Sanna Seitsonen
University of Helsinki
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Featured researches published by Sanna Seitsonen.
PLOS ONE | 2008
Sanna Seitsonen; Päivi Onkamo; Gang Peng; Momiao Xiong; Petri Tommila; Päivi Ranta; Juha M. Holopainen; Jukka A. O. Moilanen; Tapani Palosaari; Kai Kaarniranta; Seppo Meri; Immonen I; Irma Järvelä
Background Variants in the complement cascade genes and the LOC387715/HTRA1, have been widely reported to associate with age-related macular degeneration (AMD), the most common cause of visual impairment in industrialized countries. Methods/Principal Findings We investigated the association between the LOC387715 A69S and complement component C3 R102G risk alleles in the Finnish case-control material and found a significant association with both variants (OR 2.98, p = 3.75×10−9; non-AMD controls and OR 2.79, p = 2.78×10−19, blood donor controls and OR 1.83, p = 0.008; non-AMD controls and OR 1.39, p = 0.039; blood donor controls), respectively. Previously, we have shown a strong association between complement factor H (CFH) Y402H and AMD in the Finnish population. A carrier of at least one risk allele in each of the three susceptibility loci (LOC387715, C3, CFH) had an 18-fold risk of AMD when compared to a non-carrier homozygote in all three loci. A tentative gene-gene interaction between the two major AMD-associated loci, LOC387715 and CFH, was found in this study using a multiplicative (logistic regression) model, a synergy index (departure-from-additivity model) and the mutual information method (MI), suggesting that a common causative pathway may exist for these genes. Smoking (ever vs. never) exerted an extra risk for AMD, but somewhat surprisingly, only in connection with other factors such as sex and the C3 genotype. Population attributable risks (PAR) for the CFH, LOC387715 and C3 variants were 58.2%, 51.4% and 5.8%, respectively, the summary PAR for the three variants being 65.4%. Conclusions/Significance Evidence for gene-gene interaction between two major AMD associated loci CFH and LOC387715 was obtained using three methods, logistic regression, a synergy index and the mutual information (MI) index.
Ophthalmology | 2010
Ilkka Immonen; Sanna Seitsonen; Petri Tommila; Tiia Kangas-Kontio; Sakari Kakko; Eeva-Riitta Savolainen; Markku J. Savolainen; M. Johanna Liinamaa
PURPOSE To evaluate the role of vascular endothelial growth factor (VEGF) gene polymorphisms in exudative age-related macular degeneration (AMD). DESIGN Retrospective, comparative case series. PARTICIPANTS Patients with recent exudative AMD (n = 162) and age-matched subjects without AMD (n = 85). METHODS Fluorescein angiography (FA), clinical examination, and single nucleotide polymorphism (SNP) genotyping. MAIN OUTCOME MEASURES The frequencies of 3 VEGF gene SNPs were analyzed, 1 at the promoter site (rs699947, A-->C) and 2 intronic SNPs (rs2146323, A-->C, and rs3025033, A-->G), in relation to the risk of AMD, to choroidal neovascular (CNV) lesion size and configuration, and to the anatomic response to photodynamic therapy (PDT). These SNPs were chosen to cover all the haploblocks of the VEGF gene. The 86 patients who had undergone PDT were classified as either PDT responders or PDT nonresponders based on the outcome of PDT after the last treatment session. For the PDT responders, the treating physician had deemed the lesion to be clinically dry and without leakage from CNV in FA at a visit scheduled at least 12 weeks after the last PDT treatment. For the PDT nonresponders, the PDT sessions had been discontinued by the treating retina specialist because of an apparently poor response and a still exudative lesion after several PDT sessions. RESULTS The presence of exudative AMD or lesion size or configuration was not associated with the SNPs studied here. The frequencies of the rs699947 were significantly different in PDT nonresponders and PDT responders. The AA, AC, and CC genotypes were 14%, 39%, and 46%, respectively, in PDT nonresponders, compared with 40%, 48%, and 12%, respectively, in the PDT responders (P = 0.0008). The corresponding frequencies for the rs2146323 AA, AC, and CC genotypes were 4%, 32%, and 64%, respectively, in nonresponders and 24%, 38%, and 38%, respectively, in responders (P = 0.0369). The genotypes of the rs3025033 SNP were distributed evenly between the responders and nonresponders. CONCLUSIONS The VEGF gene polymorphic SNPs at rs699947 and rs2146323 are strong determinants of the anatomic outcome after PDT, but the SNPs studied were not associated with the presence of exudative AMD or with the CNV lesion size or configuration. FINANCIAL DISCLOSURE(S) The author(s) have no proprietary or commercial interest in any materials discussed in this article.
Journal of Organizational Change Management | 1997
Mika Kivimäki; Eerikki Mäki; Kari Lindström; Arto Alanko; Sanna Seitsonen; Kirsi M. Järvinen
Explores the quasi‐experimental study and the impact of the implementation of TQM on well‐being and work‐related perceptions among hospital staff. The survey was carried out before and after the implementation of TQM in a surgical clinic and at the same time in two non‐TQM surgical clinics which served as the control group. The results revealed that an economically feasible TQM implementation may not necessarily alter the wellbeing (in terms of job satisfaction, work motivation, and organizational commitment) and work‐related perceptions (including goal and process clarity, openness of communication, extent of participation and innovativeness, and degree of autonomy) of the staff. However, problems in commitment to TQM emerged among the physicians.
American Journal of Pathology | 2010
Riikka Tulamo; Juhana Frösen; Anders Paetau; Sanna Seitsonen; Juha Hernesniemi; Mika Niemelä; Irma Järvelä; Seppo Meri
Inflammation and activation of the complement system predispose to intracranial artery aneurysm (IA) rupture. Because disturbances in complement regulation may lead to increased susceptibility to complement activation and inflammation, we looked for evidence for dysregulation of the complement system in 26 unruptured and 26 ruptured IAs resected intraoperatively. Immunohistochemical and immunofluorescence results of parallel IA sections showed that deposition of the complement activation end-product C5b-9 was lacking from the luminal part of the IA wall that contained complement inhibitors factor H, C4b binding protein, and protectin as well as glycosaminoglycans. In contrast, the outer, less cellular part of the IA wall lacked protectin and had enabled full complement activation and C5b-9 formation. Decay accelerating factor and membrane cofactor protein had less evident roles in complement regulation. The Factor H Y402H variant, studied in 97 IA patients, was seen as often in aneurysm patients with or without aneurysm rupture as in the control population. The regulatory capacity of the complement system thus appears disturbed in the outer part of the IA wall, allowing full proinflammatory complement activation to occur before aneurysm rupture. Insufficient complement control might be due to matrix remodeling and cell loss by mechanical hemodynamics and/or inflammatory stress. Apparently, disturbed complement regulation leads to an increased susceptibility to complement activation, inflammation, and tissue damage in the IA wall.
Acta Ophthalmologica | 2008
Sanna Seitsonen; Irma Järvelä; Seppo Meri; Petri Tommila; Päivi Ranta; Ilkka Immonen
Purpose: The Y402H polymorphism of the complement factor H (CFH) gene is associated with age‐related macular degeneration (AMD) in many populations. The reported genotype−phenotype correlations in the CFH Y402H polymorphism have not been pronounced and no studies on the effect of the polymorphism on the subgroups within wet AMD have been performed. In this study, we wanted to evaluate whether the CFH Y402H polymorphism has an effect on clinical variables in recent exudative AMD lesions.
Retina-the Journal of Retinal and Vitreous Diseases | 2013
Asta Hautamäki; Jarno Kivioja; Satu Vavuli; Sakari Kakko; Eeva-Riitta Savolainen; Markku J. Savolainen; M. Johanna Liinamaa; Sanna Seitsonen; Päivi Onkamo; Irma Järvelä; Ilkka Immonen
Purpose: To study the association of single-nucleotide polymorphisms of interleukin 8, vascular endothelial growth factor, erythropoietin, complement factor H, complement component C3, and LOC387715 genes with the response to bevacizumab treatment in exudative age-related macular degeneration. Methods: Clinical records, smoking history, optical coherence tomography, and angiographies of 96 bevacizumab-treated exudative age-related macular degeneration patients were analyzed retrospectively. Blood DNA was collected. Based on the disappearance of intra- or subretinal fluid in optical coherence tomography, patients were graded as responders, partial responders, or nonresponders after 3 initial treatment visits and a median time of 3.5 months. Results: Interleukin 8 promoter polymorphism −251A/T was significantly associated with persisting fluid in optical coherence tomography. The A allele was more frequent in nonresponders than in responders (P = 0.033). In multivariate modeling, the AA genotype of −251A/T (P = 0.043) and occult (P = 0.042) or predominantly classic (P = 0.040) lesions predicted poorer outcome. Visual acuity change was better in responders than in nonresponders (P = 0.006). Baseline lesion size (P = 0.006) and retinal cysts after the treatment (P < 0.001) correlated with less visual acuity gain. Conclusion: The A allele and the homozygous AA genotype of interleukin 8 −251A/T were associated with anatomical nonresponse to bevacizumab treatment.
Neuroscience Letters | 2012
Kai Kaarniranta; Jussi Paananen; Tanja Nevalainen; Iiris Sorri; Sanna Seitsonen; Ilkka Immonen; Antero Salminen; Leena Pulkkinen; Matti Uusitupa
Adiponectin is an adipocyte-expressed protein that regulates the glucose, lipid, and energy metabolism via adiponectin receptors 1 and 2. Obesity is a known risk factor for age-related macular degeneration (AMD). We, therefore, examined associations of single nucleotide polymorphisms in Adiponectin (ADIPOQ) and Adiponectin receptors 1 and 2 (ADIPOR1 and ADIPOR2) genes with the prevalence of advanced AMD in Finnish population. Thirty-seven markers for ADIPOQ, ADIPOR1 and ADIPOR2 were genotyped in a sample collection of 91 men and 177 women having exudative AMD and 18 men and 26 women having severe atrophic AMD. Patients were diagnosed by fundus photographs and fluorescein angiography. The control group (no signs of AMD in fundus photographs) consisted of 55 men and 111 women. Inclusion criteria age was over 65 years old without diabetes diagnosis. Out of the tested SNPs, rs10753929 located in intron of ADIPOR1 gene was significantly associated (p=0.0471) with AMD status when using a permutation procedure that controlled for the number of tested genotypes and genetic models. Odds ratio (OR) for the association was 1.699 (95% CI 1.192-2.423). The SNP consists of C/T alleles and the risk allele T had a minor allele frequency (MAF) of 20.4%. Distribution of proportion of cases/controls between alleles revealed an additive genetic model. Our findings reveal that rs10753929 ADIPOR1 variant is a novel candidate for AMD genetic risk factor in Finnish population.
Acta Ophthalmologica | 2015
Asta Hautamäki; Sanna Seitsonen; Juha M. Holopainen; Jukka A. O. Moilanen; Jarno Kivioja; Päivi Onkamo; Irma Järvelä; Ilkka Immonen
To study the association of the single nucleotide polymorphism (SNP) rs4073 in the interleukin‐8 (IL‐8) promoter region with the diagnosis and age of onset of exudative age‐related macular degeneration (AMD) in association with the known genetic risk factors for AMD and tobacco smoking.
Acta Ophthalmologica | 2013
Ilkka Immonen; Sanna Seitsonen; Outi Saionmaa; Frej Fyhrquist
Purpose: To evaluate the association between telomere length and age‐related macular degeneration (AMD).
Scandinavian Journal of Immunology | 2012
Merja Helminen; Sanna Seitsonen; Hanna Jarva; Seppo Meri; Irma Järvelä
Properdin deficiency is a rare immunological disorder inherited as an X‐chromosomal recessive trait. Properdin deficiency poses a significant risk for severe meningococcal infections. About 20 mutations have been reported to underlie properdin deficiency. Here we report a large Finnish family with a novel mutation in the properdin gene (CFP). Based on the total absence of properdin activity in a 14‐year‐old male patient with an infection resembling meningococcal bacteraemia, the coding region and splice sites of the gene were sequenced. The mutation is located in exon 9 and changes guanine to adenine at nucleotide 1164 (c.1164G>A) that causes tryptophan to change to a premature stop codon (W388X). The mother of the patient was shown to be a carrier of the mutation. In total, the mutation was identified in six females and three young males in the family. The mutation must be inherited from the grandfather who had died of an unknown infectious disease. This is the first mutation of the properdin gene identified in Finland.