Tumor lysis syndrome in pediatric acute lymphoblastic leukemia at tertiary care center

OBJECTIVES: Tumor lysis syndrome (TLS) is common complication of acute lymphoblastic leukemia (ALL). It is characterized by presence of two or more of hyperkalemia, hyperuricemia, hyperphosphatemia and hypocalcemia. TLS may cause acute kidney injury (AKI), arrhythmias and seizures. Our objective was to determine the frequency of TLS and its biochemical abnormalities in children with ALL. METHODS: A retrospective study on 91 children, aged 2-13 years with ALL was carried out in Nephrology and Oncology departments of National Institute of Child Health, Karachi from January 2016 to December 2017. Patients already received chemotherapy were excluded. Data including risk categories, immunophenotyping, laboratory parameters like complete blood picture, serum creatinine (SCr), potassium(K), calcium (Ca), phosphorus(P) and uric acid (UA) on day 0,3 and 7 after chemotherapy were collected. Data analyzed on SPSS using descriptive statistics. Independent t- test was applied to compare means and P- value<0.05 was taken as significant. RESULTS: Ninety-one children with mean age of 6.39±3.08 years were studied. Male were 57% and 43% female. High risk ALL were 61.5%. Pre –BALL were 82.4% and 17.5% had T-cell ALL. All patients had anemia (hemoglobin7.69±2.66 g/dl) and thrombocytopenia (43.61± 18.6 x10(9)) where as hyperleukocytosis and blast cells were observed in 20.87% and 73.6% respectively. Comparing the biochemical parameters of ALL, the difference in SCr from D0 vs D3 (0.46±0.16 vs0.54± 0.35 and D7, 0.44±0.22) was significant (p=0.001). Similarly, difference in UA (D0, 4.12±2.40 vs D3, 3.82±1.73 and D7, 3.56±1.42), SP (D0, 4.24±1.34 vs D3, 4.61±1.76 and D7,4.13±1.07mg/dl)and for K (p=0.038) was significant. There was no difference in Ca from D0 vs D3 (0.092) and D7 (0.277). TLS was found in 62.6% children, it was chemotherapy induced in 72% and spontaneous in 28%. Clinical-TLS was observed in 14% and all CTLS had AKI. Hyperuricemia and hyperphosphatemia were the most common biochemical abnormalities in laboratory-TLS and CTLS. CONCLUSION: TLS was found in 62.6% despite preventive measures. Early recognition and treatment is essential to avoid morbidity and mortality.