Hemoglobin最新文献

We report a new low-affinity hemoglobinopathy (Hemoglobin Oviedo) in a family with isolated low oxygen saturation (89-92%) caused by a previously undescribed variant (NM_000518.5: c.115A > G;p.Thr39Ala) in the hemoglobin subunit β encoding gene (HBB gene) located on chromosome 11.

Beta thalassemia is one of the monogenic disorders characterized by decreased production of β-globin chains and various types of mutations have been reported to cause thalassemia phenotype. On the other hand, rare mutations also affect and diversify the disease spectrum. Herein, we present an anemic patient from Turkey diagnosed with dominant β thalassemia due to a heterozygous mutation in exon 3 of the HBB gene.

Transfusion-dependent thalassemia (TDT) is a major public health concern in India, requiring regular transfusions for survival. There is also significant morbidity caused by iron overload and transfusion related infections. Novel therapies targeting fetal hemoglobin induction are the need of the hour in resource-poor institutions for patients where transplant is not feasible for various reasons. This single arm, non-randomised prospective trial evaluated the efficacy and safety of a combination of low dose thalidomide and hydroxyurea in TDT along with the impact on quality of life (QoL). It included 41 TDT patients, who failed a reasonable trial of hydroxyurea. Complete response (CR) was defined as transfusion independence and partial response (PR) denoted at least a 50% reduction in transfusion requirement. The rest were defined as non-responders (NR). The mean age of the cohort was 20.78 years (range 12-45 years). There were 13 males and 28 females. Nineteen (46.3%), 7 (17.1%), and 15 (36.6%) patients achieved CR, PR, and no response respectively. The overall response rate (CR + PR) was 63.4%. There was a significant increase in hemoglobin levels with decrement in transfusion burden and ferritin levels. There were no significant adverse reactions. No significant predictors of response were found including amongst genetic modifiers. It improved the health related QoL amongst responders. The combination of thalidomide and hydroxyurea appear safe and effective in the reduction in transfusion requirement of TDT patients. The judicious use of these drugs can improve the quality of life and pave the way for patients not eligible for a stem cell transplant.

SUMMARYCOVID-19 infection has emerged as a comorbidity that can significantly increase morbidity and mortality in sickle cell patients with ACS (acute thoracic/chest syndrome). The aim of our study was to assess COVID-19-related morbidity and mortality in sickle cell patients with ACS. This was a retrospective, descriptive study of patient records followed over a 36-month period from January 2020 to December 2022. The study was conducted at the national blood transfusion center in Dakar. The sex ratio (M/F) was 0.82. The median age was 26 (17-39) years. The most represented age group was between 21 and 30 years. Factors associated with death were: at baseline, SS genotype, presence of comorbidities (asthma, chronic obstructive pulmonary disease, viral hepatitis B, ischemic heart disease), osteonecrosis of the femoral head, and use of NSAIDs (non-steroidal anti-inflammatory drugs) at diagnosis of COVID-19; at the diagnosis of ACS associated with COVID-19, respiratory distress, hypoxia (Sa02 < 92%), creatininemia >18.5 mg/l, CRP >192 mg/l, lymphopenia; the therapeutic modalities associated with death were: transfusion of RBCs (packed red blood cells) and curative anticoagulation. This study shows that patients with comorbidities and/or chronic complications of sickle cell disease can develop severe forms of ACS associated with COVID 19, leading to death. Other factors linked to death, notably diagnostic and therapeutic, were also identified in the course of this study.

α-thalassemia major (α-TM) often causes Hb Bart's (c4) hydrops fetalis and severe obstetric complications in the mother. Step-wise screening for couples at risk of having offspring(s) affected by α-TM is the efficient prevention method but some rare genotypes of thalassemia cannot be detected. A 32-year-old male with low HbA2 (2.4%) and mild anemia was performed real-time PCR-based multicolor melting curve analysis (MMCA) because his wife was -^SEA deletion carrier. The result of multiplex ligation-dependent probe amplification (MLPA) suggested the existence of -^SEA deletion in the proband. A novel deletion of the α-globin gene cluster was found using self-designed MLPA probes combined with longer PCR, which was further accurately described to be 16.8Kb (hg38, Chr16:1,65,236-1,82,113) deletion by the third-generation sequencing. A fragment ranging from 1,53,226 to 1,54,538(GRch38/hg38) was identified which suggested the existence of the homologous recombination event. The third-generation sequencing is accurate and efficient in obtaining accurate information for complex structural variations.

Sickle cell disease (SCD) contributes significantly to childhood morbidity and mortality in sub-Saharan Africa. Early diagnosis through newborn screening (NBS) and subsequent comprehensive follow-up care will reduce the burden. Up till now, the prevalence of SCD among newborns remains unknown in The Gambia and there is no national NBS programme to address this significant public health issue. We assessed the real-time frequency of SCD in the country and determined differences in the pattern of SCD phenotypes among different ethnic groups. A preliminary prospective feasibility study was done in eight purposively selected hospitals in the seven Health Administrative Regions and Banjul. Consecutive newborn babies delivered or managed in these facilities were screened using HemoTypeSC, a sensitive and specific ELISA-based point-of-care test (POCT). Babies identified as SCD with HemoTypeSC were retested at age ≥6 months using alkaline cellulose acetate hemoglobin electrophoresis (ACAE). Head-to-head comparison between HemoType screening and gold standard HPLC could not be done. 1,168 newborn babies were screened from April 14 to August 12, 2023. Fifteen (1.3%) had homozygous HbS (HbSS), two (0.2%) heterozygous for HbS and HbC (HbSC), 204 (17.5%) had sickle cell trait (HbAS), four (0.3%) heterozygous for HbA and HbC (HbAC), and 943 (80.7%) had normal hemoglobin (HbAA). The 17 with SCD (HbSS and HbSC) comprised of 7 (2.2%) of 324 Fula; 6 (1.4%) of 426 Mandinka; 2 (1.6%) of 125 Jola and 2 (1.3%) of 150 Wolof. Fourteen (82.4%) of the 17 accepted the diagnosis and were enrolled into the SCD program. For these 14, HemoTypeSC had 100% sensitivity with ACAE when repeated at age ≥6 months. In addition to determining the real-time newborn prevalence of SCD and trait in The Gambia for the first time, this pilot study showed that SCD-POCT is feasible in Gambian health facilities.

In 2020, a 2-month-old ethnically Danish girl was diagnosed with β-thalassemia after presenting with persistent jaundice. The peripheral blood smear showed significant aniso- and poikilocytosis, increased number of reticulocytes and erythroblastosis. Trio analysis of the index patient and both parents was performed by whole-genome sequencing. Here, both parents were found normal, however the analysis revealed an apparently de novo HBB:c.444A > C variant in the child. The child has recently been discharged three months after a successful bone marrow transplantation with a matched sibling-donor.

We report the discovery of a novel β-globin gene variant, Hb Odder, characterized by a single nucleotide substitution; HBB:c.316C > G; CD105 (Leu > Val). This variant emerged incidentally during routine HbA1c measurements for diabetes monitoring. The patient exhibited no clinical or biochemical evidence of anemia or hemolysis. Our data on this variant suggest that Hb Odder is benign, regrettably limitations in our data make formal evaluations of stability and oxygen affinity impossible; additionally this emphasizes the importance of considering hemoglobin variants in the differential diagnosis of abnormal Hb A1c levels and suggest that laboratories should use alternative methods for the correct measurement of Hb A1c when hemoglobin variants interfere with diabetes monitoring. Notably, three other mutations have been described at codon 105 of the β globin chains and correspond to three Hb variants with different characteristics: Hb South Milwaukee, Hb Bellevue IV and Hb St. George.

Menstruation-induced vaso-occlusive crisis (MIVOC) is a significant cause of morbidity in women with sickle cell disease (SCD). Secretory phospholipase A2 (sPLA2) is an inflammatory biomarker that is elevated in vaso-occlusive events such as acute chest syndrome (ACS), but its role in MIVOC is not previously studied. This study compared the serum level of sPLA2 among women with MIVOC and those without MIVOC. This is a comparative cross-sectional study. 354 women with SCD were screened for MIVOC using a structured questionnaire. sPLA2 levels were assayed using a standard ELISA while full blood counts were performed on an automated hematology analyzer. Data were analyzed using the SPSS software v26.0. Results were summarized as frequencies, percentages, and mean ± standard deviation. Variables were compared using the Student's t-test and Pearson's correlation. A p-value of <.05 was considered significant. The prevalence of MIVOC was 26.8%. Participants with MIVOC (n = 95) had significantly lower mean hemoglobin concentration (8.00 ± 2.03g/dL vs. 9.95 ± 4.15g/dL, p < .000), significantly higher mean platelets count (518.71 ± 84.58 × 10⁹/L vs 322.21 ± 63.80 × 10⁹/L, p < .000) and higher sPLA2 level (6.58 ± 1.94 IU vs 6.03 ± 0.42 IU, p = .008) compared to those without MIVOC (n = 95). Among participants with MIVOC, sPLA2 levels positively correlated with total white blood cell, absolute neutrophil, and lymphocyte counts. This study demonstrates that MIVOC is common among women with SCD and that the pathophysiology of MIVOC may have an inflammatory basis similar to that of ACS. The potential role of anti-inflammatory and antiplatelet agents in preventing and treating MIVOC may be explored.

Congenital hemolytic anemia (CHA) is defined as the premature destruction of red blood cells (RBC) due to congenital or acquired defects. The hereditary form of hemolytic anemia can be divided into hemoglobinopathies, membranopathies, and enzymopathies. Hereditary spherocytosis (HS) is the most common inherited RBC membranopathy leading to congenital hemolytic anemia. To date; five genes have been associated with HS coding for cytoskeleton and transmembrane proteins, those genes are SPTB, SLC4A1, EPB42, ANK1, and SPTA1. Due to genetic heterogeneity, clinical exome sequencing (CES) was performed on four unrelated Moroccan patients referred for CHA investigation. Sanger sequencing and qPCR were performed to confirm CES results and to study the de novo character of identified variants. The molecular analysis revealed 3 novel mutations and one previously reported pathogenic variant of the SPTB gene confirming the diagnosis of HS in the four patients. Hereditary spherocytosis anemia is a genetically heterogenous disease which could be misdiagnosed clinically. The introduction of novel sequencing technologies can facilitate accurate genetic diagnosis, allowing an adapted care of the patient and his family.