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Featured researches published by Sigrún H. Lund.


JAMA Oncology | 2015

The Role of Diagnosis and Clinical Follow-up of Monoclonal Gammopathy of Undetermined Significance on Survival in Multiple Myeloma.

Elin Edda Sigurdardottir; Ingemar Turesson; Sigrún H. Lund; Ebba K. Lindqvist; Sham Mailankody; Neha Korde; Magnus Björkholm; Ola Landgren; Sigurdur Y. Kristinsson

IMPORTANCE Multiple myeloma (MM) is consistently preceded by the precursor state, monoclonal gammopathy of undetermined significance (MGUS). The average annual risk of progression from MGUS to multiple myeloma is 0.5% to 1.0%. Current guidelines suggest life-long clinical follow-up of individuals diagnosed as having MGUS depending on risk stratification. The impact of diagnosing and conducting clinical follow-up of MGUS on MM survival is unclear. OBJECTIVE To estimate the impact of prior knowledge of MGUS diagnosis and comorbidities on MM survival. DESIGN, SETTING, AND PARTICIPANTS We conducted a population-based study including all patients with MM (MM patients) diagnosed in Sweden (n = 14,798) from 1976 to 2005 (with follow-up until 2007); 394 (2.7%) had previously been diagnosed as having MGUS. Information on comorbidities was gathered for all patients. We calculated survival rates from the time of MM diagnosis, comparing patients with vs those without prior knowledge of MGUS. Using Cox proportional hazards models, we calculated hazard ratios (HRs) and 95% CIs for risk factors for death. χ2 Tests were used to evaluate differences in comorbidities. EXPOSURES Prior knowledge of MGUS among MM patients. In a subanalysis, monoclonal (M)-protein concentration and type were used as exposure. MAIN OUTCOMES AND MEASURES Risk of death and comorbidities. RESULTS Patients with MM with prior knowledge of MGUS had significantly (HR, 0.86; 95% CI, 0.77-0.96; P < .01) better overall survival (median survival, 2.8 years) than MM patients without prior knowledge of MGUS (median survival, 2.1 years), although MM patients with (vs without) prior knowledge of MGUS had more comorbidities (P < .001). Among MM patients with prior knowledge of MGUS, low M-protein concentration (<0.5 g/dL) at MGUS diagnosis was associated with poorer MM survival (HR, 1.86; 95% CI, 1.13-3.04; P = .01). CONCLUSIONS AND RELEVANCE Patients with MM with prior knowledge of MGUS had better MM survival, suggesting that earlier treatment of MM leads to better survival. The observation that a low M-protein concentration at MGUS diagnosis was associated with poorer MM survival may reflect less frequent clinical follow-up. Our observations stress the importance of clinical follow-up in patients with MGUS, regardless of risk stratification.


Acta Ophthalmologica | 2014

Kinetics of γ-cyclodextrin nanoparticle suspension eye drops in tear fluid.

Gauti Jóhannesson; Maria D. Moya-Ortega; Gudrun Marta Asgrimsdottir; Sigrún H. Lund; Margret Thorsteinsdottir; Thorsteinn Loftsson; Einar Stefánsson

We have developed nanoparticle γ‐cyclodextrin dexamethasone (DexNP) and dorzolamide (DorzNP) eye drops that provide sustained high drug concentrations on the eye surface. To test these characteristics, we measured dexamethasone and dorzolamide levels in tear fluid in humans following eye drop administration.


European Journal of Cardio-Thoracic Surgery | 2016

The incidence and mortality of acute thoracic aortic dissection: results from a whole nation study

Melvinsdottir Ih; Sigrún H. Lund; Bjarni A. Agnarsson; Kristinn Sigvaldason; Tomas Gudbjartsson; Arnar Geirsson

OBJECTIVES Acute thoracic aortic dissection (ATAD) is a devastating condition associated with a high mortality rate. Recent reports suggest that its incidence is rising. Utilizing nationwide data comprising the whole Icelandic population, we aimed to determine the incidence, mortality rate and time-dependent mortality risk of ATAD. METHODS Data were retrospectively collected using centralized hospital discharge registries, autopsy records and Cause of Death Registry in Iceland from 1992 to 2013. RESULTS Age- and gender-adjusted incidence of ATAD was 2.53/100 000/year, and no significant change in incidence was observed during the study period. The mean age was 66.9 ± 13.6 years and 66.0% (101/153) were Stanford type A. Of the whole group, 17.6% (27/153) died prior to hospital arrival, whereas the risk of death for patients who arrived alive to a hospital was 21.4% (27/126) within 24 h and 45.2% (57/126) at 30 days. During the course of the study, patients with type A dissection were more likely to undergo an operation and the management of type B dissection changed from open to endovascular repair. The 30-day mortality rate declined every year and the 5-year survival rate improved in the last third of the study. CONCLUSIONS The incidence of ATAD was 2.53/100 000/year and remained constant throughout the study, contradicting recent perceptions of a rising incidence. ATAD, type A in particular, remains a highly lethal condition: Over half of all patients die within 30 days of the index event. A reduced 30-day mortality rate and an increased long-term survival rate indicate improved overall outcomes in patients with this complex condition.


Acta Ophthalmologica | 2015

Topical dexamethasone γ-cyclodextrin nanoparticle eye drops increase visual acuity and decrease macular thickness in diabetic macular oedema.

Akihiro Ohira; Katsunori Hara; Gauti Jóhannesson; Masaki Tanito; Gudrun Marta Asgrimsdottir; Sigrún H. Lund; Thorsteinn Loftsson; Einar Stefánsson

To compare in a randomized, controlled trial topical 1.5% dexamethasone γ‐cyclodextrin nanoparticle eye drops (DexNP) with posterior subtenon injection of triamcinolone acetonide in diabetic macular oedema (DME).


Blood | 2015

Population-based study on the impact of the familial form of Waldenström macroglobulinemia on overall survival.

Vilhjálmur Steingrímsson; Sigrún H. Lund; Ingemar Turesson; Lynn R. Goldin; Magnus Björkholm; Ola Landgren; Sigurdur Y. Kristinsson

To the editor: Waldenstrom macroglobulinemia (WM) is a chronic lymphoproliferative disorder (LP) characterized by an immunoglobulin M monoclonal gammopathy in the presence of lymphoplasmacytic lymphoma (LPL) in the bone marrow.[1][1] We have previously shown in a large population-based study that


The International Journal of Lower Extremity Wounds | 2015

Healing Rate and Autoimmune Safety of Full-Thickness Wounds Treated With Fish Skin Acellular Dermal Matrix Versus Porcine Small-Intestine Submucosa A Noninferiority Study

Baldur Tumi Baldursson; Hilmar Kjartansson; Fífa Konrádsdóttir; Palmar I. Gudnason; Gudmundur Fertram Sigurjonsson; Sigrún H. Lund

A novel product, the fish skin acellular dermal matrix (ADM) has recently been introduced into the family of biological materials for the treatment of wounds. Hitherto, these products have been produced from the organs of livestock. A noninferiority test was used to compare the effect of fish skin ADM against porcine small-intestine submucosa extracellular matrix in the healing of 162 full-thickness 4-mm wounds on the forearm of 81 volunteers. The fish skin product was noninferior at the primary end point, healing at 28 days. Furthermore, the wounds treated with fish skin acellular matrix healed significantly faster. These results might give the fish skin ADM an advantage because of its environmental neutrality when compared with livestock-derived products. The study results on these acute full-thickness wounds might apply for diabetic foot ulcers and other chronic full-thickness wounds, and the shorter healing time for the fish skin–treated group could influence treatment decisions. To test the autoimmune reactivity of the fish skin, the participants were tested with the following ELISA (enzyme-linked immunosorbent assay) tests: RF, ANA, ENA, anti ds-DNA, ANCA, anti-CCP, and anticollagen I and II. These showed no reactivity. The results demonstrate the claims of safety and efficacy of fish skin ADM for wound care.


Nephrology Dialysis Transplantation | 2016

Dialysis modality and nutritional status are associated with variability of inflammatory markers.

Sunna Snaedal; Abdul Rashid Qureshi; Sigrún H. Lund; Guna Germanis; Britta Hylander; Olof Heimbürger; Juan Jesus Carrero; Peter Stenvinkel; Peter Bárány

BACKGROUND Inflammation is a common feature in dialysis patients and is associated with cardiovascular complications and poor outcome. Measuring the variability of inflammatory markers may help in understanding underlying factors triggering inflammation. Whether the inflammatory pattern in hemodialysis (HD) and peritoneal dialysis (PD) patients differs has scarcely been studied. Here we explored factors associated with the magnitude and variability of inflammation markers in HD and PD patients. METHODS In two 3-month, prospective cohort studies comprising 228 prevalent HD and 80 prevalent PD patients, interleukin-6 (IL-6) and high-sensitivity C-reactive protein (CRP) were measured in blood samples drawn each month and every week, respectively. Information on comorbidity, protein-energy wasting (PEW) and medications was gathered at baseline, and information on symptoms potentially related to inflammation was gathered weekly. A mixed-effect model was used for multivariate analysis of factors linked to CRP and IL-6 variation. RESULTS IL-6 and CRP levels were higher and showed higher variability in HD versus PD patients [median IL-6 8.3 (interquartile range, IQR, 5.3-14.5) versus 6.7 (IQR 4.2-10.0) pg/mL, P < 0.001 and median CRP 6.1 (IQR 2.5-14.0) versus 5.4 (IQR 1.6-9.0) mg/L, P < 0.001). PEW predicted increased inflammation variability after correcting for age, sex, dialysis vintage, modality and comorbidity. Increased comorbidity predicted IL-6, but not CRP, variability. CONCLUSIONS Circulating concentrations as well as variability of IL-6 and CRP levels were higher in HD as compared with PD patients. In HD and PD patients, short-term variability of IL-6 and CRP levels associated strongly with PEW, while comorbidity was related to IL-6 but not to CRP variability.


The Lancet Haematology | 2015

Fiix-prothrombin time versus standard prothrombin time for monitoring of warfarin anticoagulation: a single centre, double-blind, randomised, non-inferiority trial

Pall T. Onundarson; Charles W. Francis; Olafur S. Indridason; David O. Arnar; Einar Björnsson; Magnus Karl Magnusson; Sigurdur Juliusson; Hulda M. Jensdottir; Brynjar Vidarsson; Petur S Gunnarsson; Sigrún H. Lund; Brynja R. Gudmundsdottir

BACKGROUND Rapid fluctuations in factor VII during warfarin anticoagulation change the international normalised ratio (INR) but contribute little to the antithrombotic effect. We aimed to assess non-inferiority of anticoagulation stabilisation with a warfarin monitoring method affected only by factors II and X (Fiix-prothrombin time [Fiix-PT]) compared with standard PT-INR monitoring that includes factor VII measurement as well. METHODS The Fiix trial was a single centre, double-blind, prospective, non-inferiority, randomised controlled clinical trial. Ambulatory adults on warfarin with an INR target of 2-3 managed by an anticoagulation dosing service using software-assisted dosing at the National University Hospital of Iceland, Reykjavik, Iceland, were eligible for inclusion in this study. We excluded patients undergoing electroconversion and nursing home residents. Patients were randomly assigned (1:1) to either the Fiix-PT monitoring group or the PT monitoring group by block randomisation. A blinded research INR (R-INR) based on results of the respective test was reported to the dosing staff. Participants were contacted by a study nurse at 4-week intervals to elicit information about thromboembolism or bleeding otherwise unknown to the anticoagulation management centre. The primary efficacy outcome was a composite of objectively diagnosed non-fatal and fatal arterial or venous thromboembolism, including myocardial infarction and transient ischaemic attacks, assessed in all eligible patients who were randomised (intention-to-monitor population). The safety endpoint was major bleeding or other clinically relevant bleeding, assessed in the per-protocol population. We assumed a 3% annual thromboembolism incidence and a non-inferiority margin of 2·5%. This trial is registered with ClinicalTrials.gov, number NCT01565239. FINDINGS Between March 1, 2012, and Feb 28, 2014, we enrolled 1156 patients. 573 patients were assigned to Fiix-PT and 575 to PT-INR monitoring after exclusion of four patients from each group for various reasons. Median follow-up was 1·7 years (IQR 1·1-1·9). During days 1-720, ten (1·2% per patient year) thromboembolic events occurred in the Fiix-PT group versus 19 (2·3% per patient year) in the PT group (relative risk [RR] 0·52, 95% CI 0·25-1·13; pnon-inferiority<0·0001). Major bleeding occurred in 17 of 571 patients in the Fiix group (2·2% per patient year) versus 20 of 573 patients in the PT group (2·5% per patient year; RR 0·85, 0·45-1·61; pnon-inferiority=0·0034). Anticoagulation stability was improved with Fiix-PT monitoring as manifested by fewer tests, fewer dose adjustments, increased time in range and less INR variability than reported with standard PT monitoring. INTERPRETATION Monitoring of warfarin with Fiix-PT improved anticoagulation and dosing stability and was clinically non-inferior to PT monitoring. Results from this trial suggest that during vitamin K antagonist treatment INR monitoring could be replaced by Fiix-PT and that this would lead to at least a non-inferior clinical outcome compared with monitoring with PT-INR. FUNDING Innovation Center Iceland, University of Iceland Science Fund, Landspitali Science Fund and Actavis.


Journal of Ocular Pharmacology and Therapeutics | 2014

Dorzolamide cyclodextrin nanoparticle suspension eye drops and trusopt in rabbit

Gauti Jóhannesson; Maria D. Moya-Ortega; Gudrun Marta Asgrimsdottir; Bjarni A. Agnarsson; Sigrún H. Lund; Thorsteinn Loftsson; Einar Stefánsson

PURPOSE Dorzolamide nanoparticle γ-cyclodextrin eye drops may prolong the effect of dorzolamide on intraocular pressure. We test whether the nanoparticle drops have an irritating or toxic effect on the eye in an in vivo rabbit model. METHODS Eighteen pigmented rabbits were divided into 4 groups receiving dorzolamide nanoparticle γ-cyclodextrin eye drops×1/day or×2/day, Trusopt® (dorzolamide HCl)×3/day, and untreated controls that received no drops. The rabbits received treatment for 1 month. After sacrifice, 33 eyes and 25 Harderian glands were evaluated for histopathology in a masked way. RESULTS Mild inflammation was seen in 19/31 eyes and 13/23 Harderian glands. The difference in inflammation (n=eyes/n=glands)between the γ-cyclodextrin nanoparticle eye drops×1/day (n=5/5),×2/day (n=5/3), Trusopt (n=7/4), or untreated control (n=2/0) groups was nonsignificant in both eyes and glands (P=0.87 and P=0.92) Acute inflammation was seen in 1 Harderian gland that received γ-cyclodextrin nanoparticle eye drops×2/day. The difference in conjunctival injection between the groups was nonsignificant (P=0.30). CONCLUSIONS Dorzolamide γ-cyclodextrin nanoparticle eye drops are no more locally toxic or irritating to the eye than Trusopt.


Blood | 2015

Survival in patients with familial and sporadic myeloproliferative neoplasms.

Malin Hultcrantz; Sigrún H. Lund; Ola Landgren; Jan Samuelsson; Lynn R. Goldin; Asmundur Oddsson; Magnus Björkholm; Sigurdur Y. Kristinsson

To the editor: Myeloproliferative neoplasms (MPNs) show a familial aggregation whereby first-degree relatives of MPN patients have a 5 to 7 times higher risk of developing MPNs.[1][1],[2][2] MPN patients have a reduced life expectancy as compared with the general population,[3][3] but there is

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Ola Landgren

Karolinska University Hospital

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Magnus Björkholm

Karolinska University Hospital

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Malin Hultcrantz

Memorial Sloan Kettering Cancer Center

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Ebba K. Lindqvist

Karolinska University Hospital

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Sham Mailankody

National Institutes of Health

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