Patients undergoing myeloablative
chemotherapy and
hematopoietic stem cell transplantation (HSCT) experience profound
neutropenia and vulnerability to
infection. Previous research has indicated that patients with
infections have depleted
vitamin C status. In this study, we recruited 38 patients with hematopoietic
cancer who were undergoing conditioning
chemotherapy and HSCT. Blood samples were collected prior to
transplantation, at one week, two weeks and four weeks following
transplantation.
Vitamin C status and
biomarkers of
inflammation (
C-reactive protein) and oxidative stress (
protein carbonyls and
thiobarbituric acid reactive substances) were assessed in association with
febrile neutropenia. The
vitamin C status of the study participants decreased from 44 ± 7 µmol/L to 29 ± 5 µmol/L by week one (p = 0.001) and 19 ± 6 µmol/L by week two (p < 0.001), by which time all of the participants had undergone a febrile episode. By week four,
vitamin C status had increased to 37 ± 10 µmol/L (p = 0.1). Pre-
transplantation, the cohort comprised 19% with hypovitaminosis C (i.e., <23 µmol/L) and 8% with deficiency (i.e., <11 µmol/L). At week one, those with hypovitaminosis C had increased to 38%, and at week two, 72% had hypovitaminosis C, and 34% had outright deficiency.
C-reactive protein concentrations increased from 3.5 ± 1.8 mg/L to 20 ± 11 mg/L at week one (p = 0.002), and 119 ± 25 mg/L at week two (p < 0.001), corresponding to the development of
febrile neutropenia in the patients. By week four, these values had dropped to 17 ± 8 mg/L (p < 0.001). There was a significant inverse correlation between
C-reactive protein concentrations and
vitamin C status (r = -0.424, p < 0.001).
Lipid oxidation (
thiobarbituric acid reactive substances (
TBARS)) increased significantly from 2.0 ± 0.3 µmol/L at baseline to 3.3 ± 0.6 µmol/L by week one (p < 0.001), and remained elevated at week two (p = 0.003), returning to baseline concentrations by week four (p = 0.3). Overall, the lowest mean
vitamin C values (recorded at week two) corresponded with the highest mean
C-reactive protein values and lowest mean neutrophil counts. Thus, depleted
vitamin C status in the HSCT patients coincides with
febrile neutropenia and elevated
inflammation and oxidative stress.