Table 1.
Patient characteristics
| Acute gout flares ( n = 24) | Acute CPP crystal arthritis ( n = 11) | None ( n = 1) | |
|---|---|---|---|
| Age, mean in years (SD) | 61 (12) | 70 (12) | 68 |
| Sex | |||
| Female, n (%) | 2 (8) | 4 (36) | 0 (0) |
| Male, n (%) | 22 (92) | 7 (64) | 1 (100) |
| Symptom duration | |||
| 0–6 months, n (%) | 10 (42) | 10 (91)* | 1 (100) |
| 7–60 months, n (%) | 6 (25) | 0 (0) | 0 (0) |
| over 60 months, n (%) | 8 (33) | 0 (0) | 0 (0) |
| Symptom duration, median in months (IQR) | 20 (3–98) | 0 (0–2) | 0 |
| History of gout/CPPD* | |||
| Prior history, n (%) | 13 (54) | 1 (9) | 1 (100) |
| New diagnosis, n (%) | 8 (33) | 10 (91) | 0 (0) |
| Latest serum urate, mean mg/dL (SD) | 6.4 (1.9) | 5.3 (1.7) | 4.8 |
| Highest serum urate, mean mg/dL (SD) | 8.1 (3.2) | 7.2 (2.3) | 4.8 |
| Podagra, n (%) | 13 (54) | 1 (9) | 1 (100) |
| Affected joint that underwent DECT, n (%) | |||
| Hand joints (MCP/IP/PIP/DIP) | 7 (29) | 0 (0) | 0 (0) |
| Wrist | 0 (0) | 4 (36) | 1 (100) |
| Elbow | 2 (8) | 0 (0) | 0 (0) |
| Shoulder | 0 (0) | 0 (0) | 0 (0) |
| Hip | 0 (0) | 0 (0) | 0 (0) |
| Knee | 4 (17) | 5 (46) | 0 (0) |
| Ankle | 1 (4) | 1 (9) | 0 (0) |
| Foot joints (MTP/IP/PIP/DIP) | 10 (42) | 1 (9) | 0 (0) |
| ACR/EULAR 2015 gout classification criteria score, median n (IQR) | 14.0 (10.0–16.0) | 2.0 (1.0–3.5) | 6.0 (0) |
| Mono sodium urate load on DECT, median cm 3 (IQR) | 0.17 (0–1.25) | 0.01 (0–0.04) | 0 |
| Serum calcium, mean mmol/l (SD) | 2.3 (0.1) | 2.2 (0.3) | * |
| Magnesium, mean mmol/l (SD) | 0.9 (0.2) | 0.8 (0.1) | * |
| Organic phosphate, mean mmol/l (SD) | 1.2 (0.2) | 1.0 (0.1) | * |
| Iron, mean µg/dl (SD) | 69.5 (39.5) | 89.0 (43.3) | * |
| Ferritin, mean ng/ml (SD) | 474.2 (387.5) | 193.2 (201.1) | * |
| CRP, mean mg/l (SD) | 26.8 (30.7) | 66.4 (72.6) | 1.5 |
| Leukocytes, mean n /µl (SD) | 8.9 (3.9) | 10.2 (3.4) | 5.1 |
| Haemoglobin, mean g/dl (SD) | 12.7 (2.3) | 11.7 (2.4) | 14.0 |
| Thrombocytes, mean G/l (SD) | 262 (108) | 342 (94) | 179 |
| Thyroid stimulating hormone, mean µU/ml (SD) | 2.2 (1.7) | 1.5 (0.9) | * |
CPP, calcium pyrophosphate; IQR, inter quartile range; DECT, dual energy computed tomography; MCP, metacarpophalangeal joint; IP, interphalangeal joint; PIP, proximal interphalangeal joint; DIP, distal interphalangeal joint; MTP, metatarsophalangeal joint; ACR, American College of Rheumatology; EULAR, European League Against Rheumatism; CRP, C-reactive protein. *Missing data