Objective: The aim of the study was to evaluate the impact of traumatic lumbar puncture (TLP) at diagnosis of relapse in childhood acute lymphoblastic leukemia (ALL). Risk factors associated with TLP were assessed. MATERIALS AND METHODS: A retrospective analysis was performed from the records of children with ALL who were treated from January 2010 to December 2012. Results: A total of 311 patients with median age of 5 years (range: 1–13) were treated for ALL. The cerebrospinal fluid analysis obtained from first LP revealed 275: Central nervous system 1 (CNS 1) (no blasts); 8: CNS 3 (blasts positive); and 28: TLP. Twenty-eight (9%) patients relapsed. Twelve (3.9%) had a CNS relapse. A TLP at diagnosis was not associated with an increased risk of systemic or CNS relapse (P = 0.298, 0.295). Three years event-free survival of patients with TLP and without atraumatic LP (ATLP) at diagnosis was 56 ± 5.2% and 51.8 ± 12.4%, (P = 0.520). Three years overall survival with TLP and ATLP was 73.3 ± 3.5% and 70.4 ± 12.5%, respectively, (P = 0.963). Median platelet count in patients with TLP was significantly lower than those without TLP (10,000/μL and 28,000/μL, P < 0.001). A receiver operating characteristic curve was constructed for predicting the risk of TLP based on platelet count. Area under the curve was 0.74 ± 0.05 (95% confidence interval 0.64–0.84). Platelet count < 23.5 × 109/L at the time of LP had 75% sensitivity and 64.4% specificity in predicting a TLP. Conclusions: Low platelet counts are significantly associated with risk of TLP. Traumatic LP at diagnosis was not associated with an increased risk of relapse.
