Acanthocytosis and the c.680 A>G Mutation in the PANK2 Gene: A Study Enrolling a Cohort of PKAN Patients from the Dominican Republic.

Pantothenate Kinase-Associated Neurodegeneration (PKAN) is a form of Neurodegeneration with Brain Iron Accumulation (NBIA) associated with mutations in the pantothenate kinase 2 gene (PANK2). Pantothenate kinases catalyze the rate-limiting step of coenzyme A synthesis and Pank2 is the only pantothenate kinase isoform in humans that is localized to mitochondria. Acanthocytosis, the occurrence of spiculated erythrocytes, is observed in about 10% of the PKAN patients. Therefore PKAN is also classified together with other rare neurodegenerative diseases like Chorea Acanthocytosis (ChAc) and McLeod syndrome (MLS) into the Neuroacanthocytosis (NA) syndromes. It has not been investigated yet whether acanthocytosis in PKAN is associated with a specific subset of Pank2 mutations. In this study, we analyzed acanthocytosis of a cohort of 25 PKAN patients from the Dominican Republic that are homozygous for the c.680 A>G mutation in the PANK2 gene as compared to control donors that are heterozygous or wild-type with respect to this mutation. 3D modeling of this mutation indicated that the replacement of a tyrosine by a cysteine at position 227 in Pank2 disrupts a polar interaction within the A domain of the enzyme. Mean acanthocyte count was elevated in the cohort of patients, however, acanthocytosis varied among the patients with nearly half of them showing high (>20%) or elevated acanthocytosis and the rest showing mild (6-10%) or no (<6%) acanthocytosis. Heterozygous control donors revealed a tendency to mild acanthocytosis. Based on the insight that Pank2 is a normal constituent of red blood cells and de novo biosynthesis of coenzyme A is likely to take place in the erythrocyte cytosol we propose a hypothetical model that accounts for the variability in the occurrence of acanthocytic cells in PKAN.

Poikilocytosis in rabbits: prevalence, type, and association with disease.

Rabbits (Oryctolagus cuniculus) are a popular companion animal, food animal, and animal model of human disease. Abnormal red cell shapes (poikilocytes) have been observed in rabbits, but their significance is unknown. The objective of this study was to investigate the prevalence and type of poikilocytosis in pet rabbits and its association with physiologic factors, clinical disease, and laboratory abnormalities. We retrospectively analyzed blood smears from 482 rabbits presented to the University of California-Davis Veterinary Medical Teaching Hospital from 1990 to 2010. Number and type of poikilocytes per 2000 red blood cells (RBCs) were counted and expressed as a percentage. Acanthocytes (>3% of RBCs) were found in 150/482 (31%) rabbits and echinocytes (>3% of RBCs) were found in 127/482 (27%) of rabbits, both healthy and diseased. Thirty-three of 482 (7%) rabbits had >30% acanthocytes and echinocytes combined. Mild to moderate (>0.5% of RBCs) fragmented red cells (schistocytes, microcytes, keratocytes, spherocytes) were found in 25/403 (6%) diseased and 0/79 (0%) healthy rabbits (P = 0.0240). Fragmentation and acanthocytosis were more severe in rabbits with inflammatory disease and malignant neoplasia compared with healthy rabbits (P<0.01). The % fragmented cells correlated with % polychromasia, RDW, and heterophil, monocyte, globulins, and fibrinogen concentrations (P<0.05). Echinocytosis was significantly associated with renal failure, azotemia, and acid-base/electrolyte abnormalities (P<0.05). Serum cholesterol concentration correlated significantly with % acanthocytes (P<0.0001), % echinocytes (P = 0.0069), and % fragmented cells (P = 0.0109), but correlations were weak (Spearman ρ <0.02). These findings provide important insights into underlying pathophysiologic mechanisms that appear to affect the prevalence and type of naturally-occurring poikilocytosis in rabbits. Our findings support the need to carefully document poikilocytes in research investigations and in clinical diagnosis and to determine their diagnostic and prognostic value.

Disease distribution in canine patients with acanthocytosis: 123 cases.

BACKGROUND: An acanthocyte is an abnormally shaped erythrocyte. In veterinary medicine, acanthocytes have historically been associated with canine hemangiosarcoma. In human medicine, acanthocytes are rarely observed with neoplastic disease and are more commonly associated with a variety of hereditary and acquired diseases. OBJECTIVES: The purpose of the study was to determine what disease processes are associated with the presence of acanthocytes in the peripheral blood of dogs. METHODS: Medical records for dogs presented to the Veterinary Teaching Hospital of Colorado State University during January 2004 through June 2008 with acanthocytes documented in their CBCs were retrospectively reviewed. RESULTS: A total of 123 dogs were included, 66 of which were diagnosed with neoplastic disease, most commonly hemangiosarcoma (n = 12), osteosarcoma (n = 11), and lymphoma (n = 11). The remaining 57 dogs had nonneoplastic disease, most commonly observed were gastrointestinal (n = 13), musculoskeletal (n = 8), renal (n = 8), and immune-mediated diseases (n = 7). No statistically significant difference was detected between percent acanthocytes present in dogs with neoplastic and nonneoplastic diseases. CONCLUSION: Acanthocytosis was observed with a variety of neoplastic and nonneoplastic diseases. While clearly commonly associated, the presence of acanthocytes in a blood smear should not be considered pathognomonic for hemangiosarcoma in dogs.

Urine erythrocyte morphology in patients with microscopic haematuria caused by a glomerulopathy.

The evaluation of urinary erythrocyte morphology (UEM) has been proposed for patients with isolated microscopic haematuria (IMH) to early orientate the diagnosis towards a glomerular or a nonglomerular disease. However, to date, the role of this test in patients with IMH has very rarely been investigated. Sixteen patients (ten children, six adults) with persistent IMH classified as glomerular on the basis of repeated UEM evaluations (55 urine samples, two to eight per patient) were submitted to renal biopsy. This showed a glomerular disease in 14/16 patients (87.5%) (nine thin basement membrane disease; three Alport syndrome; two other), whereas in two patients, no abnormalities were found. Of four microscopic criteria investigated to define a IMH as glomerular, >80% dysmorphic erythrocytes were not found in any sample, >or=40% dysmorphic erythrocytes alone were seen in seven samples (12.7%), >or=5% acanthocytes alone in 15 samples (27.3%) and erythrocytic casts in six samples (10.9%). There was >or=40% dysmorphic erythrocytes associated with >or=5% acanthocytes in 25 samples (45.5%). Sensitivity and positive predictive values in diagnosing a glomerular haematuria were 59.2% and 90.6%, respectively, for >or=40% dysmorphic erythrocytes, 69.4% and 85% for >or=5% acanthocytes/G1 cells and 12.2% and 100% for erythrocytic casts. Our findings demonstrate that the evaluation of UEM is useful to identify patients with an IMH of glomerular origin.

The McLeod syndrome without acanthocytes.

A 45-year-old man developed chorea, behavioural changes, moderate amyotrophy and polyneuropathy. Hypertrophic cardiomyopathy and increased serum lactate dehydrogenase and creatine kinase (CK) were found. Acanthocytes were not detected. The absence of XK protein and faintly expressed Kell antigens on erythrocytes were found. Genetic test revealed a R133X mutation of the XK gene, confirming the McLeod syndrome. After 7 years he suddenly developed delirium followed by severe hypoglycaemia, hyperthermia, rhabdomyolysis, hepatic and renal failure. Malignant arrhythmia caused death.

Morphology of erythrocytes of patients with ovarian cancer.

AIM OF THE STUDY: To investigate the morphology of erythrocytes in the peripheral blood of patients with ovarian cancer stage II and III. MATERIALS AND METHODS: The patient group consisted of 17 women (age 53 +/- 16 years) diagnosed with stage II or II ovarian cancer. The control group comprised 20 healthy women (age 20 +/- 2 years). Seventeen samples of peripheral venous blood were collected from the cancer patients and 20 from the healthy women. These were then prepared for observation by scanning electron microscopy. RESULTS: The percentages of knizocytes and echinocytes were higher in the blood of patients than in that of the healthy controls. For knizocytes, the values for the mean +/- SD and the range were 2.45 +/- 3.72 and 0-15.7 vs. 0.66 +/- 0.57, 0.1-2.5, with p < 0.01. For echinocytes, these values were 1.94 +/- 1.04 and 0.5-3.6 vs. 1.03 +/- 0.71, 0.1-2.6 and p < 0.01. Acanthocytes were present only in small numbers and were not evaluated. CONCLUSION: The proportion of erythrocytes with abnormal morphology in the blood of cancer patients before cancer therapy was significantly elevated as compared to that healthy controls.

Acanthocytes in the urine: useful tool to differentiate diabetic nephropathy from glomerulonephritis?

OBJECTIVE: The presence of hematuria has been suggested to indicate nondiabetic nephropathy in diabetic patients with proteinuria. However, hematuria is frequently found in patients with biopsy-proven diabetic glomerulosclerosis without nondiabetic nephropathy. Urine microscopy allows discrimination of glomerular hematuria, which is defined as acanthocyturia (urinary excretion of acanthocytes, which are dysmorphic erythrocytes with vesicle-like protrusions), from nonglomerular hematuria. We hypothesized that acanthocyturia is an uncommon finding in diabetic nephropathy, which suggests the presence of a nondiabetic nephropathy in diabetic patients with proteinuria. RESEARCH DESIGN AND METHODS: Urine samples of patients with the clinical diagnosis of diabetic nephropathy (n = 68), of patients with biopsy-proven glomerulonephritis (n = 43), and of age-matched healthy control subjects (n = 20) were examined by phase-contrast microscopy for the presence of hematuria (>/=8 erythrocytes/ micro l) and acanthocyturia. Acanthocyturia of >/=5% (5 acanthocytes among 100 excreted erythrocytes) was classified as glomerular hematuria; acanthocyturia of 2-4% was classified as suspected glomerular hematuria. RESULTS: Hematuria was found in 62% of patients with the clinical diagnosis of diabetic nephropathy, in 84% of patients with glomerulonephritis, and in 20% of the healthy control subjects upon a single urine examination. In contrast, glomerular hematuria occurred in 4% of patients with diabetic nephropathy and in 40% of patients with glomerulonephritis (P < 0.001). CONCLUSIONS: In contrast to hematuria, acanthocyturia is uncommon in patients with the clinical diagnosis of diabetic nephropathy. In diabetic patients with proteinuria, the finding of acanthocyturia points to nondiabetic glomerulopathies, and renal biopsy should be considered.

Autosomal dominant chorea-acanthocytosis with polyglutamine-containing neuronal inclusions.

BACKGROUND: The term chorea-acanthocytosis describes a heterogeneous group of neurodegenerative disorders with variable clinical features and modes of inheritance. The characteristic acanthocytic appearance of red blood cells is attributed to abnormalities of a membrane protein, band 3, although the relationship between this and the neurodegenerative process has yet to be determined. OBJECTIVE: To describe features of phenotype, inheritance, and neuropathological findings in a family with this disorder. METHODS: Clinical and hematologic evaluations were performed on all available family members and neuropathological examination was performed on one case. RESULTS: Autosomal dominant inheritance was evident, with variable clinical features of chorea or parkinsonism, marked cognitive changes, but no seizures or peripheral neurologic abnormalities. Abnormalities of band 3 were demonstrated on gel electrophoresis of red blood cell membranes. Neuropathological examination revealed severe neuronal loss of the caudate-putamen and intranuclear inclusion bodies in many areas of the cerebral cortex. These inclusion bodies were immunoreactive for ubiquitin, expanded polyglutamine repeats, and torsinA. CONCLUSIONS: This family extends the genetic spectrum of chorea-acanthocytosis to include autosomal dominant inheritance, possibly due to expanded trinucleotide repeats. Intraneuronal inclusion bodies have recently been associated with a wide range of inherited neurodegenerative disorders and may provide a clue to etiopathogenesis, in addition to potentially indicating a function of torsinA.

[Erythrocytes in the urine: glomerulonephritis or other source of bleeding. Answer with the microscope]. / Erythrozyten im Urin: Glomerulonephritis oder andere Blutungsquelle? Die Antwort gibt Ihnen Ihr Mikroskop.

On the basis of an evaluation of the morphology of erythrocytes in urinary sediment, it is possible to distinguish between nephrological and urological hematuria. In the case of the former, the cells have "disruptive characteristics" (membrane evagination, ring formations, dwarf forms and loss of hemoglobin), enabling them to be distinguished from the regularly formed erythrocytes from hemorrhage within the urinary tract. Dysmorphic erythrocytes retain their characteristic shapes even when persisting in the urine for lengthy periods. An assessment of erythrocyte morphology forms a suitable basis for choosing appropriate further diagnostic measures for urological or nephrological work-up. The method of examination is simple and readily reproducible, and should therefore form an early part of the diagnostic strategy. Microscopic assessment erythrocyte shape is not suitable for the diagnostic work-up of tumors, nor can it obviate the need for kidney biopsy for the investigation of histomorphological changes in glomerular nephritis.

Neuroacantocitose: relato de caso / Neuroacanthocytosis: a case report

Relatamos o caso de um paciente de 45 anos com neuroacantocitose. O paciente apresenta crises parciais complexas como automatismos e crises generalizadas tônico-clônicas, assim com distúrbios do movimento caracterizados por coréia do tronco e membros superiores, e discinesia orofacial. Os exames complementares revelam acantocitose de 11 por cento, eletrencefalograma com foco irritativo no lobo temporal direito, creatino fosfoquinase sérica de 101 U/L e imagem de ressonância magnética com redução volumétrica e hiper-intensidade do sinal no núcleo caudado e putâmen bilateralmente.

Kell, Kx and the McLeod syndrome.

The antigens of the Kell blood group system are carried on a 93 kDa type II glycoprotein encoded by a single gene on chromosome 7 at 7q33. XK is a 50.9 kDa protein that traverses the membrane ten times and derives from a single gene on the X chromosome at Xp21. A single disulphide bond, Kell Cys 72-XK Cys 347, links Kell to XK. The Kell component of the Kell/XK complex is important in transfusion medicine since it is a highly polymorphic protein, carrying over 23 different antigens, that can cause severe reactions if mismatched blood is transfused and in pregnant mothers antibodies to Kell may elicit serious fetal and neonatal anaemia. The different Kell phenotypes are all caused by base mutations leading to single amino acid substitutions. By contrast the XK component carries a single blood group antigen, termed Kx. The physiological functions of Kell and XK have not been fully elucidated but Kell is a zinc endopeptidase with endothelin-3-converting enzyme activity and XK has the structural characteristics of a membrane transporter. Lack of Kx, the McLeod phenotype, is associated with red cell acanthocytosis, elevated levels of serum creatine phosphokinase and late onset forms of muscular and neurological defects.

Altered membrane skeleton of red blood cells participates in cadmium-induced anemia.

Poikilocytosis of red blood cells (RBCs) was observed to be associated with anemia in rats given subcutaneous injections of cadmium (Cd). Phase-contrast light and scanning electron microscopic examinations revealed that acanthocytes appeared in the early stages of administration, and that the number of RBC fragments increased later. Ultrastructural analysis of RBC ghosts by negative staining demonstrated that the normal lattice structure of the membrane skeleton was abolished. The osmotic fragility curve of the Cd-exposed RBCs disclosed that most of the cells were less fragile than control RBCs. These data indicate that the RBC membrane skeleton is initially altered by Cd-exposure, followed by deformation of the cell, thus promoting intrasplenic hemolysis, and resulting in anemia.

[A case of McLeod syndrome].

A 52-year-old man was admitted to our hospital in 1997 because of high serum creatine kinase (CK) level. Neurologic findings revealed chorea on the trunk and extremities, mild weakness of proximal muscles, and absence of deep tendon reflexes in four extremities. Serum CK was elevated to 3,494 U/l (normal, below 235). A peripheral blood smear showed acanthocytes in approximately 1% of the red blood cells (RBCs). Very weak expression of the Kell antigens (K2, K4, K5, and K7) on his RBCs led us to make a final diagnosis of McLeod syndrome. Muscle biopsy from the left biceps showed increased variability in fiber diameter, a few regenerating fibers, scattered fibers with internal nuclei, and mild fiber type grouping. Immunohistochemical analyses of dystrophin. merosin, and adhalin were normal. Although McLeod syndrome is a rare X-linked recessive disorder, it is clinically important for differential diagnosis of chorea acanthocytosis and hyperCKemia.

Acanthocyturia--a characteristic marker for glomerular bleeding.

Erythrocyte morphology by phase contrast microscopic examination (PCM) of the urine is widely employed in distinguishing glomerular from nonglomerular bleeding. The proposed percentages of dysmorphic red cells are significant for glomerular bleeding in the range of 10 to 80% in the literature, because there is no clear cut definition of "dysmorphism." In the present study midstream urine samples of 351 patients with hematuria (greater than 8 erythrocytes/microliters) and of 33 healthy controls were examined. The various dysmorphic red cells were analyzed by PCM according to a detailed hematological classification. Most of the dysmorphic red cells, such as echinocytes, anulocytes, ghost cells, schizocytes, stomatocytes, codocytes and knizocytes, occurred in glomerular or nonglomerular disease as well, and proved to be uncharacteristic for glomerular bleeding. In contrast, a unique red cell deformity, a ringform with vesicle-shaped protrusions (acanthocyte) closely correlated to glomerular disease. In biopsy proven glomerulonephritis acanthocytes comprised 12.4% of all excreted red cells, whereas in nonglomerular diseases or in healthy subjects acanthocytes were seen very rarely (less than 2%) or not at all. Acanthocyturia greater than or equal to 5% (of excreted red cells) was seen in 75 out of 143 patients with proven glomerulonephritis (sensitivity 52%) and in four out of 187 patients with nonglomerular disease (specificity 98%). To improve the diagnostic value of erythrocyte morphology the diagnostic workup should focus on acanthocyturia, which is also indicative in very low erythrocyte counts.

Acantholytic pilomatricoma.

An 11-year-old girl had a slowly enlarging, painful, pink-red tumor on her scalp of 1 month's duration. The lesion was composed of several, round tumor cell nests in the dermis. Each nest was made up of peripheral basophilic cells and central shadow cells or eosinophilic materials. Occasionally the nests, having central eosinophilic degeneration, became epithelial cysts, some of which showed acantholytic changes in their cyst wall. This seems to be the first case of an acantholytic variant of pilomatricoma.

Spur cell anemia (acanthocytosis) complicating idiopathic hemochromatosis.

A 65-year-old male developed a rapidly progressive disease characterized by severe hemolysis, with spur cells (acanthocytes) and liver disease. Autopsy findings were consistent with a diagnosis of idiopathic hemochromatosis. Investigation of the patient's family uncovered four out of five first degree relatives with significantly raised serum ferritin levels. A sister had biopsy proven hemochromatosis. Spur cell anemia is a recognized, though rare, complication of alcoholic liver disease and indeed the patient had a regular alcohol intake of up to 50 g daily. Although the alcohol intake could have contributed to the formation of spur cells, the possible association with hemochromatosis should be considered. A diagnosis of hemochromatosis has important implications for family members.