INTRODUCTION: Haemoglobinopathy testing is performed for carrier screening and evaluation of microcytic anaemia. We evaluated the effectiveness of thalassaemia screening tests at our institution and suggest ways of improving the testing algorithm. MATERIALS AND METHODS: A total of 10,084 non-antenatal and 11,364 antenatal samples with alkaline gel electrophoresis (AGE), capillary electrophoresis (CE), haemoglobin H (HbH) inclusion test, mean corpuscular haemoglobin (MCH) and mean corpuscular volume (MCV) were retrospectively reviewed. A subgroup of 187 samples with genetic testing was correlated with HbH inclusions and MCH/ MCV. The effect of iron deficiency on percentage hemoglobin A2 (HbA2) was studied. RESULTS: HbH inclusion test showed low sensitivity of 21.43% for α-thalassaemia mutations but higher sensitivity of 78.95% for deletion. By receiver operating characteristic (ROC) analysis, MCH ≤28 pg or MCV ≤80 fl for non-antenatal samples and MCH ≤27 pg or MCV ≤81 fl for antenatal samples had >98% sensitivity for HbH inclusions. Above these thresholds, the probability that HbH inclusions would be absent was <99% (negative predictive value [NPV] >99%). MCH ≥28 pg had 100% sensitivity (95% CI 95.63%-100%) for α-thalassaemia mutations and 97.68% calculated NPV in the antenatal population. Detection of haemoglobin variants by CE correlated highly with AGE (99.89% sensitivity, 100% specificity). Severe iron deficiency reduced HbA2 in hemoglobin ( <0.001) and α-thalassaemia ( = 0.0035), but not in β-thalassaemia. CONCLUSION MCH/MCV thresholds have adequate sensitivity for α-thalassaemia in the antenatal population, and genotyping plays an important role as HbH inclusion test shows low sensitivity. CE without AGE, may be used as initial screening for haemoglobin variants. Our study provides contemporary data to guide thalassaemia screening algorithms in Singapore.
Blood Protein Electrophoresis ; Electrophoresis, Capillary ; Erythrocyte Inclusions ; pathology ; Erythrocyte Indices ; Female ; Genetic Testing ; Hemoglobin H ; analysis ; Humans ; Male ; Mass Screening ; Pregnancy ; Pregnancy Complications, Hematologic ; blood ; diagnosis ; Retrospective Studies ; Sensitivity and Specificity ; Singapore ; alpha-Thalassemia ; blood ; diagnosis

This study was purposed to investigate the relationship between HLA-A, B allele polymorphisms and red blood cell parameters of patients with --(SEA/αα) subtype of α(0)-thalassemia in Han ethnic population of Wuzhou city. The HLA genetic polymorphisms were determined by polymerase chain reaction-sequence-based typing (PCR-SBT) in 57 patients with --(SEA/αα) subtype of α(0)-thalassemia of Han ethnic population in Wuzhou city, Guangxi province, China. Mean corpuscular volume (MCV), hemoglobin (Hb), mean corpuscular hemoglobin (MCH) and mean corpuscular hemoglobin concentration (MCHC) were detected by automatic blood analyzer system. HbA2 were detected by electrophoretic method. The statistical analysis was performed by ordinal polytomous logistic regression. The results showed that Hb and HbA2 levels were significantly lower in patients positive for HLA-A*33:03, B*15:01 or B*55:02, and were significantly higher in patients positive for B*15:02 (P < 0.05). It is concluded that several HLA alleles may be associated with Hb level of --(SEA/αα) subtype of α(0)-thalassemia of Han ethnic population in Wuzhou city. This result has the value for understanding phenotype-genotype relationships in thalassemia.
Adolescent ; Adult ; Alleles ; Child ; Child, Preschool ; China ; epidemiology ; Erythrocytes ; cytology ; Ethnic Groups ; genetics ; Female ; Genotype ; HLA-A Antigens ; genetics ; HLA-B Antigens ; genetics ; Hemoglobins, Abnormal ; genetics ; Humans ; Male ; Middle Aged ; Young Adult ; alpha-Thalassemia ; blood ; classification ; epidemiology ; genetics

Hereditary spherocytosis (HS) is a genetic disorder characterized by the production and destruction of spherocytes due to a deficiency of red cell membrane cytoskeletal proteins, resulting in the clinical presentation of chronic hemolytic anemia. This disease can be accompanied by an aplastic crisis due to parvovirus B19 infection. Parvovirus B19 infection causes diseases such as erythema infectiosum and arthritis, and can also trigger various autoimmune diseases, including autoimmune hemolytic anemia (AIHA). Here, we report a rare case of AIHA developing 3 months after an aplastic crisis due to parvovirus B19 infection in an 11-year-old boy with HS and provide the relevant literature review.
Anemia, Hemolytic ; Anemia, Hemolytic, Autoimmune ; Arthritis ; Autoimmune Diseases ; Cell Membrane ; Child ; Cytoskeletal Proteins ; Erythema Infectiosum ; Humans ; Parvovirus ; Spherocytes ; Spherocytosis, Hereditary

Hereditary spherocytosis (HS) is a genetic disorder characterized by the production and destruction of spherocytes due to a deficiency of red cell membrane cytoskeletal proteins, resulting in the clinical presentation of chronic hemolytic anemia. This disease can be accompanied by an aplastic crisis due to parvovirus B19 infection. Parvovirus B19 infection causes diseases such as erythema infectiosum and arthritis, and can also trigger various autoimmune diseases, including autoimmune hemolytic anemia (AIHA). Here, we report a rare case of AIHA developing 3 months after an aplastic crisis due to parvovirus B19 infection in an 11-year-old boy with HS and provide the relevant literature review.
Anemia, Hemolytic ; Anemia, Hemolytic, Autoimmune ; Arthritis ; Autoimmune Diseases ; Cell Membrane ; Child ; Cytoskeletal Proteins ; Erythema Infectiosum ; Humans ; Parvovirus ; Spherocytes ; Spherocytosis, Hereditary

Hereditary spherocytosis is a hemolytic anemia caused by erythrocyte membrane deficiencies that lead to membrane destabilization and vesiculation. Abnormal spherocytes are trapped and destroyed in the spleen. Mutations in several genes, SPTA1, SPTB, ANK1, SLCA1 and EPB42 cause alpha-spectrin, beta-spectrin, ankyrin, band 3 or protein 4.2 protein deficiencies, respectively. The clinical severity ranged from asymptomatic to severe hemolytic anemia requiring erythrocyte transfusion. Common complications are cholelithiasis, hemolytic episodes and aplastic crises. Till now, splenectomy is considered as only curative method in this genetic disorder. However, in the future, molecular analysis will make elucidate the genotype-phenotype interactions and can innovate to modify treatment strategies.
Anemia, Hemolytic ; Ankyrins ; Cholelithiasis ; Erythrocyte Membrane ; Erythrocyte Transfusion ; Erythrocytes ; Membranes ; Protein Deficiency ; Spectrin ; Spherocytes ; Spherocytosis, Hereditary ; Spleen ; Splenectomy

Thrombocytopenia-associated multiple organ failure (TAMOF) has a high mortality rate when not treated, and early detection of TAMOF is very important diagnostically and therapeutically. We describe herein our experience of early detection of TAMOF, using an automated hematology analyzer. From 498,390 inpatients, we selected 12 patients suspected of having peripheral schistocytosis, based on the results of red blood cell (RBC) parameters and a volume/hemoglobin concentration (V/HC) cytogram. We promptly evaluated whether the individual patients had clinical manifestations and laboratory findings were consistent with TAMOF. Plasma exchanges were then performed for each patient. All 12 patients had TAMOF. The mean values of RBC parameters were significantly higher in all of the patients than with the reference range, however, 3 patients had % RBC fragments within the reference range. The mean value of ADAMTS-13 activity was slightly lower in patients compared with the reference range. Of the 12 patients, remission was obtained in 9 patients (75%) within 4 to 5 weeks using plasma exchanges. Three patients died. An increased percentage of microcytic hyperchromic cells with anisocytosis and anisochromia indicated the presence of schistocytes, making it an excellent screening marker for TAMOF. Identification of TAMOF with RBC parameters and a V/HC cytogram is a facile and rapid method along with an automated hematology analyzer already in use for routine complete blood cell counting test.
Adult ; Aged ; Aged, 80 and over ; Erythrocyte Indices ; Erythrocytes, Abnormal/pathology ; Female ; Hematologic Tests ; Hemoglobins/metabolism ; Humans ; Male ; Middle Aged ; Multiple Organ Failure/*blood/*diagnosis/etiology ; Thrombocytopenia/*blood/complications/*diagnosis

OBJECTIVETo study the clinical features and ABCG5/ABCG8 gene mutations of three pedigrees of phytosterolemia presented with macrothrombocytopenia and hemolysis.

METHODSErythrocyte and platelet morphology were examined under light microscope. Plasma sterol levels were measured by high pressure/performance liquid chromatography method. All of ABCG5 and ABCG8 exons and intron-exon boundaries were directly sequenced to identify mutations, the corresponding gene mutation sites of three families members and healthy individuals were detected.

RESULTSAll the patients presented macrothrombocytopenia, hemolysis, splenomegaly and xanthomas. The blood smears showed large platelets, some as large as erythrocytes, and abnormal erythrocyte shapes, such as stomatocytes. Plasma concentrations of phytosterols, especially sitosterol were markedly elevated (30 fold) in the affected patients. Four mutations were identified in these three pedigrees, ABCG5 C20896T (R446X) and A20883G, ABCG8 del43683-43724 and del1938C-1939G/ins1938T. The latter three were novel mutations reported for the first time.

CONCLUSIONSPhytosterolemia associated with macrothrombocytopenia and hemolysis is a new subtype of this disease. Plasma phytosterols and related gene analysis should be performed when ever an unexplained macrothrombocytopenia, especially combined with haemolysis or/and stomatocytosis.

ATP Binding Cassette Transporter, Sub-Family G, Member 5 ; ATP Binding Cassette Transporter, Sub-Family G, Member 8 ; ATP-Binding Cassette Transporters ; genetics ; Adult ; Blood Platelets ; cytology ; DNA Mutational Analysis ; Erythrocytes, Abnormal ; Female ; Hemolysis ; genetics ; Humans ; Hypercholesterolemia ; genetics ; pathology ; Intestinal Diseases ; genetics ; pathology ; Lipid Metabolism, Inborn Errors ; genetics ; pathology ; Lipoproteins ; genetics ; Male ; Middle Aged ; Mutation ; Pedigree ; Phytosterols ; adverse effects ; blood ; genetics ; Platelet Count ; Thrombocytopenia ; genetics ; pathology

Methemoglobinemia can be caused by dapsone toxicity. We report a case dapsone induced methemoglobinemia unresponsive to methylene blue successfully treated by exchange transfusion. A 52-year-old male ingested a handful of dapsone. He presented with severe peripheral cyanosis in lips and fingertips and his methemoglobin level was found to be 21.9%. After admission, methylene blue (1%) at 1 mg/kg was injected each time peripheral cyanosis and rising serum methemoglobin occurred. Despite methylene blue therapy, the patient's methemoglobin level continued to fluctuate. Five days after the injections of methylene blue, many Heinz bodies were visualized in the peripheral blood, suggestive of hemolytic anemia occurrence. By hospital day 6, serum methemoglobine levels were elevated and not measurable (> 50%) and the patient was constantly in a semi-comatose mental state. An exchange transfusion carried out by utilizing 6 units of packed red blood cells and 4 units of fresh frozen plasma was performed. The patient's methemoglobin levels were subsequently kept up below 20% and his peripheral cyanosis receded. Physicians should recognize the important role of exchange transfusion in refractory dapsoneinduced methemoglobinemia.
Anemia, Hemolytic ; Cyanosis ; Dapsone ; Erythrocytes ; Hand ; Heinz Bodies ; Humans ; Lip ; Male ; Methemoglobin ; Methemoglobinemia ; Methylene Blue ; Middle Aged ; Plasma

Thrombotic thrombocytopenic purpura-hemolytic uremic syndrome (TTP-HUS) is a rare condition that is severe and may be fatal. Adverse reactions to drugs increasingly are reported as probable causes of TTP-HUS. Many chemotherapeutic agents have also been implicated in causing TTP-HUS. We reported a woman with metastatic renal cell carcinoma who presented with TTP- HUS associated with sunitinib. She had gross hematuria and generalized edema. The hemoglobin concentration was 8.9 g/dl and the platelet count was 46,000/mm3. Her reticulocyte count was increased to 4.1% and the peripheral blood smear revealed red blood cell fragmentation and spherocytes. The patient completely recovered after discontinuing the use of sunitinib and undergoing plasmapheresis. Because of the increasing use of sunitinib in the treatment of cancer patients, oncologists should be aware of the possibility of TTP-HUS related to sunitinib, as early recognition and prompt therapeutic intervention can be beneficial.
Carcinoma, Renal Cell ; Edema ; Erythrocytes ; Female ; Hematuria ; Hemoglobins ; Hemolytic-Uremic Syndrome ; Humans ; Indoles ; Plasmapheresis ; Platelet Count ; Purpura ; Pyrroles ; Reticulocyte Count ; Spherocytes

OBJECTIVESTo investigate the relationship between the genotype and the hematologic characteristics in the fetuses with different types of thalassemia.

METHODSFetal blood samples were taken by cordocentesis, and hemograms from 572 fetuses at the gestational age of 18 to 38 weeks were examined. According to the genotypes of thalassemia, there were 117 fetuses with heterozygous alpha-thalassemia-1, and 60 with homozygous alpha-thalassemia-1. Twenty had beta-thalassemia mild, and 9 had beta-thalassemia major, respectively. The hematological parameters in these groups were compared with reference group in which 366 cases were included.

RESULTSIn alpha-thalassemia groups, hemoglobin (Hb), hematocrit (HCT), mean cell volume (MCV), mean cell hemoglobin (MCH), and mean cell hemoglobin concentration (MCHC) significantly decreased (P < 0.001), but in heterozygous alpha-thalassemia-1, red blood cell (RBC) increased. In homozygous alpha-thalassemia-1, RBC decreased significantly (P < 0.001), but white blood cell and nucleated erythrocyte increased (P < 0.001). There were no significant differences between beta-thalassemia and reference group in most hematological parameters except for decrease of MCHC.

CONCLUSIONSIn the fetal period, the hemogram of the fetuses with alpha-thalassemia changes significantly, while it does not change in beta-thalassemia. For the couple with heterozygous alpha-thalassemia, hemogram can provide some information for prenatal screening and diagnosis for those fetuses with alpha-thalassemia, especially for homozygous, but genotype detection is necessary for confirming the diagnosis.

Blood Cell Count ; Cordocentesis ; Erythrocyte Indices ; Erythrocyte Volume ; Erythrocytes, Abnormal ; Female ; Fetus ; physiopathology ; Genotype ; Gestational Age ; Hematocrit ; Hemoglobins ; genetics ; metabolism ; Hemoglobins, Abnormal ; genetics ; Humans ; Polymerase Chain Reaction ; Pregnancy ; Prenatal Diagnosis ; methods ; Thalassemia ; blood ; classification ; diagnosis ; genetics ; alpha-Thalassemia ; blood ; genetics ; beta-Thalassemia ; blood ; genetics