K Vettenranta

University of Helsinki, Helsinki, Southern Finland Province, Finland

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Publications (47)184.94 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: The left ventricular (LV) volumes, ejection fraction (EF), and dyssynchrony indexes for the 16 and 12 cardiac segments (Tmsv16-SD and Tmsv12-SD, respectively) were analyzed among nonadult, anthracycline-exposed long-term survivors of childhood cancer and compared with those of healthy controls using conventional and real-time 3-dimensional echocardiography (RT-3DE) with cardiac magnetic resonance (CMR) imaging in a prospective, cross-sectional, single tertiary center setting. Seventy-one survivors and gender-, body surface area-, and age-matched healthy controls were studied by conventional echocardiography and RT-3DE. Fifty-eight of the 71 survivors underwent also CMR. The survivors were evaluated in 2 groups. Group I consisted of 63 exposed to anthracyclines and group II consisted of 8 also exposed to cardiac irradiation. By RT-3DE, the group I survivors had a lower LVEF (57% vs 60%, respectively, p = 0.003) and larger body surface area-indexed LV end-systolic volume (31 vs 28 ml/m(2), respectively, p = 0.001) than controls. The Tmsv16-SD was higher in group II than in I (1.93% vs 1.39%, respectively, p = 0.003). None of the survivors had an abnormal fractional shortening (<28%), but 10% had an LVEF <50% by RT-3DE. An LVEF <55% was detected in 45 of 58 (78%) of those imaged with CMR. In conclusion, RT-3DE seems to detect more abnormalities in cardiac function than conventional echocardiography following childhood cancer therapy. The LV dyssynchrony indexes derived from RT-3DE appear potentially useful in assessing the early signs of cardiotoxicity between anthracycline and cardiac irradiation exposed long-term survivors of childhood cancer.
    The American journal of cardiology. 06/2014; 113(11):1886-92.
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    ABSTRACT: The Finnish Investigators Network for Paediatric Medicines (FINPEDMED) was established in 2007, to meet the expected increase in paediatric clinical trials following the new EU Paediatric Regulation. Between 2007-2012, FINPEDMED received 91 trial requests, 18 trials were started, and in 24 cases, Finnish investigators were not selected by sponsors. In conclusion, this experience from Finland highlights the need for Nordic collaboration to increase expertise, recruitment base and attractiveness for sponsors. This article is protected by copyright. All rights reserved.
    Acta Paediatrica 07/2013; · 1.97 Impact Factor
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    ABSTRACT: Among the immunocompetent, infections with parvovirus B19 (B19V) and human bocavirus (HBoV) 1 range clinically from asymptomatic to severe, while following allogeneic hematopoietic SCT (HSCT) B19V can cause a persistent severe illness. The epidemiology and clinical impact of HBoV1 and the other emerging parvovirus 4 (PARV4) among immunocompromised patients have not been established. To determine the occurrence and clinical spectrum of B19V, PARV4 and HBoV1 infections, we performed a longitudinal molecular surveillance among 53 allogeneic HSCT recipients for pre- and post-HSCT DNAemias of these parvoviruses. Quantitative real-time PCR showed B19V DNA in sera of 16 (30%) patients, at mean levels of 4.6 × 10(3), 9.9 × 10(7), 1.1 × 10(10) and 1.6 × 10(2) B19V DNA copies/mL pre-HSCT (9/53), and at 1 (6/53), 2 (4/53) and 3 months (1/25) post HSCT, respectively. However, no clinical manifestation correlated with the presence of B19V viremia. All B19V sequences were of genotype 1. None of the sera investigated contained PARV4 or HBoV1 DNAs. Our data demonstrate B19V viremia to be frequent among pediatric allogeneic HSCT recipients, yet without apparent clinical correlates. PARV4 or HBoV1 viremias were not seen in these immunocompromised patients.Bone Marrow Transplantation advance online publication, 20 May 2013; doi:10.1038/bmt.2013.63.
    Bone marrow transplantation 05/2013; · 3.00 Impact Factor
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    ABSTRACT: OBJECTIVES: Using cardiac magnetic resonance (CMR) imaging both the left and right ventricular function as well as signs of focal fibrosis were studied among long-term survivors of childhood cancer. BACKGROUND: Increased myocardial fibrosis has been detected in the endomyocardial biopsies of survivors. CMR has established its role in the assessment of both cardiac function and structure, and focal fibrosis of the myocardium is detectable with late gadolinium enhancement (LGE). METHODS: 62 anthracycline-exposed long-term survivors of childhood cancer were studied at a mean age of 14.6 years. The left (LV) and right ventricular (RV) ejection fractions (EF) and volumes were measured and LGE assessed using CMR. RESULTS: An abnormal (EF < 45.0%) LV function was detected in 18% (11/62) and RV function in 27% (17/62) of the survivors. A subnormal LV and RV function (45.0% ≤ EF < 55.0%) was demonstrable in 61% (38/62) and 53% (33/62), respectively. Both the left and right ventricular end systolic and LV end diastolic volumes were increased compared to reference values. None of the study patients showed LGE. CONCLUSION: A considerable proportion of the long-term survivors of childhood cancer with anthracycline exposure demonstrate signs of cardiac dysfunction detectable by CMR with also the right ventricle being involved. Yet, myocardial fibrosis appears not detectable at a median of 7.8 years after anthracycline therapy.
    Journal of the American College of Cardiology 03/2013; · 14.09 Impact Factor
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    ABSTRACT: BACKGROUND: The prognosis of acute lymphoblastic leukemia is poorer in adults than in children. Studies have indicated that young adults benefit from pediatric treatment, although no upper age limit has been defined. DESIGN AND METHODS: We analyzed 749 patients aged 1-45 years treated by the NOPHO ALL-2008 protocol. Minimal residual disease (MRD) on days 29 and 79, immunophenotype, white blood cell count (WBC), and cytogenetics were used to stratify patients to standard, intermediate, or high risk treatment with or without hematopoietic stem cell transplantation. RESULTS: Adults aged 18-45 had significantly lower WBCs at diagnosis compared to children aged 1-9 and 10-17 years, but significantly more adults were stratified to high-risk chemotherapy (8%, 14%, 17%; p < 0.0001) or high risk chemotherapy with transplantation (4%, 13%, 19%; p < 0.0001). This age dependent skewing of risk grouping reflected more T-ALL (11%, 27%, 33%, p < 0.0001), poorer MRD response day 29 (MRD < 0.1%: 75%, 61%, 52%; p < 0.0001), and more MLL gene rearrangements (3%, 3%, 10%; p = 0.005) in older patients. CONCLUSIONS: Even if identical diagnostics, treatment, and risk stratification are implemented, more adults will be stratified to high risk therapy, which should be considered when comparing pediatric and adult outcomes. © 2013 John Wiley & Sons A/S.
    European Journal Of Haematology 03/2013; · 2.55 Impact Factor
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    ABSTRACT: The Finnish Investigators Network for Paediatric Medicines (FINPEDMED) was established in 2007, to meet the expected increase in paediatric clinical trials following the new EU Paediatric Regulation. Between 2007 and 2012, FINPEDMED received 91 trial requests, 18 trials were started, and in 24 cases, Finnish investigators were not selected by sponsors. Conclusion This experience from Finland highlights the need for Nordic collaboration to increase expertise, recruitment base and attractiveness for sponsors.
    Acta Paediatrica 01/2013; 102(11). · 1.97 Impact Factor
  • Leukemia: official journal of the Leukemia Society of America, Leukemia Research Fund, U.K 10/2012; · 10.16 Impact Factor
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    ABSTRACT: Conflicting conclusions can be drawn from the available data concerning antileukemic efficacy and risks of intrathecal (i.t.) chemoprophylaxis to children after hematopoietic SCT (HSCT). To address this, we enrolled six transplantation centers with similar treatment and patient material. Of the 397 children included, 136 patients had received post-HSCT i.t. treatment (i.t. group) and 261 had not (non-i.t. group). The two groups were, apart from the i.t. therapy given or not given, at equal risk of post-HSCT central nervous system (CNS) relapse, which was the primary endpoint studied. Isolated CNS relapses were observed in 2 (1.5%) patients from the i.t. group and 2 (1%) from the non-i.t. group. Combined relapses, including CNS, involved 4 (3%) patients from the i.t. group and 6 (2%) from the non-i.t. group. Overall survival and the occurrence of neurological side effects did not differ significantly between the groups. There was no statistically significant difference in the incidence of isolated or mixed CNS relapses between the two groups, suggesting little or no benefit from i.t. therapy post-HSCT in children.
    Bone marrow transplantation 05/2010; 46(3):372-8. · 3.00 Impact Factor
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    ABSTRACT: Drug doses, blood levels of drug metabolites and myelotoxicity during 6-mercaptopurine/methotrexate (MTX) maintenance therapy were registered for 59 adolescents (>or=10 years) and 176 non-adolescents (<10 years) with B-cell precursor acute lymphoblastic leukemia (ALL) and a white blood cell count (WBC) <50 x 10(9)/l at diagnosis. Event-free survival was lower for adolescents than non-adolescents (pEFS(12y):0.71 vs 0.83, P=0.04). For adolescents staying in remission, the mean WBC during maintenance therapy (mWBC) was related to age (r(S)=0.36, P=0.02), which became nonsignificant for those who relapsed (r(S)=0.05, P=0.9). The best-fit multivariate Cox regression model to predict risk of relapse included mWBC and thiopurine methyltransferase activity, which methylates mercaptopurine and reduces the intracellular availability of cytotoxic 6-thioguanine nucleotides (coefficient: 0.11, P=0.02). The correlation of mWBC to the risk of relapse was more pronounced for adolescents (coefficient=0.65, P=0.003) than for non-adolescents (coefficient=0.42, P=0.04). Adolescents had higher mean neutrophil counts (P=0.002) than non-adolescents, but received nonsignificantly lower mercaptopurine and MTX doses during maintenance therapy. Red blood cell MTX levels were significantly related to the dose of MTX among adolescents who stayed in remission (r(S)=0.38, P=0.02), which was not the case for those who developed a relapse (r(S)=0.15, P=0.60). Thus, compliance to maintenance therapy may influence the risk of relapse for adolescents with ALL.
    Leukemia: official journal of the Leukemia Society of America, Leukemia Research Fund, U.K 04/2010; 24(4):715-20. · 10.16 Impact Factor
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    ABSTRACT: We present a set of tests for physical performance used for annual prospective follow-up after a pediatric transplant. Of the 103 eligible patients transplanted at a mean age of 8.8 years, 94 were included. The results were divided into early, performed 1 (n=46) or 2 (n=12) years post transplant, and late tests (n=66), performed 4-16 (mean 6) years post transplant. A total of 30 patients had tests both at early and late time points (paired tests). The control subjects included 522 healthy age- and gender-matched schoolchildren. Using their test results, the s.d. score (SDS) was calculated for each patient and for each test individually. Both in the early and late tests, patients had the mean SDS for each test significantly lower (P<0.001) than controls, varying from -0.6 to -2.0 SDS. Specifically, tests measuring trunk muscles gave impaired results. In the group with paired tests, the results improved in four of six tests. In late tests, age at SCT, extensive chronic GVHD and being a sports club member correlated with the results. The potential beneficial effect of an exercise intervention program on impaired physical performance after pediatric SCT merits prospective studies.
    Bone marrow transplantation 08/2009; 45(4):738-45. · 3.00 Impact Factor
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    ABSTRACT: Frandsen, Thomas Abrahamsson, Jonas Lausen, Birgitte Vettenranta, Kim Heyman, Mats Behrentz, Mikael Castor, Anders Schmiegelow, Kjeld
    Pediatric Blood & Cancer; 01/2009 · 2.35 Impact Factor
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    ABSTRACT: Myelotoxicity during thiopurine therapy is enhanced in patients, who because of single nucleotide polymorphisms have decreased activity of the enzyme thiopurine methyltransferase (TPMT) and thus more thiopurine converted into 6-thioguanine nucleotides. Of 601 children with acute lymphoblastic leukemia (ALL) who were treated by the NOPHO ALL-92 protocol, 117 had TPMT genotype determined, whereas for 484 patients only erythrocyte TPMT activity was available. The latter were classified as heterozygous, if TPMT activity was <14 IU/ml, or deficient (<1.0 IU/ml). 526 patients had TPMT wild type, 73 were presumed heterozygous, and two were TPMT deficient. Risk of relapse was higher for the 526 TPMT wild type patients than for the remaining 75 patients (18 vs 7%, P=0.03). In Cox multivariate regression analysis, sex (male worse; P=0.06), age (higher age worse, P=0.02), and TPMT activity (wild type worse; P=0.02) were related to risk of relapse. Despite a lower probability of relapse, patients in the low TPMT activity group did not have superior survival (P=0.82), possibly because of an excess of secondary cancers among these 75 patients (P=0.07). These data suggest that children with ALL and TPMT wild type might have their cure rate improved, if the pharmacokinetics/-dynamics of TPMT low-activity patients could be mimicked without a concurrent excessive risk of second cancers.
    Leukemia: official journal of the Leukemia Society of America, Leukemia Research Fund, U.K 12/2008; 23(3):557-64. · 10.16 Impact Factor
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    K Vettenranta
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    ABSTRACT: Myeloablative conditioning continues to be employed in hematopoietic stem cell transplantation among patients with pediatric transplant indications. Fractionated TBI (fTBI) remains, with its considerable anti-leukemic potential, the cornerstone of conditioning in the most common of pediatric indications, ALL in its first, second or subsequent remission despite its well-established long-term sequelae. The feasibility of chemotherapy-only regimens has been established and these regimens widely employed in other pediatric indications, for example, in ALL below the age of 2 years, AML, myelodysplasias or severe aplastic anemia. Conditioning regimens are being modified with data accumulating on the role of, for example, pre-transplant residual disease, advanced HLA-typing or haploidentical transplantations in the pediatric setting.
    Bone Marrow Transplantation 06/2008; 41 Suppl 2:S14-7. · 3.54 Impact Factor
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    ABSTRACT: Incompatibility in killer-cell immunoglobulin-like receptor (KIR) ligand between recipient and donor of hematopoietic stem cell transplantation has been reported to lead to natural killer (NK) cell activation. This activation may result in better transplantation outcome through reduced risk of graft-versus-host (GvH) disease, relapse and mortality. In the present study the effect of KIR ligand incompatibility was investigated retrospectively in 186 unrelated stem cell transplantations performed in Finland during years 1993-2004. No clear evidence for a better outcome in cases with KIR ligand incompatibility was obtained. Transplantation-related mortality was 64% in Kaplan-Meier analysis in the GvH direction KIR ligand-mismatched group and 33% in the KIR ligand-matched group. This difference was statistically non-significant. Consequently, no support could be obtained for a beneficial effect of KIR ligand incompatibility in the present set of unrelated donor transplantations.
    Transplant Immunology 08/2007; 18(1):62-6. · 1.52 Impact Factor
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    ABSTRACT: Delayed and/or insufficient T cell recovery post hematopoietic stem cell transplantation (HSCT) leads to an increased risk of morbidity and mortality. We evaluated thymic function and its association with T cell regeneration post HSCT and identified factors involved in the process among pediatric stem cell transplant recipients. T cell regeneration in 66 pediatric patients was prospectively followed by naive T cell phenotyping, measuring of T cell receptor excision circles (TRECs) and expression of Foxp3 by regulatory T cells for the first 18 months post HSCT. TRECs were lower pre-HSCT in children with a malignant than non-malignant primary disease or immunosuppressed controls (P=0.001). Naive T lymphocyte reconstitution and thymic recovery were slow in the recipients of allogeneic stem cell grafts post HSCT. Infections caused by herpesviruses had a prognostic impact on mortality. Children with low TRECs had a high mortality (P=0.05) and low TRECs were also associated with extensive chronic graft-versus-host disease from 6 months onwards. Low amount of Foxp3 pre-HSCT was associated with an increased mortality post HSCT (P=0.03). Our study indicates an association between impaired T cell regeneration and thymic dysfunction and the clinical post transplant complications in pediatric allogeneic stem cell transplantation.
    Bone Marrow Transplantation 03/2007; 39(3):149-56. · 3.54 Impact Factor
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    ABSTRACT: We examined the recovery of circulating monocytoid (Lin- CD11+ HLA-DR+) and plasmacytoid (Lin- CD123+ HLA-DR+) precursor (pre) dendritic cell (DC) subsets after allogeneic stem cell transplantation (SCT) in 39 children, using age-matched healthy children as controls. The frequencies of DCs in peripheral blood samples were determined by flow cytometry. The initial recovery of DC occurred simultaneously with myeloid engraftment. However, with time, DC subset values declined, being very low 40-50 days after SCT. Low monocytoid and plasmacytoid DC values were associated significantly with the development of severe acute graft-versus-host disease (aGVHD) (P=0.042 and 0.017, respectively). Plasmacytoid DC values were lower than in the age-matched controls for the entire follow-up period (range 102-2569 days), although, with time, values approached normal levels. Normal monocytoid DC numbers were observed within 300-400 days post SCT. The severity of chronic GVHD did not correlate with quantitative recovery of DC. We conclude that in pediatric SCT, initial recovery of DC production is concurrent with that of myelopoiesis, yet with time, DC subset values decline and low counts are associated with severe aGVHD. Monocytoid DC numbers approach normal levels within a year of SCT, but plasmacytoid DC counts recover very slowly.
    Bone Marrow Transplantation 04/2005; 35(5):501-7. · 3.54 Impact Factor
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    ABSTRACT: Dendritic cells (DC) are a heterogeneous group of uniquely well-equipped bone marrow-derived antigen-presenting cells. They circulate in blood as precursor cells (preDC). In humans, two blood-borne subtypes of preDC can be distinguished by their differential expression of CD11c (CD11c+ preDC; monocytoid DC) and CD123 (CD123+ preDC; plasmacytoid DC). We studied the incidence of monocytoid and plasmacytoid DC in peripheral blood samples from 39 children of various ages (0.4-16.8 years) by flow cytometry, and found a significant negative correlation between the number of plasmacytoid DC and age (r = 0.421, P = 0.012). Monocytoid DC counts did not change significantly with age. Similarly, we analysed DC subsets in 19 children with cancer at the time of diagnosis prior to initiation of any myelosuppressive or antiproliferative treatment and compared the results with those obtained from gender- and age-matched control children. Patients with cancer had significantly less circulating monocytoid DC than controls (medians 13.2 versus 21.4 cells/ micro l, respectively, P = 0.042) at diagnosis, whereas absolute plasmacytoid DC counts did not differ significantly between the study groups. However, clinical outcome of the children with cancer (2.9-5 years follow-up after diagnosis) correlated with plasmacytoid DC count. Children with high plasmacytoid DC counts at diagnosis (above median) survived significantly worse (6/10 deceased) than those with low counts (1/9 deceased) (P = 0.034). Thus, circulating plasmacytoid DC counts are related to age during childhood, and development of cancer is associated with low number of monocytoid DC. A low circulating plasmacytoid DC count at diagnosis was a good prognostic sign.
    Clinical & Experimental Immunology 04/2004; 135(3):455-61. · 3.41 Impact Factor
  • Medical and Pediatric Oncology 06/2003; 40(5):324-6.
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    ABSTRACT: Gradual allograft rejection after initial good engraftment may occur with simultaneous autologous reconstitution particularly in patients receiving nonmyeloablative conditioning. Careful post-transplant follow-up of the chimerism status can reveal these cases early on, when the immunological balance may still be shifted to the donor cells. We describe two children with nonmalignant diseases, in whom imminent rejection of their sibling allografts was prevented with donor lymphocyte transfusions (DLT). DLT dosing and timing need to be individually guided by monitoring of the chimerism status.
    Bone Marrow Transplantation 06/2003; 31(9):833-6. · 3.54 Impact Factor
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    ABSTRACT: Several specific cytogenetic changes are known to be associated with childhood acute lymphoblastic leukemia (ALL), and many of them are important prognostic factors for the disease. Little is known, however, about the changes in gene expression in ALL. Recently, the development of cDNA array technology has enabled the study of expression of hundreds to thousands of genes in a single experiment. We used the cDNA array method to study the gene expression profiles of 17 children with precursor-B ALL. Normal B cells from adenoids were used as reference material. We discuss the 25 genes that were most over-expressed compared to the reference. These included four genes that are normally expressed only in the myeloid lineages of the hematopoietic cells: RNASE2, GCSFR, PRTN3 and CLC. We also detected over-expression of S100A12, expressed in nerve cells but also in myeloid cells. In addition to the myeloid-specific genes, other over-expressed genes included AML1, LCP2 and FGF6. In conclusion, our study revealed novel information about gene expression in childhood ALL. The data obtained may contribute to further studies of the pathogenesis and prognosis of childhood ALL.
    Leukemia 12/2002; 16(11):2213-21. · 10.16 Impact Factor

Publication Stats

466 Citations
184.94 Total Impact Points

Institutions

  • 1996–2014
    • University of Helsinki
      • • The Hospital for Children and Adolescents
      • • Department of Virology
      • • Department of Pathology
      • • Department of Medical Genetics
      Helsinki, Southern Finland Province, Finland
  • 2013
    • University of Tampere
      Tammerfors, Province of Western Finland, Finland
  • 2010–2013
    • Tampere University Hospital (TAUH)
      Tammerfors, Province of Western Finland, Finland
  • 2002–2013
    • Hospital District for Helsinki and Uusimaa
      Helsinki, Southern Finland Province, Finland
  • 2004
    • University of Pittsburgh
      • Department of Surgery
      Pittsburgh, PA, United States
  • 2001
    • Helsinki University Central Hospital
      Helsinki, Southern Finland Province, Finland