21 October 2025
: Case report 
Methimazole-Induced Antithyroid Arthritis Syndrome in Graves' Disease Management: A Case Report
Challenging differential diagnosis, Diagnostic / therapeutic accidents, Unusual setting of medical care, Rare disease, Adverse events of drug therapy
Kin-Weng Sun
E 1,2, Aixin Wu ABDF 1*
DOI: 10.12659/AJCR.949509
Am J Case Rep 2025; 26:e949509
Table 2 The laboratory test results of patient.
| Indicators | Value | Reference range |
|---|---|---|
| Before admission | ||
| FT3 | 5.24 pg/mL ↑ | 2.3–4.2 |
| FT4 | 4.21 ng/dL ↑ | 0.89–1.76 |
| TSH | <0.008 IU/mL ↑ | 0.55–4.78 |
| Anti-CPP | (−) | (−) |
| RF | (−) | (−) |
| Admission, before lithium and corticosteroid use | ||
| FT3 | > 20 pg/ml ↑ | 2.3–4.2 |
| FT4 | 8.47 ng/dL ↑ | 0.89–1.76 |
| TSH | < 0.008 IU/mL ↑ | 0.55–4.78 |
| CRP | 50.88 mg/L ↑ | <5 |
| After lithium and corticosteroid use | ||
| ESR | 25 mm/h ↑ | 0–15 |
| MPO(p)-ANCA | (−) | (−) |
| PR3(c)-ANCA | (−) | (−) |
| ANA | (+) | (−) |
| IL-6 | 2.8 pg/ml | <7 |
| IgM | 0.75 g/L | 0.4–2.3 |
| IgA | 2.20 g/L | 0.7–4 |
| IgG | 12.47 g/L | 7–16 |
| Ferritin | 607.5 ng/ml ↑ | 23.9–336.2 |
| Anti-U1-nRNP/Sm | (−) | (−) |
| Anti-Sm | (−) | (−) |
| Anti-SS-A | (−) | (−) |
| Anti-Ro-52 | (−) | (−) |
| Anti-SS-B | (−) | (−) |
| Anti-Scl-70 | (−) | (−) |
| Anti-Jo-1 | (−) | (−) |
| Anti-CENP B | (−) | (−) |
| Anti-dsDNA | (−) | (−) |
| Anti-Nukleosomen | (−) | (−) |
| Anti-Histone | (−) | (−) |
| Anti-Rib.P-Prot | (−) | (−) |
| The last visit | ||
| FT3 | 2.81 pg/mL | 2.3–4.2 |
| FT4 | 1.47 ng/dL ↑ | 0.89–1.76 |
| TSH | 0.855 IU/mL ↑ | 0.55–4.78 |
| ANA – antinuclear antibody; anti-CCP – anti-cyclic citrullinated peptide antibody; anti-CENP B – anti-centromere protein B antibody; anti-dsDNA – anti-double stranded DNA antibody; anti-histone – anti-Histone antibody; anti-Jo-1 – anti-histidyl-tRNA synthetase antibody; anti-nukleosomen – anti-nucleosome antibody; anti-Rib.P-Prot –anti-ribosomal P protein antibody; anti-Ro-52 – anti-Ro52 (TRIM21) antibody; anti-Scl-70 – anti-Topoisomerase I antibody; anti-Sm – anti-Smith antibody; anti-SS-A – anti-Sjögren’s-syndrome-related antigen A antibody; anti-SS-B – anti-Sjögren’s-syndrome-related antigen B antibody; anti-U1-nRNP/Sm – anti-U1 small nuclear ribonucleoprotein/Smith antibody complex; CRP – C-reactive protein; ESR – erythrocyte sedimentation rate; FT3 – free triiodothyronine; FT4 – free thyroxine; IgA – immunoglobulin A; IgG – immunoglobulin G; IgM – immunoglobulin M; IL-6 – interleukin-6; MPO(p)-ANCA – myeloperoxidase (perinuclear) anti-neutrophil cytoplasmic antibody; PR3(c)-ANCA – proteinase 3 (cytoplasmic) anti-neutrophil cytoplasmic antibody; RF – rheumatoid factor; TSH – thyroid stimulating hormone. | ||