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Congenital analbuminaemia (CAA) is a rare autosomal recessive disorder in which affected individuals have absent or extremely low levels of serum albumin. Adults with this condition are mostly asymptomatic. To the best of our knowledge this is the first case of congenital analbuminaemia reported in Pakistan. While being treated for acute respiratory tract infection, a very low albumin level was incidentally detected. This lead to further investigations and eventually the diagnosis was made. The complication of hyperlipidaemia associated with this disease was present in our patient. However, with subsequent treatment by intravenous albumin infusion, the serum albumin level and hyperlipidaemia improved. In this case report, we highlight the importance of diagnosing and treating this condition in adults at an early stage. This prevents complications that have been known to occur in this disease which include hypercholesterolaemia, hyperlipidaemia and recurrent respiratory tract infections. Rarely, it may be complicated by hypercoagulability and osteoporosis.
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Hipoalbuminemia , Albumina Sérica , Adulto , Humanos , Hipoalbuminemia/diagnóstico , PaquistãoRESUMO
A 20-year-old, female, red-lored Amazon parrot (Amazona autumnalis) was presented for a 2-week history of weakness. On physical examination, the bird was quiet, fluffed, weak, and had a distended coelom. Radiographic and ultrasound imaging revealed coelomic distention, increased pulmonary parenchymal opacity, renomegaly, dilated intestines, and a thickened ventricular wall. The results of a complete blood cell count indicated the patient was anemic (28%) and had intermediate to large lymphocytes with immature chromatin that were suspected to be neoplastic. Immunocytochemistry on peripheral blood determined that the suspected circulating neoplastic cells were cluster of differentiation (CD) 3+ and occasionally expressed multiple myeloma oncogene 1 (MUM1). Abnormalities from a plasma biochemistry panel were moderate hyperphosphatemia (6.8 mg/dL), marked hyperproteinemia (13.6 g/L), analbuminemia (0 g/dL), and marked hyperglobulinemia (13.6 g/dL). Agarose gel plasma protein electrophoresis documented the presence of albumin (1.2 g/dL) and monoclonal bands which, on reduced lithium dodecyl sulfate polyacrylamide gel electrophoresis, resolved as 60-kd and â¼25-kd bands consistent with immunoglobulin Y heavy and light chains. On the basis of these findings, multiple myeloma was diagnosed. Because of a poor prognosis, the bird was euthanized for postmortem examination. Bone marrow cytology from samples collected during the postmortem examination revealed 17.4% plasma cells and 24% large immature cells with occasional plasmacytoid features. Histopathologic findings included aggregates of neoplastic plasma cells in the bone marrow, spleen, kidney, liver, gastrointestinal tract, muscle, ovary, and brain. The neoplastic cells were strongly immunoreactive for MUM1 and cluster of differentiation 3 (CD3), but negative for CD79a, paired box protein 5, and CD20. This confirmed the clinical diagnosis of multiple myeloma. This report describes an avian immunoglobulin Y-secreting multiple myeloma with aberrant CD3 expression and pseudoanalbuminemia. Aberrant CD3 expression by avian multiple myeloma may explain previously published cases of birds with a monoclonal gammopathy and apparent T-cell lymphoma diagnosed by CD3 immunoreactivity.
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Amazona , Mieloma Múltiplo , Psittaciformes , Feminino , Animais , Mieloma Múltiplo/veterinária , Rim , FígadoRESUMO
Bisalbuminemia is a rare, typically benign condition marked by the presence of a bifid albumin band on serum protein electrophoresis. It can either be inherited due to a point mutation or acquired in association with various medical conditions, most commonly diabetes mellitus. Bisalbuminuria, the presence of bifid albumin in urine, may or may not accompany bisalbuminemia. Both conditions are often discovered incidentally during screening for monoclonal gammopathy. Bisalbuminemia and related variants provide insights into albumin's genetic diversity and functional roles, influencing clinical diagnostics and research in human genetics. Understanding these variants aids in distinguishing benign conditions from potential disease states, guiding appropriate clinical management. In this case-based review, we present a case of hereditary bisalbuminemia identified unexpectedly during an investigation of a positive Direct Antiglobulin Test Coombs in an adult female patient. This review aims to highlight the key features of bisalbuminemia, a rare condition that should be recognized by clinicians.
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A 20-year-old male presented with severe elevation in low-density lipoprotein cholesterol (LDL-C). Initial genetic testing for familial hypercholesterolemia was negative. Patient also had low albumin, and further genetic testing showed homozygous variants in the ALB gene, suggesting congenital analbuminemia (CAA) causing severe hyperlipidemia. CAA is an autosomal recessive disorder with incidence of about 1:1,000,000. The gene for albumin is a single autosomal gene, and pathological variants that affect splicing lead to premature stop, nonsense variants, and deletions that result in a defect in albumin synthesis with CAA. CAA can be fatal in the prenatal period and cause infections in early childhood. CAA is tolerated better in adulthood because of compensatory increase in other plasma proteins. Plasma lipoproteins also increase, and CAA can cause gross hyperlipidemia with severe elevations in LDL-C and hypercholesterolemia. Genetic examination of ALB is mandatory to establish the diagnosis. Early diagnosis may be important to initiate lipid-lowering treatments to avoid premature coronary artery disease.
Assuntos
Hipercolesterolemia , Hiperlipidemias , Pré-Escolar , Masculino , Humanos , Adulto Jovem , Adulto , Hipercolesterolemia/genética , LDL-Colesterol , Albuminas , Rim/fisiologiaRESUMO
Congenital analbuminemia (CAA) is a very rare genetic disorder characterized by a significant reduced or even complete absence of human serum albumin. Our data describe the clinical features and laboratory results of a case confirmed by mutation analysis of the albumin gene in a 35-year-old man presenting recurrent acute coronary syndrome. To the best of our knowledge, only two cases of coronary artery disease have been reported worldwide without recurrence. Our findings contribute to shed light on the clinical characteristics and biochemical parameters of this disease and confirm that cardiovascular complications must be taken seriously in this pathology. Mutational screening disclosed two novel compound heterozygous nucleotide variations located in intron 12 and in 3'UTR. The prediction of the functional and structural impact of the reported variations using different bioinformatics tools demonstrates that these genetics variations affect RNA transcription and mRNA folding.
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Trombose Coronária , Hipoalbuminemia , Masculino , Humanos , Adulto Jovem , Adulto , Albumina Sérica , Nucleotídeos , Trombose Coronária/complicações , Albumina Sérica Humana/genética , Hipoalbuminemia/complicações , Hipoalbuminemia/diagnóstico , Hipoalbuminemia/genética , MutaçãoRESUMO
Serum albumin facilitates the transport of free fatty acids (FFAs) from adipose tissue to other organs. It was not known if impeding this process could protect from hepatic steatosis and metabolic dysfunction in obesity. We tested whether albumin knockout (Alb-/-) mice would exhibit a reduction in plasma FFA concentration, reduced hepatic lipid accumulation, and improved glucoregulation as compared to wild-type (WT) mice. Male homozygous albumin knockout mice (Alb-/-) and WT controls were fed a low-fat diet (LFD) or high-fat diet (HFD). Alb-/- mice exhibited a similar body weight gain and body composition as WT on both diets. Despite HFD-induced obesity, Alb-/- mice were protected from various comorbidities. Compared to WT mice on the HFD, Alb-/- exhibited lower plasma FFA levels, lower blood glucose levels during glucose tolerance and insulin tolerance tests, and lower hepatic steatosis and inflammation. Alb-/- mice on HFD also exhibited elevated expression of multiple genes in the liver and adipose tissues, such as peroxisome proliferator-activated receptor α in both tissues, as well as glucose transporter-4 and adiponectin in adipose tissues. The results indicate that albumin's FFA transport function may be involved in the development of hepatic lipid accumulation and dysregulated glucose metabolism in obesity.
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Fígado Gorduroso , Obesidade , Masculino , Animais , Camundongos , Obesidade/etiologia , Fígado Gorduroso/etiologia , Dieta Hiperlipídica/efeitos adversos , Albumina Sérica , Modelos Animais de Doenças , Glucose , LipídeosRESUMO
Albumin, a serum transport protein, provides 80% of colloid osmotic pressure. Congenital analbuminemia (CAA) is an autosomal recessive disorder characterized by absence of serum albumin. Fifty cases of CAA have been reported throughout the world; however, little is known about its clinical impact. Most reported cases have few clinical signs and symptoms. Twelve local cases from the northwestern central plains region in Saskatchewan were identified and reviewed to ascertain morbidity and mortality related with CAA. All the cases are from two remote First Nations communities. Cases had frequent hospital admissions and recurrent respiratory tract infections. Placental abnormalities included hydropic placentas, placental infarcts and microcalcifications. One-half of the cases were born preterm and one-quarter were small for their gestational age. There were three mortalities in the case series. The present case series suggests increased morbidity and mortality during infancy in patients with CAA. The long-term risks of CAA in this population are unknown and a longitudinal study is recommended.
L'albumine, une protéine du transport sérique, fournit 80 % de la pression colloïdo-osmotique. L'analbuminémie congénitale (AAC) est un trouble autosomique récessif caractérisé par l'absence d'albumine sérique. Cinquante cas d'AAC ont été signalés dans le monde, mais on ne sait pas grand-chose de ses répercussions cliniques. La plupart des cas déclarés s'associaient à peu de signes et symptômes cliniques. Les chercheurs ont dépisté 12 cas locaux, originaires de la région du nord-ouest des plaines centrales, en Saskatchewan, et les ont analysés afin de déterminer la morbidité et la mortalité liées à l'AAC. Tous les cas provenaient de deux communautés éloignées des Premières nations. Ils étaient souvent hospitalisés et avaient des infections respiratoires récurrentes. Les anomalies placentaires incluaient des placentas hydropiques, des infarctus placentaires et des microcalcifications. La moitié des cas étaient prématurés et le quart d'entre eux étaient petits par rapport à leur âge gestationnel. Trois mortalités ont été constatées. Cette série a démontré une augmentation de la morbidité et de la mortalité pendant l'enfance chez les patients ayant une AAC. On ne connaît pas les risques à long terme de l'AAC au sein de cette population. Une étude longitudinale est recommandée.
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Circulating albumin is expected to play a significant role in the trafficking of plasma free fatty acids (FFA) between tissues, such as FFA transfer from adipose tissue to the liver. However, it was not yet known how disrupting FFA binding to albumin in circulation would alter lipid metabolism and any resulting impacts upon control of glycemia. To improve understanding of metabolic control, we aimed to determine whether lack of serum albumin would decrease plasma FFA, hepatic lipid storage, whole body substrate oxidation, and glucose metabolism. Male and female homozygous albumin knockout mice and C57BL/6J wild type controls, each on a standard diet containing a moderate fat content, were studied at 6-8 weeks of age. Indirect calorimetry, glucose tolerance testing, insulin tolerance testing, exercise performance, plasma proteome, and tissue analyses were performed. In both sexes of albumin knockout mice compared to the wild type mice, significant reductions (p < 0.05) were observed for plasma FFA concentration, hepatic triacylglycerol and diacylglycerol content, blood glucose during the glucose tolerance test, and blood glucose during the insulin tolerance test. Albumin deficiency did not reduce whole body fat oxidation over a 24-h period and did not alter exercise performance in an incremental treadmill test. The system-level phenotypic changes in lipid and glucose metabolism were accompanied by reduced hepatic perilipin-2 expression (p < 0.05), as well as increased expression of adiponectin (p < 0.05) and glucose transporter-4 (p < 0.05) in adipose tissue. The results indicate an important role of albumin and plasma FFA concentration in lipid metabolism and glucoregulation.
Assuntos
Ácidos Graxos não Esterificados , Resistência à Insulina , Albuminas/metabolismo , Animais , Glicemia/metabolismo , Feminino , Insulina , Metabolismo dos Lipídeos/genética , Fígado/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos KnockoutRESUMO
Analbuminemia is a rare autosomal recessive disorder manifested by the absence, or severe reduction, of circulating serum albumin (ALB). We report here a new case diagnosed in a 45 years old man of Southwestern Asian origin, living in Switzerland, on the basis of his low ALB concentration (0.9 g/L) in the absence of renal or gastrointestinal protein loss, or liver dysfunction. The clinical diagnosis was confirmed by a mutational analysis of the albumin (ALB) gene, carried out by single-strand conformational polymorphism (SSCP), heteroduplex analysis (HA), and DNA sequencing. This screening of the ALB gene revealed that the proband is homozygous for two mutations: the insertion of a T in a stretch of eight Ts spanning positions c.1289 + 23-c.1289 + 30 of intron 10 and a c.802 G > T transversion in exon 7. Whereas the presence of an additional T in the poly-T tract has no direct deleterious effect, the latter nonsense mutation changes the codon GAA for Glu244 to the stop codon TAA, resulting in a premature termination of the polypeptide chain. The putative protein product would have a length of only 243 amino acid residues instead of the normal 585 found in the mature serum albumin, but no evidence for the presence in serum of such a truncated polypeptide chain could be obtained by two dimensional electrophoresis and western blotting analysis.
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Códon sem Sentido , Patologia Molecular/métodos , Albumina Sérica/deficiência , Albumina Sérica/genética , Povo Asiático/genética , Éxons , Análise Heteroduplex , Humanos , Masculino , Pessoa de Meia-Idade , Polimorfismo Conformacional de Fita Simples , Análise de Sequência de DNA , SuíçaRESUMO
Congenital analbuminemia (CAA) is a very rare disorder with an estimated prevalence of less than one in one million. This anomaly can be lethal at birth and in early infancy but it's not very symptomatic in adulthood. The clinical signs are edema, lipodystrophy, fatigue Hypercholesterolemia is the main biological disorder and it predisposes to cardiovascular complications. The mild symptoms of CAA leads to delay diagnosis. That's why clinical and biological signs of this disorder should be known by both of biologist and clinician to establish an early diagnosis in order to prevent cardiovascular complications. We report a new case of congenital analbuminemia complicated by recurrent acute coronary artery disease in 34-year-old man. This complication has been reported only once according to the register of analbuminemia cases.
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Síndrome Coronariana Aguda , Hipoalbuminemia , Doença Aguda , Adulto , Humanos , Recém-Nascido , Masculino , RecidivaRESUMO
BACKGROUND AND AIMS: Congenital analbuminemia is a rare autosomal recessive inherited disorder characterized by strongly decreased concentration, or complete absence, of serum albumin (SA). Several lines of evidence indicate that SA has anti-thrombotic effect. In vivo platelet function and the role of oxidative stress (OS) in platelet aggregation promotion have never been studied in analbuminaemic patients. PATIENTS AND METHODS: We report two cases of congenital analbuminemia in a 38-year-old male and in a 67-year-old woman. We analyzed platelet activation (PA) and OS at baseline and 2 h after 40 g human albumin infusion. PA was evaluated as platelet aggregation, sCD40L and surface αIIbß3 integrin and P-selectin expression. OS was evaluated measuring serum sNOX2dp, and 8-iso-PGF2α. FINDINGS: Analbuminemic patients displayed higher platelet aggregation, markers of PA and of OS. Albumin infusion reduced platelet activation by reducing oxidative stress.
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Hipoalbuminemia , Adulto , Idoso , Plaquetas , Feminino , Humanos , Masculino , Estresse Oxidativo , Ativação Plaquetária , Albumina Sérica , Albumina Sérica HumanaRESUMO
INTRODUCTION AND OBJECTIVES: Congenital analbuminaemia (CCA) (MIM #616000) is an autosomal recessive disorder (prevalence < 1/106) caused by defects in the ALB gene leading to absence or severe reduction of albuminaemia. This paper describes a case of CCA detected and diagnosed in our hospital. MATERIALS AND METHODS: A 42-year old woman showing hypoproteinaemia and hypoalbuminaemia of unknown aetiology. Biochemical study was performed according to routine quality controlled analytical procedures: Albuminaemia (colorimetric and nephelometric methods). Protein electrophoresis (capillary and agarose gel). Molecular study of the ALB gene: DNA extraction, PCR amplification of the 14 coding exons plus adjacent intron regions and Sanger sequencing. RESULTS: After discarding the most common causes of hypoalbuminaemia, the analbuminaemia was confirmed by nephelometry and protein electrophoresis. The proband was found to be homozygous for molecular defect in the ALB gene: variant c.1289+1G>A previously reported as Guimarães variant. CONCLUSIONS: This is the first case of CCA confirmed by molecular study in Spain. The proband shows the Guimarães variant previously described in 4 patients worldwide.
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Hipoalbuminemia , Adulto , Éxons , Feminino , Homozigoto , Humanos , Hipoalbuminemia/genética , Albumina Sérica , EspanhaRESUMO
BACKGROUND: Congenital analbuminemia (CAA) is a very rare disorder. Our data describes the clinical features and laboratory results of a new case established by mutation analysis of the albumin gene in a 39-year-old woman presenting with hypercholesterolemia. Our findings contribute to shed light on the molecular genetics of the disorder and confirm that safe and well tolerated hypocholesterolemic treatment with atorvastatin may be administered in dislipidemic patient with CAA in order to reduce their cardiovascular risk. CASE SUMMARY: Our patient presented with a history of hypercholesterolemia and referred asthenia and heaviness in both legs. She was born from healthy and non-consanguineous parents and her development was normal. She had not familiarity for early cardiovascular disease, and did not report personal history of hypertension, chronic kidney or liver diseases. Clinical laboratories results showed critically reduced value of albumin whereas other serum proteins were elevated. Main causes of hypoalbuminemia (proteinuria, inflammatory state and insufficient hepatic synthesis) were ruled out by normal procedures and laboratory tests. So the hypothesis of a CAA was tested through mutation analysis of the albumin gene that revealed a homozygous CA deletion in exon 12, at nucleotide positions c1614-1615. This finding brought to the diagnosis of CAA. Currently the patient receives Atorvastatin 20 mg od and undergoes clinical and laboratory follow-up every six months. She never needed albumin infusions. CONCLUSION: Our experience shows how treatment with atorvastatin may be safely administered and well tolerated in patients affected by CAA.
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Congenital analbuminemia (OMIM # 616000) is an extremely rare autosomal recessive disorder, caused by variations in the albumin gene (ALB), which is generally thought to be a relatively benign condition in adulthood, but seems to be potentially life threatening in the pre- and peri-natal period. The subject of our study was a consanguineous family, in which we identified two analbuminemic individuals. Mutation analysis of ALB revealed that both are homozygous for a previously unreported insertion in exon 9 (c.1098dupT), causing a subsequent frame-shift with the generation of a premature stop codon, and an aberrant truncated putative protein product, p.Val367fsTer12. This variation is present in heterozygous condition in several other members of the family. The phenotype and the molecular genetics of CAA are discussed.
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Hipoalbuminemia/genética , Mutação , Albumina Sérica Humana/genética , Adulto , Idoso , Códon de Terminação , Consanguinidade , Feminino , Humanos , Hipoalbuminemia/patologia , Masculino , Linhagem , FenótipoRESUMO
Congenital analbuminemia (CAA) is an inherited, autosomal recessive disorder with an incidence of 1:1,000,000 live birth. Affected individuals have a strongly decreased concentration, or complete absence, of serum albumin. The trait is usually detected by serum protein electrophoresis and immunochemistry techniques. However, due to the existence of other conditions in which the albumin concentrations are very low or null, analysis of the albumin (ALB) gene is necessary for the molecular diagnosis. CAA can lead to serious consequences in the prenatal period, because it can cause miscarriages and preterm birth, which often is due to oligohydramnios and placental abnormalities. Neonatally and in early childhood the trait is a risk factor that can lead to death, mainly from fluid retention and infections in the lower respiratory tract. By contrast, CAA is better tolerated in adulthood. Clinically, in addition to the low level of albumin, the patients almost always have hyperlipidemia, but they usually also have mild oedema, reduced blood pressure and fatigue. The fairly mild symptoms in adulthood are due to compensatory increment of other plasma proteins. The condition is rare; clinically, only about 90 cases have been detected worldwide. Among these, 53 have been studied by sequence analysis of the ALB gene, allowing the identification of 27 different loss of function (LoF) pathogenic variants. These include a variant in the start codon, frame-shift/insertions, frame-shift/deletions, nonsense variants, and variants affecting splicing. Most are unique, peculiar for each affected family, but one, a frame-shift deletion called Kayseri, has been found to cause about one third of the known cases allowing to presume a founder effect. This review provides an overview of the literature about CAA, about supportive and additional physiological and pharmacological information obtained from albumin-deficient mouse and rat models and a complete and up-to-date dataset of the pathogenic variants identified in the ALB gene.
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Congenital analbuminemia is an autosomal recessive disorder, in which albumin, the major blood protein, is present only in a minute amount. The condition is a rare allelic heterogeneous defect, only about seventy cases have been reported worldwide. To date, more than twenty different mutations within the albumin gene have been found to cause the trait. In our continuing study of the molecular genetics of congenital analbuminemia, we report here the clinical and biochemical findings and the mutation analysis of the gene in two Turkish infants. For the molecular analysis, we used our strategy, based on the screening of the gene by single-strand conformation polymorphism, heteroduplex analysis and direct DNA sequencing. The results showed that both patients are homozygous for the deletion of a cytosine residue in exon 5, in a stretch of four cytosines starting from nucleotide position 524 and ending at position 527 (NM_000477.5(ALB):c.527delC). The subsequent frame-shift inserts a stop codon in position 215, markedly reducing the size of the predicted protein product. The parents are both heterozygous for the same mutation, for which we propose the name Erzurum from the city of origin of the family. In conclusion, our results show that in this family congenital analbuminemia is caused by a novel frame-shift/deletion defect, confirm the inheritance of the trait, and contribute to advance our understanding of the molecular basis underlying this condition.
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Mutação da Fase de Leitura/genética , Deleção de Sequência/genética , Albumina Sérica/deficiência , Albumina Sérica/genética , Adulto , Feminino , Análise Heteroduplex , Sequenciamento de Nucleotídeos em Larga Escala , Homozigoto , Humanos , Lactente , Masculino , Linhagem , TurquiaRESUMO
Albumin is a large, highly abundant protein circulating in the blood stream which is regulated and actively recycled via the neonatal Fc receptor (FcRn). In humans this results in serum albumin having an exceptional long half-life of ~21 days. Some time ago it was realized that these intrinsic properties could be harnessed and albumin could be used as a privileged drug delivery vehicle. However, active development of albumin based therapeutics has been hampered by the lack of economic, relevant experimental models which can accurately recapitulate human albumin metabolism and pharmacokinetics. In mice for example, introduced human albumin is not recycled and is catabolized rapidly. This is mainly due to the failure of mouse FcRn to bind human albumin consequently, human albumin has a half-life of only 2-3 days in mice. To overcome this we developed and characterized a humanized mouse model which is null for mouse FcRn and mouse albumin, but is transgenic for, and expressing functional human FcRn. Published data clearly demonstrate that upon injection of human albumin into this model animal that it accurately recapitulates human albumin FcRn dependent serum recycling, with human albumin now having a half-life ~24 days, closely mimicking that observed in humans. In this practical review we briefly review this model and outline its use for pharmacokinetic studies of human albumin.
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Antígenos de Histocompatibilidade Classe I/metabolismo , Modelos Animais , Receptores Fc/metabolismo , Albumina Sérica Humana/farmacocinética , Animais , Técnicas de Inativação de Genes , Meia-Vida , Antígenos de Histocompatibilidade Classe I/genética , Humanos , Camundongos , Receptores Fc/genética , Albumina Sérica Humana/administração & dosagemRESUMO
Serum albumin is the major determinant of blood colloidal osmotic pressure acting as a depot and distributor of compounds including drugs. In humans, serum albumin exhibits an unusually long half-life mainly due to protection from catabolism by neonatal Fc receptor (FcRn)-mediated recycling. These properties make albumin an attractive courier of therapeutically-active compounds. However, pharmaceutical research and development of albumin-based therapeutics has been hampered by the lack of appropriate preclinical animal models. To overcome this, we developed and describe the first mouse with a genetic deficiency in albumin and its incorporation into an existing humanized FcRn mouse model, B6.Cg-Fcgrt(tm1Dcr) Tg(FCGRT)32Dcr/DcrJ (Tg32). Albumin-deficient strains (Alb(-/-)) were created by TALEN-mediated disruption of the albumin (Alb) gene directly in fertilized oocytes derived from Tg32 mice and its non-transgenic background control, C57BL/6J (B6). The resulting Alb(-/-) strains are analbuminemic but healthy. Intravenous administration of human albumin to Tg32-Alb(-/-) mFcRn(-/-) hFcRn(Tg/Tg)) mice results in a remarkably extended human albumin serum half-life of â¼24 days, comparable to that found in humans, and in contrast to half-lives of 2.6-5.8 d observed in B6, B6-Alb(-/-) and Tg32 strains. This striking increase can be explained by the absence of competing endogenous mouse albumin and the presence of an active human FcRn. These novel albumin-deficient models provide unique tools for investigating the biology and pathobiology of serum albumin and are a more appropriate rodent surrogates for evaluating human serum albumin pharmacokinetics and albumin-based compounds.
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Modelos Biológicos , Albumina Sérica/farmacologia , Albumina Sérica/farmacocinética , Animais , Meia-Vida , Humanos , Camundongos , Camundongos Knockout , Albumina Sérica/genéticaRESUMO
INTRODUCTION: Congenital analbuminemia is a rare autosomal recessive disorder manifested by the presence of a very low amount of circulating serum albumin. It is an allelic heterogeneous defect, caused by variety of mutations within the albumin gene in homozygous or compound heterozygous state. Herein we report the clinical and molecular characterization of a new case of congenital analbuminemia diagnosed in a female newborn of consanguineous (first degree cousins) parents from Ankara, Turkey, who presented with a low albumin concentration (< 8 g/L) and severe clinical symptoms. MATERIALS AND METHODS: The albumin gene of the index case was screened by single-strand conformation polymorphism, heteroduplex analysis, and direct DNA sequencing. The effect of the splicing mutation was evaluated by examining the cDNA obtained by reverse transcriptase - polymerase chain reaction (RT-PCR) from the albumin mRNA extracted from proband's leukocytes. RESULTS: DNA sequencing revealed that the proband is homozygous, and both parents are heterozygous, for a novel G>A transition at position c.1652+1, the first base of intron 12, which inactivates the strongly conserved GT dinucleotide at the 5' splice site consensus sequence of this intron. The splicing defect results in the complete skipping of the preceding exon (exon 12) and in a frame-shift within exon 13 with a premature stop codon after the translation of three mutant amino acid residues. CONCLUSIONS: Our results confirm the clinical diagnosis of congenital analbuminemia in the proband and the inheritance of the trait and contribute to shed light on the molecular genetics of analbuminemia.
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Processamento Alternativo/genética , Hipoalbuminemia/congênito , Hipoalbuminemia/genética , Mutação/genética , Albumina Sérica/genética , Adolescente , Adulto , Sequência de Bases , Feminino , Análise Heteroduplex , Humanos , Recém-Nascido , Masculino , Pessoa de Meia-Idade , Dados de Sequência Molecular , Linhagem , Polimorfismo Conformacional de Fita Simples , Albumina Sérica/deficiência , Albumina Sérica Humana , Adulto JovemRESUMO
Congenital analbuminemia is a rare autosomic recessive inherited disorder characterized by low plasma albumin and hypercholesterolemia, which may increase cardiovascular risk. Patients are essentially asymptomatic, apart from ease of fatigue, minimal ankle oedema and hypotension. There is no accepted strategy for safely treating both hypercholesterolemia and analbuminemia in order to eventually decrease the atherosclerotic risk. We report a case of congenital analbuminemia (1.0 g/dL) in a 38-year-old male with hypercholesterolemia (range: 406-475 mg/dL) and severe arterial dysfunction [no brachial artery flow-mediated dilation (FMD)]. Long-term, cholesterol-lowering treatment with atorvastatin was associated with the appearance of peripheral edema. Two-months of infusion with albumin improved FMD (7%) and reduced serum cholesterol (273 mg/dL), supporting the hypothesis of a compensatory role of hypercholesterolemia. Statin treatment, together with periodical albumin infusions, may contribute to the safe reduction of cardiovascular risk.