Which laboratory tests are essential for confirming a diagnosis of HUS in a primary care setting?

Essential laboratory tests to confirm haemolytic uraemic syndrome (HUS) in primary care include:

• Full blood count (FBC) to detect anaemia and thrombocytopenia, which are hallmark features of HUS.
• Blood film examination to identify schistocytes (fragmented red cells), indicating microangiopathic haemolysis.
• Serum lactate dehydrogenase (LDH) as a marker of haemolysis, typically elevated in HUS.
• Renal function tests (serum creatinine and urea) to assess acute kidney injury, a key component of HUS.
• Urinalysis to detect haematuria and proteinuria, supporting renal involvement.
• Coagulation profile to exclude disseminated intravascular coagulation (DIC), which can mimic HUS.

These tests help establish the triad of microangiopathic haemolytic anaemia, thrombocytopenia, and acute kidney injury characteristic of HUS, enabling prompt referral for specialist care ¹ (Michael et al., 2022). In primary care, initial confirmation relies on these accessible laboratory parameters before further specialised testing (e.g., complement studies or ADAMTS13 activity) is performed in secondary care (Michael et al., 2022; Kottke-Marchant, 2017).