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Dive into the research topics where John Meletis is active.

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Featured researches published by John Meletis.


European Journal of Haematology | 2004

Cardiac status in well-treated patients with thalassemia major.

Athanasios Aessopos; Dimitrios Farmakis; Antonia Hatziliami; Christina Fragodimitri; Fotis Karabatsos; Jacqueline Joussef; Eftichia Mitilineou; Evanthia Diamanti-Kandaraki; John Meletis; Markisia Karagiorga

Abstract:  Objective: To assess cardiac status in a large group of patients with thalassemia major who had been treated in a standard way since their early infancy with intensive transfusions and deferoxamine chelation therapy and who had good compliance with this regimen. Methods and Results: We assessed clinically and echocardiographically 202 thalassemia major patients aged 27.3 ± 6.3 yr and 75 age and sex‐matched healthy controls. Overt cardiac disease was encountered in 14 patients (6.9%), including 5 (2.5%) with congestive heart failure, aged 26–37 yr, and 9 with systolic left ventricular (LV) dysfunction, aged 23–37 yr. Ten patients (5.0%) had a history of pericarditis. Left atrial and LV diameters, LV mass and cardiac output were significantly higher in patients than in controls, while peripheral resistance and LV afterload were significantly lower. Relative LV wall thickness did not differ between patients and controls, but it was significantly lower in patients with overt cardiac disease compared to those without (P < 0.05). Restrictive LV filling was observed in 37.6% of patients and was significantly more frequent in cases with overt cardiac disease (P < 0.01). Pulmonary hypertension was practically absent. Hematological parameters and pulmonary artery pressure levels were not independently associated with the presence of overt cardiac disease. Conclusion: Strict lifelong adherence to the standard transfusion and deferoxamine therapy reduces considerably the occurrence of heart failure, LV dysfunction and pericarditis, prevents early heart failure and pulmonary hypertension, but does not eliminate completely cardiac disease in patients with thalassemia major.


Virology Journal | 2012

Antiretroviral activity of 5-azacytidine during treatment of a HTLV-1 positive myelodysplastic syndrome with autoimmune manifestations.

Panagiotis T. Diamantopoulos; Maria Michael; Olga Benopoulou; Efthymia Bazanis; George Tzeletas; John Meletis; George Vayopoulos; Nora-Athina Viniou

Myelodysplastic syndromes (MDS) are often accompanied by autoimmune phenomena. The underlying mechanisms for these associations remain uncertain, although T cell activation seems to be important. Human T-lymphotropic virus (HTLV-1) has been detected in patients with myelodysplastic syndromes, mostly in regions of the world which are endemic for the virus, and where association of HTLV-1 with rheumatological manifestation is not rare. We present here the case of a 58 year old man who presented with cytopenias, leukocytoclastic vasculitis of the skin and glomerulopathy, and was diagnosed as MDS (refractory anemia with excess blasts - RAEB 1). The patient also tested positive for HTLV-1 by PCR. After 8 monthly cycles of 5-azacytidine he achieved a complete hematologic remission. Following treatment, a second PCR for HTLV-1 was carried out and found to be negative. This is the first report in the literature of a HTLV-1-positive MDS with severe autoimmune manifestations, which was treated with the hypomethylating factor 5-azacitidine, achieving cytogenetic remission with concomitant resolution of the autoimmune manifestations, as well as HTLV-1-PCR negativity. HTLV-1-PCR negativity may be due to either immune mediated clearance of the virus, or a potential antiretroviral effect of 5-azacytidine. 5-azacytidine is known for its antiretroviral effects, although there is no proof of its activity against HTLV-1 infection in vivo.


International Journal of Cancer | 2012

Elevated circulating sclerostin correlates with advanced disease features and abnormal bone remodeling in symptomatic myeloma: Reduction post‐bortezomib monotherapy

Evangelos Terpos; Dimitrios Christoulas; Eirini Katodritou; Cornelia Bratengeier; Maria Gkotzamanidou; Eurydiki Michalis; Sosana Delimpasi; Anastasia Pouli; John Meletis; Efstathios Kastritis; Konstantinos Zervas; Meletios A. Dimopoulos

Sclerostin is a Wingless and Int‐1 inhibitor, which is produced by osteocytes and inhibits osteoblast‐driven bone formation. Sclerostin is implicated in the pathogenesis of bone loss in metabolic bone disorders but there is no information for its effect on multiple myeloma (MM)‐related osteolytic disease. We evaluated circulating sclerostin in 157 newly diagnosed patients with symptomatic myeloma, in 25 with relapsed myeloma who received bortezomib monotherapy, in 21 patients with monoclonal gammopathy of undetermined significance (MGUS), and in 21 healthy controls. Patients with active myeloma had elevated circulating sclerostin compared to MGUS patients and controls (p < 0.01). MM patients who presented with fractures at diagnosis (n = 34) had very high levels of circulating sclerostin compared with all others (p < 0.01), whereas sclerostin correlated negatively with bone specific alkaline phosphatase (a bone formation marker; r = −0.541, p < 0.0001) and positively with C‐telopeptide of collagen type‐1 (a bone resorption marker; r = 0.524, p < 0.0001). Patients with International Staging System (ISS)‐3 disease had higher circulating sclerostin compared to ISS‐1 and ISS‐2 MM (p = 0.001). Furthermore, patients with high sclerostin (upper quartile, n = 40) had a median survival of 27 months versus 98 months of all others (p = 0.031). Relapsed MM patients had higher levels of circulating sclerostin even compared to newly diagnosed patients (p < 0.01). Bortezomib monotherapy resulted in a reduction of sclerostin by almost 50% in both responders and non‐responders. These results suggest that patients with active myeloma have elevated circulating sclerostin, which correlated with advanced disease features including severe bone disease. Our study indicates sclerostin as a possible target for the development of novel therapies to enhance osteoblast function in myeloma.


British Journal of Haematology | 2002

Prolonged administration of erythropoietin increases erythroid response rate in myelodysplastic syndromes: a phase II trial in 281 patients

Evangelos Terpos; Athina Mougiou; Alexandra Kouraklis; Aria Chatzivassili; Evridiki Michalis; Nicholas Giannakoulas; Eleni Manioudaki; Anna Lazaridou; Vassiliki Bakaloudi; Maria Protopappa; Dimitra Liapi; Elisavet Grouzi; Agapi Parharidou; Argyris Symeonidis; Garoufalia Kokkini; Nikolaos P. Laoutaris; George Vaipoulos; Nikolaos Anagnostopoulos; John Christakis; John Meletis; Konstantinos L. Bourantas; N. Zoumbos; Xenophon Yataganas

Summary. Treatment with recombinant human erythropoietin (rHuEpo) improves anaemia in approximately 20% of patients with myelodysplastic syndromes (MDS). We investigated the potential advantage of a prolonged administration of rHuEpo to achieve higher erythroid response rates (RR) in 281 MDS patients: 118 with refractory anaemia (RA), 77 with refractory anaemia and ringed sideroblasts (RARS), 59 with refractory anaemia with excess of blasts and blast count < 10% (RAEB‐I), and 27 with RAEB and blast count between 11–20% (RAEB‐II). rHuEpo was given subcutaneously at a dose of 150 U/kg thrice weekly, for a minimum of 26 weeks. Response to treatment was evaluated after 12 and 26 weeks of therapy. The overall RR was 45·1%; the RR for RA, RARS, RAEB‐I and RAEB‐II were 48·3%, 58·4%, 33·8% and 13% respectively. A significant increase in RR was observed at week 26 in RA, RARS and RAEB‐I patients, as the response probability increased with treatment duration. The RR was higher in the good cytogenetic prognostic group and serum Epo level of > 150 U/l at baseline predicted for non‐response. The median duration of response was 68 weeks and the overall risk of leukaemic transformation was 21·7%. These results suggest that prolonged administration of rHuEpo produces high and long‐lasting erythroid RR in MDS patients with low blast counts, particularly in those with pretreatment serum Epo levels of < 150 U/l and good cytogenetic prognosis.


International Journal of Cancer | 2003

Tartrate-resistant acid phosphatase isoform 5b: a novel serum marker for monitoring bone disease in multiple myeloma.

Evangelos Terpos; Josu de la Fuente; Richard Szydlo; Evdoxia Hatjiharissi; Nora Viniou; John Meletis; Xenophon Yataganas; John M. Goldman; Amin Rahemtulla

Tartrate‐resistant acid phosphatase isoform‐5b (TRACP‐5b), a new marker reflecting osteoclast activity, and osteoprotegerin (OPG) were measured in 121 patients with multiple myeloma (MM) at diagnosis, and in 63 of them during pamidronate administration, to define their correlation with the extent of bone disease and disease activity in MM. Radiographic evaluation of the skeleton, measurement of other markers of bone remodelling, including N‐terminal cross‐linking telopeptide of type‐I collagen (NTX), bone alkaline phosphatase and osteocalcin and of markers of disease activity (beta2‐microglobulin, paraprotein, interleukin‐6 (IL‐6), were also performed. Levels of TRACP‐5b were increased (p < .0001), while OPG was decreased in MM patients compared to controls (p < .01). TRACP‐5b levels were associated with the radiographically assessed severity of bone disease (p < .0001) as well as with levels of NTX, IL‐6 and beta2‐microglobulin (p < .001, for each biochemical parameter, respectively). The combination of pamidronate with VAD‐chemotherapy produced a reduction in TRACP‐5b, NTX, IL‐6, paraprotein and beta2‐microglobulin levels from the 2nd month of treatment, with no effect on bone formation and OPG. A strong correlation was observed between changes in TRACP‐5b and changes in NTX, IL‐6 and beta2‐microglobulin, while TRACP‐5b predicted the disease progression in 5 patients. These findings suggest that TRACP‐5b is increased in MM, reflects the extent of myeloma bone disease and may have a predictive value. TRACP‐5b has also proved to be very useful for monitoring antimyeloma treatment, which had no effect on OPG levels.


European Journal of Haematology | 2000

Effect of pamidronate administration on markers of bone turnover and disease activity in multiple myeloma.

Evangelos Terpos; John Palermos; Konstantinos Tsionos; Konstantinos Anargyrou; Nora Viniou; Pantelis Papassavas; John Meletis; Xenophon Yataganas

Abstract: Aim: Bisphosphonates are potent inhibitors of osteoclastic activity and are used in the treatment of multiple myeloma (MM) in combination with chemotherapy. The effect of pamidronate on markers of bone resorption [cross‐linked N‐telopeptides of type I collagen (NTx)], markers of bone formation [serum alkaline phosphatase (BAP) and osteocalcin (OSC)], interleukin‐6 (IL‐6), β2‐microglobulin, CRP, paraprotein and disease‐related pain and skeletal events has been evaluated in 62 newly diagnosed patients with MM. Patients and methods: The patients were randomly assigned to two groups: the first included 32 patients under chemotherapy and pamidronate (group I) and the second 30 patients on chemotherapy only (group II). Pamidronate was administered at a monthly dose of 90 mg iv, and the above parameters were evaluated at the beginning of this study and after 1, 3, 6, 9, 12 and 14 months of treatment. Results: The addition of pamidronate to chemotherapy resulted in a significant reduction of NTx, IL‐6 and paraprotein from the 3rd month and of β2‐microglobulin, CRP and pain from the 6th month of treatment. No changes of NTx, IL‐6, β2‐microglobulin, CRP or skeletal events were observed in patients of group II, while paraprotein was significantly reduced after 6 months of treatment. The differences in NTx, IL‐6, paraprotein and β2‐microglobulin were statistically significant between the two groups. Multivariate analysis revealed a significant correlation between changes of NTx, changes of IL‐6 in both groups and reduction of pain and paraprotein in group I. Conclusions: These results suggest that pamidronate may have a synergistic action with chemotherapy in decreasing osteoclastic activity, in reducing markers of myeloma activity and myeloma related pain and in improving the quality of life in patients with MM.


Oncologist | 2012

Rituximab, Cyclophosphamide, Doxorubicin, Vincristine, and Prednisone with or Without Radiotherapy in Primary Mediastinal Large B-Cell Lymphoma: The Emerging Standard of Care

Theodoros P. Vassilakopoulos; Gerassimos A. Pangalis; Andreas Katsigiannis; Sotirios G. Papageorgiou; Nikos Constantinou; Evangelos Terpos; Alexandra Zorbala; Effimia Vrakidou; Panagiotis Repoussis; Christos Poziopoulos; Zacharoula Galani; Maria N. Dimopoulou; Stella I. Kokoris; Sotirios Sachanas; Christina Kalpadakis; Evagelia M. Dimitriadou; Marina P. Siakantaris; Marie-Christine Kyrtsonis; John Dervenoulas; Meletios A. Dimopoulos; John Meletis; Paraskevi Roussou; Panayiotis Panayiotidis; Photis Beris; Maria K. Angelopoulou

UNLABELLED More aggressive treatment approaches (methotrexate, cytarabine, cyclophosphamide, vincristine, prednisone, and bleomycin [the MACOP-B regimen] or consolidation with high-dose therapy and autologous stem cell transplantation) have been considered to be superior to cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP) in patients with primary mediastinal large B-cell lymphoma (PMLBCL). Rituximab-CHOP (R-CHOP) is the standard of care for diffuse large B-cell lymphoma, whereas efficacy in PMLBCL has not been adequately confirmed. PATIENT AND METHODS Seventy-six consecutive PMLBCL patients who received R-CHOP with or without radiotherapy (RT) were compared with 45 consecutive historical controls treated with CHOP with or without RT. Baseline characteristics of the two groups were balanced. RESULTS The rate of early treatment failure was much lower with R-CHOP with or without RT (9% versus 30%; p = .004). The 5-year freedom from progression rate after R-CHOP with or without RT was 81%, versus 48% for CHOP with or without RT (p < .0001). The 5-year event-free survival rates were 80% and 47% (p < .0001) and the 5-year overall and lymphoma-specific survival rates were 89% and 69% (p = .003) and 91% and 69% (p = .001), respectively, with only seven of 76 lymphoma-related deaths. Among R-CHOP responders, 52 of 68 received RT. CONCLUSIONS Based on these results, most patients with PMLBCL appear to be cured by R-CHOP in 21-day cycles with or without RT, which could be the current standard of care. Therefore, the need for more aggressive treatment strategies is questionable unless high-risk patients are adequately defined. Further studies are required to establish the precise role of RT.


European Journal of Haematology | 2003

Pamidronate is superior to ibandronate in decreasing bone resorption, interleukin‐6 and β2‐microglobulin in multiple myeloma

Evangelos Terpos; Nora Viniou; Josu de la Fuente; John Meletis; Ersi Voskaridou; Christos Karkantaris; George Vaiopoulos; John Palermos; Xenophon Yataganas; John M. Goldman; Amin Rahemtulla

Abstract: Objectives: Bisphosphonates have been found to reduce skeletal events in patients with multiple myeloma (MM). This is the first randomised trial to compare the efficacy of pamidronate and ibandronate, a third‐generation aminobisphosphonate, in bone turnover and disease activity in MM patients. Methods: Patients with MM, stage II or III, were randomly assigned to receive either pamidronate 90 mg (group I: 23 patients) or ibandronate 4 mg (group II: 21 patients) as a monthly intravenous infusion in addition to conventional chemotherapy. Skeletal events, such as pathologic fractures, hypercalcaemia, and bone radiotherapy were analysed. Bone resorption markers [N‐terminal cross‐linking telopeptide of type‐I collagen (NTX) and tartrate‐resistant acid phosphatase type 5b (TRACP‐5b)], bone formation markers (bone alkaline phosphatase and osteocalcin), markers of disease activity (paraprotein, CRP, β2‐microglobulin), and interleukin‐6 (IL‐6) were also studied. Results: In both groups, the combination of chemotherapy with either pamidronate or ibandronate produced a reduction in bone resorption and tumour burden as measured by NTX, IL‐6, paraprotein, CRP, and β2‐microglobulin from the second month of treatment, having no effect on bone formation. TRACP‐5b also had a significant reduction in the pamidronate group from the second month of treatment and in the ibandronate group from the sixth month. However, there was a greater reduction of NTX, IL‐6, and β2‐microglobulin in group I than in group II, starting at the second month of treatment (P = 0.002, 0.001, and 0.004, respectively) and of TRACP‐5b, starting at the fourth month (P = 0.014), that being continued throughout the 10‐month follow‐up of this study. There was no difference in skeletal events during this period. A significant correlation was observed between changes of NTX and changes of TRACP‐5b, IL‐6, and β2‐microglobulin from the second month for patients of both groups. Conclusions: These results suggest that a monthly dose of 90 mg of pamidronate is more effective than 4 mg of ibandronate in reducing osteoclast activity, bone resorption, IL‐6, and possibly tumour burden in MM. TRACP‐5b has also proved to be a useful new marker for monitoring bisphosphonates treatment in MM.


Transfusion | 2007

Thalassemia intermedia today: should patients regularly receive transfusions?

Athanassios Aessopos; Maria Kati; John Meletis

BACKGROUND: β‐Thalassemia is an inherited hemoglobin disorder characterized by reduced synthesis of β‐globin chain. The severity of clinical course distinguishes this heterogeneous disease in two main subtypes: thalassemia major (TM) and thalassemia intermedia (TI). TI has a later clinical onset with a milder anemia that does not require transfusions at least during the first few years of life. The clinical picture of TI patients who have not received transfusions or have occasionally received transfusions is dominated by the consequences of chronic hemolytic anemia, tissue hypoxia, and their compensatory reactions, such as bone deformities and fractures, extramedullary hemopoiesis, spleen and liver enlargement, hypercoagulability, and pulmonary hypertension. These complications, especially the latter two, are getting more frequent and severe over the years. Nowadays, although TI patients have almost no changes in the course of the disease, well‐treated TM patients with regular transfusion‐chelation therapy showed suppression of the anemia‐related disorders in parallel to prolongation of life. The new oral iron chelators and the magnetic resonance imaging application for early detection of heart iron load are promising for further improvement on survival.


European Journal of Haematology | 2005

Reversal of heart failure in thalassemia major by combined chelation therapy: a case report

Maria Tsironi; Spyros Deftereos; Panagiotis Andriopoulos; Dimitrios Farmakis; John Meletis; Athanasios Aessopos

Abstract:  In patients with thalassemia major (TM) who are non‐compliant with long‐term desferrioxamine (DFO) chelation, survival is limited mainly because of cardiac complications of transfusional hemosiderosis. Combined chelation therapy with DFO and deferiprone has maximized the efficacy of the therapy and reduced cardiological complications. The aim of this report is to present the results of this combination in a desperate case of heart failure.

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Evangelos Terpos

National and Kapodistrian University of Athens

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Xenophon Yataganas

National and Kapodistrian University of Athens

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George Vaiopoulos

National and Kapodistrian University of Athens

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Nora Viniou

National and Kapodistrian University of Athens

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Dimitris Loukopoulos

National and Kapodistrian University of Athens

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Maria K. Angelopoulou

National and Kapodistrian University of Athens

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Nora-Athina Viniou

National and Kapodistrian University of Athens

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Eleni Variami

National and Kapodistrian University of Athens

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Theodoros P. Vassilakopoulos

National and Kapodistrian University of Athens

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