Materials and Methods
We performed a single institution, IRB approved, retrospective study to
quantify and characterize the rate of “shunters” treated in our
center. Expert chart review by the authors was conducted on each
eligible patient. Patients were included in our cohort if they were aged
0-30 years and treated for B cell or T cell ALL or lymphoblastic
lymphoma (LL) at our institution over a 10-year period from January 1,
2009 to June 1, 2019. Additional inclusion criteria included receiving
maintenance therapy at our institution for at least a 12-month period.
All of those treated for less than 12 months were excluded from data
collection and analysis. Clinical demographics including age, gender,
ethnicity, disease type, risk stratification, and treatment protocol
were collected. Incidents of hypoglycemia (glucose <74 mg/dL),
hepatic inflammation (Alanine aminotransferase [ALT]
>123 U/L), pancreatitis (amylase >100 U/L or
lipase >60 U/L), and hypogammaglobulinemia (IgG
<400 mg/dL) were recorded. We queried the treatment records
for the maximum dose of 6-MP prescribed during maintenance therapy,
identifying if an individual had their 6-MP dosing increased above
100%. If available, thiopurine metabolite levels were recorded, noting
levels of 6-MMPN greater than 10 000 pmol/8 x 108 RBC.
We defined “shunters” as individuals who had 6-MMPN levels greater
than 10 000 pmol/8 x 108 RBC. If a patient was started
on allopurinol, we noted the dose(s) of allopurinol at the start of
therapy and throughout the treatment course, the effects of the
allopurinol intervention on the aforementioned lab values, and the
patient’s clinical course. Descriptive statistics were calculated in
Stata ver. 16.