Iron metabolism and hematological abnormalities in adult patients affected with mucopolysaccharidoses

Mucopolysaccharidoses are a heterogeneous group of rare lysosomal storage disorders (LSDs) caused by genetic mutations resulting in the deficiency of lysosomal enzymes responsible for the degradation of glycosaminoglycans (GAGs). The potential association of hematological abnormalities and clinical manifestations in MPS disorder highlights the importance of exploring the role of regular iron studies and hematological tests in at risk MPS patients as undiagnosed anemia has been shown to worsen clinical outcomes. In this study, therefore, we aimed to describe the hematological abnormalities and iron studies in adult patients with MPS disorders in the context of their therapies. Ninety-seven patients with MPS types I, II, III, IV and VI were included in the study (46 % females). The overall prevalence of iron deficiency anemia is 38 % in adult MPS cohort and affects 63 % of MPS III and 50 % of MPS I patients. It is more common in females with MPS I and IVA than males, post cardiac valve surgery and in patients with gastrointestinal dysfunction. There was high variability in Hb, mean corpuscular volume, serum iron and transferrin saturation among all the MPS subgroups, with results being higher in the HSCT and ERT group as compared to treatment naïve patients. The urine GAGs/creatine ratio negatively correlated with several critical parameters, including iron saturation (-0.07), serum iron (-0.06), Hb (-0.16), and hematocrit (-0.08). It was more pronounced among MPS III patients. Pancytopenia in treatment naive MPS III is associated with 7 to 20 fold increase of urine GAGs excretion. It is important to take into consideration hematological and iron study abnormalities in the management of MPS patients, as special approaches may be required for both intestinal health and anemia treatment.