Introduction Full blood count (FBC) indices and iron studies are utilised in initial screening of patients with clinical suspicion of haemachromatosis and HFE genetic testing is used for diagnosis. The aim of this study is to determine what effect haemachromatosis has on FBC indices and to detect any correlation with iron overload in subjects with C282Y homozygosity.
Methods Data were obtained from blood samples taken from first time donors to the Australian Red Cross Service prior to venesection. FBC indices were recorded from C282Y homozygous patients and also from an age-matched healthy control group. Ferritin levels from the haemachromatosis group were also obtained. All P values were derived from two-tailed statistical tests and Chi-square tests. P values of less than 0.05 considered significant. Multivariate regression analysis was used to assess the differences between blood donors and haemachromatosis patients.
Results The HFE group and normal controls were well matched with forty males and forty females in each group and no significant difference in age between the groups. Males homozygous for C282Y had a significantly (P = 0.001) higher mean
ferritin level 787.3 mcg/L (522.1–1052.6) compared with females
268.3 mcg/L (147.1–389.4). Eighty percent of C282Y homozygous males presented
with iron overload on their first Red Cross Blood donation visit, whereas only fifty percent of C282Y homozygous females had an elevated ferritin level on their first visit (P = 0.045). Of the forty patients homozygous for the C282Y mutations, there was evidence of iron overload in 26 patients (as defined by a ferritin greater than 200 mcg/L). There was no significant difference in all measure parameters between haemachromatosis patients with a ferritin lower than 200 mcg/L and healthy blood donors. Haemachromatosis patients with a ferritin level above 200 mcg/L (n = 26) had significant increases in haemoglobin (Hb) (P < 0.001), mean cell volume (MCV) (P < 0.026), mean corpuscular haemoglobin (MCH) (P < 0.001) and mean corpuscular haemoglobin concentration (MCHC) (P < 0.002).
Conclusion Patients with C282Y homozygous haemachromatosis had a significantly higher Hb, MCV, MCH and MCHC. There is a clear correlation between ferritin and these raised red cell indices. A ferritin greater than 200 mcg/L is associated with a significant increase these red cell indices. Further studies are required to determine whether this increase in red cell indices is reversible with therapeutic venesection.
Disclosure of Interest None Declared.