Foetal haemoglobin, erythrocytes containing foetal haemoglobin, and hematological features in congolese patients with sickle cell anaemia

Partial Splenic Embolization in Paediatric Sickle Cell Disease Patients with Hypersplenism

PURPOSE

To assess the safety and efficacy of partial splenic embolization (PSE) to reduce the need of transfusions and improve hematologic parameters in patients with hypersplenism and sickle cell disease (SCD).

MATERIAL AND METHODS

This prospective study includes 35 homozygous hemoglobin S patients with SCD and hypersplenism who underwent PSE from 2015 until 2021 in Kinshasa. Patients were evaluated, before and after PSE (1, 3 and 6 months), using clinical, laboratory and ultrasonographic methods. PSE was performed with the administration of gelatin sponge particles embolizing 60-70% of the splenic parenchyma.

RESULTS

The mean age was 10 (± 4) years and (21/35, 60%) were male. After PSE Leucocytes decreased at 3 months (16 692.94 vs 13 582.86, p = 0.02) and at six months Erythrocytes increased 2 004 000 vs. 2 804 142 (p < 0.001), Platelets increased (168 147 vs. 308 445, p < 0.001) and Hemoglobin increased (5.05 g/dL vs. 6.31 g/dL, p < 0.001) There was a significant dicrease in the need of transfusions from 6 (2-20) before PSE to 0.06 (0-1) after PSE (p < 0.001). The most frequent complication was splenic rupture (4/35, 11.4%), seen only and in all patients with hypoechogenic nodules at baseline.

CONCLUSION

PSE is a safe procedure in patients with SCD and hypersplenism, that do not have hypoechogenic nodules in the spleen. PSE improves the hematological parameters and reduces the frequency of blood transfusions.

Clinical and laboratory characterization of adult sickle cell anemia patients in Kinshasa

BACKGROUND

Sickle cell anemia (SCA) is a monogenic hemoglobinopathy associated with severe acute and chronic complications, with the highest incidence worldwide in Sub-Saharan Africa. The wide variability in clinical manifestations suggest that a uniform response to hydroxurea may not be attained. In view of a potential treatment with hydroxyurea (HU), we assessed the variability of clinical and hematological manifestations in a cohort of adults with SCA in Kinshasa, capital of the DR Congo in Central Africa.

METHODS

A cross-sectional study was conducted in a hospital dedicated to SCA management in Kinshasa. Clinical history of patients was recorded, a complete physical examination performed. The diagnosis was confirmed by means of DNA analysis. A full blood count and hemolysis markers were measured. The severity of the disease was evaluated by means of a previously reported score.

RESULTS

The study group consisted of 166 genetically confirmed SCA patients. The SCA severity was mild in 28.9%, moderate in 64.5% and severe in 6.6%. The disease severity score increased with patient's age (p ≤ 0.001). The severity was higher in males compared to females (p = 0.012). In males, the severity score was correlated with the presence of priapism (p = 0.045), a manifestation not previously incorporated in the severity score. The severity score was inversely correlated with the fetal hemoglobin (HbF) rate (p = 0.005). Malnutrition (BMI <18.5 kg/m2) was present in 47% of patients and was related to the male sex, hip disease (aOR 3.11; p = 0.019) and severe phenotype (aOR 3.53; p = 0.012). Leg ulcers were more frequent in males than in females (p = 0.001; OR 24.3) and were correlated with the number of days of hospitalization (p = 0.029). Hip disease was related to the increasing age (p = 0.008).

CONCLUSION

In this selected, hospital-based populations of adults with SCA, severe disease was rare, which may be due to survival bias. However, two thirds had moderate severity of the disease, mostly with a low HbF, and they may benefit from HU treatment. In the Central-African setting the separation between vaso-occlusive and hyperhemolytic sub-phenotypes was not applicable.

Detection of BCL11A and HBS1L-MYB Genotypes in Sickle Cell Anemia

Sickle Cell Anemia (SCA) is one of the most common monogenic disorders worldwide. Molecular modifiers of clinical symptoms play an essential role in the amelioration of the effects of the disease. Single Nucleotide Polymorphisms (SNPs) of the BCL11A gene and within the HBS1L-MYB intergenic region, which are located outside the β-globin locus on chromosome 11, are considered to be genetic modifiers that are associated with elevated levels of foetal haemoglobin HbF, and thus they reduce the clinical impact of sickle haemoglobin, HbS. The work reported here aimed to detect the most common SNPs of BCL11A and HBS1L-MYB related to HbF in SCA patients and to estimate the frequency of occurrence of these genotypes. A total of 132 SCA patients whose condition was stable were recruited from Jeddah city, Saudi Arabia. SNPs at site locus rs4671393 on BCL11A, and at loci rs28384513 and rs9399137 on HBS1L-MYB were identified using TaqMan genotyping assay. Haematological parameters were analysed based on complete blood count and haemoglobin separation using the capillary electrophoresis technique. Highly significant differences in the diagnostic haematological parameters, including all blood-cell types and HbF, were observed between the study cohort and control groups. We also found that BCL11A rs4671393 genotypes of GG and AG were more likely to show increases in HbF levels than other genotypes. In addition, a strong relationship was found between HBS1L-MYB rs9399137 and rs28384513 genotypes in the cohort, whereas no significant association was observed between BCL11A rs4671393 variant and other variants. Our study highlights the importance of investigating genetic determinants that play roles in the amelioration of the severity of clinical symptoms and complications of SCA.

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.

Association between sickle cell anemia and alpha thalassemia reveals a high prevalence of the α3.7 triplication in congolese patients than in worldwide series

BACKGROUND

Information about the association with alpha thalassemia in sickle cell patients is unknown in the Democratic Republic of Congo. There is very little data on the alpha thalassemia in patients suffering from sickle cell anemia in Central Africa, and their consequences on the clinical expression of the disease.

METHODS

A cross-sectional study was conducted in 106 sickle cell patients living in the country's capital Kinshasa. The diagnosis of sickle cell anemia was confirmed with a molecular test using PCR-RFLP (restriction fragment length polymorphism) technique. The diagnosis of thalassemia was performed by the technique of multiplex ligation dependent probe amplification.

RESULTS

The mean age of our patients was 22.4±13.6 years. The α3.7 heterozygous deletion, the α3.7 homozygous deletion and the α3.7 triplication were respectively encountered in 23.6%, 25.5% , and 11.3% of patients. Patients with normal αα/αα genotype represented 39.6% of the study population. The average of severe vaso-occlusive crises, the rates of blood transfusions per year, the rate of osteonecrosis, cholelithiasis and leg ulcers were significantly lower in the group of patients with α3.7 homozygous deletion and α3.7 triplication.

CONCLUSION

The prevalence of α3.7 triplication was higher in sickle cell patients in the Democratic Republic of Congo than in worldwide series. The α3.7 triplication and α3.7 homozygous deletion were associated with less severe forms of the Sickle cell anemia in Congolese patients. These results showed the need to investigate systematically the alpha-globin gene mutations in sickle cell population in Central Africa.

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

Background

Foetal haemoglobin (HbF) is a major modifying factor influencing sickle cell disease (SCD) severity. Despite this, HbF estimation is not routinely done in Nigeria. The relationship between HbF and SCD severity among affected children is also poorly studied.

Methods

In this descriptive cross-sectional study, we determined the relationship between steady state HbF levels and disease severity of Nigerian children aged 1 – 15 years with homozygous SCD. For each child, the socio-demographic characteristics and SCD clinical severity were determined. The latter was assessed based on the frequency of significant painful episodes, blood transfusion, and hospitalisation in the preceding 12 months; lifetime cumulative incidence of SCD-related complications; the degree of splenic and hepatic enlargement; current haematocrit and leucocyte count. Foetal haemoglobin levels were quantified with high-performance liquid chromatography.

Results

The mean HbF level of the 105 children with SCA was 9.9 ± 6.0%. Male had significantly lower mean HbF levels than females, 8.0 ± 5.6% vs. 12.2 ± 5.8% (p < 0.001). None of the children had severe disease. However, the 32 children with moderate disease had significantly lower mean foetal haemoglobin levels than the 73 with mild disease (7.7 ± 5.6% vs 10.8 ± 6.0% respectively). The mean HbF level was also significantly lower in children who had a history of acute chest syndrome and stroke compared to those without these complications, p = 0.002 and 0.010 respectively.

Conclusion

Children with SCA who had a moderate disease and those with a history of life-threatening complications such as stroke and acute chest syndrome had significantly low HbF levels. Therefore, it is recommended that facilities for early quantification of foetal haemoglobin and HbF inducement were made available to reduce the morbidity and mortality among these children.

Sickle cell disease

Sickle cell disease is a common and life-threatening haematological disorder that affects millions of people worldwide. Abnormal sickle-shaped erythrocytes disrupt blood flow in small vessels, and this vaso-occlusion leads to distal tissue ischaemia and inflammation, with symptoms defining the acute painful sickle-cell crisis. Repeated sickling and ongoing haemolytic anaemia, even when subclinical, lead to parenchymal injury and chronic organ damage, causing substantial morbidity and early mortality. Currently available treatments are limited to transfusions and hydroxycarbamide, although stem cell transplantation might be a potentially curative therapy. Several new therapeutic options are in development, including gene therapy and gene editing. Recent advances include systematic universal screening for stroke risk, improved management of iron overload using oral chelators and non-invasive MRI measurements, and point-of-care diagnostic devices. Controversies include the role of haemolysis in sickle cell disease pathophysiology, optimal management of pregnancy, and strategies to prevent cerebrovascular disease.

Prevalence and determinants of microalbuminuria in children suffering from sickle cell anemia in steady state

Background

Sickle cell anemia (SCA) is considered a major risk factor for renal complications. The main goal of this study was to determine the frequency of macroalbuminuria and microalbuminuria in Congolese children <18 years of age suffering from Sickle cell anemia and to identify associated factors.

Methods

The cross-sectional study was completed in 150 hemoglobin-SS children (77 boys and 73 girls). Microalbuminuria was defined by a urine albumin:creatinine ratio of 30–299 mg/g.

Results

The mean age of this group was 8.8 ± 4.3 years (range 2–18). Microalbuminuria was found in 27 children (18%). In multivariate logistic regression, only age emerged as a determinant of microalbuminuria odds ratio 1.11 (95% confidence interval 1.00–1.22); P = 0.042].

Conclusions

In our series, only age was a major determinant of the occurrence of microalbuminuria. These results confirm the need for early screening of microalbuminuria in Congolese children suffering from Sickle cell anemia in a context where access to renal and bone marrow transplant is nonexistent.

Glomerular hyperfiltration is strongly correlated with age in Congolese children with sickle cell anaemia

AIM

Glomerular hyperfiltration is an early marker of sickle cell nephropathy and can lead to microalbuminuria and renal failure. Our aim was to identify the associated risk factors, as these could be of preventative importance.

METHODS

We recruited 150 children with sickle cell anaemia (SCA), aged two to 18 years and living in Kinshasa, the Democratic Republic of Congo. Hyperfiltration and microalbuminuria were defined as an estimated glomerular filtration rate of less than 140 mL/min/1.73 m² and an albumin creatinine ratio of between 30 and 299 mg/g, respectively. Independent determinants of hyperfiltration were assessed using logistic regression analysis.

RESULTS

Glomerular hyperfiltration was observed in 60 (40%) children, who were significantly older (10.2 ± 4.1 versus 7.9 ± 4.3 years, p = 0.001) and had a lower body mass index level (14.7 ± 2.3 versus 15.0 ± 2.3 kg/m² ) than the 60% without. A higher proportion had microalbuminuria (25.0 versus 13.3%), but the difference was not statistically significant (p>0.05). Increased age and decreased body mass index were the main independent factors associated with glomerular hyperfiltration in the multivariate analysis. A quarter (25%) of the 60 children with SCA with glomerular hyperfiltration had microalbuminuria.

CONCLUSION

Glomerular hyperfiltration was a common finding in this study and was significantly associated with age.

Protective BCL11A and HBS1L-MYB polymorphisms in a cohort of 102 Congolese patients suffering from sickle cell anemia

BACKGROUND

We aimed to investigate the distribution of selected BCL11A and HMIP polymorphisms (SNP's), and to assess the correlation with HPFH in a cohort of sickle cell patients.

METHODS

A preliminary cross-sectional study was conducted in 102 patients. Group 1 was composed of patients with HPFH and Group 2 consisted of patients without HbF. We assessed 8 SNPs previously associated with HPFH in cohorts genetically close to the Congolese population. Observed frequencies were compared to expected frequencies.

RESULTS

In the group 1, at rs7606173, the observed frequency for the genotype GG was significantly higher and the genotype GC was significantly lower than their respective expected frequencies. At rs9399137, the observed frequency of the genotype TT was significantly lower than expected. Conversely, the observed frequency of the genotype TC was significantly higher than expected. The observed frequency of the genotype TT at rs11886868 was significantly lower than the expected whereas the frequency of the genotype TC was significantly higher than observed. The lowest HbF level was recorded in patients with genotype CC at rs11886868.

CONCLUSION

In this preliminary study, the results demonstrate that alleles of some of the 8 studied SNPs are not randomly distributed among patients with or without HPFH in this cohort.

Factors Associated with Growth Retardation in Children Suffering from Sickle Cell Anemia: First Report from Central Africa

Background. The aim of this study was to investigate and determine the risk factors associated with poor growth among SCA children. Methods. A cross-sectional study was conducted in Kinshasa, the capital's country. The nutritional status was assessed using the Z scores of the anthropometric indices. Results. We gathered data on the 256 patients, 138 females (53.9%), who entered the study. The mean age at presentation was 8.4 ± 4.9 years of age. Underweight, stunting, and wasting were found, respectively, in 47.7%, 10.5%, and 50.3% of SCA children. A history of hand-foot syndrome, more than 3 blood transfusions, being less than 12 months of age when receiving the first transfusion, more than two severe sickle crises per year, a medical history of severe infections, and the presence of hepatomegaly were associated with poor growth. When comparing sickle cell patients under 12 years of age (n = 159) to a group of 296 age-matched children with normal Hb-AA, a significantly higher proportion of subjects with stunting and underweight were found among SCA. Conclusion. Nutritional status encountered in Congolese sickle cell children has been described for the first time in this study. A high prevalence of poor growth in SCA children was found in our study.

Clinical phenotypes and the biological parameters of Congolese patients suffering from sickle cell anemia: A first report from Central Africa

BACKGROUND

The influence of phenotype on the clinical course and laboratory features of sickle cell anemia (SCA) is rarely described in sub-Saharan Africa.

METHODS

A cross-sectional study was conducted in Kinshasa. A clinical phenotype score was built up. The following definitions were applied: asymptomatic clinical phenotype (ACP; score≤5), moderate clinical phenotype (MCP; score between 6 and 15), and severe clinical phenotype (SCP; score≥16). ANOVA test were used to compare differences among categorical variables.

RESULTS

We have studied 140 patients. The mean body mass index (BMI) value of three groups was lower (<25 kg/m² ) than the limit defining overweight. BMI of the subjects with ACP was significantly higher than those of other phenotypes (P<.05). Sickle cell patients with ACP have a high mean steady-state hemoglobin concentration compared to those with MCP and SCP (P<.001). A significant elevated baseline leukocyte count is associated with SCP (P<.001). Fetal Hemoglobin (HbF) was significantly higher in ACP. Significant elevation of alpha 1 and alpha 2 globulins in SCP were observed.

CONCLUSION

In our study, fetal hemoglobin has an influence on the clinical severity and the biological parameters of SCA. The study provides data concerning the sickle cell anemia clinical and biological variability in our midst.

High rate of sickle cell anaemia in Sub-Saharan Africa underlines the need to screen all children with severe anaemia for the disease

AIM

Neonatal screening for sickle cell anaemia is not common practice in the Democratic Republic of Congo, and we determined the prevalence in children with unknown electrophoresis of haemoglobin and anaemia.

METHODS

A cross-sectional study was conducted in four hospitals in the country's capital Kinshasa.

RESULTS

We screened 807 patients with anaemia (Hb < 6 g/dL) for sickle cell disease. The overall mean age at presentation was 42.7 months ± 29.7 months, and most patients (76.3%) were less than five years of age, with a peak incidence at seven to 36 months of age (45%). The median age at the first transfusion was 29 months (range 4-159 months). Of these 807 children, 36 (4.5%) were homozygous for haemoglobin S disease and 45 (5.6%) were heterozygotes. The proportion of patients with homozygous sickle cell anaemia was slightly higher in children with a medical history of hand foot syndrome, in children who had received more than three transfusions and in children up to 36 months of age at their first transfusion.

CONCLUSION

The high prevalence of sickle cell anaemia in children in Sub-Saharan Africa underlines the need for neonatal screening or, if that is not possible, screening of all children with severe anaemia to identify patients with the disease and provide early management.

Correlation between the Lactate Dehydrogenase Levels with Laboratory Variables in the Clinical Severity of Sickle Cell Anemia in Congolese Patients

Background

Sickle cell anemia is an inflammatory disease and is characterized by chronic hemolysis. We sought to evaluate the association of lactate dehydrogenase levels with specific clinical phenotypes and laboratory variables in patients with sickle cell anemia.

Methods

The present cross-sectional study was conducted in Sickle Cell Centre of Yolo in Kinshasa, the Democratic Republic of Congo. Two hundred and eleven patients with Sickle Cell Anemia in steady state were recruited. Seventy-four participants with normal Hb (Hb-AA) were selected as a control group.

Results

The average rates of hemoglobin, hematocrit, and red blood cells tended to be significantly lower in subjects with Hb-SS (p<0.001). The average rates of white blood cells, platelets, reticulocytes and serum LDH were significantly higher in subjects with Hb-SS (p<0.001). The average rates of Hb, HbF, hematocrit and red blood cells of Hb-SS patients with asymptomatic clinical phenotype were significantly higher than those of the two other phenotypes. However, the average rates of white blood cells, platelets, reticulocytes, and LDH of Hb-SS patients with the severe clinical phenotype are higher than those of two other clinical phenotypes. Significant correlations were observed between Hb and white blood cell in severe clinical phenotype (r3 = -0.37 *) between Hb and red blood cells in the three phenotypes (r1 = 0.69 * r2 * = 0.69, r3 = 0.83 *), and finally between Hb and reticulocytes in the asymptomatic clinical phenotype and severe clinical phenotype (r1 = -0.50 * r3 = 0.45 *). A significant increase in LDH was observed in patients with leg ulcer, cholelithiasis and aseptic necrosis of the femoral head.

Conclusion

The increase in serum LDH is accompanied by changes in hematological parameters. In our midst, serum LDH may be considered as an indicator of the severity of the disease.

Depression in children suffering from sickle cell anemia

Sickle cell anemia is a chronic illness associated with important nonmedical complications. The prevalence of depression and its clinical profile among Congolese children suffering from sickle cell disease are unknown. We therefore conducted a cross-sectional study in children between 8 and 17 years. The main goal of this study was to describe prevalence and characteristics of depression in this population living in Kinshasa, the Democratic Republic of Congo. The cross-sectional survey is of patients attending 2 referral centers. Children aged 8 to 17 years old were evaluated by a semistructured interview and standardized scales for depression separated by age and sex, the Multiscore Depression Inventory for Children. Completed questionnaires were received from 81 respondents. There were 43 girls and 38 boys. Depression symptoms were observed in 70 (86.4%) cases. Among this group, 6 children (8.6%) were observed to have severe depression. The most common symptoms were observed to be social introversion (81.5%), defiance (77.8%), helplessness (76.5%), and sad mood (70.4%). Of the 70 subjects, 19 (23.5%) had suicidal ideation. In Kinshasa, the prevalence of depression was high to those reported in western countries. Psychological interventions for individuals with sickle cell disease might complement current medical treatment in our midst.

Evaluation of high performance liquid chromatography (HPLC) pattern and prevalence of beta-thalassaemia trait among sickle cell disease patients in Lagos, Nigeria

Introduction

Sickle cell disease (SCD) is the most common inherited disorder of haemoglobin worldwide. This study evaluated the chromatographic patterns and red blood cell indices of sickle cell patients to determine the co-inheritance of other haemoglobin(Hb) variants and β-thalassaemia trait.

Methods

Red cell indices, blood film, sickle solubility test, Hb electrophoresis using alkaline cellulose acetate membrane, and chromatographic patterns using Bio Rad HPLC Variant II were evaluated for 180 subjects.

Results

Based on low MCV <76fL and MCH<25 pg, in the presence of elevated A₂ >4.0% on HPLC and Hb variants eluting outside the S and C windows, at least four haemoglobin phenotypes (SS: 87.7%; SC: 1.1%; SD Punjab: 0.6%; Sβ-thalassemia: 10.6%) were identified. Mean Hb F% was 8.1±5.1 (median 7.65) for Hb SS and 6.03±5.2 (median 3.9) for Hb Sβ-thalassemia trait. Majority of Hb SS (69.1%) had Hb F% less than 10 while 27.6% had 10-19.9 and 3.2% had ≥ 20. Mean Hb F% was higher in female Hb SS (9.55±5.09; mean age 7.4±3.8 years) than the males (7.63±4.80; mean age 6.9±3.8 years) (P=0.02). A borderline significant negative correlation between age and Hb F levels among Hb SS subjects (r= -0.169 P=0.038) was also observed.

Conclusion

Our data suggests that α and β- thalassaemia traits, and other haemoglobin variants co-exist frequently with SCD in our population