05 May 2025
: Case report 
Methimazole-Induced Pancytopenia with ANCA Positivity: Diagnostic and Management Challenges
Unusual clinical course, Unusual or unexpected effect of treatment, Adverse events of drug therapy
Sanhitha Valasareddy
ABCDEF 1*, Farina Tariq E 2, Muhammad Zaheer ADF 1
DOI: 10.12659/AJCR.947323
Am J Case Rep 2025; 26:e947323
Table 1 Laboratory Values at the time of initial hospitalization.
| Variables | Values | Reference range and units |
|---|---|---|
| Free thyroxine (T4) | 0.7–1.5 ng/dL | |
| Free triiodothyronine (T3) | 1.7–3.7 pg/mL | |
| Thyroid stimulating hormone (TSH) receptor antibody | 0.00–1.75 IUnits/L | |
| White blood cell count (WBC) | 4.4–10.7×10E9/L | |
| Absolute lymphocyte count (ALC) | 1.10–3.90×10/u | |
| Absolute neutrophil count (ANC) | 2.01–7.14×10E9/L | |
| Hemoglobin (Hb) | 12.0–15.6 g/dL | |
| Platelets | 150–400×10/uL | |
| Total bilirubin | 0.2–1.2 mg/dL | |
| Alkaline phosphatase (ALP) | 40–150 U/L | |
| Aspartate aminotransferase (AST) | 5–34 U/L | |
| Alanine aminotransferase (ALT) | 5–55 U/L | |
| Cytoplasmic antineutrophilic cytoplasmic antibody (C-ANCA) | Neg: <1: 20 titer | |
| Perinuclear cytoplasmic-antineutrophilic cytoplasmic antibody (P-ANCA) | Neg: <1: 20 titer | |
| Proteinase 3 antibody (PR3) | <0.2 | 19 AU/mL or less |
| Myeloperoxidase antibody (MPO) | <0.2 | 19 AU/mL or less |
| Abnormal values indicated in bold. | ||