Guidelines for the diagnosis and management of hereditary spherocytosis--2011 update

Clinical utility of targeted gene enrichment and sequencing technique in the diagnosis of adult hereditary spherocytosis

Background

The present study aimed to use the targeted capture and sequencing technique to diagnose adult hereditary spherocytosis (HS). These results were compared with clinical features and laboratory examinations to explore the diagnosis of HS.

Methods

Whole blood and clinical data from ten patients with HS were collected. Genomic DNA was extracted, and a library was prepared. Exomes of patients with ten HS-related genes encoding red cell membrane skeleton protein were captured and sequenced. Bioinformatics analyses were carried out throughout the 1000 Genomes Project, ExAC, dbSNP147, and 1000 Normal Han Population databases.

Results

Gene mutations were found in 9 out of 10 cases of HS. Our data validation showed 90% specificity. Three types of gene mutations were found, including 6 cases of SPTB, 3 cases of ANK1, and 2 cases of SLC4A1. There were 4 mutation forms, including nonsense mutation, missense mutation, shear mutation, and code shift mutation, all of which were new, heterozygous mutations. These variations were predicted to be pathogenic in four databases.

Conclusions

Our data demonstrate that targeted gene enrichment and sequencing methods were an efficient tool for determining genetic etiologies of red blood cell (RBC) membrane disorders and can facilitate accurate diagnosis and genetic counseling. They are also in good agreement with the clinical results.

Clinical and laboratory outcomes following total or partial splenectomy in patients with hereditary spherocytosis

This study compared outcomes following total (TS) or partial splenectomy (PS) among patients with hereditary spherocytosis. Seventy-nine patients (TS = 33, PS = 46) were identified. The follow-up period was longer after PS (59.6 vs. 24.9 months, p < .001). Long-term adverse events occurred more frequently following PS (50% vs. 29%, p = .001). Anemia, jaundice, and fatigue recurred in six patients with PS, leading to five completion splenectomies. Hemoglobin was not different between PS and TS by 5 years post-procedure (12.3 vs. 13.4 g/dL, p = .25). Both PS and TS ameliorate symptoms and improve hematologic parameters. The rate of secondary surgery following PS should be considered when planning the initial surgical procedure.

Indications for Surgery in Non-Traumatic Spleen Disease

The spleen is the largest lymphatic organ that acts as a site for filtration of foreign particles from the blood, erythropoiesis and hematopoiesis. Splenectomy represents the first line of treatment for spontaneous splenic rupture, abscesses, cysts, tumours. It is also used to control hereditary, autoimmune, and myeloproliferative disorders alternatively. Numerous diseases have been indicated for surgery in non-traumatic spleen diseases such as non-traumatic spleen rupture, immune thrombocytopenic purpura (ITP), haemolytic anaemias, Felty’s syndrome, Hodgkin’s and non-Hodgkin’s lymphoma among others. This result because the spleen is the most affected lymphoid organ following its overactivity that occurs during sequestration of dead or disrupted RBCs and lymphocytes. Abdominal pain is one of the major manifestations of splenomegaly, and can also designate other associated complications such as liver cirrhosis or bacterial endocarditis. As a secondary lymphoid organ, the spleen is more often an organ for lymphomas. Although splenectomy is a curative alternative in a few diseases, it is a complementary means of treating several other diseases. Splenectomy is a salvage therapy used when other therapeutic alternatives fail. Despite its indication in numerous diseases, controversies are still inbound of its use.

A previously unrecognized Ankyrin-1 mutation associated with Hereditary Spherocytosis in an Italian family

Hereditary spherocytosis is the most common inherited hemolytic anemia characterized by the presence of spherical-shaped erythrocytes on peripheral blood smear. The clinical manifestations of HS are highly variable, from severe forms to asymptomatic forms. HS is caused by defects in red blood cell membrane proteins, encoded by the ANK1, EPB42, SLC4A1, SPTA1 and SPTB genes. Mutation of the ANK 1 gene is the most common and inheritance is autosomal dominant in 75% of cases. In our case, heterozygous an ANK1 c.4123C > T mutation was identified in a 4-year-old girl, using targeted next-generation sequencing and Sanger sequencing.

Targeted next-generation sequencing identified a novel ANK1 mutation associated with hereditary spherocytosis in a Chinese family

Objectives: Hereditary spherocytosis (HS) represents a group of congenital diseases characterized by sphere-shaped erythrocytes on peripheral blood smears. The typical clinical manifestations of HS include haemolysis, jaundice, splenomegaly, and gallstones. Ankyrin1, encoded by the ANK1 gene, is the predominant protein in red blood cells. Defects in ankyrin1 lead to a decrease in erythrocyte surface area, a spherical shape of erythrocytes and, in particular, loss of membrane elasticity and mechanical stability. The purpose of this study was to investigate a Chinese family with HS to determine the causative gene mutation and explore the genotype-phenotype correlation. Methods: A 4-year-old boy was diagnosed with HS based on typical clinical features. In addition, his father had a high possibility of HS. Targeted next-generation sequencing (NGS) followed by Sanger sequencing was performed in the proband and his parents. Results: One mutation in the ANK1 gene was recognized. c1801-1G > C in exon 17, which leads to splicing defects, was detected. To confirm the c1801-1G > C variant, samples from the proband and his parents were analysed by Sanger sequencing, and Sanger verification showed that this mutation was inherited from the father. Conclusion: The present study confirmed that a novel mutation in ANK1 may be causative of HS, which plays an important role in expanding the mutational spectrum of ANK1 mutations. This may contribute to accurate genetic counselling. And it is helpful for understanding the correlation of the genotype and phenotype.

Hereditary spherocytosis is associated with decreased pyruvate kinase activity due to impaired structural integrity of the red blood cell membrane

Hereditary spherocytosis (HS) is characterised by increased osmotic fragility and enhanced membrane loss of red blood cells (RBC) due to defective membrane protein complexes. In our diagnostic laboratory, we observed that pyruvate kinase (PK) activity in HS was merely slightly elevated with respect to the amount of reticulocytosis. In order to evaluate whether impaired PK activity is a feature of HS, we retrospectively analysed laboratory data sets from 172 unrelated patients with HS, hereditary elliptocytosis (HE), glucose-6-phosphate dehydrogenase (G6PD) or PK deficiency, sickle cell or haemoglobin C disease, or β-thalassaemia minor. Results from linear regression analysis provided proof that PK activity decreases with rising reticulocyte counts in HS (R²  = 0·15; slope = 9·09) and, less significantly, in HE (R²  = 0·021; slope = 8·92) when compared with other haemolytic disorders (R²  ≥ 0·65; slopes ≥ 78·6). Reticulocyte-adjusted erythrocyte PK activity levels were significantly lower in HS and even declined with increasing reticulocytes (R²  = 0·48; slope = -9·74). In this report, we describe a novel association between HS and decreased PK activity that is apparently caused by loss of membrane-bound PK due to impaired structural integrity of the RBC membrane and may aggravate severity of haemolysis in HS.

Flow Cytometric Test with Eosin-5-Maleimide for a Diagnosis of Hereditary Spherocytosis in a Newborn

A term male newborn born to a mother who had hereditary spherocytosis presented with neonatal jaundice at 20 hours of life. Complete blood count showed hemoglobin 17.1 g/dL, MCV 104.2 fL, MCH 32.9 pg, and MCHC 31.6 g/dL. The patient had indirect hyperbilirubinemia requiring phototherapy. The maximum total bilirubin level was 12.15 mg/dL at 20 hours of life. Peripheral blood smear revealed spherocytes, crenated red cells, and polychromasia. A flow cytometric test with eosin-5-maleimide- (EMA-) labeled RBC was performed in the patient and parents. The fluorescence histograms of EMA-labeled RBC from the patient and mother were shifted to the left, and the fluorescence ratio when compared with normal was 0.69 and 0.84, respectively. The flow cytometric test with EMA is useful in supporting the diagnosis of hereditary spherocytosis during newborn period.

A Case of Hereditary Spherocytosis Caused by a Novel Homozygous Mutation in the SPTB Gene Misdiagnosed as β-Thalassemia Intermedia Due to a KLF1 Gene Mutation

We report a rare case of hereditary spherocytosis (HS) and hereditary persistence of fetal hemoglobin (Hb) (HPFH) complicated with a β-thalassemia (β-thal) trait and a Krüppel-like factor 1 (KLF1) gene mutation misdiagnosed as β-thal intermedia (β-TI) due to a high percentage of Hb F. The proband presented with pale skin, jaundice and splenomegaly. Analysis of the thalassemia gene indicated β^{codon 17}/β^A (HBB: c.52A>T), while Hb analysis showed significantly increased Hb F levels. The proband was diagnosed to carry β-TI, and a blood transfusion regimen together with iron chelation treatment was recommended. Due to the difference between the phenotype and genotype, next generation sequencing (NGS) was performed and the proband was found to carry a homozygous mutation on the SPTB gene combined with a heterozygous mutation in KLF1. An eosin-5-maleimide binding test (EMA-BT) showed that the mean fluorescence intensity decreased by 47.1%. The proband was finally diagnosed with HS and HPFH complicated with a β-thal trait and the high percentage of Hb F was believed to be ascribed to the KLF1 gene mutation, which is frequent in areas where thalassemia is prevalent. For patients with a β gene mutation accompanying significantly high percentage of Hb F, the diagnosis of β-TI could be warranted, and the influence of the KLF1 gene mutation should be carefully excluded to avoid misdiagnosis of other types of hereditary hemolytic diseases.

Two different pathogenic gene mutations coexisted in the same hereditary spherocytosis family manifested with heterogeneous phenotypes

Background

Hereditary spherocytosis (HS) is a common type of hereditary hemolytic anemia. According to the current diagnostic criteria of HS, patients with a family history of HS, typical clinical features and laboratory investigations could be diagnosed without the requirement of any additional tests, including genetic analysis. However, the clinical heterogeneities incur difficulties in HS diagnosis. We therefore aimed to investigate the application of genetic diagnosis in a family-based cohort.

Case presentation

In the present Chinese family, two probands sharing similar clinical manifestations, including jaundice, cholelithiasis, splenomegaly and spherocytes, while the clinical features of other family members were inconclusive. Whole-exome sequencing (WES) unexpectedly unveiled two separate disease-causing mutations in the two probands. SPTB R1625X mutation detected in proband D was a de novo mutation; while proband W inherited the SLC4A1 c.G1469A mutation from her mother, which was also inherited by her brother. However, the clinical features of proband W and her mother and brother were discrepant: proband W suffered from significant splenomegaly, jaundice and cholelithiasis, which resulted in cholecystectomy and splenectomy; while her mother and brother’s HS were not complicated by cholelithiasis, and their splenomegaly and elevated serum bilirubin were moderate. In addition, additional genomic defects involved with HS-related symptoms have not been detected in this family.

Conclusions

Both genotypes and phenotypes could be heterogeneous in the same HS family. The analysis of pathogenic gene mutations may endeavor to play an indispensable role in the accurate diagnosis and genetic consultation of HS individuals and their family members.

Molecular diagnosis of hereditary spherocytosis by multi-gene target sequencing in Korea: matching with osmotic fragility test and presence of spherocyte

Background

Current diagnostic tests for hereditary spherocytosis (HS) focus on the detection of hemolysis or indirectly assessing defects of membrane protein, whereas direct methods to detect protein defects are complicated and difficult to implement. In the present study, we investigated the patterns of genetic variation associated with HS among patients clinically diagnosed with HS.

Methods

Multi-gene targeted sequencing of 43 genes (17 RBC membrane protein-encoding genes, 20 RBC enzyme-encoding genes, and six additional genes for the differential diagnosis) was performed using the Illumina HiSeq platform.

Results

Among 59 patients with HS, 50 (84.7%) had one or more significant variants in a RBC membrane protein-encoding genes. A total of 54 significant variants including 46 novel mutations were detected in six RBC membrane protein-encoding genes, with the highest number of variants found in SPTB (n = 28), and followed by ANK1 (n = 19), SLC4A1 (n = 3), SPTA1 (n = 2), EPB41 (n = 1), and EPB42 (n = 1). Concurrent mutations of genes encoding RBC enzymes (ALDOB, GAPDH, and GSR) were detected in three patients. UGT1A1 mutations were present in 24 patients (40.7%). Positive rate of osmotic fragility test was 86.8% among patients harboring HS-related gene mutations.

Conclusions

This constitutes the first large-scaled genetic study of Korean patients with HS. We demonstrated that multi-gene target sequencing is sensitive and feasible that can be used as a powerful tool for diagnosing HS. Considering the discrepancies of clinical and molecular diagnoses of HS, our findings suggest that molecular genetic analysis is required for accurate diagnosis of HS.

Electronic supplementary material

The online version of this article (10.1186/s13023-019-1070-0) contains supplementary material, which is available to authorized users.

Daily supplementation with 5 mg of folic acid in Brazilian patients with hereditary spherocytosis

Patients with hereditary spherocytosis (HS) have increased rates of erythropoiesis and higher folate requirements. In a case-control study of patients with HS, we evaluated the associations between the use of 5 mg folic acid (FA) daily and serum concentrations of folate, unmetabolized folic acid (UMFA), interleukin (IL)-6, IL-8, IL-10, interferon-γ (IFN-γ) and tumor necrosis factor-α (TNF-α); and mRNA expression of dihydrofolate reductase (DHFR), methylene tetrahydrofolate reductase (MTHFR), IL8, IFNG and TNFA genes. Total serum folate and folate forms were measured in 27 patients with HS (21 users [HS-U] and 6 non-users [HS-NU] of supplemental FA) and 54 healthy controls not consuming 5 mg/day supplemental FA. Each patient was matched to two controls based on age, sex and body mass index. The mononuclear leucocyte mRNA expression of relevant genes and their products were determined. Serum folate, UMFA, 5-methyl-tetrahydrofolate (5-methyl-THF) and tetrahydrofolate (THF) concentrations were significantly higher in HS-U compared with matched healthy controls (p<0.001, n=42). HS-NU had lower serum folate concentrations than matched healthy controls (p=0.044, n=12). HS-U and HS-NU presented similar hematological and biochemical markers profiles. No differences were found between HS-U and HS-NU for cytokine serum concentrations and mRNA expression genes. DHFR mRNA expression was higher in HS-U than in HS-NU. The use of high daily doses of FA for treatment of patients with HS may be excessive and is associated with elevated serum UMFA and elevated DHFR mRNA expression. It is not known whether long-term high-dose FA use by patients with HS might have adverse health effects.

Blood cell parameters for screening and diagnosis of hereditary spherocytosis

Background

There is currently no single index for the diagnostic screening of hereditary spherocytosis (HS). However, hematology analyzers are widely used in hospital laboratories because of their highly automated performance and quality control procedure, and detection of some blood cell parameters may be useful for the early screening of HS.

Methods

We investigated the values of blood cell parameters for the screening and differential diagnosis of HS. We performed a descriptive study of 482 samples (67 cases of HS, 59 cases of G6PD deficiency, 57 cases of AIHA, 199 cases of thalassemia, and 100 cases of healthy controls) that were run on Beckman Coulter LH780 Hematology Analyzer.

Results

HS was characterized by increased MCHC, decreased MRV, MSCV‐MCV < 0, and increased Ret with no concomitant increase in IRF. The areas under the ROC curves were MSCV‐MCV (0.97; 95% CI 0.95‐1.0) > MRV (0.94; 95% CI 0.91‐0.97) > MCHC (0.92; 95% CI 0.88‐0.97) > Ret/IRF (0.77; 95% CI 0.7‐0.84). MSCV‐MCV ≤ 0.6 fl was valuable parameter for the diagnostic screening of HS, with a sensitivity of 95.5% and specificity of 94.9%.

Conclusion

These indices have high reference values for differentiating HS from thalassemia, AIHA, and G6PD deficiency.

Whole exome sequencing identified a novel mutation (p.Ala1884Pro) of β-spectrin in a Chinese family with hereditary spherocytosis

BACKGROUND

Hereditary spherocytosis (HS) is an inherited disorder of erythrocyte. The typical feature of HS is the presence of spherical-shaped erythrocytes on the peripheral blood smear. According to previous studies, more than five candidate genes, such as ANK1, SPTB, SPTA1, SLC4A1 and EPB42 have been identified in HS patients.

METHODS

In the present study, a Chinese HS family was investigated. The proband suffered from pathologic jaundice and splenomegaly. A blood test and peripheral blood smear experiment further confirmed the diagnosis of HS. We selected the proband to perform the whole exome sequencing.

RESULTS

After data filtering and co-segregation analysis, we identified 12 mutations in affected members that were absent in healthy members. In consideration of the inheritance pattern, Online Mendelian Inheritance in Man clinical phenotypes, Toppgene function and American College of Medical Genetics classification, we considered the novel mutation (c.5650G > C/p.Ala1884Pro) of β-spectrin (SPTB) to be the genetic lesion in this family. The novel mutation, resulting in a substitution of alanine by proline, may lead to transformation of the SPTB protein structure, which affects the binding between SPTB and ankyrin.

CONCLUSIONS

The present study confirmed the hereditary red blood cell membrane disorders at a molecular level and expanded the spectrum of SPTB mutations. This may contribute to the clinical management and genetic counseling with respect to HS.

[The characteristic of hereditary spherocytosis related gene mutation in 37 Chinese hereditary spherocytisis patients]

Objective: To reveal the genetic characteristics of erythrocyte membrane protein in hereditary spherocytosis (HS) in China. Methods: Next-generation sequencing technology was used to detect mutations in genes of erythrocyte membrane proteins in 51 clinically diagnosed HS patients. The relationship between gene mutations and clinical phenotypes was analyzed. Results: Mutations in erythrocyte membrane protein genes were detected in 37 patients, including 17 with ANK1 mutations (17/37, 45.9%), 14 with SPTB mutations (14/37, 37.8%), and 5 with SLC4A1 mutations (5/37, 13.5%). One patient carried both heterozygous ANK1 mutation and SPTB mutation (1/37, 2.7%). SPTA1 and EPB42 mutation was not fou nd in any patient. Nonsense mutations (36.8%) and missense mutations (31.6%) were most common. Of the 38 mutations detected, 34 were novel mutations and have not been reported elsewhere (89.5%). Sixteen HS patients underwent parental genetic validation, 6 patients (37.5%) inherited gene mutation from parents and 10 (62.5%) were de novo. The peripheral blood cell parameters of HS patients were not related to the mutant genes and gene mutation types. However, it seems that HS patients with mild clinical status are prone to carry SPTB mutations while more patients with severe clinical status have ANK1 mutations. Conclusions: ANK1 and SPTB are the most common mutant genes in Chinese HS patients, mainly with missense mutations and nonsense mutations. There was no significant correlation between the mutation of HS related genes and the severity of HS.

Flow Cytometric Analysis of Erythrocytes Osmotic Fragility in Hereditary Spherocytosis: A Case-Controlled Study Evaluating the Best Anticoagulant, Sample Pre-Treatment and NaCl Concentration for Reliable Screening of this Red Blood Cell Membrane Disorder

BACKGROUND

The cytometric flow osmotic fragility test (FC-OFT) was recently introduced. However, the test is still under development and some variables have not yet been fully tested.

METHODS

The osmotic fragility of hereditary spherocytosis (HS) cases and healthy controls were evaluated by FC-OFT using a series of tubes containing decreasing concentrations of NaCl. The analyses were executed in fresh and incubated (37°C for 24 h) blood samples anticoagulated with EDTA and heparin. The percentages of residual red blood cells were used to plot the osmotic fragility curves. The OF curves of each tested condition were compared using the median corpuscular fragility (MCF). ROC curve analyses identified the most accurate NaCl concentrations for differentiation between HS cases and healthy controls.

RESULTS

FC-OFT curves assumed a sigmoidal dose-response shape and the MCF of cases and controls were different in all instances. MCF comparisons revealed that incubation and anticoagulant have major and minor effects on the FC-OFT, respectively. One hundred percent of sensitivity and specificity was obtained from 5.5 to 6.0 g/L of NaCl in EDTA-treated fresh blood, from 6.0 to 8.0 g/L of NaCl in EDTA-treated incubated blood, and in none of the tested NaCl concentration in heparinized blood.

CONCLUSIONS

EDTA is the anticoagulant of choice for the assay. Incubation at 37°C for 24 h increased its diagnostic capability. The most reliable NaCl concentration for the discrimination of HS case from controls was 6.0 g/L of NaCL in fresh EDTA-treated blood, and was 7.5 g/L of NaCl in incubated EDTA-treated blood. © 2018 International Clinical Cytometry Society.

Spectrum of Ankyrin Mutations in Hereditary Spherocytosis: A Case Report and Review of the Literature

BACKGROUND/AIMS

Hereditary spherocytosis (HS) is a common pediatric hemolytic anemia caused by congenital red blood cell defects. HS due to ankyrin 1 (ANK1) mutations is the most common type. We explored an ANK1 mutation from an HS patient and reviewed the literature.

METHODS

We detected the mutation in a Chinese family in which 2 members were diagnosed with HS by next-generation sequencing. The proband was diagnosed with HS in the newborn period, based on clinical manifestations, laboratory data, and family history. The mutation spectrum of the ANK1 gene was summarized based on 85 patients diagnosed with HS carrying ANK1 mutations, and the ANK1 mutation spectrum was summarized and analyzed.

RESULTS

We identified a novel mutation affecting ANK1 gene splicing (a splicing mutation) in both the patient and her mother, which is a substitution of T>G 2 nt after exon 25 in intron 26. The study expands our knowledge of the ANK1 gene mutation spectrum, providing a molecular basis for HS.

CONCLUSION

A novel ANK1 mutation (NM_000037.3, c.2960+2T>G, intron 26) that is potentially associated with HS was identified. To date, 80 ANK1 mutations have been reported to be associated with HS in humans.

Old and new insights into the diagnosis of hereditary spherocytosis

Hereditary spherocytosis (HS) belongs to the group of congenital hemolytic anemias resulting from plasma membrane protein deficiency. When diagnosed too late, HS bares the risk of long-term complications including gall stones and severe anemia. Here, there are discussed advances in HS screening and diagnostics, with a particular focus on methodologies, most of which are available in clinical laboratories worldwide.

Flow Cytometric Eosin-5'-Maleimide Test is a Sensitive Screen for Hereditary Spherocytosis

Hereditary spherocytosis (HS) is a clinically heterogeneous disease characterized by mild to moderate hemolysis resulting from red cell membrane protein defects. Diagnostic tests include hemogram, reticulocyte count and blood smear evaluation, osmotic fragility, cryohemolysis, SDS-PAGE, flow cytometry using eosin-5'-maleimide (EMA) and genetic studies. We evaluated the flow cytometric EMA-binding test and compared it with osmotic fragility in 51 consecutive cases of suspected HS aged between 10 days and 62 years. In addition, 4 cases suspected on blood smears underwent EMA testing alone. The 16 EMA-positive cases who were determined to have HS had overlapping hemoglobin levels and reticulocyte counts with the 35 patients with normal EMA results, highlighting the importance of the flow cytometric test in providing a definitive diagnosis. Flow cytometric EMA binding test was thus a simple and relatively faster method to confirm HS in our experience.

Tokyo-1 Mutation: Hereditary Spherocytosis in a Hispanic Newborn Presenting as Early Onset Severe Hyperbilirubinemia

BACKGROUND

Hereditary spherocytosis in the Hispanic population does not often present with severe hyperbilirubinemia. Spectrin and band 3 mutations are most frequent in this population.

CASE REPORT

We present a Hispanic full-term female newborn with early onset significant hyperbilirubinemia without a history of familial hemolytic disorders. She was diagnosed with hereditary spherocytosis based on laboratory findings, including presence of spherocytes on a peripheral smear, and was later found by next-generation sequencing to have Tokyo-1 mutation, an ANK1 gene mutation, that was previously only reported in Japanese population.

CONCLUSION

Our report adds to the currently limited literature of the genetic spectrum and characteristics of hereditary spherocytosis in the Hispanic population. The absence of a positive family history does not preclude hereditary spherocytosis as a differential for pathologic neonatal hyperbilirubinemia.

Assessment of the red blood cell proteome in a dog with unexplained hemolytic anemia

A 7-year-old female neutered Jack Russell Terrier was presented to Langford Vets, the University of Bristol, with a history of chronic intermittent lethargy. Investigations and clinical course were compatible with hereditary hemolysis due to a red blood cell membrane defect. Proteomics was used to explore protein alterations in the presence of a hypothesized red blood cell membrane protein deficiency. Proteomic analysis revealed downregulation of the band 3, and alpha- and beta-adducin proteins, and alterations in the red blood cell proteome consistent with previous reports of changes due to the presence of reticulocytosis and ongoing hemolysis. The spectrum of protein alterations identified in the affected dog may be homologous to a band 3 protein deficiency secondary to hereditary spherocytosis, as described in people.

Results after laparoscopic partial splenectomy for children with hereditary spherocytosis: Are outcomes influenced by genetic mutation?

BACKGROUND

Laparoscopic partial splenectomy (LPS) theoretically maintains long-term splenic immune function for children with hereditary spherocytosis (HS). Our goal was to review our results after LPS and to determine if specific genetic mutations influence outcome.

METHODS

All children with HS undergoing LPS between 2005 and 2016 were reviewed.

RESULTS

Thirty-one children underwent LPS (16 male) at a median age of 9 (range 2-18) years. All experienced an increase in hemoglobin and decrease in reticulocyte count early after LPS and at last follow-up. Twenty-two were sent for genetic analysis. Mutations in α-spectrin, β-spectrin, and Ankyrin were identified in 6, 5, and 11 patients, respectively. Gene mutation was not correlated with complications, perioperative transfusion, length of hospital stay, or median hemoglobin, platelet, or reticulocyte counts. Three children required completion splenectomy at 10.9, 6.9, and 3.2years post-LPS, each with a different gene mutation.

CONCLUSIONS

LPS is effective in reversing anemia and reducing reticulocytosis. So far less than 10% have required completion splenectomy, and those children did benefit from delaying the risks of asplenia. In this preliminary analysis, genetic mutation did not influence outcome after LPS. A larger multicenter study is necessary to further investigate potential correlations with specific genetic mutations.

TYPE OF STUDY

Prognosis Study.

LEVEL OF EVIDENCE

IV.

Investigation and management of a raised serum ferritin

Serum ferritin level is one of the most commonly requested investigations in both primary and secondary care. Whilst low serum ferritin levels invariably indicate reduced iron stores, raised serum ferritin levels can be due to multiple different aetiologies, including iron overload, inflammation, liver or renal disease, malignancy, and the recently described metabolic syndrome. A key test in the further investigation of an unexpected raised serum ferritin is the serum transferrin saturation. This guideline reviews the investigation and management of a raised serum ferritin level. The investigation and management of genetic haemochromatosis is not dealt with however and is the subject of a separate guideline.

Cryohemolysis, erythrocyte osmotic fragility, and supplementary hematimetric indices in the diagnosis of hereditary spherocytosis

Background

Hereditary spherocytosis (HS) is a chronic hemolytic anemia characterized by microspherocytes in the peripheral blood and increased erythrocyte osmotic fragility (EOF). This study evaluated the cryohemolysis test (CHT); initial hemolysis (IH); immediate and incubated hemolysis percentage in 5.5 g/L NaCl (H5.5); mean corpuscular hemoglobin concentration (MCHC); red blood cell distribution width (RDW); and Hb/MCHC, Hb/RDW, and MCHC/RDW ratios for the diagnosis of HS.

Methods

Data from 13 patients with HS were evaluated at the Instituto de Bioquímica Aplicada and compared with data from 14 unaffected individuals and 11 patients with anemia due to another etiology. Total blood and reticulocyte counts, CHT, and immediate and incubated EOF were performed in all subjects; sensitivity, specificity, efficiency, and Youden index (YI) were calculated.

Results

Eight patients with HS had MCHC ≥345 g/L, 10 had RDW ≥14.5%, 12 had IH >5.0 g/L, 11 had immediate H5.5 ≥5%, and 13 had incubated H5.5 ≥50% (the cut-off value to consider HS). The efficiency and YI were: immediate H5.5 (0.94–0.85), incubated H5.5 (0.89–0.82), IH (0.89–0.78), MCHC (0.87–0.62), CHT (0.84–0.54), and Hb/MCHC (0.71–0.56), respectively. The calculated ratios could distinguish subjects with HS from unaffected individuals (P<0.05), but not those with anemia of another etiology (P>0.05).

Conclusion

Although the CHT and supplementary hematimetric indexes were useful to differentiate individuals with SH from healthy controls, they cannot distinguish from anemias of other etiology. CHT and MCHC, in addition to EOF, are recommended for diagnosing HS patients because of their low cost and efficiency.

Optimal Reference Gene Selection for Expression Studies in Human Reticulocytes

Reference genes are indispensable for normalizing mRNA levels across samples in real-time quantitative PCR. Their expression levels vary under different experimental conditions and because of several inherent characteristics. Appropriate reference gene selection is thus critical for gene-expression studies. This study aimed at selecting optimal reference genes for gene-expression analysis of reticulocytes and at validating them in hereditary spherocytosis (HS) and β-thalassemia intermedia (βTI) patients. Seven reference genes (PGK1, MPP1, HPRT1, ACTB, GAPDH, RN18S1, and SDHA) were selected because of published reports. Real-time quantitative PCR was performed on reticulocytes in 20 healthy volunteers, 15 HS patients, and 10 βTI patients. Threshold cycle values were compared with fold-change method and RefFinder software. The stable reference genes recommended by RefFinder were validated with SLC4A1 and flow cytometric eosin-5'-maleimide binding assay values in HS patients and HBG2 and high performance liquid chromatography-derived percentage of hemoglobin F in βTI. Comprehensive ranking predicted MPP1 and GAPDH as optimal reference genes for reticulocytes that were not affected in HS and βTI. This was further confirmed on validation with eosin-5'-maleimide results and percentage of hemoglobin F in HS and βTI patients, respectively. Hence, MPP1 and GAPDH are good reference genes for reticulocyte expression studies compared with ACTB and RN18S1, the two most commonly used reference genes.

α-thalassaemia combined with hereditary spherocytosis in the same patient

A family of four from the Guangxi Zhuang Autonomous Region of China, including a child with α-thalassaemia and hereditary spherocytosis (HS), underwent laboratory identification, and genetic analysis. After harvesting peripheral blood samples from the child patient and his family members, GAP-polymerase chain reaction (PCR) and reverse dot-blot tests were used to identify thalassaemia genotypes. After amplifying exons and the adjacent introns of solute carrier family 4 member 1 (Diego blood group) (SLC4A1), ankyrin 1, spectrin α erythrocytic 1, spectrin β erythrocytic and erythrocyte membrane protein band 4.2 by PCR, DNA sequencing was utilised to detect gene mutations of HS. The thalassaemia gene of the child patient was -α^3.7/αα and identical to the genotype of his mother. DNA testing of HS identified two mutation sites on the SLC4A1 gene: Exon 3 c.113A>C (Asp 38 Ala) and intron 7 c.609+86G>A. The father and older sister of the patient also had the same mutations. Due to the mutual interference with disorders of haemoglobin synthesis and erythrocyte membrane defects of laboratory results, it is difficult to diagnose HS when it coexists with thalassaemia. When clinical manifestations and laboratory results cannot be explained by a single haemolytic anaemia, the possibility of combining with another haemolytic anaemia should be considered. Thus, it is necessary to perform pedigree investigation and genetic analyses for a final diagnosis.

Molecular Genetic Mechanisms of Hereditary Spherocytosis: Current Perspectives

With the widespread use of genetic diagnostic technologies, many novel mutations have been identified in hereditary spherocytosis (HS)-related genes, including SPTA1, SPTB, ANK1, SLC4A1, and EPB42. However, mutations in HS-related genes are dispersed and nonspecific in the diagnosis of some HS patients, indicating significant heterogeneity in the molecular deficiency of HS. It is necessary to provide the molecular and genetic characteristics of these 5 genes for clinicians to examine HS. Here, we reviewed the recent proposed molecular genetic mechanisms of HS.

Utility of mean sphered cell volume and mean reticulocyte volume for the diagnosis of hereditary spherocytosis

INTRODUCTION

Hereditary spherocytosis (HS) is the most common congenital hemolytic anemia, characterized by anemia, jaundice, and splenomegaly. The diagnosis of HS relies on symptoms of hemolysis, a family history of HS, and a positive laboratory test which is usually the osmotic fragility test (OFT). We conducted a study to assess the utility of mean corpuscular hemoglobin concentration (MCHC), mean corpuscular volume (MCV), mean sphered cell volume (MSCV), and mean reticulocyte volume (MRV) in the diagnosis of HS and if these are helpful in distinguishing cases of HS from immune hemolytic anemia.

METHODS

A total of 102 patients suspected to have HS were enrolled. In addition 10 cases of immune hemolytic anemia (IHA) were included in the study and performance of the above screening tests was evaluated. The diagnosis of HS was based on incubated OFT, eosin 5'-maleimide (EMA) dye binding test, and flowcytometric OFT.

RESULTS

A total of 29 patients were diagnosed as having HS. The sensitivity and specificity for diagnosis HS by MCHC > 35 g/dL was 44.82%, and ΔMCV-MSCV > 10 fL has a sensitivity and specificity of 82.75% and 95.9% for diagnosis of HS. Using an algorithm of ΔMCV-MSCV > 10 fL and ΔMRV-MSCV < 25, for the differentiation of HS from IHA had sensitivity of 68.9% and specificity of 98.8%.

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 20‑year‑old 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 follow‑up 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 β 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 30‑60% of the normal level. Genetic analysis was crucial for determining the diagnosis and pathogenesis of this unusual case.

Osmotic gradient ektacytometry: A valuable screening test for hereditary spherocytosis and other red blood cell membrane disorders

INTRODUCTION

New generation osmotic gradient ektacytometry has become a powerful procedure for measuring red blood cell deformability and therefore for the diagnosis of red blood cell membrane disorders. In this study, we aim to provide further support to the usefulness of osmotic gradient ektacytometry for the differential diagnosis of hereditary spherocytosis by measuring the optimal cutoff values of the parameters provided by this technique.

METHODS

A total of 65 cases of hereditary spherocytosis, 7 hereditary elliptocytosis, 3 hereditary xerocytosis, and 171 normal controls were analyzed with osmotic gradient ektacytometry in addition to the routine red blood cell laboratory techniques. The most robust osmoscan parameters for hereditary spherocytosis diagnosis were determined using receiver operating characteristic curve analysis.

RESULTS

The best diagnostic criteria for hereditary spherocytosis were the combination of decreased minimal elongation index up to 3% and increased minimal osmolality point up to 5.2% when compared to the mean of controls. Using this established criterion, osmotic gradient ektacytometry reported a sensitivity of 93.85% and a specificity of 98.38% for the diagnosis of hereditary spherocytosis.

CONCLUSION

Osmotic gradient ektacytometry is an effective diagnostic test for hereditary spherocytosis and enables its differential diagnosis with other red blood cell membrane diseases based on specific pathology profiles.

A long-term follow-up study of subtotal splenectomy in children with hereditary spherocytosis

BACKGROUND

Hereditary spherocytosis (HS) is a heterogeneous hemolytic anemia treated with splenectomy in patients suffering from severe or moderate disease. Total splenectomy, however, renders patients vulnerable to overwhelming postsplenectomy infection despite preventive measures. Although subtotal splenectomy has been advocated as an alternative to total splenectomy, long-term follow-up data are scarce. We investigated how often hematologic recurrences requiring secondary total splenectomy occurred.

PROCEDURE

With a follow-up of at least 5 years, we analyzed the data of 12 patients, aged 11 years maximum (median 6.5 years), who had undergone intended subtotal splenectomy, and 9 patients (median age 11.9 years), who had undergone total splenectomy. We compared their hematologic results and searched for factors associated with secondary spleen surgery.

RESULTS

Hemolysis was reduced after subtotal splenectomy and absent after total splenectomy. Subtotal splenectomy was not successful in three children because no functional splenic remnant remained after 6 months (one conversion at surgery; one necrosis of splenic remnant; one early secondary splenectomy). Four children required secondary splenectomy after a median of 5 years for hematologic recurrence. In the remaining five patients, a functional splenic remnant was present for at least 5.5 years. The median time to secondary total splenectomy after intended subtotal splenectomy was 5.2 years. In all patients requiring secondary total splenectomy, increased reticulocyte levels within 2 years indicated hematologic recurrence.

CONCLUSIONS

Subtotal splenectomy can be an alternative for total splenectomy in young patients with HS. It allows for hematologic improvement and may preserve splenic immune function for as many as 5 years.

Laparoscopic splenectomy: Current concepts

Since early 1990’s, when it was inaugurally introduced, laparoscopic splenectomy has been performed with excellent results in terms of intraoperative and postoperative complications. Nowadays laparoscopic splenectomy is the approach of choice for both benign and malignant diseases of the spleen. However some contraindications still apply. The evolution of the technology has allowed though, cases which were considered to be absolute contraindications for performing a minimal invasive procedure to be treated with modified laparoscopic approaches. Moreover, the introduction of advanced laparoscopic tools for ligation resulted in less intraoperative complications. Today, laparoscopic splenectomy is considered safe, with better outcomes in comparison to open splenectomy, and the increased experience of surgeons allows operative times comparable to those of an open splenectomy. In this review we discuss the indications and the contraindications of laparoscopic splenectomy. Moreover we analyze the standard and modified surgical approaches, and we evaluate the short-term and long-term outcomes.

Flow cytometric analysis of patients with hereditary spherocytosis - an Indian scenario

OBJECTIVES

Flow cytometry osmotic fragility test (FC-OFT) was a recently introduced screening test for hereditary spherocytosis (HS). This study was conducted to evaluate the utility of FC-OFT in all newly diagnosed cases of HS, to compare its diagnostic value with conventional OFT and to correlate with clinical disease severity.

METHODS

In this study, the percentage of residual red cells (%RRC) was measured using flow cytometer after creating a red cell suspension. Subsequently, this was spiked with deionized water for FC-OFT in all cases of HS (n = 40), healthy subjects (n = 40) and beta-thalassemia traits (BTT) (n = 20).

RESULTS

The receiver operator curve analysis defined the optimal cut-offs for FC-OFT-derived indices, such as %RRC value (≤16.29%) and %RRC ratio (>1.72), for HS cases when compared with healthy subjects and BTT (p < 0.05). The FC-OFT (96%) achieved higher test efficiency than the conventional OF test (68.9%). A significant positive and a negative correlation were found between number of spherocytes/hpf and %RRC ratio (p = 0.001) and %RRC values (p = 0.0486). No significant correlation was observed between %RRC value (p = 0.8934), %RRC ratio (p = 0.6348) and HS disease severity score.

CONCLUSION

Our results suggest that FC-OFT could be the better screening test for HS cases in developing countries if flow cytometer is available.

Novel mutations in patients with hereditary red blood cell membrane disorders using next-generation sequencing

To diagnose and investigate the genotype-phenotype relationship in intractable hereditary red blood cell (RBC) membrane cases, we have utilized next-generation sequencing (NGS) to develop a high-throughput, highly sensitive assay. Three unrelated families including 15 individuals were analysed with a panel interrogating 600 genes related to haematopathy disorders. Where possible, inheritance patterns of pathogenic mutations were determined by sequencing the relatives. We identified 2 novel mutations in ANK1 (Y216X and E142X) responsible for hereditary spherocytosis (HS) that were stop-gain single nucleotide variants (SNVs). Furthermore, a novel SPTA1 mutation (H54P) was identified; it is a nonsynonymous SNV and is associated with hereditary elliptocytosis (HE). In addition, patients who also carried erythropoiesis gene mutations showed more severe disease phenotype. The NGS panel provides a fast and accurate method for molecular diagnosis in patients with intractable hereditary RBC membrane disorders. An approach integrating medical history, clinical and molecular testing, and pedigree analysis is beneficial for these patients and families.

[Correlation of the degree of band 3 protein absence on erythrocyte membrane by eosin-5'-maleimide binding test and clinical phenotype in hereditary spherocytosis]

Objective: To investigate the relationship between the eosin-5'-maleimide (EMA) binding test and the clinical severity of hereditary spherocytosis (HS). Methods: A total of 258 un-splenectomize HS patients were consecutively enrolled. Correlation of hemoglobin concentration, hemolytic parameters, compensating erythropoiesis and the EMA binding test were evaluated. Results: 258 (128 male and 130 female) patients were included in this study, including 91 compensatory hemolysis patients, 53 patients with mild anemia, 78 patients with moderate anemia and 36 patients with severe anemia. The median age at diagnosis was 23 (2-70) years. The median decreased fluorescence intensity of EMA binding test was 29.97% (16.09%-47.34%) and the average intensity was (29.70±6.28) % of 258 HS patients. The decreased EMA binding fluorescence intensity correlated with MCV (r=-0.343, P<0.001) and MCHC (r=0.223, P<0.001). There was no relationship between EMA fluorescence intensity and absolute reticulocyte count (r=0.080, P=0.198) , reticulocyte percentile (r=-0.015, P=0.813) , IBIL levels (r=-0.009, P=0.902) , HGB levels (r=-0.067, P=0.280). Evaluated as a quartile variable, EMA fluorescence intensity was not correlated with anemia severity (C=0.150, P=0.746). Conclusion: EMA binding test does not related to anemia levels and has no major clinical implications for disease severity in HS.

Usefulness of Reticulocyte Parameters for Diagnosis of Hereditary Spherocytosis in Children

Innovations in laboratory equipment have enabled a widening of the spectrum of hematological parameters obtained from single measurements of peripheral blood samples, including reticulocyte parameters. The usefulness of reticulocytes indices to confirm the diagnosis of pediatric anemia was analyzed in this study. The study group consisted of 163 children, aged 1 month-17 years, with anemia. Complete blood count extended with an analysis of reticulocyte parameters were measured using a Beckman Coulter LH 750. The mean sphered corpuscular volume (MSCV) in the group of children with hereditary spherocytosis (HS) was 66.71 ± 8.45 fL, whereas in other anemic patients MSCV was 87.76 ± 11.22 fL, p < 0.0001. In HS children the average mean corpuscular volume of red blood cells was higher than the MSCV value, while an inverse correlation was observed in the group of children with other anemias, p < 0.0001. A significant difference was found between the ratio of absolute reticulocyte count and IRF fraction (Ret#/IRF)-0.6 ± 0.28 in the HS group and 0.23 ± 0.16 in the non-HS group, respectively. Our results suggest that analysis of reticulocyte parameters is useful in the diagnosis of anemia and should be included in the routine CBC analysis in anemic children.

Diagnostic approaches for inherited hemolytic anemia in the genetic era

Inherited hemolytic anemias (IHAs) are genetic diseases that present with anemia due to the increased destruction of circulating abnormal RBCs. The RBC abnormalities are classified into the three major disorders of membranopathies, hemoglobinopathies, and enzymopathies. Traditional diagnosis of IHA has been performed via a step-wise process combining clinical and laboratory findings. Nowadays, the etiology of IHA accounts for germline mutations of the responsible genes coding for the structural components of RBCs. Recent advances in molecular technologies, including next-generation sequencing, inspire us to apply these technologies as a first-line approach for the identification of potential mutations and to determine the novel causative genes in patients with IHAs. We herein review the concept and strategy for the genetic diagnosis of IHAs and provide an overview of the preparations for clinical applications of the new molecular technologies.

Recommendations regarding splenectomy in hereditary hemolytic anemias

Hereditary hemolytic anemias are a group of disorders with a variety of causes, including red cell membrane defects, red blood cell enzyme disorders, congenital dyserythropoietic anemias, thalassemia syndromes and hemoglobinopathies. As damaged red blood cells passing through the red pulp of the spleen are removed by splenic macrophages, splenectomy is one possible therapeutic approach to the management of severely affected patients. However, except for hereditary spherocytosis for which the effectiveness of splenectomy has been well documented, the efficacy of splenectomy in other anemias within this group has yet to be determined and there are concerns regarding short- and long-term infectious and thrombotic complications. In light of the priorities identified by the European Hematology Association Roadmap we generated specific recommendations for each disorder, except thalassemia syndromes for which there are other, recent guidelines. Our recommendations are intended to enable clinicians to achieve better informed decisions on disease management by splenectomy, on the type of splenectomy and the possible consequences. As no randomized clinical trials, case control or cohort studies regarding splenectomy in these disorders were found in the literature, recommendations for each disease were based on expert opinion and were subsequently critically revised and modified by the Splenectomy in Rare Anemias Study Group, which includes hematologists caring for both adults and children.