II tüüpi kollageeni neoepitoop C2C uriinis kui põlve osteoartriidi diagnoosimise ja kulu prognoosimise biomarker

Väitekirja elektrooniline versioon ei sisalda publikatsiooneOsteoartriit (OA) on sagedasim liigeshaigus, tabades ligi poolt miljardit inimest maailmas. Põlv on üks peamisi kahjustuskohti. Haiguse kaasaegse käsitluse järgi arenevad kahjustused molekulaarsetest muutustest kuni kudede (kõhr, luu, sünoviaalkest, menisk, sidemed) struktuuri muutusteni. OA on aastate jooksul ebaühtlase kiirusega süvenev haigus, mille puhul stabiilsemad perioodid vahelduvad kiiremate muutustega, kulgedes varajases järgus haigustunnusteta. Seetõttu pakuvad kudede ainevahetuse muutusi peegeldavad molekulaarsed markerid varajast hoiatust koekahjustuse tekkest, võimalust hinnata haiguse kulgu ning tulevikus ka ravivastust. Kuna II tüüpi kollageen (Kol2) on kõhre peamine struktuurne komponent, on OA hindamiseks loodud mitmeid Kol2 lammutamist mõõtvaid teste. Käesolevas uurimuses hindasime OA uue biomarkeri, uC2C kasutusvõimalusi põlve OA (pOA) korral. uC2C on Kol2 lõhustumise neoepitoop C2C uriinis. Võrdlesime uC2C väärtusi röntgenleiu, kõhre otsese vaatlusleiu ja patsiendi kliinilise seisundiga, kasutades erinevaid statistilisi mudeleid. Selgus, et uC2C on sobiv kandidaat pOA varajase diagnostilise testi arendamiseks. C2C sisaldus tõuseb juba haiguse varajases järgus ja on seotud haiguse mitme põhiprotsessiga: kõhre lammutamise ja luukasviste tekkega põlveliigese eri osades. uC2C on hea progressioonimarker naistel: uC2C kõrgem algväärtus ennustab naistel väga hästi (>90%) pOA teket või süvenemist järgneva 3 aasta jooksul. uC2C tase on kõrgem suuremate röntgenmuutuste korral, seega uC2C tase on seotud pOA raskusastmega. uC2C väärtused on suurimad kOA lõppjärgus olevatel haigetel, kes jõuavad liigeseasenduseni suhteliselt noorelt (50–70 a vanuses). Pärast põlveliigese asendamist võib C2C eritumine uriiniga väheneda, suureneda või jääda muutumatuks. Seega ei peata liigeseasendus paljudel juhtudel Kol2 lammutamist organismis ja OA on süsteemsem haigus, kui on seni arvatud. uC2C näib olevat naistel võrreldes meestega parem pOA biomarker.Osteoarthritis (OA) is the most common joint disease, affecting about half a billion people worldwide. The knee is one of the main sites of impairment. According to the new approach to the disease, the alterations develop from the molecular level to structural changes in tissues (cartilage, bone, synovium, meniscus, ligaments). OA is a disease with an alternating course, with no signs of disease at an early stage. Therefore, molecular markers that reflect changes in tissue metabolism provide an early warning of tissue damage, an opportunity to assess the course of the disease, and a response to future treatment. Because type II collagen (Col2) is a major structural component of cartilage, several tests have been developed to measure Col2 degradation. In the current study, we evaluated the potential use of a new OA biomarker, C2C, in knee OA (kOA). uC2C is a Col2 cleavage neoepitope in urine. We compared uC2C values with X-ray findings, direct visual assessment of cartilage, and clinical status using different statistical models. uC2C is a good candidate for the development of an early diagnostic test for kOA. The level of uC2C is increased in the early stages of kOA and is related to several main processes of kOA: the cartilage lesions and the osteophytes in distinct knee compartments. uC2C is a good marker of progression in women–a higher baseline uC2C is an excellent predictor (> 90%) of the initiation or worsening of kOA over the next 3 years. uC2C is higher in higher X-ray grades, so uC2C levels are associated with the severity of kOA. uC2C values are highest in patients with end-stage kOA who reach joint replacement at a relatively young age (50-70 years). After knee replacement, urinary excretion of C2C may decrease, increase, or remain unchanged. Thus, in many cases, joint replacement does not stop the breakdown of Col2 in the body, and OA is a more systemic disease than previously thought. uC2C appears to be a better biomarker of pOA in women than in men.https://www.ester.ee/record=b550707

Current laboratory and clinical practices in reporting and interpreting anti?nuclear antibody indirect immunofluorescence (ANA IIF) patterns: results of an international survey

Background: The International Consensus on Antinuclear Antibody (ANA) Patterns (ICAP) has recently proposed nomenclature in order to harmonize ANA indirect immunofluorescence (IIF) pattern reporting. ICAP distinguishes competent-level from expert-level patterns. A survey was organized to evaluate reporting, familiarity, and considered clinical value of ANA IIF patterns. Methods: Two surveys were distributed by European Autoimmunity Standardization Initiative (EASI) working groups, the International Consensus on ANA Patterns (ICAP) and UK NEQAS to laboratory professionals and clinicians. Results: 438 laboratory professionals and 248 clinicians from 67 countries responded. Except for dense fine speckled (DFS), the nuclear competent patterns were reported by>85% of the laboratories. Except for rods and rings, the cytoplasmic competent patterns were reported by>72% of laboratories. Cytoplasmic IIF staining was considered ANA positive by 55% of clinicians and 62% of laboratory professionals, with geographical and expertise-related differences. Quantification of fluorescence intensity was considered clinically relevant for nuclear patterns, but less so for cytoplasmic and mitotic patterns. Combining IIF with specific extractable nuclear antigens (ENA)/dsDNA antibody testing was considered most informative. Of the nuclear competent patterns, the centromere and homogeneous pattern obtained the highest scores for clinical relevance and the DFS pattern the lowest. Of the cytoplasmic patterns, the reticular/mitochondria-like pattern obtained the highest scores for clinical relevance and the polar/Golgi-like and rods and rings patterns the lowest. Conclusion: This survey confirms that the major nuclear and cytoplasmic ANA IIF patterns are considered clinically important. There is no unanimity on classifying DFS, rods and rings and polar/Golgi-like as a competent pattern and on reporting cytoplasmic patterns as ANA IIF positive

Risk Assessment of the Progression of Early Knee Osteoarthritis by Collagen Neoepitope C2C: A Longitudinal Study of an Estonian Middle-Aged Cohort

One of the unmet needs to be addressed is prognostic biomarkers for early knee osteoarthritis (kOA). We aimed to study the association of urinary collagen type-II C-terminal cleavage neoepitope (uC2C) with the emergence and progression of kOA. The longitudinal data of 330 subjects (aged 32–60 years) from an Estonian population-based cohort were used. The radiographic progression was evaluated by the grading system of Nagaosa et al. of knee compartments at baseline and three years later. The emerging kOA consisted of subjects with developing osteophytes or joint space narrowing, whereas kOA progressors showed aggravation of radiographic grade. Baseline uC2C levels were measured by the IBEX-uC2C assay. At baseline, the subjects were middle-aged (mean age, 47.6 years) and overweight (mean BMI, 28.0 kg/m2), and the majority of them (51.2%) had a diagnosis of kOA grade 1. Multiple logistic regression models adjusted for sex, age, and BMI were used for risk calculations. We demonstrate that increased uC2C accurately predicted the risk of emerging of kOA (OR = 5.87 (1.71–20.22); AUC = 0.79) compared with controls without radiographic kOA over 12 years. However, the most accurate prediction of progression by the biomarker was found in women (OR = 23.0 (2.2–245), AUC = 0.91). In conclusion, uC2C may be a promising candidate as a prognostic biomarker for kOA progression, particularly of emerging kOA in women

Associations of Urinary Collagen II Neoepitope C2C with Total Knee Replacement Outcomes: Is OA a Systemic Disease in Rapidly Progressive Cases?

The objective of this study was to investigate the dynamics of the urinary collagen type II C-terminal cleavage neoepitope (uC2C) before and after total knee replacement (TKR) in rapid knee OA progressors. C2C in the urine was measured by IBEX-uC2C assay in 86 patients (mean age: 59.9 years) with symptomatic knee OA (kOA) undergoing TKR, assessed before surgery and 3 and 12 months after. The patients’ condition was determined by self-assessment questionnaires, by lower limb performance tests, and by radiography. In the preoperative period, the uC2C level was significantly higher in females than in males, and was associated with the radiographic severity of kOA. A weak correlation between the C2C and knee pain was observed in the whole group and in males, but not in females. The individual dynamics of uC2C after TKR were heterogenic. In general, uC2C increased three months after TKR, but fell to the preoperative level after 12 months. A higher preoperative uC2C implied the tendency to diminish as a result of TKR, and vice versa. TKR did not stop the degradation of Coll2 in the tissues in the majority of cases. The pre-TKR uC2C predicts the postoperative uC2C level. The uC2C dynamic seems to be sex-specific, so it could be considered a prospective pre- and post-TKR biomarker for progressive kOA

The impact of the COVID-19 pandemic on autoimmune diagnostics in Europe:A lesson to be learned

INTRODUCTION: The first wave of COVID-19 pandemic has disrupted almost all areas of the health care services to some extent throughout the world. Although the negative impact of COVID-19 on patients with autoimmune diseases has also been recognized, available data in this regard are limited. In the current study of the European Autoimmunity Standardisation Initiative (EASI) we aimed to provide reliable data on the extent of the impact of COVID-19 pandemic on test requests for different autoantibodies in European countries. METHODS: Data on test numbers and on the number of positive results were collected in 97 clinical laboratories from 15 European countries on a monthly basis for the year before (2019) and the year during (2020) the COVID-19 pandemic. RESULTS: A reduction in the number of autoantibody tests was observed in all European countries in the year 2020 compared to 2019. The reduction affected all autoantibody tests with an overall decrease of 13%, ranging from 1.4% (Switzerland) to 25.5% (Greece). In all countries, the decrease was most pronounced during the first wave of the pandemic (March-May 2020) with an overall decrease in those three months of 45.2%. The most affected autoantibodies were those commonly requested by general practitioners (anti-tTG IgA (-71%), RF IgM (-66%) and ACPA (-61%)). In the second wave of the pandemic (October-December 2020) the decrease was less pronounced (6.8%). With respect to the rate of positive results, subtle differences were observed for distinct autoantibodies during the pandemic, but the total rate of positive results was similar in both years. CONCLUSIONS: Our study demonstrated a strong decrease in autoantibody requests during the first wave of the COVID-19 pandemic in 15 European countries. The second wave was characterized by a less pronounced impact, with some participating countries hardly affected, while some other countries experienced a second decline. The decrease was clearly associated with the level of lock-down and with the required adjustments in the health care systems in different countries, supporting the importance of an effective strategy for the coordination of autoimmune testing in challenging situations as the COVID-19 pandemic

Repository of intra-and inter-run variations of quantitative autoantibody assays:A European multicenter study

No reference data are available on repositories to measure precision of autoantibody assays. The scope of this study was to document inter-and intra-run variations of quantitative autoantibody assays based on a real-world large international data set. Members of the European Autoimmunity Standardisation Initiative (EASI) group collected the data of intra-and inter-run variability obtained with assays quantifying 15 different autoantibodies in voluntary participating laboratories from their country. We analyzed the impact on the assay performances of the type of immunoassay, the number of measurements used to calculate the coefficient of variation (CVs), the nature and the autoantibody level of the internal quality control (IQC). Data were obtained from 64 laboratories from 15 European countries between February and October 2021. We analyzed 686 and 1,331 values of intra-and inter-run CVs, respectively. Both CVs were significantly dependent on: The method of immunoassay, the level of IQC with higher imprecision observed when the antibody levels were lower than 2-fold the threshold for positivity, and the nature of the IQC with commercial IQCs having lower CVs than patients-derived IQCs. Our analyses also show that the type of autoantibody has low impact on the assay' performances and that 15 measurements are sufficient to establish reliable intra-and inter-run variations. This study provides for the first time an international repository yielding values of intra-and inter-run variation for quantitative autoantibody assays. These data could be useful for ISO 15189 accreditation requirements and will allow clinical diagnostic laboratories to assure quality of patient results