Dextramers: new generation of fluorescent MHC class I/peptide multimers for visualization of antigen-specific CD8+ T cells.

Direct identification as well as isolation of antigen-specific T cells became possible since the development of "tetramers" based on avidin-fluorochrome conjugates associated with mono-biotinylated class I MHC-peptide monomeric complexes. In principle, a series of distinct class I MHC-peptide tetramers, each labelled with a different fluorochrome, would allow to simultaneously enumerate as many unique antigen-specific CD8(+) T cells. Practically, however, only phycoerythrin and allophycocyanin conjugated tetramers have been generally available, imposing serious constraints for multiple labeling. To overcome this limitation, we have developed dextramers which are multimers based on a dextran backbone bearing multiple fluorescein and streptavidin moieties. Here we demonstrate the functionality and optimization of these new probes on human CD8(+) T cell clones with four independent antigen specificities. Their applications to the analysis of relatively low frequency antigen-specific T cells in peripheral blood, as well as their use in fluorescence microscopy, are demonstrated. The data show that dextramers produce a stronger signal than their fluoresceinated tetramer counterparts. Thus, these could become the reagents of choice as the antigen-specific T cell labeling transitions from basic research to clinical application.

Treatment dropout and missed appointments among adults with attention-deficit/hyperactivity disorder: associations with patient- and disorder-related factors.

OBJECTIVE: Knowledge of factors associated with treatment dropout and missed appointments in adults with attention-deficit/hyperactivity disorder (ADHD) is very limited. On the basis of proposed hypotheses that past behavior patterns are more predictive of current behaviors of treatment dropout and missed appointments than are sociodemographic and clinical characteristics, we examined the associations of sociodemographic variables, clinical variables, risk-taking behavior, educational and occupational instability, and behaviors during mandatory schooling with the primary outcome measures of treatment dropout and missed appointments. METHOD: In a naturalistic cohort study of 151 adult outpatients with ADHD initiating assessment in a Danish ADHD unit from September 1, 2010, to September 1, 2011, the Adult ADHD Self-Report Scale v1.1 symptom checklist (ASRS) and a thorough clinical interview were used to assess ADHD according to DSM-IV-TR criteria. Stepwise logistic regression analysis was used to estimate reported associations. RESULTS: A total of 27% of patients dropped out of treatment and a total of 42% had ≥ 3 missed appointments during treatment. Mood and anxiety disorders significantly lowered the odds of treatment dropout (odds ratio [OR] = 0.18; 95% confidence interval [CI], 0.05-0.65), whereas having started but not completed 2 or more educational programs apart from mandatory schooling significantly increased the odds of dropout (OR = 3.01; 95% CI, 1.32-6.89). Variables significantly associated with most missed appointments were low educational level (OR = 2.19; 95% CI, 1.12-4.31), 3 or more employments of less than 3 months' duration (OR = 2.86; 95% CI, 1.30-6.28), and having skipped class often/very often during mandatory schooling (OR = 2.65; 95% CI, 1.29-5.43). Additionally, the predominantly inattentive ADHD (ADHD-I) subtype lowered the odds of missed appointments (OR = 0.17; 95% CI, 0.05-0.62). CONCLUSION: Our results suggest that past behavior in terms of highest dropout rates in the educational and occupational systems and highest rates of skipping class during mandatory schooling is equally associated with current behavior of treatment dropout and missed appointments as are sociodemographic and clinical factors. TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT02226445.

Associations of Age, Gender, and Subtypes With ADHD Symptoms and Related Comorbidity in a Danish Sample of Clinically Referred Adults.

OBJECTIVE: The aim was to examine associations of age and gender with ADHD subtypes and subsequently to examine associations of age, gender, and subtypes with comorbid psychiatric disorders. METHOD: Odds ratios were calculated and logistic regression performed using information from a clinical sample of 155 ADHD adults referred to a Danish specialized ADHD unit from 2010 to 2011. RESULTS: A majority of men (65%) was found in the sample. Most patients were subtyped ADHD combined (78%), followed by ADHD inattentive (18%), and ADHD hyperactive-impulsive (4%). No significant differences were found in gender and age across subtypes. Current comorbid disorders were found in 57% of the ADHD patients. Significantly more comorbidity was found in the ADHD combined type and in patients ≥25 years. Significantly more men had substance use disorders and significantly more women had personality disorders. CONCLUSION: When assessing adult ADHD patients' age, gender, subtype, and related comorbid symptom profiles should be taken into account.

Education, occupation and risk-taking behaviour among adults with attention-deficit/hyperactivity disorder.

INTRODUCTION: No Danish studies examining functional impairments in a naturalistic sample of clinically referred adults with attention-deficit/hyperactivity disorder (ADHD) are available. Our study aimed to examine educational and occupational outcomes and risk-taking behaviour in a Danish clinical sample of adults with ADHD. METHODS: Naturalistic, cross-sectional study of 155 ADHD adults consecutively referred to a Danish ADHD clinic from 2010 to 2011. RESULTS: A total of 51% had primary/lower secondary school only as their highest education, and 65% were not self-supporting at the time of their assessment. Criminal behaviour was found in more than 50%, suspension of driving licence in 16% and risk-taking sexual behaviour in 37-51%. Co-morbidity did not significantly increase the odds for a low educational level or of risk-taking behaviours. Having a personality disorder (PD) increased occupational vulnerability. Male gender and ADHD-C (combined type) were significantly associated with criminality and suspension of driving licence. Patients with substance use disorders and PD had non-significantly increased odds for risk-taking behaviours. CONCLUSION: Functional impairments were evident in this Danish sample of adults with ADHD. Most of our findings could not be accounted for by co-morbidity, underlining the importance of targeting treatment at ADHD itself. FUNDING: This research was funded by The Psychiatric Research Foundation of the Central Denmark Region. TRIAL REGISTRATION: not relevant.