Background: Tumor lysis syndrome (TLS) is a major metabolic complication in patients with malignancy after initiation of chemotherapy or spontaneously without treatment. The role of Rasburicase (a recombinant urate-oxidase enzyme) in prevention and treatment of TLS has been demonstrated in recent years. We aimed to investigate the efficacy of a single dose of rasburicase in reducing the risk of TLS in children at high risk.Methods: we conducted a retrospective analysis of 560 children with various malignancies in a single referral center. On the basis of the reference values previously established in our center hyperuricemia and TLS were defined. Tumor lysis syndrome development was the primary outcome.48 children with a mean age of 7.1 years (range: 3 months to 15.8 years) developed tumor lysis syndrome.The most common malignancies were B-precursor acute lymphoblastic leukemia (ALL) (45%) followed by non-Hodgkin lymphoma (NHL) and Wilms’ tumor (each 10.4%), respectively. They received normal saline intravenously at a rate of 4-5 L/m2/day in 24-48 hours prior to initiating chemotherapy. Plasma samples were drawn to detect uric acid, calcium, phosphate, potassium, creatinine and blood urea nitrogen (BUN) 4 hours before administering a single dose of IV rasburicase (0.2 mg/kg over 30 minute). Laboratory markers were evaluated again 4 and 24 hours after administering rasburicase.Results: All patients with diagnosis of TLS had significantly decreased uric acid levels following single dose of rasburicase except 1 patient (2.1%) (P<0.001). Mean plasma uric acid concentration before treatment was 10.0±4.2 mg/dL and 4 hours after treatment declined to 2.2±5.5 (P<0.001). Hyperphosphatemia was also detected in 43.7% of these 48 cases which significantly decreased to 16.7% (P=0.012). Plasma uric acid levels remained low one day after treatment. No side effects were detected.Conclusion: Rasburicase is a safe and highly effective drug in children with hyperuricemia in the setting of malignancy at risk of developing TLS.

Severe hyperuricemia accompanied by the other comorbidities such as anuria, fluid overload, calcium-phosphate imbalance, and/ or tumor lysis syndrome is one of the indications for dialysis in the setting of acute kidney injury. Rasburicase is used in different clinical conditions such as tumor lysis syndrome and uric acid nephropathy. Among referred patients to our center from 2008 to 2010, there were 3 patients who had an indication for dialysis because of hyperuricemia. Contributing factors to the acute kidney injury were multi-organ dysfunction, rapidly progressive glomerulonephritis, and spontaneous tumor lysis syndrome. None of the patients showed any response to treatment with bicarbonate and hydration. After rasburicase administration, serum uric acid level declined, and urine output increased. Treatment with a single low dose of rasburicase would be effective to decrease the serum uric acid level and reverse kidney injury secondary to uric acid nephropathy.

Background: Efficacy of rasburicase in pediatric patients with leukemia and lymphoma is proved. This study aims to weigh efficacy and safety of rasburicase versus more conventional therapy, allopurinol, and to compare their safety and properties in tumor lysis syndrome (TLS) of leukemia and lymphoma patients.Materials and Methods: The study was done with a retrospective cohort design. Patients were selected from our hematology ward admitted from 2005 through 2008. Patients were put into two groups based on their blood levels of uric acid, before initiation of chemotherapy, treatment group (the Uric Acid level of 6.5 mg/dl or more) and the prophylaxis group (the uric acid level below 6.5 mg/dl). Evaluation of effectiveness of therapy was performed after 24, 48, 72-hour, and longer periods.Results: Of 184 patients, 69% had leukemia, and 31% lymphoma. Twenty patients were treated with rasburicase and 164 with allopurinol. Mean age of patients was 7.93 ± 4.247 years old.60.8% were male and 39.2% were female. According to Chi-square test results, there was no significant difference between two agents regarding prophylaxis (chi-square=4.247, p-value=0.193) and treatment (chi-square=0.780, p-value=0.677). Most of the response to each agent was seen in the first 24 hours after drug administration. Mean level of uric acid reduced from 7.4 to 3.4 mg/dl in rasburicase, and from 5.4 to 3.9 mg/dl in allopurinol group. Mean duration of treatment for rasburicase was 2 days, and for allopurinol 6 days. Adverse effects were minimal in both groups (in rasburicase 1.6% and in allopurinol 5.4%).Conclusion: Rasburicase seems to be highly efficient in both prophylaxis and treatment of Hyperuricemia. Due to high costs in our practice, it was only administered to 20 patients with high levels of blood uric acid or leukocytosis. It prepares patients for chemotherapy faster and decreases cost of hospital stay indirectly by lowering cost of treatment. Allopurinol, alternatively showed equal efficiency and comparable results. Thus, it can be used safely and effectively until rasburicase becomes more widely available and more cost-effective.

Tumour lysis syndrome (TLS) can cause acute kidney injury (AKI) by the breakdown of intracellular contents during treatment for malignancies with large tumour burden. We report a case with an unusual presentation of AKI needing renal replacement therapy. Investigation of the cause for AKI led to the diagnosis of an underlying malignancy (lymphoma). Treatment of a Bell’ s palsy with steroids before presenting to our service has caused the AKI giving us the overarching diagnosis of TLS in this patient with lymphoma.

Background: Tumor lysis syndrome caused by widespread tumor cell damage may lead to electrolyte imbalances and express as metabolic disturbance causing clinical abnormalities.Patients and Methods: All patients younger than 16 years with documented malignancy candidate for chemotherapy, in Hamedan province of Iran were enrolled.Results: Out of 69 cancer patients the laboratory form of tumor lysis syndrome was detected in 8 patients (11.6%) and its clinical form was observed in 2 patients (2.9%). Those two patients with clinical tumor lysis syndrome were treated using hydration, allopurinol, rasburicase and dialysis with good metabolic response.Conclusion: Although our sample size was limited we found a comparable prevalence of tumor lysis syndrome among our patients in comparison with previous studies. Further evaluation of the prevalence of this syndrome among Iranian cancer patients is recommended.

Background: Hyperleukocytosis (HL) in pediatric acute leukemia is associated with increased morbidity and mortality. The indications for leukapheresis (LPH) in these patients remain unclear, and the use of LPH remains controversial. Objectives: This study aimed to review the clinical characteristics and outcomes of newly diagnosed leukemia patients with HL, comparing those who received LPH and those who did not. Methods: We analyzed clinical data from patients enrolled in frontline protocols for acute leukemia between 2017 and 2022. We documented adverse events within the first 30 days in patients with a white blood cell (WBC) count ≥ 100,000 cells/mm³ and reviewed their management. Treatment strategies included hyperhydration, administration of allopurinol or rasburicase, early induction chemotherapy (CT), and LPH. Results: Of 404 pediatric patients with newly diagnosed acute leukemia, 41 (10.1%) presented with HL (median WBC count: 136,000 cells/mm³; range HL: 101,000 - 844,000 cells/mm³). Leukapheresis was used in 9 of the 41 (13%) patients with HL. The median WBC count in patients who received LPH was 520,000 cells/mm³ compared to 158,800 cells/mm³ in those who did not (P = 0.01). Pulmonary leukostasis occurred in 2 patients, one of whom underwent LPH. No early deaths related to cerebral leukostasis, coagulopathy, or pulmonary leukostasis were observed in any patient within the first 30 days. The LPH procedure was well tolerated, with no reported complications. The time from presentation to the initiation of CT was similar between patients who received LPH and those who did not, with a mean of 17 hours versus 18 hours, respectively (P > 0.05). Tumor lysis syndrome (clinical or laboratory) was observed in 2 patients (23%) with LPH and 2 patients (6.25%) without LPH. Conclusions: The early morbidity and mortality often associated with HL in children with newly diagnosed acute leukemia can be avoided through conservative management, potentially reducing the need for LPH. However, LPH is a safe and well-tolerated procedure at our institution. It may be considered for patients with leukostasis when early induction CT is not feasible.