京都大学 / 新制・課程博士 / 博士(医学) / 甲第23058号 / 医博第4685号 / 新制||医||1048(附属図書館) / 京都大学大学院医学研究科医学専攻 / (主査)教授 妻木 範行, 教授 浅野 雅秀, 教授 別所 和久 / 学位規則第4条第1項該当 / Doctor of Medical Science / Kyoto University / DFAM

Η ετερότοπη οστεοποίηση είναι ένα όχι σπάνιο φαινόμενο που οδηγεί σε δημιουργία οστικών δομών σε σημεία που φυσιολογικά υπάρχουν μαλακά μόρια. Ετερότοπη οστεοποίηση μπορεί να προκληθεί κατόπιν τοπικού τραύματος, κατόπιν νευρολογικού τραύματος, ύστερα από χειρουργική επέμβαση σε περιοχές όπως τα ισχία και οι αγκώνες, λόγω γενετικού υποστρώματος σε ασθενείς πολύ μικρών ηλικιών και τέλος αντιδραστικές ετερότοπες οστεοοποιήσεις άνω ή κάτω άκρων. Στην παρούσα διατριβή προσεγγίστηκε η νευρογενούς αιτιολογίας ετερότοπη οστεοποίηση, κυρίως κατόπιν ΚΕΚ. Ο παθοφυσιολογικός μηχανισμός του φαινομένου είναι εν πολλοίς άγνωστος και αυτό που θεωρείται δεδομένο είναι η διαταραχή του ισοζυγίου οστεοβλαστικής – οστεοκλαστικής δραστικότητας κατόπιν της δράσης του επαγωγικού παράγοντα. Ύστερα από τη δράση του επαγωγικού παράγοντα –στη συγκεκριμένη περίπτωση της ΚΕΚ – αυξάνεται η οστεοβλαστική δραστηριότητα τοπικά. Κατά το σχηματισμό του οστού λοιπόν, παράγονται και εκκρίνονται πρωτεογλυκάνες στις αλυσίδες των οποίων προσκολλώνται οι γλυκοζαμινογλυκάνες. Πρωτεογλυκάνες και γλυκοζαμινογλυκάνες συναποτελούν μαζί με τις κολλαγονικές και μη κολλαγονικές πρωτεΐνες, τα τρία κύρια είδη μακρομορίων του εξωκυττάριου δικτύου του οστού. Σκοπός της μελέτης μας ήταν αφενός η μελέτη των πρωτεογλυκανών και γλυκοζαμινογλυκανών στο ετερότοπο οστό σε αντιδιαστολή με φυσιολογικό-ορθότοπο οστό προκειμένου να διερευνηθεί ο ρόλος τους στην δημιουργία του φαινομένου της ετρότοπης οστεοποίησης. Αφετέρου για να διερευνηθεί καλύτερα ο παθοφυσιολογικός μηχανισμός του φαινομένου, μελετήθηκαν κυτταρικοί πληθυσμοί με οστεοβλαστική δραστηριότητα στο περιφερικό αίμα ασθενών που είχαν υποστεί ΚΕΚ και νοσηλεύονταν στη ΜΕΘ, καθώς και πειραματοζώων κατόπιν τεχνητής επαγωγής Κρανιοεγκεφαλικής Βλάβης. Η θειική χονδροϊτίνη και το υαλουρονικό οξύ είναι οι μοναδικοί τύποι γλυκοζαμινογλυκανών στο εξωκυττάριο δίκτυο ετερότοπου οστού όπως και στο φυσιολογικό. Εντούτοις, το ολικό ποσό τους είναι κατά 70% μικρότερο σε σύγκριση με αυτό του φυσιολογικού οστού. Διαφορετική είναι και η εκατοστιαία αναλογία αυτών των μακρομορίων. Η επικρατούσα μορφή δισακχαρίτη θειικής χονδροϊτίνης είναι η θειωμένη στην θέση 6. Ωστόσο η ποσοτική διαφοροποίηση από το φυσιολογικό οστό τόσο στους 4 θειωμένους όσο και στους μη θειωμένους δισακχαρίτες είναι υπαρκτή σε όλα τα ετερότοπα δείγματα. Από πλευράς πρωτεογλυκανών η αγγρικάνη και η διακοσμητίνη είναι ποιοτικά παρούσες στο εξωκυττάριο δίκτυο οστίτη ιστού. Επομένως, ποσοτικές διαφοροποιήσεις στο ετερότοπο οστό σε αντιδιαστολή με το φυσιολογικό είναι υπαρκτές και αυτή η διαφοροποίηση πιθανώς αντικατοπτρίζει διαφορετικές ενζυμικές δραστηριότητες στο φαινόμενο της ετερότοπης οστεοποίησης. Στη μελέτη των κυτταρικών πληθυσμών με οστεοβλαστική δραστηριότητα στο περιφερικό αίμα διαπιστώνονται τα ακόλουθα: Αυξημένη οστεοβλαστική δραστηριότητα στους πληθυσμούς CD-63(+) η οποία εμφανίζει κορυφή στις 6-10 ημέρες μετά την ΚΕΚ. Αυξανόμενη οστεοβλαστική δραστηριότητα πληθυσμών κυττάρων osteocalcin (+) σε όλες τις μετρήσεις μετά την ΚΕΚ. Το σύστημα οστεοπροτεγερίνης – sRANKL εμφανίζει τα εξής χαρακτηριστικά: η osteoprotegerin είναι μετρήσιμη και αυξάνει προς το τέλος των μετρήσεων. Το sRANKL απεναντίας δεν είναι μετρήσιμο σε καμία χρονική στιγμή κατόπιν της ΚΕΚ. Τα παραπάνω συνεπάγονται ότι η ΚΕΚ είναι παράγων επαγωγής οστεοβλαστικής δραστηριότητας όχι μόνο τοπικά αλλά και συστηματικά. Η εκτροπή της οστεοβλαστικής δραστηριότητας προς δημιουργία ετερότοπης οστεοποίησης χρήζει μελέτης μεγαλυτέρου δείγματος ασθενών και πιθανότατα και σε επίπεδα γονιδιακής έκφρασης κυτταρικών καλλιεργειών ασθενών κατόπιν ΚΕΚ. / Ηeterotopic ossification is a relatively frequent phenomenon that leads to the formation of heterotopic osseous structures at points where soft molecules normally do exist. Heterotopic ossification can be induced after local lesion, neurological lesion, after surgical intervention in regions as the hips and the elbows, due to genetic causes in patients of very small ages and, finally, the phenomenon has been observed as distinct, reactive cases in upper or lower limbs. In this Thesis, pathophysiology and mechanisms of neurogenic heterotopic ossification were studied. Pathways of the phenomenon still unknown to date. What is thaught to be the case in the formation of HO, is the disturbance of balance of osteoblastic to osteoclastic activities, after the induction-Head injury in this situation. After Traumatic Brain Injury, osteoblastic activity is induced locally. During bone formation proteoglycans are produced and secreted. Glucozaminoglycans are attached on the side chains of Proteoglycans. Proteoglycans and Glycozaminoglycans constitute along with collageneous and non-collageneous proteins the major macromolecules of extracellular matrix. The purpose of our study was the characterization of proteoglycans and glycozaminoglycans of the heterotopic bone versus the normotopic bone towards the elucidation of their role in the heterotopic bone formation. On the other hand, a more detailed approach to the pathophysiology of the phenomenon requires cellular populations expressing osteoblastic activities to be observed and studied. This is done in peripheral blood of patients that had sustained traumatic brain injuries and being hospitalized within IC units. Same studies on cellular populations have been conducted in a rabbit animal model of traumatic brain injury. Chondroitin-Sulfate and Hyaluronate are the only glycozaminoglycans that have been observed in extracellular matrix of heterotopic bone as well as in normotopic one. Quantitative analyses, however, revealed that their total amount is 70% less compared to normotopic bone. The commonest form of dissacharites of chondroitin-sulfate is the one sulfated at 6-O. However, there is a significant quantitative difference between normotopic and heterotopic bone in 4-O sulfated as well as in non sulfated dissacharites. With regards to proteoglycans, aggrecan and decorin are present in extracellular matrix. Quantitative differences between normotopic and heterotopic bone do exist and reflect a possible alternative pathway of bone formation in the HO phenomenon. The studies on osteoblastic activities of peripheral blood after traumatic brain injury revealed that there is increased osteoblastic activity in CD-63 (+) population that peaks 6-10 days after the inciting event. Osteocalcin (+) population do excibit increased osteoblastic activity as well which increases along with time. The system osteoprotegerin - sRANKL presents the following characteristics: osteoprotegerin is measurable and increases towards the end of measurements. sRANKL on the contrary is not measurable at any time following traumatic brain injury. Consequently, Traumatic Brain Injury do induce osteoblastic activity not only locally but also systemically. The deviation of osteoblastic activity towards heterotopic ossification requires studies of bigger sample of patients, probably to the level of differential gene expression of cellular cultures derived from patients having sustained neurotrauma.

BACKGROUND: Inflammation is a key regulator in skeletal homeostasis during normal growth and tissue repair. However, the role that inflammation plays in skeletal processes is not well understood. Previous studies showed that damage associated molecular pattern (DAMP) molecules released after injury may contribute to immune activation and subsequent fibrosis. OBJECTIVE: This project aims to elucidate the link between tissue damage caused by trauma and the subsequent inflammatory response in a genetic condition of bone morphogenetic protein (BMP) pathway over activation. METHODS: We investigated this potential link by examining immune cells from patients with fibrodysplasia ossificans progressiva (FOP), a genetic condition of endochondral heterotopic ossification caused by activating mutations in the Activin A type I receptor (ACVR1). Patients with FOP show sensitivity to trauma, elevated serum cytokines and abnormal cytokine/chemokine secretion from monocytes and macrophages when stimulated with lipopolysaccharide in vitro. This suggested that BMP pathway activation may alter immune responses in patients with FOP. We studied macrophages derived from peripheral blood monocytes or created from human induced pluripotent stem cells (iPSC) from FOP and control subjects. Macrophages were evaluated by gene expression and culture media by multiplex cytokine analysis after stimulation with key DAMPs that were previously identified to be released after tissue injury. These DAMPs act as endogenous activators of inflammation. RESULTS: Monocyte derived macrophages from control subjects showed increased expression of pro-inflammatory cytokines in response to stimulation with DAMPs, HMGB1 and S100A8/A9. FOP monocyte-derived macrophages treated with each DAMP showed elevated production of CCL22, IL-8, CCL3, and CCL8 when compared to control macrophages. However, both control and FOP macrophages showed increased production of pro-inflammatory cytokines in response to DAMPs compared to non-stimulated conditions. RNA expression profiles of FOP iPSC derived macrophages did not show significantly increased responsiveness to DAMPs compared to control. Surprisingly, control patient iPSC derived macrophages show elevated expression of TNF-a and IL-1B CONCLUSIONS: Macrophages derived from peripheral blood monocytes show that DAMPs may be responsible for macrophage activation and the development of inflammatory complications in patients with FOP. Control iPSC derived macrophages showed similarity to monocyte derived macrophages in their response to DAMPs, suggesting that our iPSC derived macrophages are an applicable model for investigating the human immune system. The dissimilarity in FOP macrophage responsiveness to endogenous activators of our two macrophage models, suggest that iPSC derived macrophages may be affected by the different differentiation and polarization methods, and needs to be characterized further. Similarly, RNA expression profiles may not reflect cytokine production patterns of stimulated iPSC macrophages and warrants further studies. / 2021-06-07T00:00:00Z

<p>In this thesis, occurrence of heterotopic ossification (HO) following total hip arthroplasty (THA) was studied. Preventive effects and complications with non-steroidal anti-inflammatory drugs (NSAIDs) were analyzed. Experimental investigations on bone formation were employed to gain insight to the mechanism of NSAIDs action on bone.</p><p>(I). Fifty-six patients with bilateral THAs were analyzed. We found a strong correlation between HO on the two sides. Incidence and grade of HO were higher in men than in women.</p><p>(II). Sixty-nine patients with bilateral THAs who had been treated with NSAIDs after one or both THAs were analyzed for HO. Widespread HO occurred in untreated THAs, but in none of the treated THAs.</p><p>(III). A consecutive series of THAs were analyzed for HO. No widespread HO occurred in patients treated with NSAIDs for 21 days. In contrast, widespread HO occurred in 23% of patients not treated.</p><p>(IV). A randomized, double-blind, prospective study on 144 patients was performed to determine the efficacy and minimum treatment time with Ibuprofen for prophylaxis of HO after THA. Treatment with Ibuprofen was effective for preventing HO and a treatment time of 8 days was sufficient.</p><p>(V). A ten-year follow-up examination was performed on the patients from study IV. Thirteen patients had been revised. All but one belonged to groups treated with Ibuprofen. However, the prosthetic survival time was not statistically different for patients treated with NSAIDs compared to the control group. Eighty-four more patients underwent radiographic examination10 years after THA. Nine loose prostheses were found. These were equally distributed between NSAIDs-treated and non-treated THAs. When combining complications (revisions and radiographic loosening) no significant effects could be verified.</p><p>(VI). Experimental induction of heterotopic new bone with demineralized allogeneic bone matrix (DABM) and with bone autografts, was used in rats to study effects of NSAIDs on new bone formation. Indomethacin inhibited net bone formation in DABMs and in orthotopic fractured bone. In contrast, a net mineral loss occurred in autografts, but neither mineral content nor ⁴⁵Ca incorporation was affected by Indomethacin treatment. The amount of bone formed per mg implanted DABM was linearly correlated to implant size.</p>

In this thesis, occurrence of heterotopic ossification (HO) following total hip arthroplasty (THA) was studied. Preventive effects and complications with non-steroidal anti-inflammatory drugs (NSAIDs) were analyzed. Experimental investigations on bone formation were employed to gain insight to the mechanism of NSAIDs action on bone. (I). Fifty-six patients with bilateral THAs were analyzed. We found a strong correlation between HO on the two sides. Incidence and grade of HO were higher in men than in women. (II). Sixty-nine patients with bilateral THAs who had been treated with NSAIDs after one or both THAs were analyzed for HO. Widespread HO occurred in untreated THAs, but in none of the treated THAs. (III). A consecutive series of THAs were analyzed for HO. No widespread HO occurred in patients treated with NSAIDs for 21 days. In contrast, widespread HO occurred in 23% of patients not treated. (IV). A randomized, double-blind, prospective study on 144 patients was performed to determine the efficacy and minimum treatment time with Ibuprofen for prophylaxis of HO after THA. Treatment with Ibuprofen was effective for preventing HO and a treatment time of 8 days was sufficient. (V). A ten-year follow-up examination was performed on the patients from study IV. Thirteen patients had been revised. All but one belonged to groups treated with Ibuprofen. However, the prosthetic survival time was not statistically different for patients treated with NSAIDs compared to the control group. Eighty-four more patients underwent radiographic examination10 years after THA. Nine loose prostheses were found. These were equally distributed between NSAIDs-treated and non-treated THAs. When combining complications (revisions and radiographic loosening) no significant effects could be verified. (VI). Experimental induction of heterotopic new bone with demineralized allogeneic bone matrix (DABM) and with bone autografts, was used in rats to study effects of NSAIDs on new bone formation. Indomethacin inhibited net bone formation in DABMs and in orthotopic fractured bone. In contrast, a net mineral loss occurred in autografts, but neither mineral content nor 45Ca incorporation was affected by Indomethacin treatment. The amount of bone formed per mg implanted DABM was linearly correlated to implant size.

京都大学 / 0048 / 新制・論文博士 / 博士(医学) / 乙第13031号 / 論医博第2113号 / 新制||医||1016(附属図書館) / 32989 / (主査)教授 妻木 範行, 教授 安達 泰治, 教授 開 祐司 / 学位規則第4条第2項該当 / Doctor of Medical Science / Kyoto University / DFAM

Résumé: Le muscle squelettique possède une excellente capacité à se regénérer notamment grâce à ses cellules progénitrices stromales (mrSC) et myogéniques (CPM). À la suite de certains traumas et pour des raisons encore méconnues, la qualité de sa régénération est compromise ce qui mène à l’apparition de structures aberrantes tel l’os mature, aussi appelée ossification hétérotopique (OH) post-traumatique. Notre laboratoire a montré dans un modèle murin que les mrSC sont pleinement impliquées dans cette pathologie. De plus, un facteur fortement ostéoinducteur, BMP9, ne cause l’OH que si, et seulement si, le muscle est endommagé. Ce modèle d’étude est unique puisqu’il présente les particularités physiopathologiques de l’OH post-traumatique, un dommage du muscle étant essentiel à la formation d’os. De plus, ce modèle a permis de mettre en évidence le rôle prédominant du microenvironnement des cellules progénitrices dans le développement de cette pathologie. Nous avons donc émis l’HYPOTHÈSE selon laquelle le microenvironnement du muscle endommagé contient des facteurs qui peuvent influencer le phénotype de ses cellules progénitrices stromales et myogéniques favorisant ainsi le développement de l’OH. Nos résultats montrent que l’état hypoxique d’un muscle sévèrement endommagé augmente la prolifération et la différenciation ostéogénique des mrSC. De plus, l’hypoxie induit spécifiquement l’expression de BMP9 par les mrSC. L’impact de BMP9 a également été évalué sur la différenciation des CPM. Les résultats montrent qu’à des concentrations physiologiques, BMP9 inhibe le potentiel myogénique des CPM en faveur d’une différenciation ostéogénique, et cela tant dans la lignée myoblastique murine C2C12 que chez les CPM primaires humaines. En résumé, le muscle endommagé développant l’OH possède un microenvironement spécifique responsable du débalancement de la capacité régénérative de ses progéniteurs. Nos travaux montrent que ce microenvironnement cause un retard de la myogenèse et une ostéogenèse où participeront non seulement les mrSC mais également les CPM. L’identification et la compréhension des mécanismes régulant ces facteurs s’avèrent clé pour offrir aux cliniciens des outils de diagnostic mais également des alternatives ou des approches complémentaires aux traitements prophylaxiques actuels. / Abstract: Skeletal muscle has an extraordinary ability to regenerate due to its resident stromal cells (mrSCs) and myogenic progenitor cells (MPCs). Following certain traumas, the quality of the regeneration of skeletal muscle can be compromised for unknown reasons, leading to the appearance of aberrant structures such as mature bone, a process called posttraumatic heterotopic ossification (HO). Our laboratory developed a mouse model to show that mrSCs are fully involved in this pathology. We also showed that BMP9, a highly osteoinductive factor, causes HO if and only if the muscle is damaged. This model is unique in that it recapitulates the pathophysiological features of post-traumatic HO in which muscle damage is essential for bone formation. The model was also used to show that the progenitor cell microenvironment plays a predominant role in the development of this pathology. Based on these results, we HYPOTHESIZED that the microenvironment of the damaged muscle contains factors that can influence the phenotype of its progenitor cell populations, thus promoting the development of HO. Our results showed that the hypoxic state of a severely damaged muscle increases the proliferation and osteogenic differentiation of mrSCs and also specifically induces the expression of BMP9 by mrSCs. The impact of BMP9 on the differentiation of MPCs was also evaluated. At physiological concentrations, BMP9 inhibited the myogenic differentiation potential of murine myoblast C2C12 cells and primary human MPCs, and triggered their differentiation into an osteogenic lineage. In summary, we showed that damaged muscle that develops HO has a specific microenvironment that is responsible for the loss of the regenerative capacity of progenitor cells, leading to a delay in myogenesis, and that mrSCs and MPCs are both involved in osteogenesis. The identification and understanding of the mechanisms regulating these key factors could provide clinicians with valuable diagnostic tools as well as alternative and/or complementary approaches to current prophylactic treatments.

O objetivo deste trabalho foi estudar o efeito da radioterapia na profilaxia da ossificação heterotópica (OH) em pacientes com lesão medular traumática. Foram estudados 19 pacientes (15 homens e quatro mulheres), média de idade de 30,4 ± 10,8 anos (19 a 58 anos), com lesão medular traumática. A causa mais freqüente da lesão medular foi acidente de trânsito (42,1%), seguida por queda (26,3%), ferimento por projétil de arma de fogo (21%), mergulho (5,3%) e queda de objeto sobre as costas (5,3%). Dez pacientes eram tetraplégicos (52,6%) e nove (47,4%) eram paraplégicos. Apresentavam lesão medular completa (Frankel A) 14 pacientes (73,7%) e cinco pacientes (25,3%) tinham lesão incompleta (Frankel B). Todos os pacientes incluídos no estudo realizaram cintilografia óssea inicial até um mês após o traumatismo raquimedular e apresentaram diagnóstico negativo para OH. Os pacientes foram divididos em dois grupos: nove pacientes receberam radioterapia em dose única de 8 Gy nos quadris (Grupo Estudo) e 10 pacientes compuseram o Grupo Controle. Após seis meses de seguimento clínico e radiológico, um paciente do Grupo Estudo (11%) e cinco pacientes do Grupo Controle (50%) apresentaram OH. A distribuição da freqüência do desenvolvimento da OH nos dois grupos não mostrou diferença estatística significante, apesar da menor incidência de OH no grupo submetido à radioterapia (Grupo Estudo). Concluiu-se que, com o número de pacientes estudados, não foi possível comprovar a eficácia da radioterapia na prevenção da ossificação heterotópica, ainda que haja uma forte tendência para a correlação estatística / The goal of this study was to evaluate the effect of radiotherapy on the prophylaxis of heterotopic ossification (HO) after spinal cord injury (SCI). Nineteen SCI patients were studied (15 men and four women). The mean age was 30.4 ± 10.8 years (range 19 to 58 years). The most frequent causes of lesion were traffic accident (42.1%), fall (26.3%), shot gun (21%), diving (5.3%) and objects falling on the vertebral column (5.3%). Ten patients were tetraplegics (52.6%) and nine were paraplegics. Fourteen patients (73.7%) had complete lesion (Frankel A) and five had incomplete lesion (Frankel B). All patients realized initial scintigraphy until one month after SCI and showed negative results for HO. The patients were randomized in two groups: nine patients received single dose irradiation with 8 Gy on the hips (Study Group) and 10 patients were the Control Group. After six months of clinical and radiological follow up, one patient of the Study Group (11%) and five patients of Control Group (50%) showed HO. The frequency distribution of the development of HO in both groups showed no significant statistical difference, although there was lower incidence of HO in the radiotherapy group. We concluded that, with the number of patients studied, it was no possible to prove the efficacy of radiotherapy to prevent HO, although had a strong tendency for the statistical correlation

Με τον όρο «Έκτοπη Οστεοποίηση» περιγράφεται ο σχηματισμός οστού σε σημεία που υπό φυσιολογικές συνθήκες δεν υφίσταται. Τα σημεία αυτά μπορεί να είναι μύες, τένοντες ή σύνδεσμοι και γενικότερα μεσεγχυματικού τύπου μαλακά μόρια, κυρίως γύρω από τις μεγαλύτερες αρθρώσεις. Η επίκτητη μορφή της νόσου, που είναι και η πιο κοινή, εμφανίζεται μετά από μυοσκελετικούς τραυματισμούς, κακώσεις του νωτιαίου μυελού και του κεντρικού νευρικού συστήματος γενικότερα, αλλά και σε περιπτώσεις σοβαρών εγκαυμάτων. Η παθοφυσιολογία της έκτοπης οστεοποίησης παραμένει άγνωστη, αυτό που γνωρίζουμε με βεβαιότητα είναι ότι για τον σχηματισμό της απαιτούνται τρείς βασικές προϋποθέσεις που είναι α) τα οστεοπρογονικά κύτταρα, β) οι κατάλληλοι επαγωγικοί παράγοντες και γ) το ευνοϊκό οστεοεπαγωγικό περιβάλλον. Στην παρούσα εργασία με την χρήση κυτταρομετρίας ροής, δοκιμασιών με ηλεκτροχημειοφωταύγεια, Elisa και ανοσοπροσδιορισμού με χρήση Cytometric Bead Array προσδιορίσαμε τις συγκεντρώσεις των total procollagen type 1 amino-terminal propeptide (TP1NP), osteoprotegerin (OPG), β-isomerized C-terminal telopeptides (β- Crosslaps), soluble receptor activator of nuclear factor kappa-B ligand (sRANKL), N-MID osteocalcin, S100 και των κυτταροκινών IL-2, IL-4, IL-6, IL-10, INF-γ και TNF-a στον ορό ασθενών και υγιών μαρτύρων. Επιπλέον, στο ολικό αίμα προσδιορίσαμε τον πληθυσμό των θετικών στην οστεοκαλσίνη κυττάρων. Όλα τα προς μελέτη μόρια είχαν άμεση ή έμμεση σχέση με την οστική ανακατασκευή και τις φλεγμονώδεις αντιδράσεις. Συνολικά μελετήθηκαν 55 ασθενείς από τους οποίους ελήφθησαν δείγματα καθόλη την διάρκεια νοσηλείας τους. Οι ασθενείς μελετήθηκαν με βάση το είδος του τραύματος, την εμφάνιση ή όχι έκτοπης οστεοποίησης και την έκβαση της κατάστασης τους. Επιπλέον, οι επιμέρους ομάδες ασθενών μελετήθηκαν συναρτήσει του χρόνου. Τα αποτελέσματα μας έδειξαν ότι στο σύνολο των ασθενών παρατηρήθηκαν στατιστικά μειωμένα επίπεδα β- crosslaps, N-MID osteocalcin, sRANKL και S100 συγκριτικά με τους υγιείς μάρτυρες. Αντίθετα, τα επίπεδα των TP1NP, των θετικών στην οστεοκαλσίνη κυττάρων, της OPG, της INF-γ και της IL-6 ήταν στατιστικά σημαντικά αυξημένα. Επιπλέον, στατιστικά σημαντικά αυξημένα παρατηρήθηκαν τα επίπεδα του S100 στους ασθενείς που είχαν υποστεί κρανιοεγκεφαλικές κακώσεις κατά το πρώτο εικοσιτετράωρο μετά την επαγωγή της κάκωσης. Στατιστικά σημαντικά αυξημένο επίσης παρατηρήθηκε και στην ομάδα των ασθενών με κακή έκβαση συγκριτικά με τους υγιείς δότες. Στην ίδια ομάδα ασθενών παρατηρήθηκε μια γενικευμένη αύξηση των επιπέδων των κυτταροκινών που φαίνεται να σχετίζεται άμεσα με την κακή έκβαση της κατάστασης τους. Πιο συγκεκριμένα η αύξηση αυτή ήταν στατιστικώς σημαντική για τις IL-4, INF-γ και TNF-α. / Heterotopic ossification (HO) is the presence of bone in soft tissue where normally does not exist. The acquired form, which is also the most common, develops after musculoskeletal trauma, spinal cord injury or central nervous system injury and severe burns. Pathophysiology of OH still remains unclear, what we know is that the formation of ectopic bone requires three entities which are a) osteogenic precursor cells, b) inducing agents and c) an appropriate environment. In the present study using either flow cytometry, Elisa, electrochemiluminescence immunoassays or cytometric bead array assays we determined the concentrations of the osteoblast progenitors: osteocalcin positive cells in peripheral blood and the serum concentrations of total procollagen type 1 amino-terminal propeptide (TP1NP), osteoprotegerin (OPG), β-isomerized C-terminal telopeptides (β- Crosslaps), soluble receptor activator of nuclear factor kappa-B ligand (sRANKL), N-MID osteocalcin, S100 and the cytokines IL-2, IL-4, IL-6, IL-10, INF-γ and TNF-a. All measured molecules participate directly or indirectly in bone formation and metabolism and in inflammation. Our 55 patients were divided and studied in 3 different ways, regarding the kind of their injury, their outcome and the formation of HO. They were also monitored in course of time. Among our most interesting results is that patients had significantly lower levels of β- crosslaps, N-MID osteocalcin, sRANKL and S100 compared to healthy donors. On the other hand, levels of TP1NP, osteocalcin positive cells, OPG, INF-γ and IL-6 were significantly higher. S100 is significantly increased during the first 24 hours in patients who have sustained traumatic brain injury. In addition, S100 was significantly increased in patients with poor outcome compared to healthy donors. Furthermore, patients with poor outcome seem to develop a cytokine storm which is of great importance for their outcome. All measured cytokine levels were increased compared to patients with good outcome. Especially for IL-4, INF-γ, TNF-α this increase was statistically significant.

Purpose: To determine whether reduced serum levels of AHSG and elevated levels of BMP-2, 4, 7 are associated with post-arthroplasty HO. Patients: Thirty arthroplasty patients were included, 15 with evidence of peri-articular HO and 15 without (NHO). Methods: Blood samples were collected from all patients ≥ 8 weeks after arthroplasty. Analytes were measured using ELISAs. Mann-Whitney U tests were performed to compare serum analyte concentrations between HO and NHO groups, and between arthroplasty patients and healthy humans. Results: There is no difference in serum concentrations of AHSG, BMP-2, 4, 7 between HO and NHO patients. Arthroplasty patients showed significantly higher BMP-2 and BMP-4 and lower AHSG serum levels compared to healthy humans (p < 0.01). Conclusion: Baseline BMP-2, 4, 7 and AHSG serum levels are not markers of acquired HO. However, elevated baseline levels of BMP- 2, 4 and reduced levels of AHSG appear to be markers of severe inflammatory arthritis.