Accuracy of power Doppler ultrasonography in the diagnosis and monitoring of idiopathic inflammatory myopathies.

OBJECTIVES: No clear-cut guidelines exist for the use of imaging procedures for the diagnosis of idiopathic inflammatory myopathies (IIM). The aim of the present study was to assess the diagnostic accuracy of power Doppler ultrasonography (PDUS) score in IIM patients compared with a control group and its usefulness during follow-up. METHODS: All patients evaluated in the Vasculitis and Myositis Clinic, Rheumatology Unit, University of Siena were prospectively collected. All patients underwent US examination of both thighs in axial and longitudinal scans, which were also performed twice (T1) or three times (T2). RESULTS: Forty-five patients with IIM (median [interquartile range] age 55 [45-66] years; 35 female) were enrolled. Receiver operating characteristic curves distinguished patients and controls based on ∑power Doppler (PD), ∑oedema, ∑atrophy and CRP. The best cut-off value for ∑PD was 0.5, ∑oedema 1.5, ∑atrophy 0.5 and CRP 0.22 mg/dl. In a logistic regression analysis, the variables that most influenced diagnosis of IIM were ∑PD and ∑oedema (P = 0.017 and P = 0.013, respectively). ∑Oedema was lower at T1 (P = 0.0108) and T2 (P = 0.0012) than at T0. Likewise, ∑PD was lower at T1 (P = 0.0294) and T2 (P = 0.0420) than at T0. Physician global assessment was lower at T1 (P = 0.0349) and T2 (P = 0.0035) than at baseline. CONCLUSION: Our findings show that PDUS is a reliable diagnostic tool in the differential diagnosis between inflammatory and non-inflammatory myopathies. Moreover, PDUS can be employed also during the follow-up of patients with IIM. A reduction in disease activity, measured by physician global assessment, led to a concomitant decrease in both oedema and PD, which was directly correlated with their rate of change. This underlines the close link between clinical assessment and PDUS findings, not only at diagnosis but also during monitoring.

Effects of antiresorptive agents on body composition: a case-control retrospective study.

Introduction: Osteoporosis is the most represented metabolic bone disease and is characterized by the reduction of bone mineral density (BMD), exposing patients to high fracture risk and disability. Bisphosphonates (BPs) are the main compounds exploited in treatment of osteoporosis and significantly reduce fracture risk. Sarcopenia is the pathological reduction of muscle masses and strength, and many studies highlighted its co-existence in patients with impaired bone mass. Indeed, the pathological reduction of lean tissue has been linked to a higher risk of falls and, consequently, fractures and disability. Moreover, the pathological reduction of lean tissue seems to share many pathological mechanisms with impaired bone strength and structure; thus, in this context, we decided to conduct a retrospective case-control study aimed at evaluating the effects of BPs on lean mass and body composition. Material and methods: We enrolled postmenopausal women from our metabolic bone diseases outpatient clinic who underwent at least two consecutive dual-energy X-ray absorptiometry (DXA) examinations concomitantly to the beginning of an antiresorptive agent. The body composition of patients and controls was compared by fat masses, lean masses and android-to-gynoid ratio (A/G ratio). Results: A total of 64 female subjects were considered for the study: 41 starting a BPs and 23 without treatment were used as control. The fat masses and lean masses appeared to be unaffected by BPs. Conversely, A/G ratio was lower in BPs group after 18 months of therapy compared to baseline (p < 0.05). From the stratification based on the single BP we failed to highlight any significant difference between the tested variables. Conclusions: Bisphosphonates treatment did not modify lean tissues, however a significant reduction of A/G ratio in BP group was documented. Thus the BPs seems to act on patients body composition and extra-skeletal tissues but larger prospective studies are needed to evaluate whether these modifications have clinical relevance.

Efficacy of intravenous neridronate in transient osteoporosis of the hip.

OBJECTIVES: To evaluate the efficacy and safety of intravenous (iv) neridronate in patients affected by transient osteoporosis of the hip (TOH). METHODS: We retrospectively evaluated the clinical records of patients affected by TOH treated with iv neridronate in our department. We treated patients with a value of visual analogue scale (VAS)-pain ≥ 80/100 mm at diagnosis, limited range of movement and magnetic resonance images (MRI) findings suggestive of TOH. The regimen used was: one iv infusion at day 0, 3, 6, 9 (100 mg for each infusion: total of 400 mg). This protocol was repeated in refractory cases. Recovery was defined as VAS-pain level ≤20/100. Concomitant use of analgesics was allowed. Paired Student t-test was used to assess VAS-pain change. RESULTS: Five patients were male, 3 were female. Mean age was 54.5±2.12 years old. Mean body mass index was 26.57±2.22. Mean time to diagnosis, since the onset of the symptoms, was 75±21.21 days. Mean number of neridronate infusions was 7.5±2.56. Mean time of recovery was 57±45.96 days. Mean VAS-pain at baseline was 84±2,24. Mean VAS-pain after treatment was significantly reduced (p<0.001) with a value of 12.12±6.46. None of the patients needed analgesics after treatment. No adverse event was reported. In 5 cases, post-treatment MRI showed complete bone marrow oedema resolution. CONCLUSIONS: Intravenous neridronate is effective and safe in the treatment of TOH and its use may lead to a faster resolution of the disease.

Bone-sparing effects of tocilizumab in rheumatoid arthritis: a monocentric observational study.

Introduction: Bone loss is a common feature in several autoimmune and chronic inflammatory diseases, such as rheumatoid arthritis (RA). Indeed, the high levels of pro-inflammatory cytokines seem to enhance bone resorption and to diminish bone formation, thus producing an uncoupling between osteoclast and osteoblast function and favoring the onset of juxtarticular as well as systemic osteoporosis. Many papers underline the high prevalence of osteoporosis in RA, as well as the negative correlation between interleukin 6 (IL-6) serum levels and bone mineral density (BMD). The aim of this study was to assess the effectiveness of one-year treatment with tocilizumab (TCZ), the first approved IL-6 receptor inhibitor, in reducing bone loss in RA. Material and methods: We enrolled 18 patients fulfilling 2010 ACR and EULAR criteria for RA from our arthritis outpatient clinic, assessing clinical and biochemical parameters during a 12-month period. The patients received TCZ 8 mg/kg i.v. every 4 weeks and underwent dual energy X-ray absorptiometry (DXA) for the measurement of bone mineral density (BMD) at baseline and at the end of study. Serum levels of C-reactive protein (CRP), erythrocytes sedimentation rate (ESR), IL-6, serum CrossLaps, osteoprotegerin (OPG), receptor activator of nuclear factor κß ligand (RANK-L) and dickkopf-1 (DKK-1) were measured at baseline, at 6 months and 1 year. Results: No significant difference in IL-6, RANK-L, DKK-1, OPG and serum CrossLaps levels between baseline, 6 months and 1 year were found. A significant increase of lumbar spine BMD was evidenced after 1 year of TCZ treatment. No difference in total body and femoral neck BMD was documented the end of the study. Conclusions: This study suggest the bone-sparing effect of TCZ in RA affected individuals.

A novel grey scale and Power Doppler ultrasonographic score for idiopathic inflammatory myopathies: Siena Myositis Ultrasound Grading Scale.

OBJECTIVES: No clear-cut guidelines exist on the use of diagnostic procedures for idiopathic inflammatory myopathies (IIM) and only minimal and conflicting data report the use of ultrasound (US). In this regard, we aimed to assess if grey-scale (GS) and Power Doppler (PD) US, graded with a 0-3-point scale, may be a reliable tool in a cohort of patients affected by IIM. METHODS: All patients underwent US examination of both thighs in axial and longitudinal scans. Oedema and atrophy, both assessed in GS and PD, were graded with a 0-3-point scale. Spearman's test was used to identify the correlations between US and clinical and serological variables. RESULTS: A total of 20 patients were included. Six and two patients were evaluated twice and three times, respectively. Muscle oedema was found to be directly correlated with physician global assessment (PhGA), serum myoglobin and PD and negatively with disease duration. PD score was positively correlated to PhGA and negatively to disease duration. Muscle atrophy directly correlated with Myositis Damage Index, disease duration and patient's age. The single-thigh sub-analysis evidenced a direct correlation between PD score and Manual Muscle Test. CONCLUSIONS: In our cohort, we found that oedema and PD are strictly related to early, active myositis, suggesting that an inflamed muscle should appear swollen, thickened and with Doppler signal. Conversely, muscle atrophy reflects the age of the patient and the overall severity of the disease. Such findings shed a new, promising, light on the role of US in diagnosis and monitoring of IIMs.

Power and spectral Doppler ultrasound in suspected active sacroiliitis: a comparison with magnetic resonance imaging as gold standard.

OBJECTIVES: The objectives of this study were to study with Power Doppler US (PDUS) the SI joints (SIJs) of patients with suspected active sacroiliitis, to describe SIJ flows with spectral wave analysis (SWA) on Doppler US, and to correlate US data with both clinical characteristics and presence of SIJ bone marrow oedema (BME) in subsequent MRI. METHODS: A total of 42 patients (32 females and 10 males, mean age 46.8 years) with recent onset of inflammatory back pain (IBP) were included. Every patient underwent US examination with a convex 1-8 MHz probe [scoring PDUS signals with a three-point scale and describing flows in SWA calculating the mean Resistive Index (RI)] and subsequent MRI of the SIJs. RESULTS: PDUS signals were detected in 34 patients and 62 SIJs. In 29 patients and 56 SIJs, MRI revealed BME. A definite diagnosis of SpA was made in 32 patients. PDUS signals were more frequent (P < 0.0001) in patients with a final diagnosis of SpA, yielding a higher PDUS score (P = 0.0304). PDUS grading correlated with both BME grading (r = 0.740, P = 0.0001) and AS DAS (ASDAS) (r = 0.6257, P = 0.0004), but not with inflammatory reactants nor anthropometric data. Mean RI were, respectively, 0.60 and 0.73 (P < 0.0001) in patients with or without diagnosis of active sacroiliitis. The most inclusive RI cut-off resulted <0.70 [positive predictive value (PPV) 94%, accuracy 90%, P = 0.0001]. The best Likelihood Ratio (5.471) for RI to detect pathologic cases was obtained with a cut-off of <0.60 (PPV 96%). CONCLUSIONS: PDUS and SWA of SIJs demonstrate good diagnostic accuracy for active sacroiliitis compared with MRI.

Psychosocial burden in young patients with primary anti-phospholipid syndrome: an Italian nationwide survey (The AQUEOUS study).

OBJECTIVES: The AQUEOUS (Anti-phospholipid syndrome: a QUEstionnaire for yOUng patientS) study aimed to assess how the diagnosis of primary anti-phospholipid syndrome (PAPS) affects the psychosocial status of young patients. METHODS: Subjects with PAPS aged 18-45 years were invited to compile an ad hoc designed questionnaire and the Short Form-12 to assess quality of life (QoL). RESULTS: Ninety-two patients (83.7% females) were recruited in 10 Italian centres. Vascular and obstetric manifestations were equally represented. Nearly half of the patients perceived the need for psychological support, 89.2% when considering women after pregnancy complications. Social activities and working efficiency were reduced in APS patients, also intimacy was threatened. In all cases, fatigue appeared to be the main determinant. PAPS affected family planning, due to fears of treatment side-effects, disease hereditariness, inability to care for the newborn child. Fertility appeared to be conserved: the median time to pregnancy was 2 months; assisted reproduction techniques were pursued by 5 women. Our survey documented significantly lower rates of hospitalisation and learning disabilities in 51 children born after APS diagnosis as compared to 48 children born before. PAPS patients displayed lower QoL in physical and, to a greater extent, mental scores compared to the general Italian population. Both components were significantly lower in women and in patients with fatigue. CONCLUSIONS: The AQUEOUS study assessed for the first time the unmet needs of young PAPS patients, enabling the development of a future "youth-focused" strategy to reduce disease burden.

Alternative lengthening of telomeres in molecular subgroups of paediatric high-grade glioma.

PURPOSE: The maintenance of telomere length prevents cancer cell senescence and occurs via two mutually exclusive mechanisms: (a) reactivation of telomerase expression and (b) activation of alternative lengthening of telomeres (ALT). ALT is frequently related to alterations on ATRX, a chromatin-remodelling protein. Recent data have identified different molecular subgroups of paediatric high-grade glioma (pHGG) with mutations of H3F3A, TERTp and ATRX; however, differences in telomere length among these molecular subgroups were not thoroughly examined. METHODS: We investigated which genetic alterations trigger the ALT mechanism in 52 IDH-wildtype, 1p/19q-wildtype pHGG. Samples were analysed for telomere length using Tel-FISH. ATRX nuclear loss of expression was assessed by IHC, H3F3A and TERTp mutations by DNA sequencing, and TERTp methylation by MS-PCR. RESULTS: Mutant H3.3 was found in 21 cases (40.3%): 19.2% with K27M mutation and 21.1% with G34R mutation. All H3.3G34R-mutated cases showed the ALT phenotype (100%); on the opposite, only 40% of the H3.3K27M-mutated showed ALT activation. ATRX nuclear loss was seen in 16 cases (30.7%), associated sometimes with the G34R mutation, and never with the K27M mutation. ATRX nuclear loss was always related to telomere elongation. TERTp C250T mutations were rare (5.4%) and were not associated with high intensity Tel-FISH signals, as TERTp hyper-methylation detected in 21% of the cases. H3.3/ATRX/TERTp-wildtype pHGG revealed all basal levels of telomere length. CONCLUSION: Our results show a strong association between H3.3 mutations and ALT, and highlight the different telomeric profiles in histone-defined subgroups: H3.3-G34R mutants always trigger ALT to maintain telomere length, irrespective of ATRX status, whereas only some H3.3-K27M tumours activate ALT. These findings suggest that acquiring the gly34 mutation on H3.3 might suffice to trigger the ALT mechanism.

Difference in pain and accuracy of two hyaluronic acid injection techniques for symptomatic knee osteoarthritis in overweight patients.

OBJECTIVES: To evaluate differences of injection related pain, and the accuracy of the techniques in two groups of overweight patients, performing the anterolateral approach for one group (G1) and the superolateral approach for the second group (G2). MATERIAL AND METHODS: In the study, 126 knee joints from 86 osteoarthritis (OA) patients were evaluated. Inclusion criteria were body mass index (BMI) ≥ 25, absence of effusion and coagulopathy. Pain evaluation during injection was evaluated with Visual Analogue Scale (VAS), while accuracy of the procedure was evaluated with ultrasound (US). RESULTS: The patients' mean age was 69.9 ±9.01, VAS for G1 group was 1.71 ±1.89, for G2 group was 1.74 ±1.31. Mean BMI was 29.69 ±2.86, for G1 group was 28.29 ±3.29, for G2 group was 30.32 ±2.41. No adverse events (AE) occurred in both studied groups. The accuracy rate of the procedure was 69.1% for G1 (38/55 knees), 95.7% for G2 (68/71 knees). No significant difference was found in VAS pain score between G1 and G2 group (p = 0.45). We found the significant correlation between BMI and VAS pain score in anterolateral accesses (G1) (r = 0.51; p < 0.005). No correlation was found between age and VAS pain score in anterolateral access (G1). For the superolateral access (G2), no correlation was found for age or BMI and VAS pain score. CONCLUSIONS: Hyaluronic acid injection is safe therapeutic option for knee OA with no significant differences between anterolateral and superolateral approaches in terms of pain in overweight patients. However, higher BMI seems to be a predictor of pain in anterolateral access, and the superolateral approach should be preferred in this group of patients.

Low muscle mass and body composition analysis in a group of postmenopausal women affected by primary Sjögren's syndrome.

OBJECTIVES: Sarcopenia is the pathological reduction of skeletal muscle mass and strength. This condition is often underestimated in clinical practice, particularly in connective tissue diseases. The purpose of this study is to evaluate the prevalence of low muscle mass in primary Sjögren's syndrome (pSS) and to explore the relationships linking muscles and bone tissue. MATERIAL AND METHODS: Twenty-eight postmenopausal pSS patients were matched with 30 healthy controls and their body composition analysis was performed by dual-energy X-ray absorptiometry to investigate for sarcopenia considering appendicular lean mass (ALM) and the skeletal muscle mass index (SMI) as references. Bone mineral density analysis of lumbar spine (L1-L4), whole femur, femoral neck and whole body was also performed. Linear regression was used to assess the relationship between body composition and bone mineralization. RESULTS: Low muscle mass was significantly higher in the pSS group compared to controls whether expressed as ALM, SMI [odds ratio (OR) = 18.40, confidence interval (CI): 4.84-72.08, p < 0.0001] or considering total body lean masses. Lean masses appeared to be the best estimators of bone mineralization: total lean body mass (TLBM) lumbar spine R 2 = 0.72, p < 0.0001; TLBM femoral neck R 2 = 0.36, p < 0.004; lean mass of upper limbs lumbar spine R 2 = 0.70, p < 0.0001; femoral neck R 2 = 0.66; lean mass of lower limbs lumbar spine R 2 = 0.66, p < 0.0001; femoral neck R 2 = 0.44, p = 0.008). Primary Sjögren's syndrome patients had a significantly higher android/gynoid fat ratio compared to controls. CONCLUSIONS: Female pSS patients have lower muscle mass compared to healthy controls and are exposed to a higher risk of developing sarcopenia than healthy subjects. Our research demonstrates that the amount of lean tissue is the main predictor of bone mineralization in pSS.

Bone-sparing effects of rituximab and body composition analysis in a cohort of postmenopausal women affected by rheumatoid arthritis - retrospective study.

OBJECTIVE: Osteoporosis is the most common bone tissue disease and it is characterized by a reduced bone mineral density (BMD). The main physiopathological mechanisms converge on the uncoupling between bone formation and resorption, thus leading to an enhanced risk of fractures. Several papers have documented the inverse relationships linking high inflammatory cytokines, anti-citrullinated protein antibodies, rheumatoid factor, and BMD in rheumatoid arthritis (RA). Rituximab (RTX) is a chimeric monoclonal antibody directed against the CD20 receptor of B cells. Since the Food and Drug Administration approved it for RA in 2006, there have been many clinical experiences regarding its use. Nevertheless, few studies evaluate the effect of rituximab on BMD. RA is a disease characterized by immune dysfunction with high levels of inflammatory cytokines, autoantibodies, and it is reasonable that a B cell depleting therapy could restore a physiological cytokine balance, thus exerting an osteoprotective effect on the bone tissue. The purpose of this paper is to highlight any difference in BMD and to assess differences in body composition over a retrospective 18-month follow-up period after RTX treatment with a B cell depleting therapy. MATERIAL AND METHODS: We analyzed by dual energy X-ray absorptiometry BMD expressed as g/cm2 and body composition modifications over 18 months with RTX treatment of 20 postmenopausal RA patients. RESULTS: After eighteen months of therapy with RTX, a statistically significant increase in vertebral (L1-L4) BMD and the stability of femoral BMD were documented. CONCLUSIONS: Rituximab is associated with an improvement of vertebral and preservation of femoral BMD, suggesting a bone-sparing effect due to B cell depletion. Furthermore, patients displayed a redistribution of fat masses toward the hip region.

The Role of Multimodality Imaging in Monitoring Disease Activity and Therapeutic Response to Tocilizumab in Giant Cell Arteritis.

INTRODUCTION: Giant cell arteritis (GCA) is a large vessel (LV) vasculitis, mainly affecting elder patients. Monitoring GCA activity during tocilizumab (TCZ) treatment is an unmet need, since low serum levels of C-reactive protein (CRP) during treatment may underestimate disease activity. To date, few data are available on the role of different imaging techniques in monitoring GCA activity and response to treatment. We report herein a cohort of GCA patients treated with TCZ and followed up with multimodal imaging. Patients and Methods. We collected clinical, laboratory, and imaging data of 11 GCA patients treated with TCZ 162 mg subcutaneously every week. Disease activity was assessed at baseline and within 12 months from the start of treatment using different imaging techniques such as color Doppler ultrasonography (CDUS), magnetic resonance imaging/angiography (MRI/MRA), computed tomography angiography (CTA), and/or positron emission tomography (PET). RESULTS: Four patients were affected by cranial and 7 by LV-GCA. All patients were treated with oral glucocorticoids (GCs) (mean dose 55.68 mg ± 8.19 of prednisone or equivalent) in combination with TCZ. Treatment was preceded in 5 cases by 3 intravenous boluses of 1000 mg methylprednisolone. A significant decrease of the mean dose of oral GCs was observed between baseline and the last follow-up visit (4.65 ± 3.69 mg) (p = 0.003). TCZ treatment significantly decreased erythrocyte sedimentation rate (p < 0.01) and CRP levels (p < 0.01). At follow-up (mean 8.18 ± 3.63 months), all patients were in clinical and serological remission. Moreover, PET, CDUS, MRI/MRA, and CTA did not show any LVV finding. CONCLUSIONS: Our study highlights TCZ efficacy in inducing GCA remission and its steroid-sparing effect. We highlighted a reliability of imaging procedures in the evaluation of disease activity and treatment response. A close disease monitoring with imaging techniques should be taken into account in GCA patients during TCZ treatment.

Polymyalgia rheumatica following infective triggers or vaccinations: a different subset of disease?

OBJECTIVES: Polymyalgia rheumatica (PMR) is the commonest inflammatory disorder of the elderly; an association with environmental triggers and a deregulated immune response have been described. The aim of this study was to investigate the association of environmental triggers before the onset of PMR. MATERIAL AND METHODS: The database of 58 consecutive PMR patients recruited from a single rheumatology secondary care setting was retrospectively analyzed to investigate the frequency of environmental triggers and correlations with clinical characteristics, ultrasound and laboratory data. RESULTS: Fifteen PMR patients (26%) described a connection with environmental agents: six PMR patients reported a vaccination, 4 reported a respiratory tract infection, 5 reported seasonal influenza before the onset of the disease. The model of multivariate linear regression which better predicted a shorter time to normalize inflammatory reactants (R 2 = 27.46%, p = 0.0042) comprised the presence of an environmental trigger and a higher PCR. A linear regression analysis confirmed an inverse correlation between PCR at onset and time to normalize inflammatory reactant (r = -0.3031, p = 0.0208). A significant correlation was demonstrated between presence of environmental trigger and shorter time to normalize inflammation (r = -0.5215, p< 0.0001), and lesser frequency of gleno-humeral synovitis on US (r = -0.3774, p = 0.0038). CONCLUSIONS: Our work describes a correlation between environmental triggers in PMR and higher CRP at diagnosis, faster response to therapy, and milder shoulder synovitis. We may suppose that these patients belong to a more specific subtype of PMR, in whom external stimuli, such as vaccination or infection, may lead to a deregulated response within the context of an impaired senescent immuno-endocrine system.

Telomere elongation via alternative lengthening of telomeres (ALT) and telomerase activation in primary metastatic medulloblastoma of childhood.

PURPOSE: Elongation of telomeres is necessary for tumor cell immortalization and senescence escape; neoplastic cells use to alternative pathways to elongate telomeres: telomerase reactivation or a telomerase-independent mechanism termed alternative lengthening of telomeres (ALT). Telomerase and ALT pathway has been explored in adult and pediatric gliomas and medulloblastomas (MDBs); however, these mechanisms were not previously investigated in MDBs metastatic at the onset. Therefore, we analyzed the activation of telomerase and ALT pathway in a homogenous cohort of 43 pediatric metastatic medulloblastomas, to investigate whether telomere elongation could play a role in the biology of metastatic MDB. METHODS: We evaluated telomeres length via telomere-specific fluorescence in situ hybridization (Telo-FISH); we assessed nuclear expression of ATRX by immunohistochemistry (IHC). H3F3A and TERT promoter mutations were analyzed by pyrosequencing, while UTSS methylation status was analyzed via methylation-specific-PCR (MS-PCR). RESULTS: H3F3A mutations were absent in all MDBs, 30% of samples showed ATRX nuclear loss, 18.2% of cases were characterized by TERT promoter mutations, while 60.9% harboured TERT promoter hyper-methylation in the UTSS region. Elongation of telomeres was found in 42.8% of cases. Metastatic MDBs control telomere elongation via telomerase activation (10.7%), induced by TERT promoter mutations in association with UTSS hyper-methylation, and ALT mechanism (32.1%), triggered by ATRX inactivation. Among non-metastatic MDBs, only 5.9% (1/17) showed ATRX nuclear loss with activation of ALT. CONCLUSIONS: Our metastatic cases frequently activate ALT pathway, suggesting that it is a common process for senescence escape in primary metastatic medulloblastomas. Furthermore, the activation of mechanisms for telomere elongation is not restricted to certain molecular subgroups in this high-risk group of MDBs.

Wnt activation affects proliferation, invasiveness and radiosensitivity in medulloblastoma.

Medulloblastomas (MBs) associated with the Wnt activation represent a subgroup with a favorable prognosis, but it remains unclear whether Wnt activation confers a less aggressive phenotype and/or enhances radiosensitivity. To investigate this issue, we evaluated the biological behavior of an MB cell line, UW228-1, stably transfected with human ß-catenin cDNA encoding a nondegradable form of ß-catenin (UW-B) in standard culture conditions and after radiation treatment. We evaluated the expression, transcriptional activity, and localization of ß-catenin in the stably transfected cells using immunofluorescence and WB. We performed morphological analysis using light and electron microscopy. We then analyzed changes in the invasiveness, growth, and mortality in standard culture conditions and after radiation. We demonstrated that (A) Wnt activation inhibited 97 % of the invasion capability of the cells, (B) the growth of the UW-B cells was statistically significantly lower than that of all the other control cells (p < 0.01), (C) the mortality of irradiated UW-B cells was statistically significantly higher than that of the controls and their nonirradiated counterparts (p < 0.05), and (D) morphological features of neuronal differentiation were observed in the Wnt-activated cells. In tissue samples, the Ki-67 labeling index (LI) was lower in ß-catenin-positive samples compared to non-ß-catenin positive ones. The Ki-67 LI median (LI = 40) of the nuclear ß-catenin-positive tumor samples was lower than that of non-nuclear ß-catenin-positive samples (LI = 50), but the difference was not statistically significant. Overall, our data suggest that activation of the Wnt pathway reduces the proliferation and invasion of MBs and increases the tumor's radiosensitivity.

KIAA1549:BRAF fusion gene in pediatric brain tumors of various histogenesis.

The KIAA1549:BRAF fusion gene is considered a driver genetic event in pilocytic astrocytoma. We investigated a series of 69 pediatric brain neoplasms of diverse histogenesis and grade using the RT-PCR and sequencing. We detected the KIAA1549:BRAF fusion gene in five of 34 non-PA tumors (14.7%), that is, one glioblastoma, one anaplastic astrocytoma, one anaplastic pleomorphic xanthoastrocytoma, 1 ependymoma, and 1 Atypical Teratoid Rhabdoid Tumor. Our study showed that the K-B, although uncommon, it can be detected in non-PA tumors of various histogenesis and grading.