Urinary level of nickel and acute leukaemia in Chinese children

The 8-hydroxy-2'-deoxyguanosine (8-OHdG), an oxidized nucleoside of DNA, not only is a widely used biomarker for the measurement of endogenous oxidative DNA damage but might also be a risk factor for many diseases including cancer. Metal exposure may play an important role in oxidative DNA damage among children. However, few studies on urinary 8-OHdG and metals have been conducted in children with acute leukemia. In the present study, urinary Ni and 8-OHdG were examined in 116 children with acute leukaemia (94 acute lymphoid leukaemia [ALL] and 22 acute myeloid leukaemia [AML]) and 51 healthy child controls. Our result showed that urinary Ni in acute leukaemia patients (ALL: 68.40 +/- 133.98, AML: 41.48 +/- 76.31 ng/mg creatinine) was significantly higher than that in controls (62.47 +/- 124.90 vs 17.63 +/- 46.17 ng/mg creatinine, P < 0.05). Similarly, the pretherapy level of urinary 8-OHdG in patients (ALL: 11.83 +/- 16.23, AML: 12.36 +/- 11.36 ng/mg creatinine) was significantly elevated compared with controls (11.92 +/- 15.42 vs 4.03 +/- 4.70 ng/mg creatinine, P < 0.05). Moreover, urinary 8-OHdG and urinary Ni showed a weak but significant association with increased risk of childhood leukaemia. The present study suggests that Ni may be an etiologic factor for childhood acute leukaemia by oxidative DNA damage.