A) Experimental design. B) UV-visible spectral deconvolution was used to measure plasma cell free hemoglobin, a combination of oxyhemoglobin and methemoglobin, after 10 weeks of treatment. C) An ELISA was used to measure plasma haptoglobin concentration after 10 weeks of treatment. D) UV-visible spectral deconvolution was used to measure plasma cell free hemin concentration after 10 weeks of treatment. E) An ELISA was used to measure plasma hemopexin concentration after 10 weeks of treatment. Values are mean ± SEM using an unpaired Student’s t test unless otherwise noted. +Values are mean ± SEM using an unpaired Student’s t test with Welch’s correction. #Values are mean ± SEM using a Mann-Whitney test. WT, wild type; febux, febuxostat; ELISA, enzyme-linked immunosorbent assay.