Foetal Haemoglobin and Disease Severity in Nigerian Children with Sickle Cell Anaemia

Association between fetal hemoglobin, lactate dehydrogenase, and disease severity in patients with sickle cell disease at Bugando Medical Centre, Mwanza, Tanzania

INTRODUCTION

There is a wide range of clinical manifestations in sickle cell disease (SCD). Despite having the same condition, each person's response to disease complications differs greatly. Individuals can be categorized according to the severity of their diseases to determine which group they fall into and receive the appropriate care based on their needs. The relationship between fetal hemoglobin (HbF), lactate dehydrogenase (LDH), and disease severity in Tanzania is little understood. This investigation sought to ascertain the relationship between HbF, LDH, and disease severity in SCD patients at the Bugando Medical Center.

METHOD

This cross-sectional study was carried out on SCD patients aged 6 months and older at the Bugando Medical Center in Mwanza, Tanzania. A total of 130 SCD patients were enrolled. The clinical history and laboratory test results for SCD patients were recorded on a specially constructed patient report form.

RESULTS

The majority of participants (56.9%) were men. For the population under study, more than half (60.8%) of participants had a moderate clinical phenotype (MCP), followed by 31.5% of asymptomatic participants and 7.7% of people with severe clinical phenotypes (SCP). Participants with SCP had substantially higher levels of LDH, with a mean level of 810.97IU/L (95% CI: 559.31-1062.64) and a p-value of 0.005. The severe clinical phenotype exhibited a significantly higher mean HbF score value of 10.09% (95% CI: 7.44-13.74%) with a p-value of 0.024 when compared to the asymptomatic and moderate clinical phenotypes.

CONCLUSION

In SCD patients with SCP compared to ACP and MCP, the HbF levels were higher, but did not show a protective effects, and LDH can be used to predict the severity of SCD.

Electrocardiographic Changes and Their Association With Disease Severity in Adults With Sickle Cell Anemia at a Tertiary Care Center: A Cross-Sectional Study

Introduction Sickle cell anemia (SCA), a severe hematological disorder, is characterized by the presence of sickle-shaped erythrocytes that obstruct capillaries and restrict blood flow. This pathophysiology not only promotes systemic complications but may also influence cardiac function. Cardiac complications are a leading cause of mortality in SCA patients, yet the specific electrocardiographic (ECG) changes associated with disease severity are not thoroughly understood. This cross-sectional study aimed to explore ECG abnormalities in adults with SCA and correlate these findings with disease severity. Methods An observational cross-sectional study was conducted over 18 months, from January 2022 to June 2023, among 140 SCA patients at the Sickle Cell OPD of All India Institute of Medical Sciences, Raipur, Raipur, India. Steady-state SCA (HbS >50%) patients screened by high-performance liquid chromatography were enrolled. A history, physical examination, complete blood count, and ECG were done for all cases. The disease severity score was calculated using the Adegoke and Kuti severity scores, and their association with various ECG changes was studied. The chi-square test (Fisher's exact test, wherever applicable) was used for comparing the proportion. The correlation was done using the Pearson correlation coefficient or Spearman's rho. Results Out of 140 patients, the mean age of the study participants was 26 ± 6 years. More than half of the cases (80; 57%) fall under the 18-27 age group, with a male-to-female ratio of 4:3. A total of 99 (70.7%) of the participants had mild disease, and 41 (29.3%) had moderate disease. The QT interval was significantly higher among patients with mild disease compared to those with moderate disease (p-value: <0.01). QTc dispersion and prolonged QTc interval were significantly higher among patients with moderate disease compared to mild disease (p-value <0.01, 0.04, respectively). Sinus tachycardia and right ventricular hypertrophy with p-pulmonale were significantly higher in moderate severity (p < 0.01). A significant positive correlation was observed between QTc dispersion, P-wave dispersion, and severity (r: 0.19, 0.17; p-value: 0.02, 0.04, respectively). Conclusion As the disease severity progressed, the ECG changes studied had a higher distribution and significance. ECG is a readily and widely accessible investigation that can be used to screen all SCA patients for early recognition of various underlying cardiac complications.

A-296G variant of THBS1 gene (rs1478605) is associated with a lower frequency of stroke in a Brazilian population with sickle cell anemia

OBJECTIVES

Stroke is a devastating clinical outcome that significantly contributes to the morbidity and mortality of sickle cell anemia (SCA) patients. Despite its advantages in predicting stroke risk, transcranial Doppler screening has limitations that restrict its applicability, highlighting the need for emerging prognostic tools. Thrombospondin-1 plays a crucial role in endothelial injury, platelet adhesion, and nitric oxide metabolism and may be implicated in stroke pathophysiology. Here, we aimed to evaluate the association of THBS1 genetic variations with the occurrence of stroke in SCA patients MATERIALS AND METHODS: By real-time PCR, 512 SCA patients were fully genotyped for THBS1 A-296G (rs1478605) polymorphism RESULTS: THBS1 GG genotype was associated with a lower risk for stroke occurrence [odds ratio (OR): 0.30; 95% confidence interval (CI): 0.11-0.78; P = 0.011], although these findings were not consistent with multivariate logistic regression analysis (OR: 0.73, 95% CI: 0.12 - 4.37; P = 0.736). In agreement, the cumulative incidence of stroke for patients with AG/AA genotypes was higher when compared to the GG genotype (P = 0.018). However, the association was not maintained in the multivariate proportional hazards model (hazard ratio: 0.67, 95% CI: 0.12-3.61; P = 0.643) CONCLUSIONS: In summary, the present study shows that the THBS1 A-296G (rs1478605) polymorphism may be a potential modifier for stroke in SCA.

Varied Age of First Presentation of Sickle Cell Disease: Case Presentations and Review

Sickle cell disease is a multisystem condition characterized by hemolytic anemia and vasoocclusion. Not only are the symptoms of the first presentation but also the ages of presentation are very variable. Following three case reports, different causes of possible late presentation are discussed. Many factors are responsible for the age at which sickle cell disease is diagnosed: doctor's delay (unfamiliarity with the disease), patient's delay (education and financial position of the parents, cultural factors), high- versus low-resource country (availability of newborn screening), fetal hemoglobin, reticulocyte count, and genetic modulators, such as SCD genotype, alpha-thalassemia, fetal hemoglobin concentration, and G6PD deficiency. The individual course of sickle cell disease depends on (epi) genetic and environmental properties and the underlying interactions. In further studies, the role of each factor should be evaluated more deeply, and its use as a marker of disease severity or activity should be assessed.

Standardized microfluidic assessment of red blood cell-mediated microcapillary occlusion: Association with clinical phenotype and hydroxyurea responsiveness in sickle cell disease

OBJECTIVES

We present a standardized in vitro microfluidic assay and Occlusion Index (OI) for the assessment of red blood cell (RBC)-mediated microcapillary occlusion and its clinical associations in sickle cell disease (SCD).

METHODS

Red blood cell mediated microcapillary occlusion represented by OI and its clinical associations were assessed for seven subjects with hemoglobin-SC disease (HbSC), 18 subjects with homozygous SCD (HbSS), and five control individuals (HbAA).

RESULTS

We identified two sub-populations with HbSS based on the OI distribution. HbSS subjects with relatively higher OIs had significantly lower hemoglobin levels, lower fetal hemoglobin (HbF) levels, and lower mean corpuscular volume (MCV), but significantly higher serum lactate dehydrogenase levels and absolute reticulocyte counts, compared to subjects with HbSS and lower OIs. HbSS subjects who had relatively higher OIs were more likely to have had a concomitant diagnosis of intrapulmonary shunting (IPS). Further, lower OI associated with hydroxyurea (HU) responsiveness in subjects with HbSS, as evidenced by significantly elevated HbF levels and MCV.

CONCLUSIONS

We demonstrated that RBC-mediated microcapillary occlusion and OI associated with subject clinical phenotype and HU responsiveness in SCD. The presented standardized microfluidic assay may be useful for evaluating clinical phenotype and assessing therapeutic outcomes in SCD, including emerging targeted and curative treatments that aim to improve RBC deformability and microcirculatory health.

Effectiveness and Safety of Hydroxyurea in the Treatment of Sickle Cell Anaemia Children in Jos, North Central Nigeria

BACKGROUND

Hydroxyurea has been shown to positively modify sickle cell disease pathogenesis, but its use is low among Nigerian sickle cell anaemia (SCA) patients because of effectiveness and safety concerns.

METHODS

We conducted a quasi-experimental study to evaluate the effectiveness and safety of hydroxyurea in 54 SCA children aged 4-17 years. Clinical and haematological parameters were compared at baseline and 12 months after hydroxyurea therapy. The participants were monitored for adverse events. The parameters were compared using relative risk and Wilcoxon Signed-Rank Test.

RESULTS

The number of subjects who had more than two episodes of painful crises reduced from 27 (50%) to 2 (2.7%) (p < 0.001), while those who had acute chest syndrome reduced from 6 (11.1%) to 0 (0.0%; p < 0.001). The risk of being transfused more than once was 0.11 times the risk in the 12 months period preceding therapy (95% CI = 0.02-0.85; p = 0.016). Similarly, the risk of hospital stay >7 days was 0.08 times the risk at the baseline (95% CI = 0.02-0.24; p < 0.0001). The median haematocrit and percentage foetal haemoglobin increased from 26 to 28% and 7.8 to 14%, respectively (p < 0.0001). A dose-dependent but reversible leucopenia was observed among six children (11.1%), otherwise, hydroxyurea was safe in the study population.

CONCLUSION

Hydroxyurea is effective and safe in SCA children in Jos, Nigeria. The findings could strengthen educational programme aimed at improving the utilization of hydroxyurea among SCA children.

Genetic modulators of fetal hemoglobin expression and ischemic stroke occurrence in African descendant children with sickle cell anemia

Sickle cell anemia (SCA) is an autosomal recessive monogenic disease with significant clinical variability. Cerebrovascular disease, particularly ischemic stroke, is one of the most severe complications of SCA in children. This study aimed to investigate the influence of genetic variants on the levels of fetal hemoglobin (Hb F) and biochemical parameters related with chronic hemolysis, as well as on ischemic stroke risk, in ninety-one unrelated SCA patients, children of sub-Saharan progenitors. Our results show that a higher Hb F level has an inverse relationship with the occurrence of stroke, since the group of patients who suffered stroke presents a significantly lower mean Hb F level (5.34 ± 4.57% versus 9.36 ± 6.48%; p = 0.024). Furthermore, the co-inheritance of alpha-thalassemia improves the chronic hemolytic pattern, evidenced by a decreased reticulocyte count (8.61 ± 3.58% versus 12.85 ± 4.71%; p < 0.001). In addition, our findings have confirmed the importance of HBG2 and BCL11A loci in the regulation of Hb F expression in sub-Saharan African SCA patients, as rs7482144_A, rs11886868_C, and rs4671393_A alleles are significantly associated with a considerable increase in Hb F levels (p = 0.019, p = 0.026, and p = 0.028, respectively). Concerning KLF1, twelve different variants were identified, two of them novel. Seventy-three patients (80.2%) presented at least one variant in this gene. However, no correlation was observed between the presence of these variants and Hb F level, severity of hemolysis, or stroke occurrence, which is consistent with their in silico-predicted minor functional consequences. Thus, we conclude that the prevalence of functional KLF1 variants in a sub-Saharan African background does not seem to be relevant to SCA clinical modulation.