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).

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.

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.