Endocrine Abstracts

Introduction: Acute intermittent porphyria (AIP) is an autosomal dominant disorder resulting from partial deficiency of the haeme biosynthetic enzyme porphobilinogen deaminase.

Case report: A 17-year-old female presented with progressive abdominal pain. She had history of recurrent abdominal pain and darkening in urine colour. She was on lansoprazol and metaclopramide, initiated 2 days earlier. She did not have additional personal or relevant family history. Physical examination did not reveal any pathologic finding.

Laboratory findings were as following: glucose: 84 mg/dl (N: 74–106), urea: 14 mg/dl (N: 17–43), creatinin: 0.6 mg/dl (N: 0.5–0.9), sodium: 103 mmol/l (N: 136–146), potasium: 3.6 mmol/l (N: 3.55.1), chloride: 76 mmol/l (N:101109), ALT: 21 U/l (N: 035), CK: 281 U/l (N: 0145), triglyceride: 46 mg/dl (N: 0–150), total protein: 6.9 g/dl (N: 6.6–8.3). In urine sediment erythrocyte was 11 p/Hpf (N: 0–2), leucocyte was 60 p/Hpf (N: 0–2), and nitrite was (+). Search for euvolemic hyponatraemia was initiated. Sodium in spot urine was 95 mmol/l, urine osmolarity was 490 mOsm/kg and plasma osmolarity was 230 mOsm/kg. TSH was 3.1 IU/ml (N: 0.3–5.6) and basal morning cortisol level was 34 μg/dl (N: 6.7–22.6). She was diagnosed with syndrome of inappropriate ADH. Plasma Na level was gradually increased up to 133 mmol/l with infusion of %0.3 NaCl solution. Chest X ray, cranial MRI and abdominal ultrasonography did not reveal any abnormality. Based on her history of periodic abdominal pain and dark urine porphyria was suspected. Porphoblinogen in 24-h urine sample was 19.7 mg/24 h (N: 0–1.6) and total porphyrin was 646 μg/24 h (N: 0–100). She did not have any cutaneous lesions. With the laboratory findings and her personal history she was diagnosed with inappropriate ADH syndrome secondary to AIP. The acute attack of AIP was taken under control with glucose loading and antibiotherapy for urinary tract infection.

Conclusion: It is important not only to treat syndrome of inappropriate ADH, but also to address any underlying condition. Diagnosis and management of AIP can be challenging and close monitoring for complications is needed.