TABLE 1.
Characteristics of the Treg cohort sample with longitudinal nTreg measurements, compared with the full cohort
| Characteristic | Total Cohort N = 1074 | All with birth Treg measures N = 463 | nTreg at all 3 time points N = 191 |
|---|---|---|---|
| Prenatal factors | |||
| Parental allergy history (% (n/N)) | 83.9% (870/1037) | 86.20% (387/449) | 91.0% (171/188) |
| Number of residents (% (n/N)) | |||
| <3 | 39.3% (422/1074) | 36.3% (168/463) | 29.8% (57/191) |
| 3–4 | 55.2% (558/1074) | 57.0% (264/463) | 65.5% (125/191) |
| >4 | 8.75% (94/1074) | 6.7% (31/463) | 4.71% (9/191) |
| Number of older siblings (% (n/N)) | |||
| 0 | 45.0% (483/1073) | 40.0% (185/462) | 33.5% (64/191) |
| 1 | 34.9% (374/1073) | 39.8% (184/462) | 43.5% (83/191) |
| >1 | 20.1% (216/1073) | 20.1% (93/462) | 23.0% (44/191) |
| Pet dog during pregnancy (% (n/N)) | 55.4% (595/1074) | 51.6% (239/463) | 47.12% (90/191) |
| Maternal history of smoking (% (n/N)) | 16.0% (167/1043) | 16.6% (75/452) | 14.4% (27/188) |
| All 4 grandparents European (% (n/N)) | 94.7% (1010/1067) | 95.2% (439/461) | 96.7% (184/190) |
| SEIFA disadvantage* | |||
| Low (% (n/N)) | 33.3% (347/1041) | 33.1% (150/453) | 27.7% (52/188) |
| Medium (% (n/N)) | 33.3% (347/1041) | 29.8% (135/453) | 33.5% (63/188) |
| High (% (n/N)) | 33.3% (347/1041) | 37.1% (168/453) | 38.8% (73/188) |
| Perinatal factor | |||
| Sex | |||
| Male (% (n/N)) | 51.7% (519/1074) | 50.5% (234/463) | 50.8% (97/191) |
| Female (% (n/N)) | 48.3% (555/1074) | 49.5% (229/463) | 49.2% (94/191) |
| Caesarean section (% (n/N)) | 31.0% (333/1074) | 29.2% (135/463) | 30.9% (59/191) |
| Gestational age at birth (weeks) | 39.44 (1.52) | 39.50 (1.34) | 39.58 (1.2) |
| Labor time in hours | 6.07 (5.65) | 5.83 (5.85) | 5.72 (6.62) |
| Birthweight (kg) | 3.54 (0.51) | 3.58 (0.48) | 3.55 (0.44) |
| Birthweight Z score (unit) | 0.51 (0.9) | 0.57 (0.89) | 0.50 (0.83) |
| Postnatal factors | |||
| Pet dog during infancy (% (n/N)) | 54.4% (469/863) | 49.2% (189/384) | 48.7% (91/187) |
| Breastfeeding | |||
| Any breastmilk feeding at 6 months | 60.7% (603/993) | 60.6% (263/434) | 62.3% (119/191) |
| Any breastmilk feeding at 12 months | 37.8% (364/964) | 34.7% (145/418) | 32.5% (62/191) |
| Any breastfeeding | |||
| None | 2.3% (22/964) | 2.4% (10/418) | 2.1% (4/191) |
| <1 week | 2.9% (28/964) | 3.1% (13/418) | 3.1% (6/191) |
| 1 week to <6 months | 35.3% (340/964) | 35.4% (148/418) | 32.5% (62/191) |
| 6 to <12 months | 21.8% (210/964) | 24.4% (102/418) | 29.8% (57/191) |
| 12 months | 37.8% (364/964) | 34.7% (145/418) | 32.5% (62/191) |
| Exclusive breastfeeding up to 12 months | |||
| None | 70.6% (758/1074) | 68.9% (319/463) | 69.6% (133/191) |
| 1–4 | 20.6% (221/1074) | 22.3% (103/463) | 20.4% (39/191) |
| 5–8 | 4.9% (52/1074) | 4.9% (23/463) | 4.2% (8/191) |
| 9–12 | 4.0% (43/1074) | 3.9% (18/463) | 5.8% (11/191) |
|
Exclusive up to 12 months (completed months) (%(n/N)) |
18.8% (181/961) | 16.6% (69/417) | 18.9% (35/185) |
| Attended a formal childcare center in the first 12 months (% (n/N)) | 71.3% (417/585) | 71.7% (187/261) | 75.2% (94/125) |
| Avoiding egg by 6 months (% (n/N)) | 81.2 (675/831) | 80.8 (286/354) | 83.2 (134/161) |
| Avoiding peanut by 12 months (% (n/N)) | 34.5% (333/965) | 36.9% (156/422) | 37.6% (70/186) |
| Age at skin prick test (months) | 13.09 (0.89) | 13.02 (0.88) Socio‐Economic Indexes for Areas | 13.01 (0.93) |
| Cellular measures | |||
| Naïve T regulatory cells (nTreg) | |||
| Birth | ‐ | 4.45 (1.27) | 4.17 (1.27) |
| 6 months | ‐ | 5.50 (1.42) | 5.46 (1.41) |
| 12 months | ‐ | 5.53 (1.59) | 5.51 (1.82) |
| Activated T regulatory cells (aTreg) | ‐ | ||
| Birth | ‐ | 0.80 (0.48) | 0.72 (0.44) |
| 6 months | ‐ | 1.63 (0.81) | 1.56 (0.76) |
| 12 months | ‐ | 1.87 (1.05) | 1.97 (1.08) |
| 3% or more nTreg | ‐ | ||
| Birth (% (n/N)) | ‐ | 88.6% (410/463) | 84.3% (161/191) |
| 6 months (% (n/N)) | ‐ | 98.7% (592/600) | 100.0% (191/191) |
| 12 months (% (n/N)) | ‐ | 96.3% (650/675) | 99.5% (190/191) |
| Outcome measures | |||
| Polysensitization (% (n/N)) | 6.4% (52/814) | 7.8% (29/371) | 7.4% (16/186) |
| Food allergy (% (n/N)) | 7.6% (61/803) | 7.7% (28/365) | 8.6% (16/186) |
| Atopic eczema (% (n/N)) | 5.10% (54/1065) | 5.9% (27/458) | 6.4% (12/188) |
| Atopic wheeze (% (n/N)) | 5.10% (51/1006) | 5.9% (26/441) | 6.3% (12/190) |
Values are mean (SD) unless otherwise stated. *Socio‐Economic Indexes for Areas, values are low, medium, and high. Individuals were classified as Caucasian, values are low, medium, and high. Individuals were classified as Caucasian; values are low, medium, and high. Individuals were classified as Caucasian if both parents were born in Australia, Europe, UK, Northern America, or New Zealand (n = 503). Individuals were classified as Asian if both parents were born in South East Asia (n = 74). Those with one parent in each category were classified as mixed Asian‐Caucasian (n = 145).