Mid Sweden University

Previous studies indicate that blood type O has a protective effect against Covid-19 disease. In the present study, we aimed to further explore and clarify the connection between ABO blood groups and the Covid-19 disease by examining the levels of Covid antibodies in patients with different ABO blood types. During the first pandemic year, and before the vaccine was available, SARS-CoV-2 antibody level were randomly analyzed at the regional hospital laboratory and the data was stored in the laboratory information system (LIS) Flexlab/Chemistry. The investigated cohort was created by cross-referencing the SARS-CoV-2 antibody results with the ABO Rh(D) blood group status available in the LIS Prosang. The association between antibody level and blood group was further analyzed within this cohort. There was a significantly higher odds of Covid positivity among individuals in the cohort with blood type A or AB compared to blood type O. There was no significant difference in odds of Covid positivity among between phenotypes B compared to blood type O. The quantitative levels of SARS-CoV-2 antibodies were similar in individuals with a positive Covid-19 test regardless of ABO and Rh(D) phenotype. The present cohort study supports the hypothesis that the presence of anti-A antibodies in serum should be considered as a factor more significant than the blood group itself. However, the study showed a similar immune response in individuals with a positive Covid-19 test regardless ABO phenotype.

Acute pulmonary embolism (PE) is a common emergency with a high morbidity and mortality. Most clinical presentations are non-specific and there is a lack of suitable biomarkers for PE. For example, the traditional D-dimer tests shows a rather high sensitivity for PE, but yet a rather low positive predictive value due to its lack of specificity. Research on novel biomarkers for PE is thus of interest to improve early diagnostics and reduce the number of unnecessary computed tomography pulmonary angiogram (CTPA) scans performed. In this study we evaluate the feasibility to use label-free quantitative proteomics to discover potential biomarkers for acute PE and to monitor changes in proteins levels in PE patients over time. Blood was collected from 8 patients with CTPA verified PE and from 8 patients presenting with same symptoms but with a negative CTPA. The samples were analyzed by liquid chromatography-mass spectrometry and thirteen protein concentrations were found to be significantly changed in PE patients compared to the CTPA negative controls. This exploratory study shows that proteomic analysis can be used to identify potential biomarkers for PE as well as to monitor changes of protein levels over time. The complement proteins play a part in PE but further studies are needed to clarify their specific role in the pathophysiological process and to look for more specific proteins. 

BACKGROUND Release of cardiac biomarkers is common after strenuous endurance exercise, but data on intermittent exercise are scarce. It has not been investigated whether cardiac troponin elevation is influenced depending on the type of exercise that an athlete is adapted to perform. We hypothesized that intermittent but not continuous exercise induces cardiac troponin elevation in professional athletes adapted to high-intensity intermittent exercise. AIM To examine how training specificity impacts high-sensitivity cardiac troponin T (hs-cTnT) release. METHODS Nine professional floorball players participated in the study, which comprised two different exercise tests: a continuous incremental cycle ergometer test and a Yo-Yo Intermittent Recovery 2 (Yo-Yo IR2) test. Serial assessment of hs-cTnT was performed after the cycle ergometer test and the Yo-Yo IR2 test (baseline, 0, 2, 6, and 24 h). RESULTS No hs-cTnT elevation above the myocardial damage cutoff (>= 14 ng/L) was shown after the cycle ergometer test, whereas hs-cTnT levels rose over the cutoff in three of nine participants after the Yo-Yo IR2 test. The hs-cTnT levels peaked at 6 h after both tests, but were significantly higher after the Yo-Yo IR2 test compared to the cycle ergometer test (median hs-cTnT concentration 10.6 ng/L vs 7.8 ng/L, P = 0.038). All levels returned to baseline within 24 h. CONCLUSION In professional athletes adapted to high-intensity intermittent exercise, hs-cTnT was significantly elevated after intermittent but not continuous exercise. This principle of specificity training should be considered when designing future studies to avoid misinterpretation of hs-cTnT elevation.

Assessment of hematological parameters is common in sports medicine. Although physical exercise is an important preanalytical variable, data about acute hematological changes after high-intensity intermittent exercise are scarce. This study aimed to examine floorball as a potential preanalytical variable for hematological parameters used in health assessment and antidoping testing. Twenty-three professional male floorball players participated in a floorball game. Hematological parameters including hemoglobin, erythrocyte count and erythrocyte indices, reticulocytes, white blood cells (WBC), platelets, reticulocytes, and OFF-hr score were assessed at baseline, immediately postgame, and at 2 h postgame. Median hemoglobin concentration decreased significantly from 146 g/L pregame to 141 g/L immediately postgame (). WBC count increased from 7.2 × 109/L pregame to 10.1 × 109/L 2 h postgame (). The median OFF-hr score decreased from 99.5 to 94.2 immediately postgame and remained significantly lower than baseline at 2 h postgame (94.4, ). Looking at individual results, the highest OFF-hr score increased from 120 at baseline to 124 at 2 h postgame. Our findings suggest that participation in a floorball game affects several hematological parameters and consequently can affect health assessment and antidoping testing.

Plasma biomarkers that identify abdominal aortic aneurysm (AAA) rupture risk would greatly assist in stratifying patients with small aneurysms. Identification of such biomarkers has hitherto been unsuccessful over a range of studies using different methods. The present study used an alternative proteomic approach to find new, potential plasma AAA biomarker candidates. Pre-fractionated plasma samples from twelve patients with AAA and eight matched controls without aneurysm were analyzed by mass spectrometry applying a tandem mass tag (TMT) technique. Eight proteins were differentially regulated in patients compared to controls, including decreased levels of the enzyme bleomycin hydrolase. The down-regulation of this enzyme was confirmed in an extended validation study using an enzyme-linked immunosorbent assay (ELISA). The TMT-based proteomic approach thus identified novel potential plasma biomarkers for AAA. 

Regular measurement of prothrombin time (PT) as an international normalized ratio (INR) is of great importance in ensuring a safe Warfarin treatment due to the narrow therapeutic range. Hence, accurate results of the PT/INR analysis are crucial. Due to the high sampling load that patients on Warfarin experience, some prefer capillary sampling (from the tip of the finger) as an alternative to standard venous sampling (from the cubital fossa). The present study evaluated the method of capillary sampling compared to the standard venous method for plasma PT/INR measurement. Both venous and capillary samples were collected simultaneously for plasma PT/INR testing from 100 patients of which the majority undergoing active Warfarin treatment. The samples were analyzed on a Sysmex 2100i instrument (Siemens) using the Owrens method with PT reagents from MediRox. The capillary sampling method showed statistically significant lower values (p <.001) for plasma PT/INR than the standard venous sampling method with a mean difference (bias) of –0.14. It is improbable that the difference (bias) between capillary and venous sampling for plasma PT/INR analysis has clinical relevance. However, since the capillary blood collection and handling for plasma PT/INR is more technically demanding than the standard venous method we recommended that only specially trained personnel be entrusted to draw capillary blood for plasma PT/INR analysis.

Background A blood test for S100B can be used to rule out intracranial complications after minor head injury and thereby reduce the need for computed tomography (CT) examinations. The aim of this study was to investigate the clinical importance of a possible influence of seasonal variation on S100B. Methods The individual seasonal variation of S100B in 69 healthy volunteers living at latitudes with extremely variable seasonal exposure to sunlight was investigated. Results The mean serum concentration of S100B was 13% higher in August than in February, but however, not statistically significant (p = 0.068). A good agreement between summer and winter S100B values was confirmed by Bland-Altman analysis and a significant correlation (r = 0.317, p = 0.008) was shown between summer and winter S100B values. Conclusion This study did not show any clinical importance of seasonal variation of S100B that may influence the decision of CT scanning patients with head injuries.

Background: Primary hyperparathyroidism is often diagnosed by high calcium levels in blood. It is well known that calcium levels are dependent on vitamin D and Parathyroid hormone (PTH). Since vitamin D has a seasonal variation the calcium levels might also be influenced by seasonal variation. If a seasonal variation in calcium levels exists, this must be considered in the investigation of suspected hyperparathyroidism. The aim of the present study was to investigate the possible influence and magnitude of the seasonal variation of vitamin D and PTH on calcium levels. Method: In the present study the individual seasonal variation of 25-hydroxyvitamin D [25(OH) D], PTH and calcium in 69 healthy volunteers living at latitudes with extremely variable seasonal exposure to sunlight have been investigated. Results: As expected the 25(OH) D levels were significantly higher (42%) in summer compared to winter. PTH levels were significantly lower (7%) in summer than in winter. The mean serum concentration of calcium was 1% higher in August than in February, however not statistically significant. A good agreement between summer and winter calcium values was confirmed by Bland-Altman analysis. Conclusion: This study did not show any clinically important influence of seasonal variation of 25(OH) D and PTH on calcium that may influence a clinician's decision to investigate suspected hyperparathyroidism.

Cardiac biomarker release after exercise is well documented in endurance sports, but neither the impact of intermittent high-intensity exercise nor the reproducibility has yet been established. Floorball, a popular sport in Scandinavia, involves intermittent periods of high-intensity exercise. This study aimed to determine the prevalence and reproducibility of elevated cardiac marker levels among elite floorball players after two games. Twenty-three healthy male elite floorball players of median age 19 years (range 16-34 years) participated in two standard games. Blood was drawn at three time points: pregame, immediately after, and 2h after the game. Creatine kinase MB (CK-MB), myoglobin, and high-sensitivity cardiac troponin T (hs-cTnT) were measured. The results showed significantly elevated median postgame values in all markers. In both games, hs-cTnT exceeded the cutoff for myocardial damage (14ng/L) 2h postgame in the same six players. The major findings were that postgame cardiac hs-cTnT values among elite floorball players were significantly elevated and reproducible. The findings imply that extended investigations should incorporate evaluation of myocardial function and myocardial perfusion during exercise to seek the clinical significance and underlying mechanisms of elevated cardiac troponin after high-intensity exercise.

Abdominal aortic aneurysm (AAA) is a common condition with high mortality when ruptured. Most clinicians agree that small AAAs are best managed by ultrasonographic surveillance. However, it has been stated in recent reviews that a serum/plasma biomarker that predicts AAA rupture risk would be a powerful tool in stratifying patients with small AAAs. Identification of such circulating biomarkers with traditional hypothesis driven studies has been unsuccessful. In this review we summarize six studies using different proteomic approaches to find new, potential plasma AAA biomarker candidates. In conclusion, by using proteomic approaches novel potential plasma biomarkers for AAA have been identified.