CRP and isolated hyperferritinemia: The results indicate that serum HO-1 correlates closely with serum ferritin (P = 0.0048, Fig. 3a) but not CRP or lactate dehydrogenase (LDH) levels (Fig. 3b,c), a finding consistent with an association between HO-1 and hyperferritinemia in patients with HPS and ASD.