Narcolepsy risk loci outline role of T cell autoimmunity and infectious triggers in narcolepsy

Narcolepsy type 1 (NT1) is caused by a loss of hypocretin/orexin transmission. Risk factors include pandemic 2009 H1N1 influenza A infection and immunization with Pandemrix®. Here, we dissect disease mechanisms and interactions with environmental triggers in a multi-ethnic sample of 6,073 cases and 84,856 controls. We fine-mapped GWAS signals within HLA (DQ0602, DQB1*03:01 and DPB1*04:02) and discovered seven novel associations (CD207, NAB1, IKZF4-ERBB3, CTSC, DENND1B, SIRPG, PRF1). Significant signals at TRA and DQB1*06:02 loci were found in 245 vaccination-related cases, who also shared polygenic risk. T cell receptor associations in NT1 modulated TRAJ*24, TRAJ*28 and TRBV*4-2 chain-usage. Partitioned heritability and immune cell enrichment analyses found genetic signals to be driven by dendritic and helper T cells. Lastly comorbidity analysis using data from FinnGen, suggests shared effects between NT1 and other autoimmune diseases. NT1 genetic variants shape autoimmunity and response to environmental triggers, including influenza A infection and immunization with Pandemrix®.

[Can we rely on self-reported smoking habits?]

The reliability of self-reporting on smoking habits has been evaluated by comparing the reported smoking habits with the concentration of serum thiocyanate, which is higher in smokers than in non-smokers and increases with increasing cigarette consumption. When a smoker stops smoking, the level of serum thiocyanate decreases and falls to the level observed in non-smokers after about one month. When the questions asked about smoking were neutral, the reported smoking habits were generally reliable. However, in cases where the questions asked and the interview situation could be regarded as unpleasant, the reported smoking habits were not always correct. Some smokers underreported the number of cigarettes they smoked on a daily basis and some of them denied smoking altogether.

[Smoking habits among Norwegian soldiers in Lebanon 1986]

The smoking habits in 287 Norwegian soldiers, mean age 24 years, who served for six months in the United Nations' peace-keeping forces in Lebanon was studied by self-administered questionnaire and determination of serum-thiocyanate. According to the questionnaires and verified by serum thiocyanate 42% were non-smokers at departure, 88% of them were still non-smokers at return. 7% of the smokers quit smoking while in Lebanon. The other smokers increased the consumption of cigarettes. The study indicates that campaigns against smoking should preferably be directed toward the youngsters since success among them will have long lasting effect.

Hepatitis A in Norwegian troops

More than 40,000 Norwegian troops have served in various UN peacekeeping operations since 1947. Coming from an area with low natural protection against hepatitis A, this disease has been a major concern to military authorities planning peacekeeping operations. More than 50 individuals have been repatriated due to hepatitis A, causing additional cost to the operations. After introduction of standard passive immunization with 2 ml immune globulins, reasonable protection was obtained for a limited time despite increasing risk of infection.

The actioculographic monitor of sleep

The actioculographic monitor (AOGM) is a newly developed, flexible system for sleep recording using three criteria: eye movements, body movements, and submental electromyogram. The signals are recorded on a four-channel Medilog casette tape and displayed by a mingograph at very low speed. The record is then scored after certain criteria for stages wake, nonrapid eye movement, and rapid eye movement sleep. High statistical correlations were obtained when scoring of the AOGM was compared to scoring of standard polygraphic sleep recordings.