Prolonged prothrombin time does not correlate with clinical bleeding symptoms in newly diagnosed paediatric leukaemia patients.

Prolonged prothrombin time (PT) and/or activated partial thromboplastin time (aPTT) are frequently seen in newly diagnosed paediatric leukaemia patients (NDPLP), which can lead to delayed diagnostic and therapeutic procedures due to concern for bleeding. A single-centre retrospective chart review of NDPLP between 2015 and 2018 aged 1-21 years. We analysed 93 NDPLP of whom 33.3% had bleeding symptoms within 30 days of presentation, predominantly mucosal bleeding (80.6%) and petechiae (64.5%). Median laboratory values: white blood cell count 15.7, haemoglobin 8.1, platelets 64, PT 13.2 and a PTT 31. Red blood cells were administered in 41.2%, platelets in 52.9%, fresh frozen plasma in 7.8% and vitamin K in 21.6% of patients. Prolonged PT was found in 54.8% of patients, while aPTT was prolonged in 5.4%. Anaemia and thrombocytopenia did not correlate with prolonged PT ( P  = 0.73 and P  = 0.18, respectively), or prolonged aPTT ( P  = 0.52 and 0.42). Leukocytosis showed significant correlation with elevated PT ( P  < 0.001), but not aPTT ( P  = 0.3). Bleeding symptoms upon presentation did not correlate with prolonged PT ( P  = 0.83), prolonged aPTT ( P  = 1) or anaemia ( P  = 0.06) but had a significant correlation with thrombocytopenia ( P  ≤ 0.0001). Therefore, a prolonged PT in NDPLP may not necessitate the reflexive use of blood product replacement, in the absence of significant bleeding, which is likely related to leukocytosis than to a true coagulopathy.