Table 1. . Study characteristics of recent epigenome-wide studies in asthma.
| Methylation platform | Tissue | Sample size | Age | Exposure | Phenotype | Ref. |
|---|---|---|---|---|---|---|
| NimbleGen 2.1M Human Promoter Deluxe | CBMC | Genome-wide discovery phase: n = 36 (IIS) Targeted analysis phase: n = 60 (IIS) n = 30 (MAAS) n = 28 (COAST) |
Birth | Genome-wide discovery phase: NA Targeted analysis phase: maternal asthma |
Asthma (2–9 years) | [12] |
| Illumina HumanMethylation27 and HumanMethylation450 | Whole blood | n = 527 (CAMP) n = 526 (Asthma BRIDGE) n = 1062 (MoBa) |
Age 5–12 years | Prenatal smoking | Asthma (5–12 years) | [17] |
| Illumina HumanMethylation450 | Whole blood | n = 6685 newborns n = 3187 older children |
Birth and older children | Prenatal smoking | NA | [18] |
| Illumina HumanMethylation450 | Whole blood | n = 1062 (MoBa1) n = 685 (MoBa2) |
Birth | Prenatal smoking | NA | [19] |
| Illumina HumanMethylation27 | Whole blood | n = 40 | Age 12 months | Maternal asthma | NA | |
| Whole genome bisulfite-sequencing | Whole blood | n = 443 | Birth | Maternal prenatal stress | Persistent wheeze (5 years) | [20] |
| Illumina HumanMethylation450 | Whole blood | n = 1018 | Birth and older children | Maternal obesity | NA | [21] |
| Illumina HumanMethylation450 | Bronchial epithelial cells | n = 17 | Mean age: 28.4 years | Ex vivo diesel exhaust and allergen | Asthma (mean age: 28.4 years) | [22] |
| Illumina HumanMethylation450 | Airway epithelial cells | n = 58 primary AEC cultures n = 116 freshly isolated AEC |
Primary AEC cultures (mean age: 45 years) freshly isolated AEC (mean age: 38.41 years) |
In vitro IL-13 treatment | Asthma (mean age: 38.41 years) | [23] |
| Illumina HumanMethylation450 | Nasal epithelial cells | n = 29 | Mean age: 25 years | In vitro rhinovirus infection | Asthma (mean age: 25 years) | [24] |
AEC: Airway epithelial cell; Asthma BRIDGE: Asthma BioRepository for Integrative Genomic Exploration study; CAMP: Childhood Asthma Management Program; CBMC: Cord blood mononuclear cell; COAST: Childhood Origins of ASThma Study; IIS: Infant Immune Study; MAAS: Manchester Asthma and Allergy Study; MoBa: The Norwegian Mother and Child Cohort Study; NA: Not applicable; PBMC: Peripheral blood mononuclear cell.