Screening for hereditary haemochromatosis in patients undergoing knee arthroplasty

Aims Hereditary haemochromatosis is a genetic disorder that is caused by several known mutations in the human homeostatic iron regulator protein ( HFE) gene. Abnormal accumulation of iron causes a joint disease that resembles osteoarthritis (OA), but appears at a relatively younger age and is accompanied by cirrhosis, diabetes, and injury to other organs. Increased serum transferrin saturation and ferritin levels are known markers of haemochromatosis with high positive predictive values. Methods We have retrospectively analyzed the iron studies of a cohort of 2,035 patients undergoing knee joint arthroplasty due to OA. Results No patients had HFE gene C282Y, S65C, or H63D mutations testing. In total, 18 patients (2.96%) of the male cohort and 51 (3.58%) of the female cohort had pathologically increased ferritin levels that may be indicative of haemochromatosis. Seven patients (0.34%) had serum transferrin saturation above 45%. Conclusion The awareness for the diagnosis of this disorder in Orthopaedics is low and needs improvement. Osteoarthritic patients undergoing knee arthroplasty should be routinely screened for haemochromatosis by iron studies and referred to genetic testing when needed. Level of evidence: Level III - Retrospective cohort study. Cite this article: Bone Jt Open 2021;2(12):1062–1066.

Combined heart–liver transplantation in a case of haemochromatosis

Hereditary haemochromatosis results in multiorgan dysfunction secondary to iron overload. Haemojuvelin (HJV)-associated haemochromatosis, is a rapidly progressing form of haemochromatosis caused by mutation in the HJV that frequently results in heart and liver failure. Herein, we describe the successful treatment of a 39-year-old woman with decompensated heart failure and liver cirrhosis requiring extracorporeal membrane oxygenation who was successfully treated with combined heart–liver transplantation. Following her life-saving multiorgan transplantation, she was also noted to have rapid correction of her serum ferritin to normal levels. She remains healthy with excellent allograft function and normal iron and ferratin levels 4 years after the procedure. To our knowledge, this case is the first demonstration that combined heart–liver transplantation is a feasible option for patients with heart and liver failure secondary to HJV-associated haemochromatosis and indeed offers a long-standing corrective solution to treat this condition and restore physiologically normal iron metabolism.

An efficient machine learning-based approach for screening individuals at risk of hereditary haemochromatosis

Hereditary haemochromatosis (HH) is an autosomal recessive disease, where HFE C282Y homozygosity accounts for 80–85% of clinical cases among the Caucasian population. HH is characterised by the accumulation of iron, which, if untreated, can lead to the development of liver cirrhosis and liver cancer. Since iron overload is preventable and treatable if diagnosed early, high-risk individuals can be identified through effective screening employing artificial intelligence-based approaches. However, such tools expose novel challenges associated with the handling and integration of large heterogeneous datasets. We have developed an efficient computational model to screen individuals for HH using the family study data of the Hemochromatosis and Iron Overload Screening (HEIRS) cohort. This dataset, consisting of 254 cases and 701 controls, contains variables extracted from questionnaires and laboratory blood tests. The final model was trained on an extreme gradient boosting classifier using the most relevant risk factors: HFE C282Y homozygosity, age, mean corpuscular volume, iron level, serum ferritin level, transferrin saturation, and unsaturated iron-binding capacity. Hyperparameter optimisation was carried out with multiple runs, resulting in 0.94 ± 0.02 area under the receiving operating characteristic curve (AUCROC) for tenfold stratified cross-validation, demonstrating its outperformance when compared to the iron overload screening (IRON) tool.