Table 3.
Characteristics and results of screening algorithms used for NBS for SCID in pilot and population-based screening cohorts identified by systematic review
| Author (year) | Ref | Location | Para-meter | Cut-off | Nr screened | Nr retests | Nr re-peat DBS | Nr referrals | Nr SCID | Nr other TCL | PPV SCID (% (95 % CI)) | PPV TCL (% (95 % CI)) | Incidence SCID/100,000 | Incidence TCL/100,000 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Pilot studies | ||||||||||||||
| Borte et al. (2012) | [13] | Sweden | TREC + KREC |
15 TRECs/μl 10 KRECs/μl |
2560 |
22 (0.86 %) |
1 (0.04 %) |
6 (0.23 %) |
NA | NA | NA | NA | NA | NA |
| Adams et al. (2014) | [16] | UK | TREC | 40 TRECs/μl | 5081 |
191 (3.76 %) |
1 (0.02 %) |
51 (1.00 %) |
NA | NA | NA | NA | NA | NA |
| 20 TRECs/ μl | 5081 |
10 (0.20 %) |
1 (0.02 %) |
2 (0.04 %) |
NA | NA | NA | NA | NA | NA | ||||
| Audrain et al. (2014) | [12] | France | TREC | 183 TRECs/reactiona | 5028 |
132 (2.63 %) |
2 (0.04 %) |
9 (0.18 %) |
NA | NA | NA | NA | NA | NA |
| 100 TRECs/reaction | 5028 |
59 (1.17 %) |
0 (0.00 %) |
2 (0.04 %) |
NA | NA | NA | NA | NA | NA | ||||
| Population-based screening | ||||||||||||||
| Chien et al. (2012) | [26] | Taiwan | TREC | 40 TRECs/μl | 106,391 |
0 (0.00 %) |
432 (0.41 %) |
24 (0.02 %) |
2 | 16 | 8.3 (−2.7–19.4) | 75.0 (57.7–92.3) | 1.9 | 16.9 |
| Verbsky et al. (2012) | [25] |
USA Wisconsin |
TREC |
25/40 b TRECs/μl |
207,696 |
449 (0.22 %) |
292 (0.14 %) |
72 (0.03 %) |
2 | 31 | 2.8 (−1.0–6.6) | 45.8 (34.3–57.3) | 1.0 | 15.9 |
| Kwan et al. (2014) | [36] |
USA Wisconsin |
TREC |
25/40 b TRECs/μl |
340,037 | NR | NR |
108 (0.03 %) |
4 | 45 | 3.7 (1.0–7.3) | 45.4 (36.0–54.8) | 1.2 | 14.4 |
| Kwan et al. (2013) | [34] |
USA California |
TREC |
25 TRECs/μl |
993,724 |
>897 (>0.09 %) |
806 (0.08 %) |
161 (0.02 %) |
12 | 38 | 7.5 (3.4–11.5) | 31.1 (23.9–38.2) | 1.2 | 5.0 |
| Kwan et al. (2014) | [36] |
USA California |
TREC |
25 TRECs/μl |
1,384,606 | NR | NR |
206 (0.01 %) |
23 | 57 | 11.2 (6.9–15.5) | 38.8 (32.2–45.5) | 1.7 | 5.8 |
| Vogel et al. (2014), Kwan et al. (2014) | [33, 36] |
USA New York State |
TREC |
125 TRECs/μld |
485,912* |
1745* (0.36 %) |
1307 (0.27 %) |
531 e (0.11 %) |
9 | 88 | 1.7 (0.6–2.8) | 18.3 (15.0–21.6) | 1.9 | 20.0 |
| Kwan et al. (2014) | [36] |
USA Colorado |
TREC | 40 TRECs/μl | 70,989 | NR | NR |
10 (0.01 %) |
1 | 3 | 10.0 (−8.6–28.6) | 40.0 (9.6–70.4) | 1.4 | 5.6 |
| Kwan et al. (2014) | [36] |
USA Connecticut |
TREC | 30 TRECs/μl | 57,136 | NR | NR |
22 (0.04 %) |
3 | 6 | 13.6 (−0.7–28.0) | 40.9 (20.4–61.5) | 5.3 | 15.8 |
| Kwan et al. (2014) | [36] |
USA Delaware |
TREC | 16 TRECs/μlf | 11,202 | NR | NR |
9 (0.08 %) |
1 | 3 | 11.1 (−9.4–31.6) | 44.4 (12.0–76.9) | 8.9 | 35.7 |
| Kwan et al. (2014) | [36] |
USA Massachusetts |
TREC | 252 TRECs/μl | 293,371 | NR | NR |
63 (0.02 %) |
4 | 47 | 6.3 (0.3–12.4) | 81.0 (71.3–90.6) | 1.4 | 17.4 |
| Kwan et al. (2014) | [36] |
USA Michigan |
TREC | 7 TRECs/μl | 162,528 | NR | NR | 114 (0.07 %) | 2 | 76 | 1.8 (−0.7–4.2) | 68.4 (59.9–77.0) | 1.2 | 48.0 |
| Kwan et al. (2014) | [36] |
USA Mississippi |
TREC | 25 TRECs/μl | 37,613 | NR | NR |
5 (0.01 %) |
1 | 4 | 20.0 (−15.1–55.1) | 100 | 2.7 | 13.3 |
| Kwan et al. (2014) | [36] |
USA Navajo Nation |
TREC | 25 TRECs/μl | 3498 | NR | NR |
1 (0.03 %) |
1 | 0 | 100 | 100 | 28.6 | 28.6 |
| Kwan et al. (2014) | [36] |
USA Texas |
TREC | 150 TRECs/μl | 183,191 | NR | NR | 249 (1.35 %) | 2 | 80 | 0.8 (−0.3–1.9) | 32.9 (27.1–38.8) | 1.1 | 44.8 |
* Screening results cover the period 2010-2012
NA not applicable, NR not reported
aBorderline category (39–183)
bThe cut-off value was changed to 40 after 19 months of screening for the next 17 months of screening
cSCID cases reported by Kwan et al. 2014 [36] include typical SCID (n = 42), leaky SCID (CD3 300–1500, few naïve T cells) (n = 9) and Omenn syndrome (oligoclonal T cells) (n = 1)
dBorderline category (125–200)
e531 Patients were referred for further evaluation, in 478 this evaluation was completed
fBorderline category (17–26)