Allergic Reactions to E. coli Asparaginase are Associated with Decreased Asparaginase Activity in an Indonesian Pediatric Population with ALL

Purpose:The asparaginase’s (ASP) utility for ALL treatment is limited by neutralizing antibodies, which is
problematic in countries whose access limited to alternative preparations. ASP antibody levels and activity was measured
during remission induction and associated with allergy manifestations. Methods: E. coli ASP was dosed at 7500
IU/m2. ASP IgG antibody levels were quantified at the beginning and end of induction. ASP activity was measured 24
hours after 1st and 5th dose (standard-risk) or 7th dose (high-risk patients) administration, and within 24 hours in case of
allergic reactions. Allergy was monitored by CTCAE version 3. Parametric and non-parametric was performed for data
analysis. Results:ASP antibody and activity levels were available in 41/63 consecutive patients. Allergic manifestations
occurred in 13/41, with urticaria being the most frequent. There were no significant differences in subject characteristics
based on allergic reactions. The 5th dose was the most frequent time of onset. Antibody levels in allergy group at the
end of induction did not differ from those at baseline (p<0.05). Using a 24-hour level of 100 mU/mL as a threshold
for adequate ASP activity, 6/13 patients with allergy had adequate levels compared to 26/28 patients without (p<0.05).
The ASP activity level at the end of induction phase in both groups did not show a significant decrement. Conclusion:
The E. coli ASP activity with adequate levels were significantly higher in non-allergy group. Its activity level was not
accompanied by increment of IgG in allergic group indicates other factors might affect activity levels in allergy group.