Hereditary hemochromatosis masquerading as rheumatoid arthritis.

Early erroneous diagnosis of rheumatic disease is common in subjects with arthropathy due to hereditary hemochromatosis. A 71-year-old male with chronic obstructive pulmonary disease and monoclonal gammopathy underwent hip replacement and was referred to our Department because of altered liver function tests. Test results were negative for hepatitis B surface antigen and hepatitis C virus, and positive for rheumatoid factor. A diagnosis of rheumatoid arthritis had been made on the basis of compatible joint involvement and laboratory data and steroid treatment prescribed. Since his serum ferritin was 3249 ng/mL, genetic testing for hereditary hemochromatosis was carried out and revealed homozygosity for Cys282Tyr mutation in the HFE gene. Liver biopsy disclosed cirrhosis compatible with hemochromatosis. Following a review of the patients' radiographs, the diagnosis of hemochromatosis arthropathy was made. Phlebotomies and family screening for hereditary hemochromatosis were done. The most logical explanation for the positive rheumatoid factor result in this subject are his age and the presence of two chronic diseases involving long-standing antigenic stimulation and monoclonal gammopathy of uncertain significance. It is important to distinguish rheumatoid arthritis from hemochromatosis arthropathy for several reasons: patients with hereditary hemochromatosis do not require corticosteroid treatment; in case of erroneous diagnosis of rheumatoid arthritis, phlebotomy is not started early, and familial genetic counseling is not considered. In male subjects with positive rheumatoid factor and joint and liver disease, hereditary hemochromatosis should be considered. More liberal use of genetic testing is justified in such cases.