28th August 2020

You are reviewing the blood results of a few of your patients

You are reviewing the blood results of a few of your patients. One presented with a cough productive of sputum and shortness of breath. A diagnosis of community acquired pneumonia was suspected. A sputum culture was sent off, and bloods were taken in order to aid treatment decision making. Her blood results were as follows: 

• Haemoglobin: 102 g/L (120-150 g/L for adult females, 130-170 g/L for adult males)
• White cell count: 13 x 10^9/L (4.0-11.0 x 10^9/L)
• Neutrophils: 79% (40-75%)
• Lymphocytes: 45% (20-40%)
• Sodium: 135 mmol/L (135-145 mmol/L)
• Potassium: 4.2 mmol/L (3.5-5.0 mmol/L)
• Creatinine: 141 mmol/L (60-110 mmol/L for adult females, 70-120 mmol/L for adult males)
• Urea: 6.1 mmol/L (2.5-7.5 mmol/L)
• eGFR (estimated glomerular filtration rate): 93 (Above 60 mL/min/1.73m² is generally considered normal)
• TSH (Thyroid Stimulating Hormone): 0.4 mu/L (0.4-4.0 mu/L)
• Free T4 (Thyroxine): 15 pmol/L (10-24 pmol/L)
• Free T3 (Triiodothyronine): 1.5 pmol/L (3.5-6.5 pmol/L)

Which of the following is the most likely cause of her abnormal Free T3?

Select the SINGLE most appropriate option from the list below. Select ONE option only.