Haematological abnormalities in children with sickle cell disease and non-severe malaria infection in western Kenya

Blood count changes in malaria patients according to blood groups (ABO/Rh) and sickle cell trait

INTRODUCTION

Introduction: Malaria continues to be the leading cause of hospitalization and death in Angola, a country in sub- Saharan Africa. In 2023, in the first quarter, 2,744,682 cases were registered, and of these 2,673 patients died due to malaria disease. Previous studies have shown that the ABO blood group can affect the progression of malaria to severe conditions after P. falciparum infection, while the sickle cell gene offers relative protection.

OBJECTIVE

We investigated changes in the blood count according to blood groups (ABO/Rh) and sickle cell trait in patients with malaria in Luanda, capital of Angola.

METHODOLOGY

This was a longitudinal, prospective and observational study with 198 patients hospitalized for malaria.

RESULTS

Of the 198 patients studied, 13(6.6%) were ABRh(+), 4(2.0%) were ARh(-), 49(24.7%) were ARh(+), 42(21, 2%) were BRh (+), 5(2.5%) were ORh(-) and 85(42.9%) were ORh(+). For sickle cell trait, 145(73.2%) were AA, 37(18.7%) were AS and 16(8.1%) were SS. No statistical relationship was observed between age group, sex, parasitemia, clinical picture, hematocrit, MCV, HCM, MCHC, leukocytes, NEUT, LINF and PTL values with blood groups (p<0.05), but there was a relationship between values of hemoglobin and ABO/Rh blood groups (p>0.05). There was no relationship between age, parasitemia, clinical condition, MCV, HCM and MCHC values, leukocytes, NEUT and LINF with sickle cell trait (p<0.05), but there was a relationship between sex, hemoglobin and PTL and sickle cell values. sickle cell trait (p>0.05).

CONCLUSION

It is imperative to differentiate patients with malaria based on blood groups and sickle cell trait, taking into account mainly the blood count parameters that demonstrate that there are patients who, depending on blood group or sickle cell trait, may react weakly to malaria infection regardless of the degree of parasitemia and medical prognosis.

In vitro delayed response to dihydroartemisinin of malaria parasites infecting sickle cell erythocytes

BACKGROUND

Decreased efficacy of artemisinin-based combination therapy (ACT) for Plasmodium falciparum malaria has been previously reported in patients with sickle cell disease (SCD). The main purpose of this study was to investigate the in vitro susceptibility of isolates to dihydro-artemisinin (DHA) to provide a hypothesis to explain this treatment failure.

METHODS

Isolates were collected from patients attending health centres in Abidjan with uncomplicated P. falciparum malaria. The haemoglobin type has been identified and in vitro drug sensitivity tests were conducted with the ring stage assay and maturation inhibition assay.

RESULTS

134 isolates were obtained. Parasitaemia and haemoglobin levels at inclusion were lower in patients with haemoglobin HbSS and HbSC than in patients with normal HbAA. After ex vivo RSA and drug inhibition assays, the lowest rate of parasitic growth was found with isolates from HbAS red cells. Conversely, a significantly higher survival rate of parasites ranging from 15 to 34% were observed in isolates from HbSS. Isolates with in vitro reduced DHA sensitivity correlate with lower RBC count and haematocrit and higher parasitaemia at inclusion compared to those with isolates with normal DHA sensitivity. However, this decrease of in vitro sensitivity to DHA was not associated with Kelch 13-Propeller gene polymorphism.

CONCLUSION

This study highlights an in vitro decreased sensitivity to DHA, for isolates collected from HbSS patients, not related to the Pfkelch13 gene mutations. These results are in line with recent studies pointing out the role of the redox context in the efficacy of the drug. Indeed, SCD red cells harbour a highly different ionic and redox context in comparison with normal red cells. This study offers new insights into the understanding of artemisinin selective pressure on the malaria parasite in the context of haemoglobinopathies in Africa.

Distribution of hemoglobinopathy phenotypes in western Kenya: a retrospective study done at Aga Khan Hospital, Kisumu

Background

Hemoglobinopathies are inheritable disorders of hemoglobin and are the most common genetic defects in humans. This is a neglected public health problem whose undiagnosis remain a major threat to its prevention and control in sub-Saharan Africa countries; thus its exact magnitude on morbidity and mortality remains poorly documented. These hemoglobin disorders have been associated with Plasmodium falciparum; therefore, the current study sought to determine its distribution in a malaria-holoendemic region of Western Kenya as part of remedial intervention recommended by World Health Organization (WHO).

Method

This study analyzed data conveniently selected through census from 2015 to 2020 from hematology laboratory database for patients examined in Aga Khan, Hospital, Kisumu, and its satellites in Western Kenya. A total of 247 cases were selected whose sample size was calculated using Cochran’s formula. Distribution of hemoglobinopathies based on stations, gender, and age was expressed in frequencies, proportions, bar graphs, and pie charts.

Results

The distribution of hemoglobinopathies had varying proportions in different locations in Western Kenya with regions that were at proximity to Lake Victoria (Kisumu 41.3%, n = 102; Busia 21.5%, n = 53; Homabay 15.4%, n = 38) recording a higher overall hemoglobinopathy proportions than those that were far from the lake that include Bungoma 5.7%, n = 14; Kakamega 4.0%, n = 10; Kitale 4.0%, n = 10; Kisii 4.0%, n = 10, and Migori 4.0% n = 10.

Conclusion

The study represents the burden of hemoglobinopathies in a malaria-holoendemic region of Western Kenya, and even though the present study did not include ethnicity in data collection, stations from where the data was collected are predominated by different communities; therefore, there may be an ethnic correlation in the variation of hemoglobinopathies in Western Kenya. The communities juxtaposed to the lake seems to be the most affected ethnic group along the Lake Victoria economic block region; thus, it may be erroneous to assume that the entire malaria-holoendemic region of Western Kenya has high prevalence of hemoglobin disorders without factoring ethnicity and geographical location in a properly conducted population-based prevalence study in the wider Western Kenya.

Prognostic Potential of RDW in Discriminating Hemoglobinopathies among Patients reporting to Aga Khan Hospital, Kisumu

Background

Red cell distribution width (RDW) measures the extent of variation in red blood cell (RBC) volume in terms of coefficient of variation. It reflects the degree of variation in RBC’s sizes and shapes, characteristic of iron deficiency and anemias involving RBC destruction, especially hemoglobinopathies. Its values are often available as one of the RBC indices generated as complete blood cell count (CBC) using automated hematology analyzers. Hemoglobinopathies are highly prevalent in malaria-endemic geographical settings like the Sub-Saharan African which has over 200,000 currently documented annual major hemoglobinopathies with an alarming mortality rate of 50–90% by the age of 5 years usually undiagnosed. With a vast growing majority of hemoglobinopathy carriers, this public health problem is projected to escalate by the year 2050 due to unaffordable laboratory tests for screening of newborns and populations as recommended by World Health Organization in resource-limited settings. Therefore, innovative of a cost-effective diagnostic method would improve the survival of these children. The current study aimed to evaluate the overall ability of RDW in discriminating hemoglobinopathy and hemoglobinopathy-free cases within the Lake Victoria Economic Block region of Western Kenya served partly by the Aga Khan Hospital, Kisumu.

Objective

To determine the significance of RDW as a tool to differentiate between individuals with hemoglobinopathies and those without.

Method

This was a cross-sectional retrospective comparative hospital-based study that analyzed data from the hematology laboratory database for patients examined using high-performance liquid chromatography during the years 2015–2020. The study consisted of 488 participants (49.4%, n = 241 control; 50.6% n = 247 case, p = 0.786) aged between 1 month and 66 years selected conveniently through census. The relationship between RDW of the controls and cases was analyzed using Mann–Whitney U, Kruskal–Wallis tests among population groups and Dunn’s post hoc test within groups since the data were non-normally distributed.

Results

The RDW cutoff value was computed at 95% confidence interval (CI), and values greater than this indicated a diagnosis of hemoglobinopathy.

Conclusion

RDW at 95% CI was 19.9 [14.5 + (2.7 × 2 = 19.9)] cutoff point which proved to be an excellent screening tool for sickle cell disease phenotypes in Western Kenya but would generate many false positive and false negatives for pure Hb AS. RDW is a poor screening tool for, Hb AS + HbF, Hb AS + β thal and β-thalassemia since it could not differentiate diseased from non-diseases populations. Even though RDW proved to be a poor screening tool for beta thalassemia, other complete blood count (CBC) parameters such as MCV and red cell count can be used to identify thalassemia syndromes as well as iron deficiency anemia. Though out of the scope of this work, highlighting the significance of these parameters in addition to the RDW would improve its feasibility as a screening tool for all hemoglobinopathies. Normal reference range for children ≤ 5 years needs to be developed using prospective data for precise marking of disorders associated with red cell anisocytosis, and individuals ≥ 6 years can share RDW normal reference range regardless of their gender.

Transfusion-Transmitted Malaria: Two Pediatric Cases From the United States and Their Relevance in an Increasingly Globalized World

In non-endemic settings, transfusion-transmitted malaria (TTM) is rare but potentially fatal and becoming more common with globalization. We present two pediatric cases that demonstrate donor screening using questionnaires is subject to error and that TTM should be considered with fever following numerous transfusions in children, particularly sickle cell patients.