[Massive pancarditis-autopsy report]. / Massive Pankarditis ­ ein Autopsiebericht.

We report on a 69-year-old man suffering from chronic progressive oligoarthritis (localized in metacarpal and knee joints), which clinically was interpreted as steroid-sensitive seronegative chronic arthritis. The patient died from sudden death at the emergency department after a 4-week history of increasing cough and dyspnea (meanwhile obtaining negative testing results for SARS-CoV-2). During the autopsy, we found massive pancarditis affecting all cardiac compartments, in particular exhibiting constrictive pericarditis, myocarditis, and multivalvular endocarditis. Microscopically, interstitial myocarditis could be observed. Performing extensive molecular analyses, we detected Tropheryma whipplei in the tissue specimens of the heart, but not in various duodenal tissue probes or in the synovial membrane. Taken together, in the present case the cause of death was acute cardiac failure due to multivalvular pancarditis due to T. whipplei. Besides from classical symptoms and morphological signs, Whipple's disease may present with various features. Regarding the differential diagnosis of a chronic multisystem disorder with aspects of hitherto unknown arthralgia, Whipple's disease should be considered.

15 years of the histopathological synovitis score, further development and review: A diagnostic score for rheumatology and orthopaedics.

The histopathological synovitis score evaluates the immunological and inflammatory changes of synovitis in a graduated manner generally customary for diagnostic histopathological scores. The score results from semiquantitative evaluation of the width of the synovial surface cell layer, the cell density of the stroma and the density of the inflammatory infiltration into 4 semiquantitative levels (normal 0, mild 1, moderate 2, severe 3). The addition of these values results in a final score of 0-9 out of 9. On the basis of this summation the condition is divided into low-grade synovitis and high-grade synovitis: A synovitis score of 1 to≤4 is called low-grade synovitis (arthrosis-associated/OA synovitis, posttraumatic synovitis, meniscopathy-associated synovitis and synovitis with haemochromatosis). A synovitis score of≥5 to 9 is called high-grade synovitis (rheumatoid arthritis, psoriatic arthritis, Lyme arthritis, postinfection/reactive arthritis and peripheral arthritis with Bechterew's disease). By means of the synovitis score it is therefore possible to distinguish between degenerative/posttraumatic diseases (low-grade synovitis) and inflammatory rheumatic diseases (high-grade synovitis) with a sensitivity of 61.7% and a specificity of 96.1%. The diagnostic accuracy according to ROC analysis (AUC: 0.8-0.9) is good. Since the first publication (2002) and an associated subsequent publication (2006), the synovitis score has nationally and internationally been accepted for histopathological assessment of the synovitis. In a PubMed data analysis (status: 14.02.2017), the following citation rates according to Cited by PubMed Central articles resulted for the two synovitis score publications: For DOI: 10.1078/0344-0338-5710261 there were 29 Cited by PubMed Central articles and for the second extended publication DOI:10.1111/j.1365-2559.2006.02508 there were 44 Cited by PubMed Central articles. Therefore a total of 73 PubMed citations are observed over a period of 15 years, which demonstrates an international acceptance of the score. This synovitis score provides for the first time a diagnostic, standardised and reproducible histopathological evaluation method enabling a contribution to the differential diagnosis of chronic inflammatory general joint diseases. This is particularly the case by incorporation into the joint pathology algorithm. To specify the synovitis score an immunohistochemical determination of various inflammation-relevant CD antigens is proposed to enable a risk stratification of high-grade synovitis (e.g.: progression risk and sensitivity for biologicals).

[Fifteen years of the histopathological synovitis score : Review and further developments of a diagnostic score]. / 15 Jahre histopathologischer Synovialitis-Score : Rückblick und Weiterentwicklung eines diagnostischen Scores.

The histopathological synovitis score evaluates in a graded approach, as is largely usual for diagnostic histopathological scores, the immunological and inflammatory changes caused by synovitis. A synovitis score of between 1 and ≤ 4 is classified as low-grade (osteoarthritis-related synovitis, post-traumatic synovitis, meniscopathy-related synovitis and synovitis in hemochromatosis). Synovitis scores of between ≥ 5 and 9 are classified as high-grade synovitis (rheumatoid arthritis, psoriatic arthritis, Lyme's arthritis, post-infection/reactive arthritis and peripheral arthritis in Bechterew disease); sensitivity is 61.7% and sensitivity 96.1%. According to receiver operating characteristic (ROC) analysis (AUC: 0.8-0.9), diagnostic value is good. National and international acceptance of the synovitis score has grown since the first publication in 2002 and a related follow-up publication in 2006. PubMed data analysis (as of 11.01.2017) yielded the following citation values according to "cited by PubMed Central articles" for two publications relating to the synovitis score: there were 29 cited-by-PubMed articles for DOI: 10.1078/0344-0338-5710261 , and 44 cited-in-PubMed articles for the second publication, DOI: 10.1111/j.1365-2559.2006.02508 . This makes a total of 73 PubMed citations over a period of 15 years, thereby evidencing the score's international acceptance. Immunohistochemical determination of a number of CD antigens relevant to inflammation has been proposed to further specify the synovitis score for the purposes of risk stratification of high-grade synovitis (e.g., risk of progression and sensitivity to biological agents).

MALDI IMS and Cancer Tissue Microarrays.

Matrix-assisted laser desorption/ionization imaging mass spectrometry (MALDI IMS) technology creates a link between the molecular assessment of numerous molecules and the morphological information about their special distribution. The application of MALDI IMS on formalin-fixed paraffin-embedded (FFPE) tissue microarrays (TMAs) is suitable for large-scale discovery analyses. Data acquired from FFPE TMA cancer samples in current research are very promising, and applications for routine diagnostics are under development. With the current rapid advances in both technology and applications, MALDI IMS technology is expected to enter into routine diagnostics soon. This chapter is intended to be comprehensive with respect to all aspects and considerations for the application of MALDI IMS on FFPE cancer TMAs with in-depth notes on technical aspects.

[MALDI mass spectrometry of the meniscus. Objectification of morphological findings]. / MALDI-Massenspektrometrie am Meniskus. Objektivierung morphologischer Befunde.

BACKGROUND: The classification of meniscal lesions requires correlation with clinical data. For the standardization of histopathology reports a discrimination between normal, low-grade lesions and high-grade lesions is feasible. This classification can be further specified using other methods. MATERIAL AND METHODS: Formalin-fixed, paraffin-embedded specimens of meniscal tissue from 68 patients were analyzed by matrix-assisted laser desorption ionization (MALDI) imaging. RESULTS: The classification of meniscal lesions and differentiation between low-grade and high-grade and acute versus non-acute degeneration is possible by determination of the differential expression of mass-to-charge ratios by statistical comparisons using the P-value from combined Wilcoxon and Kruskal-Wallis (PWKW) tests and a predefined average two-fold difference in intensity. CONCLUSION: The concept of a "meniscus report" is introduced for documentation of meniscus tissue specimens integrating histological, histochemical and proteomic data, thereby specifying the degree of degeneration and the assessment of acute or non-acute lesions. Mass spectrometry contributes to an objective histopathology report. An advisory opinion should always be based on close correlation of clinical and morphological evaluations.

[Molecular pathological diagnostics of infections in orthopedic pathology]. / Molekularpathologische Infektionsdiagnostik in der orthopädischen Pathologie.

The diagnosis of infections in patients with arthritis and/or in joint prostheses requires interdisciplinary cooperation and the application of up-to-date methods. The histological investigation of the synovial membrane allows the differentiation of acute, chronic and granulomatous synovialitis. Detection of conserved regions of the microbial genome by PCR, especially 16S rRNA for bacteria and 18S rRNA for fungi, is a broad approach for the classification of pathogens which cannot be cultured. Acute infectious arthritis and periprosthetic infections share the spectrum of pathogens with sepsis, therefore multiplex PCR-based methods for the detection of sepsis can be employed. Molecular diagnostics can detect minimal infections in periprosthetic tissues even after antibiotic therapy. The anamnesis (enteral or urogenital infection), clinical picture (oligoarthritis) and further parameters (e.g. HLA B27 status) are important for the diagnosis of reactive arthritis. In many cases of reactive arthritis, molecular methods allow the detection of bacterial DNA or RNA in synovial fluid or tissue samples. The low sensitivity of histopathological methods may be compensated by application of PCR techniques, especially in the differential diagnosis of granulomatous synovitis including mycobacterial infections. Molecular methods can be used to support the differential diagnosis of septic and reactive arthritis. MicroRNA techniques combined with PCR for detection of pathogens support the differential diagnosis of rheumatoid arthritis with severe inflammatory activity compared to infectious arthritis. Proteomic methods could expand the methodological spectrum for the diagnosis of infections.

[Soft tissue tumor near the joint: hibernoma]. / Weichgewebstumor in der Nähe von Gelenken: Hibernom.

Joint associated tumors must undergo histological analysis, since not only inflammatory, but also benign and malign tumors exist in this location. We report a well circumscribed tumor, located in the elbow that histologically turned out to be a hibernoma. Complete surgical excision is the therapy of choice and recurrences are rare. To rule out liposarcoma with hibernoma like changes, fluorescence in-situ hybridisation has been performed and showed no MDM-2 amplification. Hibernomas are tumors of brown adipose tissue that may be localized next to joints.

MALDI imaging of predictive ferritin, fibrinogen and proteases in haemophilic arthropathy.

Arthropathy as a result of repeated joint bleeding is a severe complication in patients with haemophilia. In the evaluation of synovial tissue specimens, histology alone is non-specific and there is considerable morphological overlap with other joint diseases. Formalin-fixed paraffin-embedded specimens are available in pathological institutes and can be studied to understand the pathogenesis of haemophilic arthropathy. A powerful technique to identify hundreds of proteins in a tissue section combining proteomics with morphology is imaging mass spectrometry (IMS). We determined whether matrix-assisted laser desorption/ionization (MALDI) IMS can be used to identify and map protein signatures in the synovial tissue of patients with haemophilic arthropathy. MALDI IMS was applied to synovial tissue of six patients with haemophilic arthropathy. We detected several peaks predictive in mass with ferritin light (m/z 1608) and heavy chain (m/z 1345), alpha- (m/z 1071) and beta (m/z 1274) haemoglobin subunits, truncated coagulation factor VIII peptide (m/z 1502, 1176), beta- and gamma fibrinogen peptides (m/z 980, 1032, 1117 and 1683), and annexin A2 (m/z 1111, 1268, 1460, 2164). In addition, the distribution of these proteins in synovial tissue sections was demonstrated. MALDI IMS identified and mapped specific proteins in the synovial membrane of patients with haemophilic arthropathy known to be involved in the pathogenesis of other joint diseases. This technique is a powerful tool to analyse the distribution of proteins in synovial tissue sections.

MALDI MS imaging as a powerful tool for investigating synovial tissue.

OBJECTIVE: To identify and image protein biomarker candidates in the synovial tissue of patients with rheumatoid arthritis (RA) and patients with osteoarthritis (OA). METHODS: A novel matrix-assisted laser desorption/ionization (MALDI) imaging mass spectrometry (IMS) technique was applied to the analysis of synovial tissue. Patients were classified according to the American College of Rheumatology (ACR) criteria for RA. Frozen sections were stained to obtain morphological data. Serial sections were desiccated, and spotted with matrix for MALDI analysis. Ions generated by laser irradiation of the tissue were separated in time, based on their m/z ratio, and were subsequently detected. IMS was used in a 'profiling' mode to detect discrete spots for rapid evaluation of proteomic patterns in various tissue compartments. Photomicrographs of the stained tissue images were reviewed by a pathologist. Areas of interest (10 discrete areas/compartment) were marked digitally and the histology-annotated images were merged to form a photomicrograph of the section taken before the MALDI measurement. Pixel coordinates of these areas were transferred to a robotic spotter, the matrix was spotted, and the coordinates of the spots were transferred to a mass spectrometer for spectral acquisition. The data generated were then subjected to biocomputation analysis to reveal the biomarker candidates. RESULTS: Several peaks (m/z) consistent in mass with calgranulins, defensins, and thymosins were detected and their distribution in various synovial compartments (synovial lining and sublining layer) was demonstrated. CONCLUSION: MALDI IMS is a powerful tool for the rapid detection of numerous proteins (in situ proteomics) and was applied here for the analysis of the distribution of proteins in synovial tissue sections.

[Bone marrow edema in magnetic resonance imaging. A misleading term?]. / Knochenmarködem in der Magnetresonanztomographie. Ein irreführender Begriff?

Magnetic resonance imaging (MRI) is a mainstay in musculoskeletal imaging. The term"bone marrow edema" is frequently used for describing the radiological findings, especially with respect to rheumatic diseases. The referring physician should be aware that this term has a purely descriptive character and the pathophysiology of signal alterations in MRI shows a broad spectrum certainly not always corresponding to increased liquid contents. The recommendations therefore tend towards the use of the neutral terms"osteitis","bone marrow edema-like lesion" or"bone marrow lesion" instead of the misleading term"bone marrow edema".

[Gout - regardless of therapeutic options a "forgotten" disease]. / Gicht - die "vergessene" Erkrankung trotz vieler therapeutischer Optionen.

Compared to other chronic inflammatory diseases, gout appears to based on a rather "simple" pathophysiology and therefore the amount of teaching time in medical school and during internship is rather limited. On the other hand, several problems in short- and long-term management still need to be solved - combined with the problem of an increased incidence in elderly people. However, there is significant advance in the knowledge of its pathophysiology including the fact that gout is more than a pure "crystal arthopathy" but rather within the spectrum of chronic inflammatory immunologic diseases. This includes cytokines such as interleukin-1 and intracellular signaling via the inflammasome. For treatment, the novel and effective xanthine oxidase inhibitor febuxostat has been added to the therapeutic armamentarium. Guidelines of EULAR and BSR support the physician in the long-term management of the numerous gout patients.

[Is bioptic assurance reasonable in patients with Sjögren's syndrome? From focus score to diagnosing vasculitides]. / Ist eine bioptische Sicherung beim Sjögren-Syndrom sinnvoll? Vom Focus-Score zur Vaskulitisdiagnostik.

Sjögren's syndrome is an autoimmune disease which targets the salivary and lacrimal glands in particular, causing sicca syndrome. Extraglandular manifestations are often seen. Chronic sialadenitis of the parotid gland is the most common symptom to be assessed for differential diagnosis. Common HE and Giemsa slices are histopathologically examined and graduated for lymphocyte infiltration (focus): grade 0: absent, grade 1: slight, grade 2: moderate non-focal infiltration, grade 3: 1 focus (> or =50 lymphocytes) per 4 mm2, grade 4: >1 focus. Grade 3 infiltrates correspond to a focus score of 1, which is one of four disease-classifying criteria acknowledged for diagnosis. Bioptic examination is also performed to rule out different (non-) immunologic sialadenitises, such as the necrotizing or epithelioid-like form (in sarcoidosis), and the extranodal marginal-zone lymphoma. Extraglandular manifestations of Sjögren's syndrome can also be safely diagnosed by histopathological examination. Emphases lie on vasculitides and myositides. Bioptic work-up, therefore, is not only reasonable but also an essential tool for diagnostics in Sjögren's syndrome.

[Applications of molecular pathology in the diagnosis of joint infections]. / Molekularpathologische Diagnostik von Gelenkinfektionen.

The diagnosis of infections in patients with arthritis and/or joint prostheses requires interdisciplinary cooperation and the use of up-to-date methods. Massive bacterial infection can be identified by bacterial culture, and minimal infection can be detected by molecular pathological methods. These processes include specific enrichment of bacterial and fungal DNA, amplification, and identification of the DNA by gel electrophoresis, sequencing techniques, and chip technologies.Anamnesis (enteral or urogenital infection), the clinical picture (oligoarthritis), and further parameters (e.g., HLA B27 status) are important for the diagnosis of reactive arthritis. In many cases of reactive arthritis, molecular methods allow detection of bacterial DNA or RNA in synovial fluid or tissue. Molecular pathological methods allow the fast and reliable differential diagnosis of granulomatous synovialitis without prior cultivation of bacteria or fungi. The development of new molecular pathological methods for detecting bacterial and fungal nucleic acids will increase diagnostic accuracy.

[Diagnostics of glomerulonephritis]. / Diagnostik der Glomerulonephritiden.

Glomerulonephritis occurs frequently in patients with multisystemic rheumatic disease, especially in collagen vascular disorders and vasculitides. From a clinical point of view nephrotic syndrome has to be distinguished from nephritic syndrome. Rapid deterioration of renal function is referred to as rapid progressive glomerulonephritis. The differential diagnosis of glomerulonephritis can be narrowed by the findings on urine sediment, amount of proteinuria, degree of renal insufficiency and serological findings. In particular, the presence of urine acanthocytes and cellular casts are diagnostic for glomerulonephritis or vasculitis. Renal biopsy is necessary to establish the final diagnosis in most cases; however, some histological pattern such as membranous glomerulonephritis may occur in several different etiopathogenetic diseases and one disease process may lead to different histomorphologic pictures. Rapid progressive glomerulonephritis is a nephrological emergency and should be diagnosed and treated early to prevent dialysis-dependent renal insufficiency.

Sensory rhodopsin II/transducer complex formation in detergent and in lipid bilayers studied with FRET.

The photophobic receptor from Natronomonas pharaonis (NpSRII) forms a photo-signalling complex with its cognate transducer (NpHtrII). In order to elucidate the complex formation in more detail, we have studied the intermolecular binding of both constituents (NpSRII and NpHtrII157; truncated at residue 157) in detergent buffers, and in lipid bilayers using FRET. The data for hetero-dimer formation of NpSRII/NpHtrII in detergent agrees well with KD values (approximately 200 nM) described in the literature. In lipid bilayers, the binding affinity between proteins in the NpSRII/NpHtrII complex is at least one order of magnitude stronger. In detergent the strength of binding is similar for both homo-dimers (NpSRII/NpSRII and NpHtrII/NpHtrII) but significantly weaker (KD approximately 16 microM) when compared to the hetero-dimer. The intermolecular binding is again considerably stronger in lipid bilayers; however, it is not as strong as that observed for the hetero-dimer. At a molar transducer/lipid ratio of 1:2000, which is still well above physiological concentrations, only 40% homo-dimers are formed. Apparently, in cell membranes the formation of the assumed functionally active oligomeric 2:2 complex depends on the full-length transducer including the helical cytoplasmic part, which is thought to tighten the transducer-dimer association.

Colocalization of C4d deposits/CD68+ macrophages in rheumatoid nodule and granuloma annulare: immunohistochemical evidence of a complement-mediated mechanism in fibrinoid necrosis.

Rheumatoid nodule (RN) represents a palisading granuloma with central fibrinoid necrosis, which is not only a classical manifestation of rheumatoid arthritis (RA) and part of the American College of Rheumatology (ACR)-criteria, but also is its diagnostic hallmark. The pathogenesis of RN is still not fully understood. At present, only data on serum analyses indicating a complement-mediated pathogenesis in the development of RA are available. Equivalent examinations for RN have not yet been performed. Granuloma annulare (GA) represents another type of palisading granuloma. A special subtype of GA, subcutaneous GA (SGA), is an important differential diagnosis to RN. Therefore, our aim was to examine RN and SGA regarding the complement deposition (C4d) by immunohistochemical means. All RN and GA were stained by hematoxylin/eosin and different special stains. In addition, all specimens were stained immunohistochemically with antibodies against CD68. Five GA and five RN were analyzed immunohistochemically with antibodies against C4d and CD68, and evaluated using single- and doublestaining immunohistochemistry. All RN and GA displayed depositions of C4d within their central necroses and between the surrounding palisading macrophages. Most importantly, C4d/CD68 double staining was visible in the palisading macrophages next to the necroses, while macrophages in the periphery were negative for C4d but positive for CD68. The main difference between RN and GA was a quantitative phenomenon with less positively reacting macrophages in a more incomplete palisade in GA. The positive reactions of all central necroses to C4d and colocalization of CD68 and C4d suggest that a complement-mediated mechanism may be operative in the formation of fibrinoid necrosis. This mechanism may be involved in any form of "fibrinoid necrosis", since no different patterns of C4d/CD68 expression could be observed in GA. This may explain why RG/GA are not distinguishable morphologically.

[Diagnostic spectrum of synovitis]. / Das differenzialdiagnostische Spektrum der Synovialitis.

This review will suggest an algorithm for standardised histopathological diagnosis of synovial biopsies and synovectomy specimens. In principal, changes of the synovial membrane can be inflammatory or non-inflammatory. To the latter group belong some benign tumors, such as tenosynovial giant cell tumor, lipoma or synovial chondromatosis. Rare non-inflammatory changes are the group of storage diseases. Inflammatory synovial diseases can be differentiated into crystal-induced arthropathy, such as gout and pseudogout, granulomatous diseases, such as tuberculosis, sarcoidosis and foreign body reactions and into the large group of non-granulomatous synovitis. This last group is by far the most common and often causes difficulties in assigning the histopathological findings to a definite diagnosis. Therefore, the synovitis score should be applied in these cases as a diagnostic means, leading to the diagnosis of low-grade synovitis (which is associated with degenerative and posttraumatic arthropathies) or high-grade synovitis (associated with rheumatic diseases), the sensitivity and specificity being 60.5% and 95.5%, respectively. In detritus synovitis the synovitis score is not applicable.

[Wear particles: key to aseptic prosthetic loosening?]. / Abriebpartikel. Schlüssel der aseptischen Prothesenlockerung?

The aseptic prosthetic loosening of hip and knee prosthesis is the most important cause of implant insufficiency. Bone loss as a result of the biological effect of wear particles is the main cause of such loosening. Wear particles develop their biological activity along different cellular pathways, above all via macrophages, foreign body giant cells as well as fibroblasts of the periprosthetic membrane. These cells induce particle-dependent bone resorption by means of proinflammatory cytokines, such as IL-1beta, TNF-alpha, IL-6 and PGE2. These factors induce the activation of osteoclasts as well as the suppression of osteoblasts. Neutrophil granulocytes and lymphocytes do not play an important role in the process of aseptic loosening. The different wear particles, such as ultra-high molecular weight polyethylene, metal particles, ceramic particles and polymethylmethacrylate can be morphologically recognized very easily. From the clinical point of view, the differentiation between acute or chronic implant infection and particle induced prosthetic loosening is very important, with the histomorphological differential diagnosis between septic and aseptic loosening and their combination being the key clinicopathological factor.