Table 1.
Clinical Features of Down Syndrome-Associated Arthritis (at Diagnosis)
| Case SeriesReference | 117 | 218 | 36 | 49 | 519 | 610 | 720 | 821 | 98 | 107 | 1122 | 1212 | Total (Percent) |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Patients | 1 | 1 | 6 | 9 | 4 | 9 | 1 | 11 | 43 | 33 | 1 | 36 | 155 |
| Female sex | 1 | 1 | 2 | 5 | 3 | 4 | 1 | 6 | 25 | 15 | 1 | 24 | 88 (57%) |
| Down syndrome Characteristics | |||||||||||||
| Celiac disease | NR | NR | NR | NR | NR | 1 | NR | NR | 5 | NR | NR | NR | 6/52 (12%) |
| Thyroid disease | NR | NR | NR | NR | NR | 5 | NR | 7 | 22 | NR | NR | NR | 34/65 (52%) |
| Morning stiffness reported | 1 | NR | 6 | 5 | NR | 6 | 1 | NR | 33 | NR | 1 | 14 | 67/106 (63%) |
| Age at onset (years) | 6 | 10 | 7.4 (4–10.5) | 4.3 (3–11) | 5.2 (3–10) | 5 (1.7–12) | 7 | 6 (1–13) | 7.4 (3.5–11.3) | 6.3 (1.1–16) | 3 | 6.9 (2–15) | 6.2 (2.4–12.5) |
| Time to diagnosis (years) | NR | NR | 1.6 (0.1–4.5) | 3.3 (0.3–9) | NR | 1.2 (0.2–3.5) | 3 | NR | 1.6 (0.2–3) | 1.2 (0.1–4.5) | 1 | 0.7 (0.1–4.1) | 1.1 (0.2–4.8) |
| Arthritis Subtype | |||||||||||||
| Oligoarticular | 0 | 0 | 2 | 2 | 1 | 1 | 0 | 1 | 4 | 1 | 0 | 3 | 15 |
| Polyarticular RF- | 1 | 1 | 4 | 6 | 3 | 8 | 1 | 9 | 30 | 27 | 1 | 24 | 115 |
| Polyarticular RF+ | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
| Systemic | 0 | 0 | 0 | 1 | 0 | 0 | 0 | 1 | 1 | 0 | 0 | 1 | 4 |
| Psoriatic | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 4 | 5 | 0 | 3 | 12 |
| Enthesitis-related | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 4 | 0 | 0 | 3 | 7 |
| Undifferentiated | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 2 | 2 |
| Laboratory tests | |||||||||||||
| Normal testing | 0 | NR | 0 | 0 | 0 | 5 | 0 | NR | 12 | NR | 0 | 16 | 33/110 (30%) |
| ANA | 1 | NR | 1 | 1 | 1 | 2 | 0 | NR | 8 | 0 | 0 | 12 | 26/143 (18%) |
| RF | 0 | NR | 0 | 0 | NR | 0 | 0 | NR | 0 | 0 | 0 | 0 | 0/139 (0%) |
| ESR | 1 | NR | 6 | 8 | 4 | 2 | 1 | NR | 24 | 8/25 | 1 | 6 | 61/136 (45%) |
| CRP | NR | NR | NR | NR | NR | 1 | 1 | NR | 9 | 3/29 | 1 | 6 | 21/119 (18%) |
| HLA-B27 | NR | NR | NR | NR | NR | 1 | 0 | NR | 5 | NR | 0 | 2 | 8/90 (9%) |
| Imaging | |||||||||||||
| Damage present | NR | NR | 4 | 7 | NR | 2 | 1 | 9 | 28/30 | 22 | 1 | 9 | 83/136 (61%) |
| Damage absent | NR | NR | NR | 2 | NR | 2 | 0 | 2 | 2/30 | NR | 0 | 15 | 23/97 (24%) |
| Uveitis* | NR | NR | 0 | 0 | 0 | 0 | 0 | 0 | 3 | 0 | 0 | 0 | 3/153 (2%) |
| Response to first-line therapy** | 0 | NR | 4 | 2 | 2 | 1 | 0 | 5 | 11 | NR | 0 | 6 | 31/121 (26%) |
Notes: *Uveitis was diagnosed via slit lamp eye exam, and this was not exclusive to time of diagnosis, but over the course of disease; **Response to first line-therapy was defined by change in therapy or addition of therapy in setting of active arthritis.
Abbreviation: NR, not reported.