COPSAC2000 cohort

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The COPSAC₂₀₀₀ cohort

The COPSAC₂₀₀₀ cohort is a prospective clinical mother-child cohort study of 411 children of asthmatic mothers. The study is designed to assess gene-environment interactions in the origin of atopic diseases with an aim to identify early-life exposures that can be modified to improve preventive strategies. The children attend the COPSAC clinical research unit from birth till adolescence at scheduled clinical investigations according to standard operating procedures. Additional visits are arranged at onset of any respiratory or skin symptom.

See available data on the cohort

Read the detailed paper about the baseline data (Ann Allergy Asthma Immunol 2004 Volume 93 Issue 4 Pages 381–389)

Cohort Recruitment

COPSAC recruited pregnant women from greater Copenhagen, Denmark.

Inclusion criteria included mothers fluent in Danish and a physician’s diagnosis of asthma and the need of daily treatment of asthma after the age of 7 years.

Exclusion criteria were failure to show up at this first visit, severe congenital anomaly, gestational age <36 weeks, and mechanical ventilation or lower respiratory tract infection prior to enrollment.

411 infants were enrolled in the cohort at one month of age between Aug 1998 and Dec 2001.

The study was conducted in accordance with the Declaration of Helsinki and was approved by the Copenhagen Ethics Committee (KF 01-289/96) and the Danish Data Protection Agency (2008-41-1754).

Randomized Control Trial

A randomized trial: Prevention of Asthma in Childhood (the PAC study) was nested in the COPSAC₂₀₀₀ cohort.
Participants were randomly assigned to either 400μg inhaled Budesonid per day or matching placebo for a two week period beginning day three of any episode of wheezing.

The primary outcome was the number of symptom-free days; key secondary outcomes were the time to discontinuation due to persistent wheezing and safety, as evaluated by height and bone mineral density at the end of the study.

The study showed that intermittent inhaled corticosteroid therapy had no effect on the progression from episodic to persistent wheezing and no short-term benefit during episodes of wheezing in the first three years of life.

Clinical Outcomes

Wheezy Episodes

A wheezy episode is defined from the diary cards as 3 consecutive days with troublesome lung symptoms. Troublesome lung symptoms were explained as wheeze or whistling sounds, breathlessness or recurrent troublesome cough severely affecting the wellbeing of the child.

All wheezy episodes lead to a consultation at the COPSAC clinical research unit where the doctors performed a full physical examination and reviewed the diary entries with the parents. The first confirmed wheezy episode resulted in prescription of an inhaled ß2-agonist for acute relief use (1-2 puff of terbutaline 0.25mg/dose in a pressurized metered dose inhaler with a spacer).

Preasthma/Recurrent wheeze

Preasthma/Recurrent Wheeze is defined from the diaries as 5 wheezy episodes within 6 months, or daily symptoms for 4 consecutive weeks. A preasthma/recurrent wheeze diagnosis lead to prescription of a 3-month inhaled corticosteroid trial (2 puffs per day of budesonide 200µg/dose in a pressurized metered dose inhaler with a spacer). At the end of the trial the medication was stopped and the child evaluated for relapse.

Asthma

Asthma is diagnosed according to the GINA guidelines based on Preasthma/Recurrent Wheeze. The symptom character judged by the COPSAC doctor to be typical of asthma with discrete exacerbations, but also symptoms between episodes, such as exercise induced symptoms; prolonged nocturnal cough; persistent cough outside common cold; symptoms causing wakening at night; in need of intermittent rescue use of inhaled ß2-agonist; and responding to a 3-month trial of inhaled corticosteroids and relapsing when stopping treatment. A relapse is defined as 2 wheezy episodes within 3 months, daily symptoms for 2 consecutive weeks, or acute severe asthma. Children meeting the criteria for asthma were all evaluated by chest X-ray and sweat chloride test.

Allergic Sensitization

Allergic Sensitization is defined from
- Skin prick test results as a wheal size of >=3 mm larger than the negative control
- Specific IgE levels >=0.35kUA/l (>= RAST class 1)

Allergic and Non-Allergic Rhinitis

Rhinitis is defined by troublesome sneezing, blocked or runny nose severely affecting the well-being of the child in periods outside common cold or flu. Allergic rhinitis is defined as rhinitis with allergic sensitization against inhaled allergens and symptom periods congruent with exposure. Non-allergic rhinitis is defined as rhinitis without sensitization or sensitization to allergens without exposure relevant symptoms.

Eczema

Eczema/Atopic Dermatitis is defined based on the criteria of Hanifin and Rajka. The diagnosis requires the presence of 3 of 4 major criteria and at least 3 of 23 minor signs (e.g. typical morphology and distribution, pruritus, chronic or chronically relapsing dermatitis, personal or family history of atopy). The severity of AD is scored using the SCORAD (Scoring Atopic Dermatitis) index.