the study an unselected group of patients with inflammatory and noninflammatory joint and soft tissue diseases were examined and the obtained results were compared with the findings of the conventional real-time sonography. Comparison of the 2D and 3D procedure showed a superiority of the 3D method with regard to the assessment of large (hip), middle-sized (elbow) and small joints (finger, toe). Additional information about the synovial space, the surface of the cartilage, and the thickness of the synovial membrane was provided by 3D sonography. Volumetry of joint effusions and Baker cysts was easier to perform and more reliable than with the conventional method. Soft tissue alterations could be delineated reliably, depending on their size. Our results demonstrate that 3D sonography can improve the diagnostics of musculo-skeletal diseases. In the future, 3D sonography should play an important part in the diagnosis of joint and soft tissue diseases.

Arthritis, Rheumatoid↗
PubMed1992

The pathogenetic aspects of spondyloarthropathies from the point of view of HLA-B27.

The association of HLA-B27 and seronegative spondyloarthropathies, especially ankylosing spondylitis has been known for almost two decades. The spontaneous development of spondyloarthropathy like joint disease in HLA-B27 transgenic rats verifies the suspicion that the HLA-B27 antigens are directly responsible for disease development. With the recently revealed crystal structure of HLA-B27 and understanding of the class I molecule in general, a new hypothesis can be formulated based on the assumption that the pathogenesis of these diseases is a subversion of the physiological function.

Amino Acid Sequence↗
PubMed1992

Immunogenetics of spondyloarthropathies.

The association of HLA-B27 with ankylosing spondylitis and related spondyloarthropathies has been known for two decades and has provided a great impetus to the epidemiologic studies and also helped broaden the clinical spectrum of these diseases. The etiology of these diseases is likely to be multifactorial and include genetic, immunologic, and environmental mechanisms. The detailed three-dimensional x-ray crystallographic structure of B27 has now been reported. It has revealed electron density compatible with oligopeptides that are nine amino acid-long (nonamers) bound in the antigen-binding cleft of the molecule. Microsequence analysis of 11 peptides eluted from the antigen-binding cleft has confirmed that all are nonamers. The most restricted position in the bound peptide is the second position, where all the 11 peptides contain arginine. The side chain of arginine extends into the B pocket ("45 pocket"), which seems to act as a specificity side pocket in the antigen-binding cleft of the B27 molecule. It is very likely that an understanding of the detailed structure of B27, including the peptide-binding motif and the structural domains recognized by cytotoxic T cells, along with the recent development of the B27 transgenic rat model for spondyloarthropathies, will further enhance our understanding of the immunogenetics of these diseases. It is hoped that this will lead to the source of the arthritogenic triggers and possibly disease prevention by antigen-specific immunomodulation. Because T-cell activation is initiated by the formation of antigen-MHC complexes that are the ligands that are recognized by the antigen-specific T-cell receptor (TCR), it might be possible to inhibit this activation by blocking the antigen-binding cleft of MHC molecules by using high-affinity MHC-binding peptides (MHC blockade) or by a novel, new, and more efficient method of TCR antagonism.

Amino Acid Sequence↗
PubMed1992

Repeated isovolemic large-volume erythrocytapheresis in the treatment of idiopathic hemochromatosis.

In order to assess the effectiveness of cytapheresis as a possible alternative therapy for iron depletion, we performed a prospective study on eight unrelated patients with idiopathic hemochromatosis (HC). Isovolemic large-volume erythrocytapheresis (EA) (1000 ml apherisate) was carried out every four weeks until serum ferritin levels dropped below 300 micrograms/l (initial therapy). In all patients iron depletion was achieved after a mean of 8.5 months (8.9 EA with a total removal of 9.41 RBC). Serum ferritin levels decreased during initial therapy from 2596 +/- 399 to 168 +/- 83 ug/l. Serum iron level (240 +/- 35 to 125 +/- 48 ug/dl) and transferrin saturation (91 +/- 6 to 19 +/- 10%) declined accordingly. Clinical reexamination after initial therapy revealed improvement of clinical symptoms, normalization of hepatic iron, but liver histology remained unchanged. Reaccumulation of iron was prevented by maintenance EA therapy every five to six months (follow-up 18-36 months). Isovolemic large-volume EA is an effective, fast and safe method to remove excessive stored iron in patients with HC. Compared to phlebotomy, EA can selectively remove RBC, while saving plasma proteins, platelets, and clotting factors. Although, the need for special equipment and trained personnel as well as the relatively high costs are limiting factors of EA so far, it can be of crucial advance in some patients with HC.

Adult↗