Genetic diagnosis and pathogenic analysis of an atypical hereditary spherocytosis combined with UGT1A1 partial deficiency: A case report.

Patients with combined hereditary spherocytosis (HS) and uridine diphosphate glucuronosyltransferase 1A1 (UGT1A1) deficiency have been reported sporadically. A discrepancy between the level of elevated serum bilirubin concentration and the degree of anemia may suggest the possibility of a coexistence of these conditions. In the present case report, a 20­year­old female presented with congenital jaundice and anemia, but did not present with the discrepancy between hyperbilirubinemia and anemia in the patient's childhood, and was not previously diagnosed with either HS or UGT1A1 deficiency. During a follow­up of >10 years, the patient's hyperbilirubinemia accumulated progressively, whereas the patient's anemia became relatively mild. Upon further genetic analysis, it was determined that the patient had HS combined with UGT1A1 partial deficiency. Next generation sequencing combined with direct sequencing was used to identify a novel heterozygous mutation (c.G828T; p.Y276X) in the spectrin ß gene, which is causative for HS. Sequence analysis of the patients' UGT1A1 gene revealed a compound heterozygote with c.G211A (p.G71R) and T3279G mutations, which reduced UGT1A1 activity to 30­60% of the normal level. Genetic analysis was crucial for determining the diagnosis and pathogenesis of this unusual case.

Lattice Boltzmann Simulation of Healthy and Defective Red Blood Cell Settling in Blood Plasma.

In this paper, an attempt has been made to study sedimentation of a red blood cell (RBC) in a plasma-filled tube numerically. Such behaviors are studied for a healthy and a defective cell which might be created due to human diseases, such as diabetes, sickle-cell anemia, and hereditary spherocytosis. Flow-induced deformation of RBC is obtained using finite-element method (FEM), while flow and fluid-membrane interaction are handled using lattice Boltzmann (LB) and immersed boundary methods (IBMs), respectively. The effects of RBC properties as well as its geometry and orientation on its sedimentation rate are investigated and discussed. The results show that decreasing frontal area of an RBC and/or increasing tube diameter results in a faster settling. Comparison of healthy and diabetic cells reveals that less cell deformability leads to slower settling. The simulation results show that the sicklelike and spherelike RBCs have lower settling velocity as compared with a biconcave discoid cell.

Mean reticulocyte volume enhances the utility of red cell mean sphered cell volume in differentiating peripheral blood spherocytes of hereditary spherocytosis from other causes.

CONTEXT: Mean sphered cell volume (MSCV) and mean reticulocyte volume (MRV) are additional reticulocyte parameters generated while processing the blood samples on Beckman coulter LH 755 in the reticulocyte mode using the volume, conductivity and scatter technology. It has been observed that the difference between mean corpuscular volume (MCV) and MSCV is higher in the cases of hereditary spherocytosis (HS) and this difference is increasingly being utilized as a screening tool for spherocytes. In addition now there have been new observations that reticulocyte volume in cases of HS is less as compared to normal reticulocyte. AIMS: Our aim was to test the usefulness of reticulocyte parameters like MSCV and MRV in distinguishing cases of HS and autoimmune hemolytic anemia (AIHA). MATERIALS AND METHODS: This is a retrospective and partly prospective study where peripheral blood ethylenediaminetetraacetic acid samples from cases of HS (n = 57) and AIHA (n = 29) were processed on LH 755 in both the differential and the reticulocyte mode. The data generated were analyzed and compared with data from normal healthy donors (n = 46). RESULTS: Using an algorithm of MCV - MSCV >10 and MRV - MSCV <25, a sensitivity of 84.2% and specificity of 94.7% was observed in cases of HS. CONCLUSIONS: With the reticulocyte analysis, we may now have a simple and cheap additional tool for screening of HS.

Quantitative assessment of sensing and sequestration of spherocytic erythrocytes by the human spleen.

Splenic sequestration of RBCs with reduced surface area and cellular deformability has long been recognized as contributing to pathogenesis of several RBC disorders, including hereditary spherocytosis. However, the quantitative relationship between the extent of surface area loss and splenic entrapment remains to be defined. To address this issue, in the present study, we perfused ex vivo normal human spleens with RBCs displaying various degrees of surface area loss and monitored the kinetics of their splenic retention. Treatment with increasing concentrations of lysophosphatidylcholine resulted in a dose-dependent reduction of RBC surface area at constant volume, increased osmotic fragility, and decreased deformability. The degree of splenic retention of treated RBCs increased with increasing surface area loss. RBCs with a > 18% average surface area loss (> 27% reduced surface area-to-volume ratio) were rapidly and completely entrapped in the spleen. Surface-deficient RBCs appeared to undergo volume loss after repeated passages through the spleen and escape from splenic retention. The results of the present study for the first time define the critical extent of surface area loss leading to splenic entrapment and identify an adaptive volume regulation mechanism that allows spherocytic RBCs to prolong their life span in circulation. These results have significant implications for understanding the clinical heterogeneity of RBC membrane disorders.

Aplastic crisis induced by human parvovirus B19 as an initial presentation of hereditary spherocytosis.

The association between aplastic crisis and human parvovirus (HPV) B19 infection has been described in patients with hereditary spherocytosis (HS). Most cases of aplastic crisis in patients with HS induced by HPV B19 have been reported in children and adolescents. In this paper, we describe an aplastic crisis induced by HPV B19 in the 34 year old female as an initial presentation of HS. Although other viral illnesses cause some decompensation in HS, the anemia is rarely as profound as seen in acute HPV B19 infections.

Beta-spectrinBari: a truncated beta-chain responsible for dominant hereditary spherocytosis.

We describe a beta-spectrin variant, named beta-spectrin Bari, characterized by a truncated chain and associated with hereditary spherocytosis. The clinical phenotype consists of a moderately severe hemolytic anemia, splenomegaly, and spherocytes and acanthocytes in the blood smear. The occurrence of the truncated protein, that represents about 8% of the total beta-spectrin occurring on the membrane, results in a marked spectrin deficiency. The altered protein is due to a single point mutation at position -2 (A->G) of the acceptor splice site of intron 16 leading to an aberrant beta-spectrin message skipping exons 16 and 17 indistinguishable from that reported for beta-spectrin Winston-Salem. We provide evidence that the mutated gene is transcribed but its mRNA is less abundant than either its normal counterpart or beta-spectrin Winston-Salem mRNA. Our findings are an example of how mutations in different splice sites, although causing the same truncating effect, result in clearly different clinical pictures.

Clinico-hematological profile of hereditary spherocytosis: experience from a tertiary care center in North India.

Hereditary spherocytosis (HS) is an inherited membranopathy characterized by phenotypic and genotypic heterogeneity. This study describes the clinico-hematological profile of 70 HS patients diagnosed at a tertiary care center in North India over a period of five years. Patients commonly presented with intermittent jaundice (82.9%), pallor (80%) and dark colored urine (11.4%). The common signs were splenomegaly (92.9%), hepatomegaly (50%), cholelithiasis or choledocholithiasis (36.8%) and hemolytic facies (10%). Family history was contributory in 28.6% patients. Blood transfusion (BT) requirement was present in 35.7% patients. Unconjugated and conjugated hyperbilirubinemia was seen in 89.1 and 10.9% patients respectively. At presentation, the hemoglobin ranged from 3-14 g/dl with a mean of 9.37 g/dl (SD2.43). Spherocytes were seen in 88.6% and incubated Osmotic fragility test (OFT) was positive in 88.2% patients. The Eosin-5-maleimide (EMA) flow cytometric test was done in 28 patients. Mean fluorescence intensity (MFI) for normal subjects was 11861.5 (SD-883.51) and for confirmed HS patients was 7949.3 (SD1304.1). Taking the MFI range of 5341.1-10 557.5 for HS, eight cases of suspected HS/undiagnosed hemolytic anemia with a negative (n=5) or equivocal (n=3) incubated OFT were diagnosed as HS. An increase in HbF level was seen in 10 cases ranging from 2.1 to 17.7% with a mean of 5.66%, three of these had associated beta thalassaemia trait. Twelve patients (17%) underwent splenectomy and 91% of them did not require any BT post-splenectomy. Among the patients treated conservatively 49% had persisting pallor and 16.3% had transfusion requirement.

Targeted deletion of alpha-adducin results in absent beta- and gamma-adducin, compensated hemolytic anemia, and lethal hydrocephalus in mice.

In the red blood cell (RBC), adducin is present primarily as tetramers of alpha- and beta-subunits at spectrin-actin junctions, or junctional complexes. Mouse RBCs also contain small amounts of gamma-adducin. Platelets contain alpha- and gamma-adducin only. Adducin functions as a barbed-end actin capping protein to regulate actin filament length and recruits spectrin to the ends of actin filaments. To further define adducin's role in vivo, we generated alpha-adducin knockout mice. alpha-Adducin is absent in all tissues examined in homozygous null mice. In RBCs, beta- and gamma-adducin are also absent, indicating that alpha-adducin is the limiting subunit in tetramer formation at the spectrin-actin junction. Similarly, gamma-adducin is absent in alpha-null platelets. alpha-Adducin-null mice display compensated hemolytic anemia with features characteristic of RBCs in hereditary spherocytosis (HS), including spherocytes with significant loss of surface area, decreased mean corpuscular volume (MCV), cell dehydration, and increased osmotic fragility. Platelets maintain their normal discoid shape, and bleeding times are normal. alpha-Adducin-null mice show growth retardation at birth and throughout adulthood. Approximately 50% develop lethal communicating hydrocephalus with striking dilation of the lateral, third, and fourth ventricles. These data indicate that adducin plays a role in RBC membrane stability and in cerebrospinal fluid homeostasis.

Pitting of malaria parasites and spherocyte formation.

BACKGROUND: A high prevalence of spherocytes was detected in blood smears of children enrolled in a case control study conducted in the malaria holoendemic Lake Victoria basin. It was speculated that the spherocytes reflect intraerythrocytic removal of malarial parasites with a concurrent removal of RBC membrane through a process analogous to pitting of intraerythrocytic inclusion bodies. Pitting and re-circulation of RBCs devoid of malaria parasites could be a host mechanism for parasite clearance while minimizing the anaemia that would occur were the entire parasitized RBC removed. The prior demonstration of RBCs containing ring-infected erythrocyte surface antigen (pf 155 or RESA) but no intracellular parasites, support the idea of pitting. METHODS: An in vitro model was developed to examine the phenomenon of pitting and spherocyte formation in Plasmodium falciparum infected RBCs (iRBC) co-incubated with human macrophages. In vivo application of this model was evaluated using blood specimens from patients attending Kisumu Ditrict Hospital. RBCs were probed with anti-RESA monoclonal antibody and a DNA stain (propidium iodide). Flow cytometry and fluorescent microscopy was used to compare RBCs containing both the antigen and the parasites to those that were only RESA positive. RESULTS: Co-incubation of iRBC and tumor necrosis factor-alpha activated macrophages led to pitting (14% +/- 1.31% macrophages with engulfed trophozoites) as opposed to erythrophagocytosis (5.33% +/- 0.95%) (P < 0.01). Following the interaction, 26.9% +/- 8.1% of the RBCs were spherocytes as determined by flow cytometric reduction in eosin-5-maleimide binding which detects RBC membrane band 3. The median of patient RBCs with pitted parasites (RESA+, PI-) was more than 3 times (95,275/muL) that of RESA+, PI+ RBCs (28,365/muL) (P < 0.01). RBCs with pitted parasites showed other morphological abnormalities, including spherocyte formation. CONCLUSION: It is proposed that in malaria holoendemic areas where prevalence of asexual stage parasites approaches 100% in children, RBCs with pitted parasites are re-circulated and pitting may produce spherocytes.

Idiopathic myelofibrosis without dacryocytes.

Idiopathic myelofibrosis (IMF) typically presents with marrow fibrosis, splenomegaly, progressive anemia, and a leukoerythroblastic blood smear with dacryocytes. We present a patient with IMF who did not have dacryocytes.

Hereditary spherocytosis veiled by anemia and iron deficiency.

Permanent significant hyperchromia, equivalent to hyperspherocytosis, the leading symptom of hereditary spherocytosis (HS), has become accessible to routine screening by hematologic automats using double angle laser technology. This has resulted in the discovery of a much higher incidence of this anomaly. In previous investigations we suggested the permanence of significant hyperchromia as obligate criterion for the diagnosis HS. Intercurrent normal percentages of hyperchromic RBC rather pointed to secondary, non-hereditary spherocytosis. Describing 6 typical cases, we demonstrate that occasional normal percentages of hyperchromic red blood cells occurring during phases of anemia and/or iron deficiency are compatible with the diagnosis of HS.

Evidence for a protective role of the Gardos channel against hemolysis in murine spherocytosis.

It has been shown that mice with complete deficiency of all 4.1R protein isoforms (4.1-/-) exhibit moderate hemolytic anemia, with abnormal erythrocyte morphology (spherocytosis) and decreased membrane stability. Here, we characterized the Gardos channel function in vitro and in vivo in erythrocytes of 4.1-/- mice. Compared with wild-type, the Gardos channel of 4.1-/- erythrocytes showed an increase in Vmax (9.75 +/- 1.06 vs 6.08 +/- 0.09 mM cell x minute; P < .04) and a decrease in Km (1.01 +/- 0.06 vs 1.47 +/- 1.02 microM; P < .03), indicating an increased sensitivity to activation by intracellular calcium. In vivo function of the Gardos channel was assessed by the oral administration of clotrimazole, a well-characterized Gardos channel blocker. Clotrimazole treatment resulted in worsening of anemia and hemolysis, with decreased red cell survival and increased numbers of circulating hyperchromic spherocytes and microspherocytes. Clotrimazole induced similar changes in 4.2-/- and band 3+/- mice, indicating that these effects of the Gardos channel are shared in different models of murine spherocytosis. Thus, potassium and water loss through the Gardos channel may play an important protective role in compensating for the reduced surface-membrane area of hereditary spherocytosis (HS) erythrocytes and reducing hemolysis in erythrocytes with cytoskeletal impairments.

[Myospherulosis of the middle ear -- a rare differential diagnosis of cholesteatoma]. / Myospherulose des Mittelohres -- eine seltene Differenzialdiagnose des Cholesteatoms.

BACKGROUND: Myospherulosis is a chronic-inflammatory lesion that is most commonly iatrogenic of origin and occurs in tissues exposed to petrolatum-based products. The disease does not exhibit characteristic symptoms and is therefore not diagnosed in some instances. In previous otorhinolaryngological studies, myospherulosis was mainly found in paranasal sinuses, while only four otitic cases have been reported. METHODS: A 48-year-old female Egyptian patient suffered from bilateral chronic otitis media that had been treated in Egypt by tympanoplasty. The patient presented few months later at the university ENT department (Mainz) with deteriorated otorrhea and otalgia. Clinical, otoscopical, and radiological examination led to the diagnosis of cholesteatoma. During revision surgery of the right side, ointment-like material was found, which was embedded in granulation tissue. Middle ear biopsies were taken from both sides and routinely processed for standard histological examination and transmission electron microscopy. RESULTS: Histological examination of the right middle ear biopsy showed cystic tissue spaces lined by histiocytes and foreign-body giant cells in a fibrous stroma. In the tissue spaces, scattered debris and sac-like structures containing round spherules of aggregated erythrocytes were found. In addition, erosion of adjacent bone matrix was seen. Diagnosis of myospherulosis was made. By contrast, histological evaluation of the left middle ear biopsy revealed cholesterol granuloma. CONCLUSION: Myospherulosis of the middle ear has been hitherto diagnosed in a very few otitic cases, but might be overlooked as it mimicks other chronic proliferative and inflammatory lesions such as cholesteatoma in the present case. Thus myospherulosis should be considered in otitic cases with a suspicious history (exposure to petrolatum-based products). Furthermore, patients with myospherulosis have a significantly higher likelihood of developing postoperative complications. Since the lesion exhibits distinct histological findings, microscopy plays a central role for the diagnosis of this important disease.