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Background: The ABO blood group system has shown an association with cardiovascular disease. The susceptibility to CVD is proposed to be partly mediated by dyslipidaemia in non-O individuals. Previous studies are scarce for the RhD blood group, but we recently showed that RhD − young individuals are associated with subclinical atherosclerosis. Hence, we sought to examine whether the ABO blood groups and RhD factor are associated with dyslipidaemia.

Methods: All participants were part of the VIPVIZA study, including 3532 individuals with available plasma lipid levels. Lipids were assessed as total, LDL, HDL, remnant, non-HDL cholesterol and triglycerides. Information about ABO and RhD was retrieved by linking VIPVIZA with the SCANDAT-3 database, where 85% of VIPVIZA participants were registered.

Results: For the ABO blood groups, no significant differences in lipid levels between non-O and O individuals were seen. In 40-year-old males, RhD − individuals compared to RhD + had higher levels of non-HDL cholesterol, LDL cholesterol, and remnant cholesterol, with ratios of geometric means of 1.21 (CI95% 1.03; 1.43), 1.20 (1.02; 1.41) and 1.38 (1.00; 1.92), respectively. No differences in lipid levels depending on the RhD blood group were seen in women or the older age groups.

Conclusion: Our study indicates that younger RhD − men have increased non-HDL, LDL, and remnant cholesterol levels. Thus, the RhD blood group, but not ABO, seems to be associated with dyslipidaemia and may act as a future possible risk marker of cardiovascular disease.

Guidelines on storage for samples intended for Prothrombin Time–International Normalized Ratio (PT-INR) analysis have changed over time, sometimes advising against cold storage due to presumed cold activation of the coagulation cascade. Previous studies on PT-INR storage have mainly been underpowered, performed in glass tubes, and not in a modern laboratory setting. In this study, we re-analyzed 1149 PT-INR samples, divided into low-level samples (PT-INR <1.3), and high-level samples (PT-INR 1.8–3.5) after 3 h of cold storage. We found no statistical difference for high-level samples but statistically higher PT-INR values in low-level samples. The differences were minor and not considered clinically relevant. No cold activation could be detected, as cold activation would have diminished PT-INR. These findings open the possibility of transporting and storing centrifuged PT-INR samples refrigerated. The higher PT-INR values in low-level samples after cold storage impede a mechanistic principle that needs to be further investigated.

Objectives: We examined the magnitude of transcription errors in lipid variables in the VIPVIZA study and assessed whether education among the research personnel reduced the error frequency at follow-up. We also examined how the errors affected the SCORE2 risk prediction algorithm for cardiovascular disease, which includes lipid parameters, as this could lead to an incorrect treatment decision.

Methods: The VIPVIZA study includes assessment of lipid parameters, where results for total cholesterol, triglycerides, HDL cholesterol, and calculated LDL cholesterol are transcribed into the research database by research nurses. Transcription errors were identified by recalculating LDL cholesterol, and a difference>0.15 indicated a transcription error in any of the four lipid parameters. To assess the presence of risk category misclassification, we compared the individual's SCORE2 risk category based on incorrect lipid levels to the SCORE2 categories based on the correct lipid levels.

Results: The transcription error frequency was 0.55 % in the 2019 VIPVIZA research database and halved after the educational intervention to 0.25 % in 2023. Of the 39 individuals who had a transcription error in total or HDL cholesterol (with the possibility of affecting the SCORE2 risk category based on non-HDL cholesterol), six individuals (15 %) received an incorrect risk category due to the error.

Conclusions: Transcription errors persist despite digitalisation improvements. It is essential to minimise transcriptions in fields outside the laboratory environment, as we observed that critical decisions also rely on accurate information such as the SCORE2-risk algorithm, which is dependent on lab results but not necessarily reported by the laboratory.

Background: The ABO blood group system has previously been associated with cardiovascular disease (CVD), where non-O blood group individuals have shown an increased risk. Studies assessing early atherosclerotic disease while also including RhD are few. We aimed to determine whether the ABO and RhD blood groups are associated with subclinical atherosclerosis in a healthy population.

Methods: We included 3532 participants from the VIPVIZA trial with available carotid ultrasonography results to assess subclinical disease. Information about blood groups was obtained from the SCANDAT-3 database, where 85% of VIPVIZA participants were registered.

Results: RhD− individuals aged 40 years showed increased carotid intima–media thickness (B 1.09 CI 95% 1.03; 1.14) compared to RhD+ individuals. For ABO, there were no differences in ultrasonography results when assessing the whole study population. However, 60-year-old individuals with heredity for CVD and a non-O blood group had decreased odds for carotid plaques (OR 0.54 CI 95% 0.33; 0.88).

Conclusions: RhD blood group is associated with subclinical atherosclerosis in younger individuals, indicating a role as a mediator in the atherosclerotic process. In addition, a non-O blood group was associated with decreased subclinical atherosclerosis in individuals aged 60 and with heredity (corresponding to the group with the highest atherosclerotic burden).

This study aimed to describe differences in prevalence and the long-term presence of nucleocapsid antibodies (N-antibodies) elicited by SARS-CoV-2 infection in a Swedish blood donor population not subjected to lockdown. We tested 20,651 blood donor samples for nucleocapsid antibodies from the beginning of March 2020 and 27 months onwards using the Roche Elecsys Anti-SARS-CoV-2 assay. The proportion of positive SARS-CoV-2 antibody samples was determined each week. After the exclusions of one-time donors and subjects with incomplete data, 19,726 samples from 4003 donors remained. Differences in antibody prevalences stratified for age, sex, and blood groups (ABO and RhD) were determined, as well as antibody loss and recovery. Lower antibody prevalence was seen for older donors, blood group AB, and RhD-negative subjects. A significant decrease in antibody titer between the first and the second antibody-positive donation was seen for the whole study group, females, older subjects, blood group O, AB, and RhD-positive subjects. The titer waned below the detection limit in 60 (3.0%) of 1983 N-antibody-positive donors, and for 18 of these donors, a second episode with antibodies was detected. We showed that N-antibodies persist for months or years and that surprisingly few antibody-positive donors lost their antibodies. We also conclude that antibody prevalence in a Swedish population never subject to lockdown did not apparently differ from populations that were subject to stricter regulations.

Background: There has been a notable decrease in antibiotic prescribing in the last thirty years in Sweden. Little is known about factors influencing antibiotic prescribing over several years.

Objective: To compare primary care physicians who, over time, reduced their antibiotic prescribing for respiratory tract infections with those who remained either high or low prescribers regarding potentially influencing factors.

Design and setting: A register-based study including all RTI visits in primary care in Region Kronoberg, Sweden 2006-2014. The data were divided into three 3-year periods.

Subjects: The data comprised all physicians who had diagnosed at least one RTI for each of the three-year periods. The antibiotic prescribing rate adjusted for the patients' sex and age group was calculated for each physician and period, and based on the change between the first and the third period, the physicians were divided into three prescriber groups: The High Prescribing Group, the Decreasing Prescribing Group, and the Low Prescribing Group.

Main outcome measures: For the three prescriber groups, we compared factors influencing antibiotic prescribing such as the characteristics of the physicians, their use of point-of-care tests, their choice of diagnoses, and whether the patients returned and received antibiotics.

Results: The High Prescribing Group ordered more point-of-care tests, registered more potential bacterial diagnoses, prescribed antibiotics at lower C-reactive protein levels, and prescribed antibiotics more often despite negative group A Streptococci test than in the Low Prescribing Group. The Decreasing Prescribing Group was between the High Prescribing Group and the Low Prescribing Group regarding these variables. The lower prescription rate in the Low Prescribing Group did not result in more return visits or new antibiotic prescriptions within 30 days.

Conclusion: Point-of-care testing and its interpretation differed between the prescriber groups. Focus on interpreting point-of-care test results could be a way forward in antibiotic stewardship. 

Objectives: Spectrophotometric absorption curve analysis of cerebrospinal fluid (CSF) for oxyhaemoglobin and bilirubin is necessary to accurately diagnose subarachnoid haemorrhage (SAH) in patients with typical symptoms but with negative findings on X-ray examinations. In this study, we evaluated the performance of two methods for interpreting absorption curves; one method from the United Kingdom National External Quality Assessment Service (UK-NEQAS) and the other from the national quality assurance programme in Sweden (Equalis).

Methods: Consecutive absorbance curves (n=336) were interpreted with two different methods, and their performance was compared to the diagnosis as stated in the patient records.

Results: The UK-NEQAS method displayed equal sensitivity to the Equalis method, but the specificity of the UK-NEQAS method was significantly higher than the Equalis method resulting in fewer false positive results. For UK-NEQAS, a positive predictive value (PPV) of 84.6% and a negative predictive value (NPV) of 99.7% were observed, whereas the Equalis method had a PPV of 27.5% and an NPV of 99.7%.

Conclusions: The semi-automated method based on the guidelines from UK-NEQAS provides an efficient and correct interpretation of absorbance curves with short turn-around times. We propose using this method for the routine interpretation of CSF spectrophotometric curves.

Background: The recently launched high-throughput assays for detecting antibodies against SARS-CoV-2 has contributed to the managing strategies for the COVID-19 pandemic. This study aimed to investigate the performance of three high-throughput assays and one rapid lateral flow test relative to regulatory authorities' recommended criteria.

Methods: A total of 315 samples, including 150 pre-pandemic samples, 152 samples from SARS-CoV-2 RT-PCR positive individuals and 13 potentially cross-reactive samples were analysed with SARS-CoV-2 IgG (Abbott, Abbott Park, IL), Elecsys Anti-SARS-CoV-2 (Roche, Solna, Sweden), LIAISON SARS-CoV-2 S1/S2 IgG (DiaSorin, Saluggia, Italy) and 2019-nCOV IgG/IgM Rapid Test (Dynamiker Biotechnology Co., Tianjin, China).

Results: All assays performed with a high level of specificity ranging from 96.7% to 99.3%. Sensitivity differed more between the assays, Roche exhibiting the highest sensitivity of 98.7%. The corresponding figures for Abbott, DiaSorin and Dynamiker Biotechnology were 80.9%, 89.0% and 72.4%, respectively.

Conclusions: The results of the evaluated SARS-CoV-2 assays vary considerably, as well as their ability to fulfil the performance criteria proposed by regulatory authorities. Introduction into clinical use in low-prevalent settings, should, therefore, be made with caution.

Background: The rise in antibiotic resistance is a global public health concern, and antibiotic overuse needs to be reduced. Earlier studies of out-of-hours care have indicated that antibiotic prescribing is less appropriate than that of in-hours care. However, no study has compared the out-of-hours treatment of infections to in-hours treatment within the same population.

Methods: This retrospective, descriptive study was based on data retrieved from the Kronoberg Infection Database in Primary Care (KIDPC), which consists of all visits to primary care with an infection diagnosis or prescription of antibiotics during 2006-2014. The purpose was to study the trends in antibiotic prescribing and to compare consultations and prescriptions between in-hours and out-of-hours.

Results: The visit rate for all infections was 434 visits per 1000 inhabitants per year. The visit rate was stable during the study period, but the antibiotic prescribing rate decreased from 266 prescriptions per 1000 inhabitants in 2006 to 194 prescriptions in 2014 (mean annual change - 8.5 [95% CI - 11.9 to - 5.2]). For the out-of-hours visits (12% of the total visits), a similar reduction in antibiotic prescribing was seen. The decrease was most apparent among children and in respiratory tract infections. When antibiotic prescribing during out-of-hours was compared to in-hours, the unadjusted relative risk of antibiotic prescribing was 1.37 (95% CI 1.36 to 1.38), but when adjusted for age, sex, and diagnosis, the relative risk of antibiotic prescribing was 1.09 (95% CI 1.08 to 1.10). The reduction after adjustment was largely explained by a higher visit rate during out-of-hours for infections requiring antibiotics (acute otitis media, pharyngotonsillitis, and lower urinary tract infection). The choices of antibiotics used for common diagnoses were similar.

Conclusions: Although the infection visit rate was unchanged over the study period, there was a significant reduction in antibiotic prescribing, especially to children and for respiratory tract infections. The higher antibiotic prescribing rate during out-of-hours was small when adjusted for age, sex, and diagnosis. No excess prescription of broad-spectrum antibiotics was seen. Therefore, interventions selectively aiming at out-of-hours centres seem to be unmotivated in a low-prescribing context.