Typical Lab Findings of adult onset Stills disease
Characteristic laboratory features of AOSD
There is no diagnostic test for Still’s disease. Rather, the diagnosis is one of exclusion, made in the setting of the proper clinical features and laboratory abnormalities and the absence of another explanation (such as infection or malignancy).
Laboratory Findings in Adult-Onset Still’s Disease
| Laboratory Test | Frequency (%) |
|---|---|
| Elevated erythrocyte sedimentation rate (>50) | 96–100 |
| Elevated C-reactive protein (often >10× upper limit of normal) | 90–100 |
| Leukocytosis (range 12–40,000/mm 3 ) | 71–97 |
| Anemia | 59–92 |
| Neutrophils (≥80%) | 55–88 |
| Hypoalbuminemia | 44–85 |
| Elevated hepatic enzymes | 35–85 |
| Thrombocytosis | 52–62 |
| Ferritin >1000 ng/mL | 40–70 |
| Positive antinuclear antibodies | 0–11 (should be negative) |
| Positive rheumatoid factor | 2–8 (usually negative) |
Pearl: Aldolase is frequently elevated, whereas creatine phosphokinase is normal. Aldolase elevation is due to liver inflammation. Procalcitonin can be elevated in AOSD even in the absence of infection.
