Frequency and distribution of structural variants of hemoglobin and thalassemic states in Western Japan

Postoperative acute multiple organ failure after hepatectomy in a Nigerian male with sickle cell trait: a case report

Background

Sickle cell disease (SCD) is a monogenic disease characterized by sickle hemoglobin (HbS). Patients homozygous for HbS experience symptoms resulting from sickled erythrocytes no later than adolescence. However, heterozygous HbS carriers, or those with the so-called sickle cell trait (SCT), may undergo surgery without their hemoglobinopathy being known.

Case presentation

A 53-year-old Nigerian male with hepatitis C infection underwent radiofrequency ablation therapy for multiple hepatocellular carcinomas (HCCs) 17 months prior. Follow-up computed tomography (CT) revealed a solitary tumor (3.2 cm) in the medial section of the cirrhotic liver. The Child–Pugh score was five, and the indocyanine green retention rate at 15 min was 17.4%. The nontumorous liver of the medial section accounted for 10% of the total liver volume according to CT volumetry. With the diagnosis of recurrent HCC, left medial sectionectomy was performed under intermittent blood flow occlusion by Pringle’s maneuver. Intraoperative ultrasonography confirmed that hepatic blood flow had been preserved after hepatectomy. However, laboratory tests on postoperative day (POD) 1 revealed severe liver damage: aspartate aminotransferase 9250 IU/L, alanine aminotransferase 6120 IU/L, total bilirubin 2.8 mg/dL, and prothrombin time% 20.9%. The patient’s renal and respiratory functions also deteriorated; therefore, continuous hemodiafiltration and plasma exchange were initiated under mechanical ventilation. Whole-body contrast-enhanced CT showed no apparent ischemia of the remnant liver, but diffuse cerebral infarction was detected. Despite intensive treatments, he died of multiple organ failure on POD 20. The pathological examination of the resected specimen revealed that the intrahepatic peripheral vessels were occluded by sickled erythrocytes. Additionally, chromatographic analysis of hemoglobin detected the presence of abnormal hemoglobin, although microscopic examination of the peripheral blood erythrocytes did not show morphological abnormalities. Based on these findings, we determined that he had SCT and developed vaso-occlusive crisis involving multiple organs just after hepatectomy.

Conclusion

SCD is a rare disease in eastern Asia, but its prevalence is increasing globally. Surgeons should pay increased attention to this disease, especially when performing hepatectomy under blood flow occlusion.

Epidemiology of haemoglobin disorders in Europe: an overview

OBJECTIVE

As a result of global population movements, haemoglobin disorders (thalassaemias and sickle cell disorders) are increasingly common in the formerly non-indigenous countries of Northern and Western Europe and in the indigenous countries of Southern Europe. This article presents an overview of the changing picture and a method for assessing service needs.

METHOD

Data on country of birth or ethnic origin of residents are adjusted to obtain the estimated proportions of residents and births in non-indigenous groups at risk for haemoglobin disorders in European countries. The results are combined with prevalence data in each country of origin to obtain country prevalence estimates. Service indicators (annual tests or other interventions required to ensure equitable delivery of treatment and prevention) are then derived by country.

RESULTS

Haemoglobin disorders now occur at comparable frequency throughout Northern, Western and Southern Europe. Annually, there are more affected conceptions in Northern and Western than in Southern Europe, and sickle cell disorders are more common than thalassaemias. There is growing need for health policy-makers to support motivated professionals working to develop optimal patient care, carrier diagnosis, genetic counselling and access to prenatal diagnosis throughout the Region.

CONCLUSION

There is a strong case for pan-European collaboration on haemoglobin disorders to share policies, standards and the instruments required to support them. These include methods for needs assessment, service standards, education and information strategies and materials, and methods for evaluating service delivery.

Hb Moriguchi or alpha 2 beta 2(97) (FG4)His---Tyr substitution at the alpha 1-beta 2 interface

An abnormal profile of cation exchange high performance liquid chromatography for the determination of Hb A1c led to the discovery of a new hemoglobin variant with a His----Tyr substitution at position 97(FG4) of the beta chain. The variant comprised about equal proportion to normal Hb A. It showed an increased oxygen affinity, normal n value and slightly reduced alkaline Bohr effect. However, the magnitude of the functional deviation is less than that of other variants with substitutions at the same position, and the heterozygous carrier was not erythremic.

Fetal hemoglobin variants in 80,000 Japanese neonates: high prevalence of Hb F Yamaguchi (A gamma T 80 Asp----Asn)

A population-based screening of newborns for the structural variants of fetal hemoglobin was carried out in Osaka Prefecture, Japan, by isoelectric focusing of globin chains using dried blood on filter paper. Of 80,000 newborns, 18 had alpha globin variants and 55 had gamma globin variants. The incidence of gamma globin variants (1/1,455) was much higher than that of alpha globin variants (1/4,444). Structural studies were then carried out on the abnormal gamma globins in 36 samples, and revealed that 25 of them were Hb F Yamaguchi (A gamma T 80 Asp----Asn). The prevalence of this variant in Japanese was estimated to be as high as one per 2,100.

Hemoglobin Rahere, a human hemoglobin variant with amino acid substitution at the 2,3-diphosphoglycerate binding site. Functional consequences of the alteration and effects of bezafibrate on the oxygen bindings

We encountered an abnormal hemoglobin (Rahere), with a threonine residue replacing the beta 82 (EF6) lysine residue at the binding site of 2,3-diphosphoglycerate, which was responsible for overt erythrocytosis in two individuals of a Japanese family. Hemoglobin Rahere shows a lower oxygen affinity on the binding of 2,3-diphosphoglycerate or chloride ions than hemoglobin A. Although a decrease in the positive charge density at the binding sites of 2,3-diphosphoglycerate in hemoglobin Rahere apparently shifts the allosteric equilibrium toward the low affinity state, it greatly diminishes the cofactor effects by anions. The oxygen affinity of the patient's erythrocytes is substantially lowered by the presence of bezafibrate, which combines with sites different from those of 2,3-diphosphoglycerate in either hemoglobin Rahere or hemoglobin A.

A new electrophoretic variant of hemoglobin (Ogi) in which a leucine residue is replaced by an arginine residue at position 34 of the alpha-chain

Hemoglobin Ogi, in which an arginine is substituted for a leucine residue at position 34 of the alpha-chain, was detected in a Japanese family. Although slightly increased oxygen affinity is associated with this amino acid substitution in the alpha 1 beta 1 contact, it is without obvious deleterious effect on the hematological parameters of the individuals heterozygous for this variant.