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

Identification of a novel splice variant in SEC23B gene in a patient with concomitant presence of congenital dyserythropoietic anemia II and Gilbert's syndrome

BACKGROUND

Congenital dyserythropoietic anemia Ⅱ (CDA Ⅱ) is a rare inherited disorder of defective erythropoiesis caused by SEC23B gene mutation. CDA Ⅱ is often misdiagnosed as a more common type of clinically related anemia, or it remains undiagnosed due to phenotypic variability caused by the coexistence of inherited liver diseases, including Gilbert's syndrome (GS) and hereditary hemochromatosis.

METHODS

We describe the case of a boy with genetically undetermined severe hemolytic anemia, hepatosplenomegaly, and gallstones whose diagnosis was achieved by targeted next generation sequencing.

RESULTS

Molecular analysis revealed a maternally inherited novel intronic variant and a paternally inherited missense variant, c.[994-3C > T];[1831C > T] in the SEC23B gene, confirming diagnosis of CDA Ⅱ. cDNA analysis verified that the splice acceptor site variant results in two mutant transcripts, one with an exon 9 skip and one in which exons 9 and 10 are deleted. SEC23B mRNA levels in the patient were lower than those in healthy controls. The patient was also homozygous for the UGT1A1*6 allele, consistent with GS.

CONCLUSION

Identification of the novel splice variant in this study further expands the spectrum of known SEC23B gene mutations. Molecular genetic approaches can lead to accurate diagnosis and management of CDA Ⅱ patients, particularly for those with GS coexisting.

Complex heterozygous mutations in hereditary spherocytosis: A case report

BACKGROUND

The aim of this study was to investigate the complex heterozygous mutations of ANK1 and SPTA1 in the same individual and improve our understanding of hereditary spherocytosis (HS) in children. We also hope to promote the application of gene detection technology in children with HS, with the goals of identifying more related gene mutations, supporting the acquisition of improved molecular genetic information to further reveal the pathogenesis of HS in children, and providing important guidance for the diagnosis, treatment, and prevention of HS in children.

CASE SUMMARY

A 1-year and 5-month-old patient presented jaundice during the neonatal period, mild anemia 8 months later, splenic enlargement at 1 year and 5 months, and brittle red blood cell permeability. Genetic testing was performed on the patient, their parents, and sister. Swiss Model software was used to predict the protein structure of complex heterozygous mutations in ANK1 and SPTA1. Genetic testing revealed that the patient harbored a new mutation in the ANK1 gene from the father and a mutation in the SPTA1 gene from the mother. Combined with the clinical symptoms of the children, it is suggested that the newly discovered complex heterozygous mutations of ANK1 and SPTA1 may be the cause, providing important guidance for revealing the pathogenesis, diagnosis, treatment, and promotion of gene detection technology in children with HS.

CONCLUSION

This case involves an unreported complex heterozygous mutation of ANK1 and SPTA1, which provides a reference for exploring HS.

Precise diagnosis of a hereditary spherocytosis patient with complicated hematological phenotype

Hereditary spherocytosis (HS) is one of the most common causes of hereditary hemolytic anemia. The current diagnostic guidelines for HS are mainly based on a combination of physical examination and laboratory investigation. However, some patients present with complicated clinical manifestations that cannot be explained by routine diagnostic protocols. Here, we report a rare HS case of mild anemia with extremely high indirect bilirubin levels and high expression of fetal hemoglobin. Using whole exome sequencing analysis, this patient was identified as a heterozygous carrier of a de novo SPTB nonsense mutation (c.605G > A; p.W202*) and a compound heterozygous carrier of known UGT1A1 and KLF1 mutations. This genetic analysis based on the interpretation of the patient's genomic data not only achieved precise diagnosis by an excellent explanation of the complicated phenotype but also provided valuable suggestions for subsequent appropriate approaches for treatment, surveillance and prophylaxis.

Current Status of Molecular Diagnosis of Hereditary Hemolytic Anemia in Korea

Hereditary hemolytic anemia (HHA) is considered a group of rare hematological diseases in Korea, primarily because of its unique ethnic characteristics and diagnostic challenges. Recently, the prevalence of HHA has increased in Korea, reflecting the increasing number of international marriages and increased awareness of the disease. In particular, the diagnosis of red blood cell (RBC) enzymopathy experienced a resurgence, given the advances in diagnostic techniques. In 2007, the RBC Disorder Working Party of the Korean Society of Hematology developed the Korean Standard Operating Procedure for the Diagnosis of Hereditary Hemolytic Anemia, which has been continuously updated since then. The latest Korean clinical practice guidelines for diagnosing HHA recommends performing next-generation sequencing as a preliminary step before analyzing RBC membrane proteins and enzymes. Recent breakthroughs in molecular genetic testing methods, particularly next-generation sequencing, are proving critical in identifying and providing insight into cases of HHA with previously unknown diagnoses. These innovative molecular genetic testing methods have now become important tools for the management and care planning of patients with HHA. This review aims to provide a comprehensive overview of recent advances in molecular genetic testing for the diagnosis of HHA, with particular emphasis on the Korean context.

Identification of a novel ANK1 gene variant c.1504-9G>A and its mechanism of intron retention in hereditary spherocytosis

Objective: The objective of this study was to pinpoint pathogenic genes and assess the mutagenic pathogenicity in two pediatric patients with hereditary spherocytosis. Methods: We utilized whole-exome sequencing (WES) for individual analysis (case 1) and family-based trio analysis (case 2). The significance of the intronic mutation was validated through a Minigene splicing assay and supported by subsequent in vitro experiments. Results: Both probands received a diagnosis of hereditary spherocytosis. WES identified a novel ANK1 c.1504-9G>A mutation in both patients, causing the retention of seven nucleotides at the 5' end of intron 13, as substantiated by the Minigene assay. This variant results in a premature stop codon and the production of a truncated protein. In vitro studies indicated a reduced expression of the ANK1 gene. Conclusion: The novel ANK1 c.1504-9G>A variant is established as the causative factor for hereditary spherocytosis, with the c.1504-9G site functioning as a splicing receptor.

Minimal endoscopic sphincterotomy followed by papillary balloon dilation to relieve choledocholithiasis in a 6-year-old girl with hereditary spherocytosis

A 6-year-old girl previously diagnosed with hereditary spherocytosis was admitted to our hospital with gallstones and cholangitis. Endoscopic retrograde cholangiopancreatography (ERCP) was performed, and fluoroscopy revealed a dilated common bile duct (CBD) without evident stones, possibly due to spontaneous excretion through the papilla of Vater. A 7-French plastic stent was inserted into the CBD. After the procedure, a marked increase in pancreatic enzyme levels was observed, and she was diagnosed with post-ERCP pancreatitis (PEP). Stent placement could have been a cause of pancreatitis; therefore, we removed the stent. Subsequently, recovery from pancreatitis was confirmed, although she suddenly complained of abdominal pain and was diagnosed with choledocholithiasis recurrence. ERCP was repeated, and fluoroscopy revealed a dilated CBD with a stone. A minimal endoscopic sphincterotomy (EST) was performed to reduce the risk of PEP, and a biliary dilation balloon placed across the papilla was gradually inflated until the waist of the balloon disappeared. Stones were extracted using a retrieval balloon catheter. The abdominal pain resolved immediately, and the patient recovered without developing PEP. To our knowledge, this is the first case report of a pediatric patient treated with minimal EST followed by papillary balloon dilation for choledocholithiasis.

P, Maskey R. Hereditary spherocytosis in a young female in Eastern Nepal: a case report

Introduction and importance

Hereditary spherocytosis (HS), a rare familial extravascular haemolytic disorder, typically follows an autosomal dominant inheritance pattern with variable expressivity. Despite its classical presentation of anaemia, jaundice, and splenomegaly, HS is infrequently reported among individuals of Asian descent, contributing to its under diagnosis or delayed diagnosis. The primary objective of this case report is to underscore the pivotal role of the osmotic fragility test in diagnosing HS, emphasizing the importance of accurate and timely identification for effective clinical management and improved patient outcomes.

Case presentation

The patient, without known prior co-morbidities, presented with recurrent abdominal distension, early satiety, and easy fatigability persisting for 6 years. Physical examination revealed icterus, gnathopathy, left hypochondrium tenderness, and palpable splenomegaly. The osmotic fragility of red cells was significantly elevated. The patient underwent optimization before splenectomy, receiving immunization against encapsulated bacteria. Packed red blood cell transfusions were administered to achieve optimal haemoglobin levels. Follow-up showed symptom relief, significantly improving the patient's quality of life.

Clinical discussion

This case underscores the challenges of delayed HS diagnosis, with the patient enduring symptoms for years before seeking appropriate medical attention. Overlooking the simplicity and cost-effectiveness of an osmotic fragility test prolonged the diagnostic journey, emphasizing the impact on overall well-being.

Conclusion

HS remains underdiagnosed, especially in our regions. The osmotic fragility test emerges as an economical diagnostic tool in resource-limited settings, particularly when spherocytosis is absent in the peripheral blood smears. Its inclusion in diagnostic protocols can expedite accurate HS identification and enhance patient outcomes.

Novel mutation in alpha-spectrin gene in Saudi patients with hereditary spherocytosis

Hereditary spherocytosis (HS) is the most common hereditary hemolytic disorder induced by red blood cell (RBC) membrane defect. This study was undertaken to determine mutations in genes associated with RBC membrane defect in patients with HS such as α-spectrin gene (SPTA1), β-spectrin gene (SPTB), ankyrin gene (ANK1), band 3 anion transport gene (SLC4A1) and erythrocyte membrane protein band 4.1 gene (EPB41). Blood samples were collected from 23 unrelated patients with HS. Patients were diagnosed according to the guidelines from the British Society for Hematology. All hematological examinations for the determination of RBC abnormalities and osmotic fragility tests were conducted. Genomic DNA were extracted from peripheral blood cells and coding exons of known genes for hereditary spherocytosis were enriched using Roche/KAPA sequence capture technology and sequenced on an Illumina system via next-generation sequencing (NGS). The data showed that most of the HS patients confirmed splenomegaly and showed elevated reticulocytes and abnormal bilirubin values. NGS analysis identified the heterozygous variant c.5501G > A in the exon 39 of SPTA1 gene, resulted in a Trp1834*, which leads to a premature stop codon and subsequent mRNA degradation (nonsense- mediated decay) or truncation in α spectrin. Moreover, our data also revealed conventional mutations in genes SPTB, ANK, SLC4A1 and EBP41 in severe patients of HS. In short, this is the first report that determined a novel mutation c.5501G > A in SPTA1 gene in the Saudi population. To the best of our knowledge, this variant c.5501G > A has not been described in global literature so far. This novel mutation in SPTA1 gene is unique in the Saudi population.

Concurrent Cholecystectomy Does Not Increase Splenectomy Morbidity in Patients With Hemolytic Anemia: A Pediatric NSQIP Analysis

PURPOSE

Children undergoing splenectomy for hemolytic anemia often have cholelithiasis, which may or may not be symptomatic. It is unclear whether concurrent cholecystectomy increases length of stay or morbidity after splenectomy. The purpose of this study was to compare morbidity among children undergoing laparoscopic splenectomy alone versus splenectomy with concurrent cholecystectomy in patients with hemolytic anemia.

METHODS

We retrospectively evaluated children with hemolytic anemia undergoing non-traumatic laparoscopic splenectomy in the National Surgical Quality Improvement Program-Pediatric database (2012-2020). Outcomes were compared for patients undergoing splenectomy alone (n = 1010) versus splenectomy with cholecystectomy (n = 371). Pearson's Chi-square and Student's t-tests were utilized as appropriate. Propensity score-matching was completed, controlling for eight demographic and clinical variables.

RESULTS

1381 patients were identified, 73.1% undergoing splenectomy alone and 26.9% splenectomy with cholecystectomy. Splenectomy with cholecystectomy patients were older (10.9 years vs. 8.4 years, p < 0.01), more likely to have hereditary spherocytosis (56.1% vs. 40.8%, p < 0.01), less likely to have sickle cell disease (12.1% vs. 33.5%, p < 0.01), more likely ASA class 1 or 2 (49.3% vs. 42.1%, p < 0.01), and had similar preoperative hematocrit levels (29.6 vs. 29.3, p = 0.33). The splenectomy with cholecystectomy group was less likely to receive preoperative blood transfusions (13.5% vs. 25.4%, p < 0.01). There were 360 pairs selected on propensity score-matching, and splenectomy with cholecystectomy was associated with increased operative time (182 min vs. 145 min, p < 0.01) and decreased occurrences of a postoperative transfusion (4.2% vs. 8.9%, p = 0.01). Length of stay after surgery (2.5 days vs. 2.3 days, p = 0.13), composite morbidity (3.9% vs. 3.4%, p = 0.69), and 30-day readmission rates (3.3% vs. 7.4%, p = 0.08) were all similar.

CONCLUSIONS

Splenectomy with cholecystectomy is associated with similar postoperative morbidity, length of stay and readmission rates compared to splenectomy alone. These data support the safety of concurrent cholecystectomy with splenectomy for children with cholelithiasis in the setting of hemolytic anemia.

TYPE OF STUDY

Retrospective Cohort Study.

LEVEL OF EVIDENCE

Level III.

Hereditary Spherocytosis: Can Next-Generation Sequencing of the Five Most Frequently Affected Genes Replace Time-Consuming Functional Investigations?

Congenital defects of the erythrocyte membrane are common in northern Europe and all over the world. The resulting diseases, for example, hereditary spherocytosis (HS), are often underdiagnosed, partly due to their sometimes mild and asymptomatic courses. In addition to a broad clinical spectrum, this is also due to the occasionally complex diagnostics that are not available to every patient. To test whether next-generation sequencing (NGS) could replace time-consuming spherocytosis-specific functional tests, 22 consecutive patients with suspected red cell membranopathy underwent functional blood tests. We were able to identify the causative genetic defect in all patients with suspected HS who underwent genetic testing (n = 17). The sensitivity of the NGS approach, which tests five genes (ANK1 (gene product: ankyrin1), EPB42 (erythrocyte membrane protein band4.2), SLC4A1 (band3), SPTA1 (α-spectrin), and SPTB (β-spectrin)), was 100% (95% confidence interval: 81.5-100.0%). The major advantage of genetic testing in the paediatric setting is the small amount of blood required (<200 µL), and compared to functional assays, sample stability is not an issue. The combination of medical history, basic laboratory parameters, and an NGS panel with five genes is sufficient for diagnosis in most cases. Only in rare cases, a more comprehensive functional screening is required.

Long-term haematological response and maintained immunological function after laparoscopic subtotal splenectomy in patients with hereditary spherocytosis

INTRODUCTION

Subtotal or total splenectomy are recommended in severe and should be considered in intermediate forms of hereditary spherocytosis (HS). Data on laparoscopic subtotal splenectomy (LSTS) in HS patients are sparse.

METHODS

Thirty three patients with HS (median age 10.7 years (yrs), range 1.8-15.5) underwent LSTS. Baseline and follow-up investigation included haematological parameters, microscopic analysis of pitted erythrocytes (pitE), and B-cell subpopulations assessed by flow cytometry. Results were compared to those of non-splenectomised HS patients, HS patients after total splenectomy (TS), and healthy individuals.

RESULTS

After LSTS, haemoglobin levels were normalised in all patients. During median long-term follow-up of 3.9 yrs (range 1.1-14.9), only four patients presented mild anaemia. Despite re-growing of the remnant spleen none of the patients required a second surgical intervention. As compared to TS, PitE in LSTS patients were significantly lower and indicated normal to only moderately decreased spleen function. Relative but not absolute IgM memory B-cell counts were reduced in both LSTS and TS patients.

CONCLUSIONS

LSTS is effective for the treatment of patients with HS. A small remnant spleen is sufficient to provide adequate phagocytic function and to induce a pool of IgM memory B-cells.

Hematological characteristics and hepatobiliary complications of hereditary spherocytosis in a tertiary care pediatric center: optimizing diagnosis and care through local and international networks

Background

Hereditary Spherocytosis (HS) is a rare, congenital red blood cell disorder presenting with variable clinical manifestations ranging from mild hemolytic anemia to severe anemia with hypersplenism and hepatobiliary complications.

Methods

The objectives of the study were to evaluate the diagnostic pathway of HS, the presence and management of hepatobiliary complications in pediatric patients with HS followed in a tertiary care center. The demographic, clinical, hematological information were retrieved from medical records of patients having at least 1 hematology visit between 2010 and 2020.

Results

Forty-two patients were enrolled, 23 M. Mean age at onset of symptoms was 2.8 years, at diagnosis was 3.5 years. Anemia was the first manifestation in 73%; suspect of HS arose for all patients in first or second level outpatient clinics. Only 64% of patients performed two confirmation tests in the reference center. 28/42 had familiarity for HS; of the 13/42 who did not, only 47% performed further analysis. Sixteen patients developed gallbladder stones (40%), visible at the first ultrasound (5.6 years). Hemolytic crises and parvovirus infections were more frequent in patients with stones (53.6% vs. 26.1% and 63.6% vs. 28.6%, respectively). 10/16 (62.5%) underwent elective cholecystectomy: 8 had concomitant splenectomy.

Conclusions

our study highlights the need to optimize the diagnostic pathway in networks of care involving general and specialized centers in order to reduce time to diagnosis and ensure that all patients receive confirmatory tests. A high frequency of hepatobiliary complications since young age was observed suggesting that screening with ultrasound should begin earlier.

Integrative preimplantation genetic testing analysis for a Chinese family with hereditary spherocytosis caused by a novel splicing variant of SPTB

Hereditary spherocytosis (HS), the most common inherited hemolytic anemia disorder, is characterized by osmotically fragile microspherocytic red cells with a reduced surface area on the peripheral blood smear. Pathogenic variants in five erythrocyte membrane structure-related genes ANK1 (Spherocytosis, type 1; MIM#182900), SPTB (Spherocytosis, type 2; MIM#616649), SPTA1 (Spherocytosis, type 3; MIM#270970), SLC4A1 (Spherocytosis, type 4; MIM#612653) and EPB42 (Spherocytosis, type 5; MIM#612690) have been confirmed to be related to HS. There have been many studies on the pathogenic variants and mechanisms of HS, however, studies on how to manage the transmission of HS to the next-generation have not been reported. In this study, we recruited a patient with HS. Targeted next-generation sequencing with a panel of 208 genes related to blood system diseases detected a novel heterozygous variant in the SPTB: c.300+2dup in the proband. Sanger sequencing of variant alleles and haplotype linkage analysis of single nucleotide polymorphism (SNP) based on next-generation sequencing were performed simultaneously. Five embryos were identified with one heterozygous and four not carrying the SPTB variant. Single-cell amplification and whole genome sequencing showed that three embryos had varying degrees of trisomy mosaicism. One of two normal embryos was transferred to the proband. Ultimately, a healthy boy was born, confirmed by noninvasive prenatal testing for monogenic conditions (NIPT-M) to be disease-free. This confirmed our successful application of PGT in preventing transmission of the pathogenic variant allele in the HS family.

Utility of Cryohemolysis Test in the Diagnosis of Hereditary Spherocytosis

Diagnosis of Hereditary spherocytosis (HS) often requires time-consuming and/or expensive tests. Cryohemolysis test (CHT) is a simple and easy to perform test with high predictive value for HS diagnosis. In this prospective study, we evaluated the diagnostic utility of CHT for the diagnosis of HS. We included 60 suspected HS patients, 18 patients with Autoimmune hemolytic anemia (AIHA) and 120 healthy controls. Among the 60 suspected cases, there were 36 HS cases and 24 with other hemolytic anemias. The mean CHT (%) ± SD for controls, AIHA, other hemolytic anemias, and HS was 6.63 ± 2.79, 6.79 ± 4.36, 6.61 ± 2.76 and 26.7 ± 8.9, respectively. The CHT % was significantly higher in HS group when compared to controls (p =  < 0.0001), AIHA (p =  < 0.0001) and other hemolytic anemia groups (p =  < 0.0001). At a CHT cut off of > 18.3%, the sensitivity, specificity, positive predictive value and negative predictive value for diagnosis of HS in our study were 97.1%, 94.4%, 97.2% and 90.3%, respectively. CHT is a simple and sensitive test for the diagnosis of HS but remains underutilized. The addition of CHT in the diagnostic workup of HS will be very useful, especially in a resource limited setting.

Genotype-degree of hemolysis correlation in hereditary spherocytosis

BACKGROUND

Hereditary spherocytosis (HS) is a common inherited hemolytic anemia, caused by mutations in five genes that encode erythrocyte membrane skeleton proteins. The red blood cell (RBC) lifespan could directly reflect the degree of hemolysis. In the present cohort of 23 patients with HS, we performed next-generation sequencing (NGS) and Levitt's carbon monoxide (CO) breath test to investigate the potential genotype-degree of hemolysis correlation.

RESULTS

In the present cohort, we identified 8 ANK1,9 SPTB,5 SLC4A1 and 1 SPTA1 mutations in 23 patients with HS, and the median RBC lifespan was 14(8-48) days. The median RBC lifespan of patients with ANK1, SPTB and SLC4A1 mutations was 13 (8-23), 13 (8-48) and 14 (12-39) days, respectively, with no statistically significant difference (P = 0.618). The median RBC lifespan of patients with missense, splice and nonsense/insertion/deletion mutations was 16.5 (8-48), 14 (11-40) and 13 (8-20) days, respectively, with no significant difference (P = 0.514). Similarly, we found no significant difference in the RBC lifespan of patients with mutations located in the spectrin-binding domain and the nonspectrin-binding domain [14 (8-18) vs. 12.5 (8-48) days, P = 0.959]. In terms of the composition of mutated genes, 25% of patients with mild hemolysis carried ANK1 or SPTA1 mutations, while 75% of patients with mild hemolysis carried SPTB or SLC4A1 mutations. In contrast, 46.7% of patients with severe hemolysis had ANK1 or SPTA1 mutations and 53.3% of patients with severe hemolysis had SPTB or SLC4A1 mutations. However, there was no statistically significant difference in the distribution of mutated genes between the two groups (P = 0.400).

CONCLUSION

The present study is the first to investigate the potential association between genotype and degree of hemolysis in HS. The present findings indicated that there is no significant correlation between genotype and degree of hemolysis in HS.

Clinical Presentation of Parvovirus B19 Infection in Adults Living with HIV/AIDS: A Case Series

Parvovirus B19 (B19V) infection varies clinically depending on the host's immune status. Due to red blood cell precursors tropism, B19V can cause chronic anemia and transient aplastic crisis in patients with immunosuppression or chronic hemolysis. We report three rare cases of Brazilian adults living with human immunodeficiency virus (HIV) with B19V infection. All cases presented severe anemia and required red blood cell transfusions. The first patient had low CD4⁺ counts and was treated with intravenous immunoglobulin (IVIG). As he remained poorly adherent to antiretroviral therapy (ART), B19V detection persisted. The second patient had sudden pancytopenia despite being on ART with an undetectable HIV viral load. He had historically low CD4⁺ counts, fully responded to IVIG, and had undiagnosed hereditary spherocytosis. The third individual was recently diagnosed with HIV and tuberculosis (TB). One month after ART initiation, he was hospitalized with anemia aggravation and cholestatic hepatitis. An analysis of his serum revealed B19V DNA and anti-B19V IgG, corroborating bone marrow findings and a persistent B19V infection. The symptoms resolved and B19V became undetectable. In all cases, real time PCR was essential for diagnosing B19V. Our findings showed that adherence to ART was crucial to B19V clearance in HIV-patients and highlighted the importance of the early recognition of B19V disease in unexplained cytopenias.

Treatment of asymptomatic gallstones in children with hereditary spherocytosis requiring splenectomy

BACKGROUND

Gallstones are common in hereditary spherocytosis (HS) and other chronic hemolytic diseases, with most affected patients being asymptomatic. Whether and how asymptomatic gallstones should be treated is controversial.

METHODS

We conducted a retrospective cohort study of pediatric patients with HS and asymptomatic gallstones to compare the clinical outcomes between the observation group (followed up with gallstones in situ) and the intervention group (cholecystectomy or cholecystolithotomy). The primary outcome was the composite of adverse outcomes, including gallstone-associated, gallbladder surgery-associated, and splenectomy-associated events. Secondary outcomes included the changes in the size and number of gallstones and the recurrence of gallstones.

RESULTS

Fifty-two patients were included (38 in the observation group and 14 in the intervention group), with a mean follow-up length of 5.2 years. Patients in the intervention group had a lower incidence of primary outcomes (7.1% vs. 42.1%) than patients in the observation group (OR, 0.12; 95%CI, 0.01-0.99). Patients with gallstones >5 mm in diameter had the highest risk of adverse events (47.4%). In the observation group, gallstone growth, disappearance, and stability were observed in 19.4%, 29.0%, and 51.6% of splenectomized HS patients, respectively. Small gallstones (diameter ≤5 mm) or sludge were more likely to be associated with disappearance (P = 0.04).

CONCLUSIONS

Most asymptomatic gallstones grow or persist in splenectomized HS patients for an extended period. Surgical treatment of asymptomatic gallstones in HS patients requiring splenectomy is associated with a lower risk of adverse outcomes.

LEVELS OF EVIDENCE

III (retrospective comparative study).

Novel Variant of the SLC4A1 Gene Associated with Hereditary Spherocytosis

Hereditary spherocytosis (HS) refers to the group of the most frequently occurring non-immune hereditary hemolytic anemia in people of Caucasian central or northern European ancestry. HS is mainly associated with pathogenic variants of genes encoding defects in five membrane proteins, including anion exchanger 1 encoded by the SLC4A1 gene. In this study, in a family affected with HS, we identified a hitherto unreported AE1 defect, variant p.G720W. The result of it is most likely the HS phenotype. Molecular dynamics simulation study of the AE1 transmembrane domain may indicate reasonable changes in AE1 domain structure, i.e., significant displacement of the tryptophan residue towards the membrane surface connected with possible changes in AE1 function. The WES analysis verified by classical sequencing in conjunction with biochemical analysis and molecular simulation studies shed light on the molecular mechanism underlying this case of hereditary spherocytosis, for which the newly discovered AE1 variant p.G720W seems crucial.

Targeted next-generation sequencing identifies novel deleterious variants in ANK1 gene causing severe hereditary spherocytosis in Indian patients: expanding the molecular and clinical spectrum

Hereditary Spherocytosis (HS) is a common cause of hemolytic anemia varying from mild to severe hemolysis due to defects in red cell membrane protein genes, namely ANK1, SPTB, SPTA1, SLC4A1, and EPB42. These genes are considerably very large spaning 40-50 exons making gene-by-gene analysis costly and laborious by conventional methods. In this study, we explored 26 HS patients harboring 21 ANK1 variants identified by next-generation sequencing (NGS), characteristics and spectrum of the detected ANK1variants were analyzed in this study. Clinically, all the HS patients showed moderate to severe transfusion-dependent hemolytic anemia, some requiring splenectomy. We identified 13 novel and 8 reported variants, mainly 9 frameshifts, 2 missense, 6 nonsense, and 4 splice site ANK1 variants, using NGS technology. Frameshifts were remarkably the most common variant type seen in Indian HS patients with ANK1 gene defects. We have also explored expression levels of red cell membrane ankyrin protein by flow cytometry in 14 HS patients with ANK1 gene defects and a significant reduction in ankyrin protein expression has been found. This report mainly illustrates the molecular and phenotypic heterogeneity of ANK1 variants causing HS in Indian patients. Ankyrin-1 mutations are a significant cause of loss of function in dominant HS in the Indian population. Comprehensive genetic and phenotypic evaluation assists in implementing the knowledge of genetic patterns and spectrum of ANK1 gene variants, providing molecular support for HS diagnosis.

[Hereditary Spherocytosis and Pregnancy: A Case Report]

Even though it is a rare condition, hereditary spherocytosis (EH) is the main inherited cause of haemolytic anaemia and presents with a broad spectrum of symptoms. In the few reported cases of pregnancy and EH, maternal and foetal outcomes are controversial. Particularly, reports of pregnancies with EH associated with thrombosis or portal hypertension are scarce. We present a case of a woman who underwent splenectomy with EH and non-cirrhotic portal hypertension. Our patient presented polymorphisms of the methylenetetrahydrofolate reductase (MTHFR) and plasminogen activator inhibit-1 that have a controversial impact on thrombotic risk. During pregnancy, the woman showed no signs of haemodynamical or cirrhosis deterioration. Concerning the foetus, late-onset foetal growth restriction was diagnosed but did not determine preterm delivery. Five weeks post-partum after an episode of acute abdominal pain, mesenteric venous thrombosis was diagnosed. In this case report, we describe our experience in managing pregnancy, labour and post-partum of a woman with EH, highlighting potential complications of this condition.

Clinical manifestations of 17 Chinese children with hereditary spherocytosis caused by novel mutations of the ANK1 gene and phenotypic analysis

Background: Hereditary spherocytosis (HS) is an autosomal dominant (AD) and autosomal recessive (AR) disorder that is mostly caused by mutations of the erythrocyte membrane-related gene ANK1. Methods: Clinical and genetic testing data of 17 HS children with ANK1 gene mutations were retrospectively collected. Clinical manifestations and phenotypic analysis of HS were summarized based on our experience and literature review. Results: A total of 17 mutations of the ANK1 gene were identified from 17 probands (12 sporadic cases and five familial cases), including 15 novel mutations and two previously reported ones. Among the 15 novel variants of ANK1, there were four non-sense mutations, four frameshift mutations, three splicing mutations, three missense mutations and one in-frame deletion of three amino acids. In the present study, HS patients with mutations in membrane binding domains had significantly lower hemoglobin (Hb) levels and higher total bilirubin (T-Bil) levels than those with mutations in regulatory domains. After reviewing and analyzing all available published reports of Chinese HS patients carrying ANK1 mutations in PubMed and Chinese journals, there were no significant differences in Hb, Ret and T-Bil between different mutation types or mutation regions. Conclusion: Mutations of the ANK1 can be inherited or de novo. Clinical manifestations of HS in children caused by ANK1 mutations are similar to those of other types of hemolytic anemia. Our report expands the mutation spectrum of HS, thus providing references for clinical management and genetic counseling of HS.

A large family of hereditary spherocytosis and a rare case of hereditary elliptocytosis with a novel SPTA1 mutation underdiagnosed in Taiwan: A case report and literature review

RATIONALE

Hereditary spherocytosis (HS) has a defect in the vertically connected proteins on the cell membrane of red blood cells (RBC). Hereditary elliptocytosis (HE) has a defect in proteins that connect the cell membrane horizontally. We reported two families of RBC membrane disorders in Taiwanese, one was HS and the other was HE.

PATIENT CONCERNS

Case 1. A 19-year-old male student with chronic jaundice and splenomegaly. His mother, maternal uncle, grandmother, and many members of older generations also had splenomegaly and underwent splenectomy. Case 2. A 40-year-old man has experienced pallor and jaundice since the age of 20 and was found to have splenomegaly, and gall bladder stones in the older age. His younger sister also had pallor and jaundice for a long time.

DIAGNOSES

In case 1, a peripheral blood smear showed 20% spherocytes. Eosin-5-maleimide labeled RBC by flow cytometry showed a result of 30.6 MCF (cutoff value: 45.5 MCF). He was diagnosed with HS. The gene analysis identified a heterozygous mutation with c.166A > G (p.Lys56Glu) in the SLC4A1 gene in this proband, his mother, and maternal uncle. In case 2, more than 40% of ellipsoid RBC present in the peripheral blood smear. He was diagnosed with HE. Genetic analysis of the SPTA1 gene identified a novel heterozygous exon2, c.86A > C, p.Gln29Prol mutation.

INTERVENTIONS

The two patients had compensated anemia, clinical follow-up instead of splenectomy was done.

OUTCOMES

The two patients had normal daily activities and lives.

LESSONS

We reported two Taiwanese families, one was hereditary spherocytosis affected by a heterozygous mutation with c.166A > G (p.Lys56Glu) in SLC4A1, and the other was hereditary elliptocytosis caused by a novel heterozygous SPTA1 gene mutation, c. 86A > C, p.Gln29Prol. These 2 seemingly common hereditary red blood cell membrane protein defects induced by hemolysis are usually underdiagnosed or misdiagnosed.

Mutations and clinical characteristics of dRTA caused by SLC4A1 mutations: Analysis based on published patients

BACKGROUND AND AIMS

The genetic and clinical characteristics of patients with distal renal tubular acidosis (dRTA) caused by SLC4A1 mutations have not been systematically recorded before. Here, we summarized the SLC4A1 mutations and clinical characteristics associated with dRTA.

METHODS

Database was searched, and the mutations and clinical manifestations of patients were summarized from the relevant articles.

RESULTS

Fifty-three eligible articles involving 169 patients were included and 41 mutations were identified totally. Fifteen mutations involving 100 patients were autosomal dominant inheritance, 21 mutations involving 61 patients were autosomal recessive inheritance. Nephrocalcinosis or kidney stones were found in 72.27%, impairment in renal function in 14.29%, developmental disorders in 61.16%, hematological abnormalities in 33.88%, and muscle weakness in 13.45% of patients. The age of onset was younger (P < 0.01), urine pH was higher (P < 0.01), and serum potassium was lower (P < 0.001) in recessive patients than patients with dominant SLC4A1 mutations. Autosomal recessive inheritance was more often found in Asian patients (P < 0.05).

CONCLUSIONS

The children present with metabolic acidosis with high urinary pH, accompanying hypokalemia, hyperchloremia, nephrocalcinosis, growth retardation and hematological abnormalities should be suspected as dRTA and suggested a genetic testing. The patients with recessive dRTA are generally more severely affected than that with dominant SLC4A1 mutations. Autosomal recessive inheritance was more often found in Asian patients, and more attentions should be paid to the Asian patients.

A Novel SPTA1 Mutation in a Patient with Hereditary Spherocytosis without a Family History and Coexisting Gilbert's Syndrome

Most patients with hereditary spherocytosis (HS) have a family history of disease, while those without such a history are difficult to diagnose. We herein report a case of HS with no family history harboring a novel heterozygous mutation of SPTA1, c.2161G>A (p.E721K), and a homozygous polymorphism of UGT1A1*6. In silico analyses suggested that the mutation might contribute to the pathogenesis of HS. The coexistence of HS and Gilbert's syndrome increases the risk of gallstones. Therefore, splenectomy, alone or in combination with cholecystectomy, is recommended. The determination of genetic diathesis provides useful information for the management of hemolytic anemia.

A novel splicing mutation of ANK1 is associated with phenotypic heterogeneity of hereditary spherocytosis in a Chinese family

Hereditary spherocytosis (HS) is a common hematological genetic disorder that results in anemia, jaundice and splenomegaly. It is caused by mutations in the ANK1, SPTA, SPTB, SLC4A1 and EPB42 genes, which encode red blood cell membrane and skeletal proteins. Patients show high heterogeneity in phenotype and genotype and the genotype-phenotype correlation still requires clarification. Here, a novel splicing mutation (ANK1: c.4391-2 A>C) was identified by whole-exome sequencing (WES) and Sanger sequencing in a Chinese boy who exhibited a moderately severe HS phenotype. However, his father exhibited a mild phenotype, despite carrying the same HS-causing mutation. The function of the mutant ANK1 protein was analyzed by both bioinformatics and experimental analysis. The mutant protein (p.N1463Kfs*4) showed a different 3D-structure and altered subcellular localization, when compared with the wild-type ANK1 protein. These changes disrupted the normal cell membrane structure and resulted in spheroidized red blood cells. Amplification of cDNA from the son and his father revealed a difference in expression of the abnormal transcript produced by the splicing mutation. We proposed that the lower expression of the mutant allele may have contributed to the relatively mild symptoms of the father. Our study verified ANK1 c. c.4391-2 A>C as a novel pathogenic mutation that causes HS. We have also provided new insights into the interpretation of phenotypic variability within families, which could greatly improve the clinical diagnosis and genetic counseling of HS.

A novel variant of SLC4A1 for hereditary spherocytosis in a Chinese family: a case report and systematic review

BACKGROUND

The incidence of hereditary spherocytosis (HS) is approximately 1:2000 in the western population, while it is much lower in the Chinese population. It is difficult to make a definite diagnosis due to the variable genotypic features and the lack of well-documented evidence for HS patients. Gene sequence examination is helpful for clear diagnosis.

CASE PRESENTATION

We presented the case of a 29-year-old male HS patient with skin yellowness, anorexia, and cholecystolithiasis as the first manifestations. Laboratory examination of the patient and his parents showed a mild reduction in hemoglobin and mean corpuscular hemoglobin concentration, increased reticulocytes, and promotion of indirect bilirubin in the patient and his father. Furthermore, small globular red blood cells with increased osmotic fragility were observed. In particular, the eosin-5'-maleimide binding test provided the strong evidence that band 3 protein was deleted in the erythrocyte membrane. Next-generation sequencing (NGS) and Sanger sequencing further demonstrated a heterozygous nonsense variant (exon16, c.G1985A: p.W662X) in SLC4A1, inherited from his father. Thus, the patient was diagnosed with HS, and then was effectively treated. After splenectomy, the anemia was relieved without any obvious unpleasant side effects.

CONCLUSION

We report an extremely rare case of HS in China that presented with hereditary hemolytic anemia with band 3 deletion resulting from a novel variant of SLC4A1, and systematically review a large number of related literatures. This study, therefore, significantly contributes to the literature on HS.

Identification of a novel ANK1 mutation in a Chinese family with hereditary spherocytosis: A case report

The present study describes the clinical profile and ankyrin 1 (ANK1) mutation status of a Chinese family with hereditary spherocytosis (HS). A young male patient (proband) was diagnosed with HS after presenting with anaemia and jaundice. The Coombs test was negative and spherocytes were found in peripheral blood smears. Magnetic resonance imaging showed splenomegaly and splenic iron depositions. The red blood cell osmotic fragility test was positive. The eosin-5'-maleimide binding test showed reduced mean channel fluorescence. Whole-exome sequencing revealed a novel ANK1 mutation (c.4707G>A), resulting in a nonsense mutation (p.Trp1569*). The patient's father, paternal aunt and paternal grandmother exhibited comparable clinical symptoms and Sanger sequencing confirmed the same mutation in these family members. To the best of our knowledge, an HS pedigree with this novel ANK1 nonsense mutation has not been previously reported. At the same time, the unique clinical presentation of this pedigree helps our understanding of the heterogeneity of clinical manifestations of HS.

Literature review on genotype-phenotype correlation in patients with hereditary spherocytosis

Hereditary spherocytosis (HS) is a prevalent inherited hemolytic disorder primarily reported in Caucasians. Recently, next-generation sequencing (NGS) techniques have shown tremendous potential in the diagnosis of HS. HS commonly originates from variants in ANK1, SPTB, SLC4A1, SPTA1, and EPB42. This review is focused on thirteen previous clinical studies on genotype-phenotype correlation, which might promote the role of causative variants in the diagnosis and prognosis of HS. Most studies were focused on the pediatric population and Asian countries. The occurrence of novel variants was common in each cohort, and variants with a high frequency of causative genes were demonstrated. In conclusion, patients with variants in SPTA1 and SLC4A1 were reported to have more severe and milder anemia, respectively. ANK1 and SPTB are the most common variants in patients with HS, and no significant difference in phenotypes was observed between patients with variants in ANK1 vs SPTB. The types and locations of variants might influence the phenotype of each genotype, whereas the roles of concomitant pathogenic genes and the source of variants deserve further investigation.

[Congenital hemolytic anemias due to erythrocyte membrane and enzyme defects]

Erythrocyte membrane and enzyme defects are the most common cause of congenital hemolytic anemias in the Central European population. Diagnostics include erythrocyte morphology, special biochemical tests such as osmotic fragility (AGLT) and EMA. For enzymopenic hemolytic anemias, cost-effective biochemical analysis remains the gold standard, supplemented by molecular genetic diagnostics when appropriate. Therapeutically, near complete splenectomy reduces hemolysis significantly for spherocytosis. The residual spleen at least provides a considerable phagocytic function and better response to immunisation and by inference possibly better protection against severe post-splenectomy infection. For pyruvate kinase deficiency, which is not so rare, a new molecular therapy (Mitapivat) is currently being introduced. In G6PD deficiency, there are very few drugs that cause hemolytic crisis. Sudden onset of hemoglobinuria is an early important hallmark of severe hemolytic crisis in G6PD deficiency and these patients should be hospitalized. Aplastic crises in the setting of parvovirus B19 infection occur in all congenital hemolytic anemias. Transfusion is not preventable in most cases. Iron-excreting treatment is required in the rare patients in need of chronic transfusion.

Effect of primary lesions in cytoskeleton proteins on red cell membrane stability in patients with hereditary spherocytosis

We investigated by targeted next generation sequencing the genetic bases of hereditary spherocytosis in 25 patients and compared the molecular results with the biochemical lesion of RBC membrane obtained by SDS-PAGE analysis. The HS diagnosis was based on available guidelines for diagnosis of congenital hemolytic anemia, and patients were selected because of atypical clinical presentation or intra-family variability, or because presented discrepancies between laboratory investigation and biochemical findings. In all patients but 5 we identified pathogenic variants in SPTA1, SPTB, ANK1, SLC4A1, EPB42 genes able to justify the clinical phenotype. Interestingly, a correspondence between the biochemical lesion and the molecular defect was identified in only 11/25 cases, mostly with band 3 deficiency due to SLC4A1 mutations. Most of the mutations in SPTB and ANK1 gene didn’t hesitate in abnormalities of RBC membrane protein; conversely, in two cases the molecular lesion didn’t correspond to the biochemical defect, suggesting that a mutation in a specific cytoskeleton protein may result in a more complex RBC membrane damage or suffering. Finally, in two cases the HS diagnosis was maintained despite absence of both protein defect and molecular lesion, basing on clinical and family history, and on presence of clear laboratory markers of HS. The study revealed complex relationships between the primary molecular lesion and the final effect in the RBC membrane cytoskeleton, and further underlines the concept that there is not a unique approach to the diagnosis of HS.

Hereditary spherocytosis before and after splenectomy and risk of hospitalization for infection

BACKGROUND

The infectious burden in hereditary spherocytosis (HS) children before splenectomy has rarely been reported and the risk of severe postsplenectomy infection is controversial.

METHODS

We conducted a retrospective study of pediatric patients with HS to evaluate the risk of infection presplenectomy and postsplenectomy. The primary outcome was any bacterial, Mycoplasma, or fungal infection that required hospitalization. The secondary outcomes were sepsis and septic shock. Appendectomized children were matched on age at surgery and enrolled as controls.

RESULTS

In all, 232 patients were included. Before splenectomy, the primary outcome was identified in 51 (22.0%) patients, and the secondary outcome was identified in 1 (0.4%) patient. After splenectomy, the primary and secondary outcomes were detected in 8 (4.1%) and 1 (0.5%) patients, respectively. The risk of infection was higher presplenectomy than postsplenectomy (OR, 6.6; 95% CI, 3.0-14.2). HS patients had a higher risk of infection than the controls before surgery (OR, 3.7; 95% CI, 2.3-5.9) but not after surgery (OR, 1.4; 95% CI, 0.6-3.6).

CONCLUSIONS

HS patients who require splenectomy later in life had a high incidence of hospitalization for infections. In contrast, postsplenectomy risk of hospitalization involving infection or severe infection was low.

IMPACT

Patients with hereditary spherocytosis who require splenectomy later in life have a high risk of hospital admission for infections, especially those with severe hereditary spherocytosis. With vaccines or postoperative antibiotics, splenectomy does not increase the risk of infection or severe infections. Splenectomy may reduce the risk of hospitalization for infections by alleviating the complications of hereditary spherocytosis. With vaccines, prophylaxis, or advanced antibiotics, the benefits of splenectomy in children with hereditary spherocytosis and a heavy disease burden may outweigh the risks.

Novel SPTB frameshift mutation in a Chinese neonatal case of hereditary spherocytosis type 2: A case report

Hereditary spherocytosis (HS) is an erythrocyte membrane disease with a non-specific phenotype, particularly occurring in neonatal patients, and its diagnosis is challenging. The present study reports on a patient with neonatal HS and reviewed the genetic characteristics of reported neonatal HS cases in China. The patient was admitted only a few hours after birth with jaundice. Auxiliary examination indicated anemia and hyperbilirubinemia. Spherical erythrocytes were occasionally observed in peripheral blood smears. Genetic testing suggested that the patient harbored a novel frameshift mutation (p.Asp495fsTer78) in spectrum, β, erythrocytic (SPTB), which was carried by the father. Review of 160 cases of HS in China revealed 24 to be neonatal cases. In these neonatal cases, the frequency of ankyrin 1 (ANK1) mutations and loss-of-function mutations of pathogenic genes (including ANK1 and SPTB) was higher than that in the non-neonatal group. In conclusion, the present study further expanded the mutation spectrum of SPTB and reaffirms the diagnostic value of gene detection in neonatal HS.

Whole-exome sequencing uncovered genetic diagnosis of severe inherited haemolytic anaemia: Correlation with clinical phenotypes

Next-generation sequencing has shed light on the diagnosis of previously unsolved cases of inherited haemolytic anaemia (IHA). We employed whole-exome sequencing to explore the molecular diagnostic spectrum of 21 unrelated Thai paediatric patients with non-thalassemic IHA, presenting hydrops fetalis and/or becoming transfusion-dependent for 1 year or more or throughout their lifespan. Anaemia was detected prenatally, within the first month and the fifth year of life in three, 12 and six patients respectively. Molecular diagnosis obtained from all patients revealed SPTB as the most frequently mutated gene (four reported, three novel), found in 31 of 42 studied alleles. The other two mutated genes identified were ANK1 (three novel) and KLF1 (two reported). Four recurring mutations within exon 29/30 (NM_001024858.2) accounted for the vast majority (90%) of mutated SPTB alleles, biallelic inheritance of which resulted in the most severe phenotypes: hydrops fetalis and life-long transfusion dependency. Dominant ANK1 (n = 3) and SPTB (n = 2) mutations and biallelic class 2 KLF1 mutations (n = 1) led to a shorter period of transfusion dependency. Our study demonstrated that mutated SPTB causing red-cell membranopathy is likely the most common cause of severe non-thalassemic IHA among Thai patients. This urges carrier screening in the population to prevent subsequent, severely affected births.

Targeted next-generation sequencing identifies a novel nonsense mutation in ANK1 for hereditary spherocytosis: A case report

BACKGROUND

Hereditary spherocytosis (HS) is characterized by anemia, jaundice, splenomegaly, and cholelithiasis, and is caused by abnormal genes encoding red blood cell membrane components. The most common mutations found in HS are in the ANK1 gene.

CASE SUMMARY

A 4-mo-old girl was admitted to our hospital with pallor that had lasted for more than 2 mo. She presented with jaundice, anemia and splenomegaly. A heterozygous mutation of ANK1 (exon23: c.G2467T:p.E823X) was identified, and the mutation was determined to be autosomal dominant. This mutation is linked to the relatively serious anemia she had after birth; this anemia improved with age.

CONCLUSION

The utilization of next-generation sequencing may assist with the accurate diagnosis of HS, especially in atypical cases.

Korean clinical practice guidelines for the diagnosis of hereditary hemolytic anemia

Although the prevalence of hereditary hemolytic anemia (HHA) is relatively low in Korea, it has been gradually increasing in recent decades due to increment in the proportions of hemoglobinopathies from immigrants of South East Asia, raising awareness of the disease among clinicians, and advances in diagnostic technology. As such, the red blood cell (RBC) Disorder Working Party (WP), previously called HHA WP, of the Korean Society of Hematology (KSH) developed the Korean Standard Operating Procedures (SOPs) for the diagnosis of HHA in 2007. These SOPs have been continuously revised and updated following advances in diagnostic technology [e.g., flow cytometric osmotic fragility test (FOFT) and eosin-5-maleimide (EMA) binding test], current methods for membrane protein or enzyme analysis [e.g., liquid chromatography-tandem mass spectrometry (LC-MS/MS), ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS), high-performance liquid chromatography (HPLC)], and molecular genetic tests using next-generation sequencing (NGS). However, the diagnosis and treatment of HHA remain challenging as they require considerable experience and understanding of the disease. Therefore, in this new Korean Clinical Practice Guidelines for the Diagnosis of HHA, on behalf of the RBC Disorder WP of KSH, updated guidelines to approach patients suspected of HHA are summarized. NGS is proposed to perform prior to membrane protein or enzyme analysis by LC-MS/MS, UPLC-MS/MS or HPLC techniques due to the availability of gene testing in more laboratories in Korea. We hope that this guideline will be helpful for clinicians in making diagnostic decisions for patients with HHA in Korea.

How to approach haemolysis: Haemolytic anaemia for the general physician

Haemolytic anaemia can seem like a complicated topic. The constellation of reticulocytosis, increased lactate dehydrogenase levels, increased unconjugated bilirubin levels and decreased haptoglobin levels should prompt general physicians to consider haemolysis as a differential diagnosis. When further approaching haemolytic anaemia, subdividing patients into those who are 'direct antiglobulin test (DAT) positive' (immune) or 'DAT negative' (non-immune) is a simple and clinically relevant way to start to formulate a cause for the haemolytic anaemia. Immune causes of haemolytic anaemia include autoimmune haemolytic anaemia, drugs and delayed haemolytic transfusion reactions. Non-immune causes include the haemoglobinopathies (such as sickle cell disease) and microangiopathic haemolytic anaemias (such as disseminated intravascular coagulation). Early supportive care in haemolytic anaemia is important and may involve blood transfusions as well as interventions to slow the rate of haemolysis, such as steroids in autoimmune haemolytic anaemia. Complications of haemolysis include pigment gallstones, high-output cardiac failure and thromboembolism. Haemolytic anaemia should be referred to the haematologist for further investigation, however, the recognition and early management by the general physician is imperative in improving the patient's outcome.

Spectrins and human diseases

Spectrin, as one of the major components of a plasma membrane-associated cytoskeleton, is a cytoskeletal protein composed of the modular structure of α and β subunits. The spectrin-based skeleton is essential for preserving the integrity and mechanical characteristics of the cell membrane. Moreover, spectrin regulates a variety of cell processes including cell apoptosis, cell adhesion, cell spreading, and cell cycle. Dysfunction of spectrins is implicated in various human diseases including hemolytic anemia, neurodegenerative diseases, ataxia, heart diseases, and cancers. Here, we briefly discuss spectrins function as well as the clinical manifestations and currently known molecular mechanisms of human diseases related to spectrins, highlighting that strategies for targeting regulation of spectrins function may provide new avenues for therapeutic intervention for these diseases.

Screening for hereditary spherocytosis in daily practice: what is the best algorithm using erythrocyte and reticulocyte parameters?

Hereditary spherocytosis (HS) is the most common inherited chronic haemolytic anaemia in Northern Europe. During the last decade, additional erythrocyte and reticulocyte parameters have been developed on last-generation haematology analysers, leading to many publications about their effectiveness as a HS screening tool. For the first time on an independent cohort, we evaluated and compared the effectiveness of six published algorithms for the screening of HS using the UniCel DxH800 (Beckman-Coulter) and the XN-9000 (Sysmex) and determined which algorithm could be the most suitable in our daily clinical practice. A total of 95 EDTA samples were analysed prospectively on both haematology analysers. These included 11 confirmed HS patients and 84 non-HS patients. The specific reticulocyte parameters used on the DxH800 were mean reticulocyte volume, immature reticulocyte fraction and mean sphered cell volume, and on the XN-9000 were hypohaemoglobinised erythrocytes, microcytic erythrocytes and immature reticulocyte fraction. The three algorithms using parameters specific to Beckman-Coulter analysers provided a sensitivity of 100% with various specificities, ranging from 7.1 to 73.8%. The three algorithms published based on the parameters specific to Sysmex showed much lower performances, i.e. out of the 11 patients with HS, between one to five patients were screened as negative for HS. However, 100% sensitivity and specificity were reached using the EMA binding test concomitantly with those three algorithms. The algorithms using reticulocyte and erythrocyte parameters offered by the recent analysers are promising options as a HS first-tier screening tool. Nevertheless, they must be evaluated by each laboratory on their own analyser before implementation.

Splenic infarction after Epstein–Barr virus infection in a patient with hereditary spherocytosis: a case report and literature review

Background

Hereditary spherocytosis (HS) complicated by splenic infarction is very rare, and it is even rarer to develop splenic infarction after infectious mononucleosis (IM) as a result of Epstein–Barr virus (EBV) infection. Therefore, misdiagnosis or missed diagnosis is prone to occur.

Case presentation

A 19-year-old Chinese female previously diagnosed with HS was admitted to our institution with persistent high fever and icterus. On admission, the physical examination showed anemia, jaundice, marked splenomegaly, obvious tenderness in the left upper abdomen (LUA). Peripheral blood film shows that spherical red blood cells accounted for about 6%, and Immunoglobulin M (IgM) antibodies specific to Epstein–Barr virus (EBV) viral capsid antigen were detected. An abdominal CT scan revealed a splenic infarction. The patient was diagnosed with HS with splenic infarction following EBV infection and underwent an emergency laparoscopic splenectomy (LS). Pathological analysis showed a splenic infarction with red pulp expansion, white pulp atrophy and a splenic sinus filled with red blood cells. After two months of follow-up visits, the patient showed no signs of relapse.

Conclusions

HS complicated by splenic infarction is very rare and mostly occurs in men under 20 years of age and is often accompanied by other diseases, such as sickle cell traits (SCT) or IM. Although symptomatic management may be sufficient, emergency laparoscopic splenectomy may be safe and effective when conservative treatment is ineffective.

Clinical Features and Outcome of Children With Hereditary Spherocytosis

OBJECTIVE

The aim of this study was to evaluate the demographics, clinical, and laboratory findings and treatment responses of patients with hereditary spherocytosis (HS).

MATERIALS AND METHODS

Data of children with HS were examined. Diagnosis was based on clinical history, physical examination, family history, presence of spherocytes on peripheral blood smear, and osmotic fragility test.

RESULTS

A total of 101 patients were included. The median (range) age at diagnosis was 38.0 (1 to 188) months. Mild, moderate, and severe forms of HS were present in 29 (28.7%), 15 (14.9%), and 57 (56.4%) patients, respectively. Family history was available in 73 patients and 56 of these (76.7%) had a positive family history for HS. Forty-five (44.5%) patients needed regular transfusions and all of these had severe disease. Although most patients did not require transfusion postsplenectomy, 2 of 45 (4.4%) patients continued to require transfusion. Transfusion dependence was significantly (P<0.001) higher in patients with severe spherocytosis.

CONCLUSIONS

In HS, splenomegaly, pallor, and jaundice are the most common clinical features. Splenectomy dramatically reduces hemolysis in most cases and virtually abolishes further requirement for transfusion.

Super-Selective Partial Splenic Embolization for Hereditary Spherocytosis in Children: A Single-Center Retrospective Study

Background

Hereditary spherocytosis (HS) is the most common hemolytic anemia due to erythrocyte membrane defects. Total splenectomy is the most effective treatment for moderate or severe HS. As a conservative alternative, partial splenic embolization (PSE) can preserve part of the spleen's function, thus reducing the risk of overwhelming post-splenectomy infection (OPSI) or sepsis, especially for pediatric patients. However, it is not easy to precisely control the scope of interventional embolization, limiting PSE applications. The present study aims to optimize the PSE procedure on smaller, which is named super-selective PSE (SPSE), to improve the controllability and assess the feasibility and effectiveness of SPSE.

Results

This study was conducted by retrospectively reviewing clinical data from HS patients treated by surgical treatments, which were diagnosed at the children's hospital of Chongqing medical university from January 2015 to December 2019. Patients were divided into two groups according to their treatment preference: SPSE (16 patients) group and total splenectomy (41 patients) group. The mean proportion range of splenic embolism by SPSE was 82.4%, close to the expected value (70–85%). The average hemoglobin value was increased significantly from 6.85 (5.6–8.0) g/dl before SPSE to 12.4 (10.4–13.3) g/dl after SPSE (p < 0.001). All children after SPSE suffered mild post-embolization syndrome, such as pain, fever, and vomiting, which could easily be controlled with appropriate supportive therapy.

Conclusions

Super-selective partial splenic embolization is a safe and effective treatment for moderate or severe HS in children. However, with a longer follow-up, more patients further assess the value of SPSE.

Hereditary Spherocytosis With Liver Transplantation After Cirrhosis: A Case Report

The clinical manifestations of hereditary spherocytosis are similar to those of various hemolytic anemias, which causes hereditary spherocytosis to be difficult to diagnose clinically. In this case, we obtained the peripheral blood of a patient and family members, and through a whole exome test of the 6,297 genetic phenotypes confirmed by OMIM, we found a heterozygous nonsense mutation (c.4117C>T, P.Q1373X) in the SPTB gene. Combined with the patient's clinical data, the diagnosis was hereditary spherocytosis. Compared with the public population sequence database, the mutation was found to be unique. Through protein structure prediction analysis and literature studies, we found that the mutation may cause SPTB mRNA instability, resulting in insufficient spectrin protein synthesis and affecting the integrity and flexibility of the red blood cell membrane skeleton. This case report found that SPTB gene mutations may cause liver dysfunction and cirrhosis in addition to hereditary spherocytosis, and this finding expands the phenotypic spectrum of SPTB. This study confirmed that NGS can be used to diagnose hereditary spherocytosis. Identifying mutated genes can not only accurately treat diseases, but also avoid potential genetic risks and improve prenatal and postnatal care.

[Characteristics of bone marrow compensatory erythropoiesis in hereditary spherocytosis]

Objective: To reveal the compensatory features of bone marrow (BM) erythropoiesis in hereditary spherocytosis (HS) and to explore the effect of diferent hemoglobin levels on this compensation. Methods: Clinical and laboratory data of patients with HS were collected, and the peripheral blood absolute reticulocytes counts value was taken as the surrogate parameter to evaluate the ability of erythropoiesis compensation. BM erythropoiesis compensation in HS with diferent degrees of anemia were evaluated. Results: ①Three hundred and two patients were enrolled, including 115 with compensated hemolytic disease, 74 with mild anemia, 90 with moderate anemia, and 23 with severe anemia. ②Hemoglobin (HGB) was negatively correlated with serum erythropoietin in the decompensated hemolytic anemia group (EPO; rs=-0.585, P<0.001) . ③The median absolute reticulocyte count (ARC) of HS patients was 0.34 (0.27, 0.44) ×10(12)/L, up to 4.25 times that of normal people. The maximum ARC was 0.81×10(12)/L, about 10 times that of normal people. The median ARC of patients with compensated hemolytic disease was 0.29 (0.22, 0.38) ×10(12)/L, up to 3.63 times that of normal people. The median ARC of patients with hemolytic anemia was 0.38 (0.30, 0.46) ×10(12)/L, which was significantly higher than the patients with compensated hemolytic disease, up to 4.75 times that of normal people (z=4.999, P=0.003) . ④ ARC was negatively correlated with HGB in the compensated hemolytic disease group (rs=-0.177, P=0.002) and positively correlated with HGB in the decompensated hemolytic anemia group (rs=0.191, P=0.009) . There was no significant difference in the ARC among patients with mild, moderate, and severe anemia (χ(2)=4.588, P=0.101) . ⑤The median immature reticulocyte production index of the mild, moderate, and severe anemia groups was 13.1% (9.1%, 18.4%) , 17.0% (13.4%, 20.8%) , and 17.8% (14.6%, 21.8%) , respectively; the mild anemia group had lower index values than the moderate and severe anemia groups (P(adj) values were both<0.05) , but there was no significant difference between the latter groups (P(adj)=1.000) . The median immature reticulocyte count of patients in the mild, moderate, and severe groups was 5.09 (2.60, 7.74) ×10(10)/L, 6.24 (4.34, 8.83) ×10(10)/L, and 7.00 (3.07, 8.22) ×10(10)/L, respectively; there was no significant difference among the groups (χ(2)=3.081, P=0.214) . Conclusion: HGB can be maintained at a normal level through bone marrow erythropoiesis, while red blood cells are reduced in HS. However, once anemia develops, the bone marrow exerts its maximum erythropoiesis capacity and does not increase, regardless of anemia aggravation or serum EPO increase.

A novel SPTB mutation causes hereditary spherocytosis via loss-of-function of β-spectrin

Hereditary spherocytosis (HS) is the most frequently observed chronic non-immune hemolytic disorder caused by altered red cell membrane function. SPTB gene mutation is one of the most common causes of HS, but pathogenicity analyses and pathogenesis research on these mutations have not been widely conducted. In this study, a novel heterozygous mutation of the SPTB gene (c.1509_1518del; p.K503Nfs*67) was identified in a Chinese family with HS by whole-exome sequencing (WES) and was then confirmed by Sanger sequencing. Next, the pathogenicity and pathogenesis of this mutation were studied using peripheral blood. We found that this mutation disrupted the synthesis and localization of β-spectrin and weakened the interaction between β-spectrin and ankyrin, which may be caused by the nonsense-mediated mRNA degradation pathway. These changes lead to the transformation of discoid erythrocytes into spherocytes, resulting in hemolytic anemia. Therefore, we classified this novel mutation as a pathogenic mutation leading to loss-of-function of β-spectrin. It would be insightful to perform the same mutation test and to provide genetic counseling to other relatives of the proband. Our study increases the current understanding of the molecular mechanisms related to mutations in SPTB.

Study on Management of Blood Transfusion Therapy in Patients with Hereditary Spherocytosis

Hereditary spherocytosis (HS) is a chronic hemolytic disorder caused by inherited defects in the red blood cell membrane. This study discusses the treatment strategy for the decline in hemoglobin level in three HS probands with moderately severe or severe hemolysis and summarizes the appropriate laboratory tests that help improve clinical management of blood transfusion in HS patients. Three probands who were diagnosed with HS in our hospital and their family members were included in this study. Clinical data of the three families were reviewed to summarize their hematopoietic characteristics. DNA from all family members of the 3 HS probands was amplified by polymerase chain reaction (PCR) and sequenced by the Sanger method to assess genetic relation for HS. Based on the sequencing results, the type of mutated membrane protein in each proband was analyzed using the eosin-5'-maleimide (EMA) binding test and sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). The hemoglobin level was reduced in all 3 probands after different levels of infection. The fluorescence of EMA-labeled red blood cell (RBC) was decreased. DNA sequencing showed that His54Pro, Leu1858Val, and 6531-12C>T compound heterozygous mutations were present in the SPTA1 gene of patient I-1, Arg344Gln and c.609+86G>A heterozygous mutations were present in the SLC4A1 gene of patient II-1, and Leu2032Pro homozygous mutation was present in the SPTB gene of patient III-1. SDS-PAGE results demonstrated that the concentration of band 3 was reduced in II-1, whereas the levels of the corresponding mutant proteins in the other probands were unchanged. The family members of the respective patients presented mutations in major genes causing HS. The Leu2032Pro mutation identified in patient III-1 is a new missense mutation of the SPTB gene in the Chinese population that has never been reported in literature previously. The presence or absence of acute or chronic infections is a critical deciding factor for the treatment and clinical management of HS patient via blood transfusion. For patients with infections, hemoglobin concentration can be restored once the infection is controlled, thus obviating the need for proper infection control before blood transfusion.