MAGNETIC RESONANCE IMAGING R2* AS A METHOD TO MONITOR IRON OVERLOAD IN PATIENTS UNDERGOING THERAPEUTIC PHLEBOTOMY FOR HEREDITARY HEMOCHROMATOSIS

Abstract

: to determine if there was a reduction in liver iron overload due to therapeutic phlebotomy as a treatment for iron overload in patients with hereditary hemochromatosis. : Through a retrospective observational study, we analyzed Magnetic Resonance imaging (MRI) R2* of 5 patients, before and after phlebotomy treatment, who are in medical follow-up for hereditary hemochromatosis. Data were collected from a hospital database and included patients with the diagnosis of hereditary hemochromatosis, with two MRI R2* (one before and one after treatment with phlebotomy), and with serum ferritin and transferrin saturation (TS) data collected in a period next to each MRI. The mean number of phlebotomies between MRIs was seven for each patient. The mean interval between MRIs was 25.6 months (maximum of 66 and minimum of 12). On the first MRI, four patients presented liver iron overload (80%) and 1 did not (20%); the iron overload was severe in all four patients. On the second MRI, all patients with iron overload in the first showed a large reduction to mild overload in the deposits. The only patient who did not have it continued without an iron deposit in the liver. No patient had pancreatic iron deposits at the first or second MRI. One patient initially presented a splenic deposit (20%), which was not evidenced in the second. One liver (20%) had mild hepatic steatosis at the first MRI, which remained mild at the second. No patient developed steatosis during the study period. The mean serum ferritin on the first MRI period was 521.1 (minimum of 139 and maximum of 1000); over the second MRI, the average was 218.4 (minimum of 83 and maximum of 401). All patients showed a reduction in serum ferritin between images. The average reduction was 46.8% (minimum of 5.0% and maximum of 86.5%). The average TS in the first MRI period was 38.35% (minimum of 23% and maximum of 53%) and in the second, 37.47% (minimum of 25% and maximum of 42%). Three patients (60%) had an increase in TS, despite a decrease in serum ferritin. All patients had values within the normal range for ALT and AST in the study period. : Liver iron overload is one of the most serious complications of hereditary hemochromatosis since it is one of the main iron storage organs and the first one to show iron overload. It mayslowly lead to irreversible hepatic damage, such as cirrhosis, or even hepatocellular carcinoma, in addition to multiple organ complications. Measurement of the liver concentration of iron may guide physicians to have better decisions regarding when to initiate or stop therapeutic phlebotomy as a therapy in hereditary hemochromatosis. MRI R2* can be used for detection and quantification of liver iron content, being proposed as a non-invasive method to guide therapy. However, the exact correlation between liver iron content, number, and interval of phlebotomies prescribed, and laboratory findings are not yet well established. : Periodic phlebotomy demonstrated to be an efficient way to reduce body overload, especially liver deposits, as seen in MRI R2* images. In agreement with the literature, the liver accumulates iron before other abdominal organs, such as the pancreas and spleen. Serum ferritin appears to be a better marker for liver iron overload reduction in patients undergoing phlebotomy for hereditary hemochromatosis than transferrin saturation.