PubMed | Massey University and Wellington Southern Community Laboratories
Type: | Journal: Internal medicine journal | Year: 2016
The diagnosis of Hereditary Haemochromatosis (HH) is not straightforward since symptoms are often absent or non-specific. Biochemical markers of iron-overloading, may be affected by other conditions. This study measured the correlation between iron studies and HFE genotype to inform evidence-based recommendations for laboratory testing in NZ.Results from 2388 patients genotyped for C282Y, H63D and S65C in Wellington NZ from 2007- 2013 were compared to their biochemical phenotype as quantified by SF, transferrin saturation (TS), serum iron (SI) and serum transferrin (ST). The predictive power of these markers was evaluated by Receiver Operator Characteristic (ROC) curve analysis, and if a statistically significant association for a variable was seen, sensitivity, specificity and predictive values were calculated.Test ordering patterns showed that 62% of HFE genotyping tests were ordered because of an elevated SF alone and only 11% of these had a C-Reactive Protein (CRP) test to rule out an acute phase reaction. The association between SF and significant HFE genotypes SF was low. However, TS values 45% predicted HH mutations with the highest sensitivity and specificity. A SF of >1000 g/L was found in one at-risk patient (C282Y homozygote) who had a TS < 45%.Our analysis highlights the need for clear guidelines for investigation of hyperferritinaemia and HH in NZ. Using our findings we developed an evidence-based laboratory testing algorithm based on a TS 45%, a SF 1000 g/L and/or a family history of HH which identified all C282Y homozygotes in this study.