To investigate the distribution of blood hemoglobin levels in healthy blood donors and elite athletes, a retrospective cohort study from 2001 to 2005 of candidate blood donors and elite rowers in Denmark was performed. Eighty-five thousand eight hundred and forty-six blood donors were identified (36 962 males), and 3.9% of the males had a blood hemoglobin above 10.5 mM, equalling a hematocrit of 51% and, 1.6% of the females had hemoglobin above 9.7 mM, corresponding to a hematocrit above 47%. One thousand four hundred and six rowers (1116 males) were investigated and 10.4% of the males and 8.3% of the females demonstrated values above the recommended limit for athletic competition. Thus, the prevalence of a high hemoglobin value was greater in the rowers, of both gender, than in the candidate blood donors (P
Human immunodeficiency virus-1 (HIV-1) infection has been shown to result in up-regulation of the urokinase-type plasminogen activator receptor (uPAR/CD87) on leukocytes in vitro and in vivo. The objective of this study was to investigate whether this up-regulation is paralleled by higher serum levels of soluble uPAR (suPAR) in patients with advanced HIV-1 disease and whether the serum level of suPAR is predictive of clinical outcome. Using an enzyme-linked immunosorbent assay, the level of suPAR was measured retrospectively in serum samples from 314 patients with HIV-1 infection. By Kaplan-Meier and Cox regression analyses, the serum suPAR levels were correlated to survival with AIDS-related death as the end point. High levels of serum suPAR (greater than median) were associated with poor overall survival, and Kaplan-Meier analysis on patients stratified by suPAR level demonstrated a continuous increase in mortality rates with higher suPAR levels. After adjustment for accepted prognostic markers-including Centers for Disease Control and Prevention-defined clinical stages, CD4 counts, viral load, beta2-microglobulin, and age-the prognostic strength of suPAR remained highly significant, indicating that the serum suPAR level is a novel, strong, and independent predictor of survival in HIV-1 infection. This report is the first to demonstrate an important association between the plasminogen activator system and disease progression in HIV-1 infection.
OBJECTIVE: It has been suggested that the plasma HIV RNA level is a better predictor of AIDS and death than the CD4 lymphocyte count. We assessed whether the prognostic value of plasma virus levels was different according to the CD4 count. DESIGN: Prospective cohort study of HIV-infected patients followed for a median of 2.91 years (range, 0.02-4.54). SETTING: Department of Infectious Diseases at Rigshospitalet, Copenhagen, Denmark. PARTICIPANTS: A group of 255 HIV-infected individuals with an initial measurement of CD4 lymphocyte count and plasma HIV RNA. MAIN OUTCOME MEASURE: Survival time. RESULTS: The plasma HIV RNA (median 101410 copies/ml; range (range 200-7200000) and the CD4 lymphocyte count (median 250 cells x 10(6)/l; range 1-1247) were negatively correlated (Pearson r = -0.53; P
No clear association between human disease and TT virus (TTV) has been documented. A possible pathogenic role of TTV was investigated in patients infected with human immunodeficiency virus (HIV). TTV serum concentrations were estimated in 185 HIV-infected patients by dilution polymerase chain reaction. Of these, 149 (76%) were TTV-positive, compared with 18 (7%) of 252 Danish blood donors (P/=5 times the highest concentration observed among blood donors, i.e., >/=3.5x105 TTV/mL of serum). High TTV viremia was associated with decreased survival (P
Epidemiological studies suggest an important role for environmental factors in developing multiple sclerosis (MS). Furthermore several studies have indicated that the effect of environmental factors may be especially pronounced in adolescents. Recently only one study investigated and found that shift work at young age is associated with an increased risk of developing MS. In this study we focused on the effect of shift work in the vulnerable period between 15-19 years.
The aim of this study was to investigate the association between shift work at young age and the risk of developing MS.
We performed a large case-control study including 1723 patients diagnosed with MS and 4067 controls. MS patients were recruited from the Danish Multiple Sclerosis Biobank and controls from The Danish Blood Donor Study. Information on working patterns and lifestyle factors was obtained using a comprehensive lifestyle-environmental factor questionnaire with participants enrolled between 2009 and 2014. Logistic regression models were used to investigate the association between shift work at age 15-19 years and the subsequent risk of MS and were controlled for effects due to established MS risk factors.
We found a statistically significant association when total numbers of night shifts were compared with non-shift workers. For every additional 100 night shifts the odds ratio (OR) for MS was 1.20 (95% confidence interval (CI), 1.08-1.34, p=0.001). Increasing intensity of shift work also increased MS risk. For every additional night per month the OR was 1.04 (95% CI, 1.01-1.06, p=0.002). Duration of shift work in years was not associated with risk of MS.
This study supports a statistically significant association between shift work at age 15-19 years and MS risk.
The Danish Blood Donor Study (DBDS) is a prospective, population-based study and biobank. Since 2010, 100,000 Danish blood donors have been included in the study. Prior to July 2015 all participating donors had to complete a paper-based questionnaire. Here we describe the establishment of a digital tablet-based questionnaire platform implemented in blood bank sites across Denmark.
The digital questionnaire was developed using the open source survey software tool LimeSurvey. The participants accesses the questionnaire online with a standard SSL encrypted HTTP connection using their personal civil registration numbers. The questionnaire is placed at a front-end web server and a collection server retrieves the completed questionnaires. Data from blood samples, register data, genetic data and verification of signed informed consent are then transferred to and merged with the questionnaire data in the DBDS database.
The digital platform enables personalized questionnaires, presenting only questions relevant to the specific donor by hiding unneeded follow-up questions on screening question results. New versions of questionnaires are immediately available at all blood collection facilities when new projects are initiated.
The digital platform is a faster, cost-effective and more flexible solution to collect valid data from participating donors compared to paper-based questionnaires. The overall system can be used around the world by the use of Internet connection, but the level of security depends on the sensitivity of the data to be collected.