Late onset diabetes mellitus in patients with hereditary aceruloplasminemia

Aceruloplasminemia: A Case Report and Review of a Rare and Misunderstood Disorder of Iron Accumulation

Aceruloplasminemia is a rare disorder of iron accumulation inherited in an autosomal recessive fashion. It commonly presents as chronic microcytic anemia, and then progresses to signs and symptoms that are due to the accumulation of iron in multiple organs such as the brain, liver, pancreas, and thyroid. We present an asymptomatic patient with a history of microcytic anemia, who was evaluated for abnormal liver enzymes, and ultimately diagnosed with aceruloplasminemia.

Ablation of hephaestin and ceruloplasmin results in iron accumulation in adipocytes and type 2 diabetes

Little is known about the iron efflux mechanism in adipocytes. Here, we used hephaestin (Heph) and ceruloplasmin (Cp) single-knockout (KO) mice and Heph/Cp double-KO mice to investigate the roles of multicopper ferroxidases (MCFs) in this process. We show that both HEPH and CP are expressed in subcutaneous adipose tissue. Ablation of either MCF leads to a compensatory increase in the other, which contributes to the balance of iron status. However, ablation of both MCFs together induces severe iron deposition in adipocytes which is associated with decreased adiponectin and leptin mRNA expression. Furthermore, Heph/Cp KO mice display disordered carbohydrate metabolism characterized as type 2 diabetes. Together, these results demonstrate the protective roles of HEPH and CP in preventing iron overload in adipocytes.

Neurodegeneration With Brain Iron Accumulation (NBIA) Syndromes Presenting With Late-Onset Craniocervical Dystonia: An Illustrative Case Series‎

Neurodegeneration with brain iron accumulation (NBIA) mostly has its disease onset in childhood, adolescence, or early adulthood and usually presents with predominant bulbar and axial dystonia along with signs such as spasticity, indicating an involvement of additional neurological systems. Because of their early onset and presentation with a combination of dystonia plus other neurological symptoms, they are usually not considered as differential diagnosis for late-onset isolated (idiopathic) craniocervical dystonia. In this case series, we present 4 genetically proven cases of NBIA (including neuroferritinopathy, pantothenate-kinase-associated neurodegeneration, and aceruloplasminemia) with late disease onset, which resembled isolated adult-onset craniocervical dystonia at disease onset. We also want to highlight the importance of taking NBIA into consideration when dealing with putatively isolated late-onset dystonias and of picking up unusual signs at later stages of the disease.

Criteria for early identification of aceruloplasminemia

A 52-year-old Japanese woman being treated for type 1 diabetes showed forgetfulness and microcytic anemia with a high serum ferritin concentration. Serum and brain radiological examinations revealed aceruloplasminemia, which was confirmed by genetic testing. Aceruloplasminemia is characterized by the triad of retinal degeneration, diabetes mellitus, and adult-onset disorder of the extrapyramidal system. Though physicians should treat such patients earlier, it is difficult to diagnose the disease before the presentation of neurological symptoms. Despite the presence of microcytic anemia, aceruloplasminemia patients usually have a high serum ferritin concentration due to the complete absence of ceruloplasmin ferroxidase activity. Thus, physicians should consider aceruloplasminemia when diabetic patients present with microcytic anemia and a high serum ferritin concentration.

T2* and FSE MRI distinguishes four subtypes of neurodegeneration with brain iron accumulation

BACKGROUND

Neurodegeneration with brain iron accumulation (NBIA) defines a group of genetic disorders characterized by brain iron deposition and associated with neuronal death. The known causes of NBIA include pantothenate kinase-associated neurodegeneration (PKAN), neuroferritinopathy, infantile neuroaxonal dystrophy (INAD), and aceruloplasminemia.

OBJECTIVE

To define the radiologic features of each NBIA subtype.

METHODS

Brain MRIs from patients with molecularly confirmed PKAN (26 cases), neuroferritinopathy (21 cases), INAD (four cases), and aceruloplasminemia (10 cases) were analyzed blindly to delineate patterns of iron deposition and neurodegeneration.

RESULTS

In most cases of PKAN, abnormalities were restricted to globus pallidus and substantia nigra, with 100% having an eye of the tiger sign. In a minority of PKAN cases there was hypointensity of the dentate nuclei (1/5 on T2* sequences, 2/26 on fast spin echo [FSE]). In INAD, globus pallidus and substantia nigra were involved on T2* and FSE scans, with dentate involvement only seen on T2*. By contrast, neuroferritinopathy had consistent involvement of the dentate nuclei, globus pallidus, and putamen, with confluent areas of hyperintensity due to probable cavitation, involving the pallida and putamen in 52%, and a subset having lesions in caudate nuclei and thalami. More uniform involvement of all basal ganglia and the thalami was typical in aceruloplasminemia, but without cavitation.

CONCLUSIONS

In the majority of cases, different subtypes of neurodegeneration associated with brain iron accumulation can be reliably distinguished with T2* and T2 fast spin echo brain MRI, leading to accurate clinical and subsequent molecular diagnosis.

Early onset insulin-dependent diabetes mellitus as an initial manifestation of aceruloplasminaemia

BACKGROUND

Aceruloplasminaemia is an autosomal recessive disorder caused by specific mutations in the ceruloplasmin gene. Aceruloplasminaemia is clinically characterized by diabetes mellitus, pigment degeneration of the retina, and neurological abnormalities, such as cerebellar ataxia, extrapyramidal signs, and dementia. We present a patient with aceruloplasminaemia who, until progressive neurological abnormalities were noticed, had been treated for more than 30 years as having Type 1 diabetes mellitus requiring multiple insulin injection therapy.

CASE REPORT

The patient was a 58-year-old man. At the age of 23 years, he developed diabetes that required multiple insulin injection therapy. At the age of 39 years, he was commenced on continuous subcutaneous insulin infusion (CSII) therapy. Despite CSII therapy, the patient's blood glucose levels were poorly controlled (HbA(1c), approximately 9.5%). He was diagnosed as having aceruloplasminaemia at 58 years of age when he presented with progressive cerebellar ataxia, extrapyramidal signs of recent onset and pigment degeneration of the retina.

CONCLUSIONS

It is possible that some diabetic patients with aceruloplasminaemia are mistakenly diagnosed as having Type 1 diabetes mellitus, as they have reduced insulin secretion and develop diabetes at a younger age, before neurological abnormalities associated with aceruloplasminaemia are apparent. Therefore, aceruloplasminaemia should be considered in patients with insulin-dependent diabetes mellitus who develop progressive neurological abnormalities of unknown aetiology along with a microcytic hypochromic anaemia and retinal degeneration.

Aceruloplasminemia, an iron metabolic disorder

Aceruloplasminemia is an inherited disorder of iron metabolism caused by the complete lack of ceruloplasmin ferroxidase activity caused by mutations in the ceruloplasmin gene. It is characterized by iron accumulation in the brain as well as visceral organs. Clinically, the disease consists of the triad of adult-onset neurologic disease, retinal degeneration and diabetes mellitus. The neurological symptoms, which include involuntary movements, ataxia, and dementia, reflect the sites of iron deposition. Severe iron overload and extensive neuronal loss were observed in the basal ganglia, while iron deposition and neuronal cell loss were trivial in the frontal cortices. The cerebellar cortex showed marked loss of Purkinje cells. Iron deposition was more prominent in the astrocytes than in the neurons. Excess iron functions as a potent catalyst of biologic oxidation. Astrocytic deformity and globular structures are characteristic features in aceruloplasminemia brains. The globular structures in the astrocytes were seen in proportion to the degree of iron deposition and reacted positively to anti-4-hydroxynonenal, one of the indicators of lipid peroxidation, and anti-ubiquitin antibodies, but not to anti-alpha-synuclein antibody. The lack of ceruloplasmin may primarily damage astrocytes in the aceruloplasminemia brains through lipid peroxidation. Ceruloplasmin may play an essential role in neuronal survival in the central nervous system.

Increased lipid peroxidation and mitochondrial dysfunction in aceruloplasminemia brains

Aceruloplasminemia is characterized by iron accumulation in the brain as well as in visceral organs, due to the absence of ceruloplasmin ferroxidase activity. The neurological symptoms, which include involuntary movements, ataxia, and dementia, reflect the sites of iron deposition. The unique involvement of the central nervous system distinguishes aceruloplasminemia from other inherited and acquired iron storage disorders. Excess iron functions as a potent catalyst of biologic oxidation. An increased iron concentration was associated with increased lipid peroxidation in the brains of three aceruloplasminemia patients. Positron emission tomography showed brain glucose and oxygen hypometabolism. Enzyme activities in the mitochondrial respiratory chain of the basal ganglia were reduced to about 50 and 43%, respectively, for complexes I and IV. Those of the cerebral and cerebellar cortices also were decreased approximately 62 and 65%. These findings suggest that iron-mediated free radicals may contribute to neuronal cell damage through increased lipid peroxidation and the impairment of mitochondrial energy metabolism in aceruloplasminemia brains.

Inherited iron overload disorders

Iron is an essential nutrient that is highly toxic in excess. Normal iron balance is maintained primarily by regulation of intestinal absorption of the metal from the diet. Iron overload generally results from a chronic increase in intestinal absorption. During the past 5 years, it has become apparent that there are at least eight inherited disorders of iron metabolism characterized by the toxic accumulation of iron. This review provides an update for pediatricians on the clinical features and pathogenesis of these disorders.

Genetic disorders affecting proteins of iron metabolism: clinical implications

Remarkable progress is being made in understanding the molecular basis of disorders of human iron metabolism. Recent work has uncovered unanticipated relationships with the immune and nervous systems, intricate interconnections with copper metabolism, and striking homologies between yeast and human genes involved in the transport of transition metals. This review examines the clinical consequences of new insights into the pathophysiology of genetic abnormalities affecting iron metabolism. The proteins recently found to be involved in the absorption, transport, utilization, and storage of iron are briefly described, and the clinical manifestations of genetic disorders that affect these proteins are discussed. This chapter considers the most common inherited disorder in individuals of European ancestry (hereditary hemochromatosis), a widespread disease in sub-Saharan populations for which the genetic basis is still uncertain (African dietary iron overload), and several less frequent or rare disorders (juvenile hemochromatosis, atransferrinemia, aceruloplasminemia, hyperferritinemia with autosomal dominant congenital cataract, Friedreich's ataxia, and X-linked sideroblastic anemia with ataxia).