Tatiana Baglo

Introduction: Disease knowledge and health literacy are important health competencies that individuals with chronic conditions like Sickle Cell Disease (SCD) need for self-management. This study aimed to: (I) describe and compare SCD knowledge and health literacy levels in adolescents and young adults (AYAs) with SCD in Benin; (II) examine associations between genotype, socio-demographic factors, health literacy, and SCD knowledge; and (III) examine the associations between patients SCD knowledge, health literacy, socio-demographic factors, and (a) frequency of hospitalisations and (b) frequency of occurrence of painful episodes. Methods: AYAs aged 14 to 25 years with SCD attending routine consultations at two Benin clinics—the National Sickle Cell Disease Centre (CPMI-NFED) and the Haematology clinic of the University Teaching Hospital (CUMAS), completed a questionnaire assessing SCD knowledge and health literacy (Health Literacy Measure for Adolescents, HELMA). Results: Most participants had inadequate health literacy: 72.1% at CPMI-NFED and 82.1% at CUMAS, with no significant differences between centres (t = 1.642, p = 0.200). CPMI-NFED participants had higher SCD knowledge than those at CUMAS (t = 4.303, p = 0.038). Higher SCD knowledge (β = 0.466; p < 0.001) and health literacy (β = 5.081; p < 0.001) were associated with older age. Tertiary-level education was associated with higher health literacy (β = 4.286; p = 0.023). Participants with high SCD knowledge experienced fewer painful episodes (IRR = 0.777, p = 0.046), but no significant differences in hospital admissions (IRR = 0.764, p = 0.162). Conclusions: Inadequate health literacy is common in AYAs with SCD in Benin. Having high SCD knowledge may have an impact on the occurrence of painful episodes.

Aim: determine the prevalence of a FVIII inhibitors and identify the genetic mutations associated with their development in beninese personne with hemophilia (PwH) A. Study Design: this is cross-sectional descrptive study conducted from June 2022 to May 2023 in hemophilia treatment centers in Benin. Methodology: Inhibitor screening was carried out systematically in all PwHs A receiving FVIII infusion through determination of the circulating anticoagulant index and the Nijmegen-Bethesda assay. The molecular study strategy used for the F8 gene associated with hemophilia A is dependent on the severity of the hemophilia. Other data were collected either from patients' responses to the questionnaire or by studying their medical records and the center's hemophilia registry. Results: Of the 97 PwHs A followed up, 57 had been treated with FVIII infusion. Of these, 21 had developed inhibitors, representing a frequency of 36.8% of treated PwHs A and 43.75% of severe PwHs. None of the moderate or mild PwHs A had developed anti-FVIII antibodies. PwHs A with inhibitors had a median age of 11 years, ranging from 1 to 66 years. The Nijmegen-Bethesda test revealed 11 high responders and 10 low responders. Mutation analysis of the F8 gene revealed seven cases of intron 22 inversion, seven cases of nonsense mutations, three cases of deletion and one case of missense mutation. Mutations weren’t identified in three patients because their DNA did not amplify on long-distance PCR. In terms of therapy, immune tolerance induction wasn’t achieved in any of the 21 patients, but they are treated with emicizumab and bypass depending on the context. Conclusion: Although a cross-sectional study with a limited sample size, this study provides valuable information on beninese PwHs A with inhibitors. The frequency of inhibitors is high in treated PwHs A, and almost all patients who have developed inhibitors have high-risk genetic mutations.

For many years, the treatment of malaria was based on clinical presumptive diagnosis, making its differential diagnosis with other causes of hyperthermia difficult. This drug pressure has led to the emergence of Plasmodium strains resistant to the most commonly used antimalarial drugs. This is why in 2004, the health authorities decided to revise the policy of malaria management by adopting a new strategy based on the rational use of artemisininbased combination therapies after the biological confirmation of suspected malaria cases. The biological diagnosis is an essential part of malaria management. The gold standard technique for diagnosis is the thick drop combined with the calculation of parasite density (PD), which is determined on the basis of the number of parasites counted in a microscopic field against a proposed standard number of leukocytes. The number of leukocytes used to calculate the parasite density should ideally be the actual number of leukocytes in the patient per cubic millimetre of blood. However, in the absence of the availability of a blood count at the time of the thick drop, an average number of 8 000 leukocytes/mm³ was used by the World Health Organisation (WHO) to estimate the parasite density. Nonetheless, in Benin the average number of leukocytes adopted by the National Malaria Control Programme (PNLP) is 6 000/mm³. The aim of our study was to determine the impact of the leukocyte count on the calculation of the parasite density in cases of uncomplicated malaria. The study was a cross-sectional study with an analytical aim and took place in 2 hospitals in Benin, the Klouékanmey zone hospital in the south of Benin and the Djougou health centre in the north. It involved a population of 476 children aged between 6 and 59 months who were seen in consultation and in whom the clinical diagnosis of simple Plasmodium falciparum malaria was suspected. Children aged between 6 and 59 months, weighing at least 5 kg, with an axillary temperature ≥ 37.5°C at the time of consultation or a history of fever in the last 24 hours or other symptoms pointing to the diagnosis of malaria were included. Infestation was mono-specific for Plasmodium falciparum. Informed consent was required from the child's parents or guardian. The criteria for non-inclusion in our study were the presence of at least one sign of malaria severity, signs of severe malnutrition or a febrile state related to underlying infectious diseases other than malaria. Thick blood count and haemogram were systematically performed in all included children. Parasite density was calculated according to 3 methods, first using a weighted leukocyte count of 6 000/mm³ recommended by the Benin National Malaria Control Programme (PNLP), then a leukocyte count of 8 000/mm³ recommended by the World Health Organisation and finally the patient's actual leukocyte count obtained from the blood count. It should be noted that these different samples were respectively taken on the day of inclusion in compliance with the conditions of the pre-analytical phase in force in our medical biology laboratory. At the end of our study, 313 children, i.e. 65.76% of our study population had a positive white blood cell count with a positivity rate of 62.14% in Djougou, i.e. 174 children, and 70.9% in Klouékanmey, i.e. 139 children. The average leukocyte count in these children was 11,580/mm³. Among them, 205 children had an abnormal white blood cell count, i.e. 17 cases of leukopenia (5.43%) and 188 cases of hyperleukocytosis (60.06%). Using successively the average number of 6 000 leukocytes/mm³ proposed by the Benin PNLP and that of 8 000 leukocytes/mm³ proposed by the WHO, the average parasite densities were respectively 47,943 and 63,936 trophozoïtes/µl against 92,290 trophozoïtes/µl when the real number of leukocytes of the patients was used for the calculation of the PD. By using an average of 6 000 leukocytes/mm³ for PD calculation, 60% of the calculated PDs were underestimated and 6% were overestimated. Using an average of 8 000 leukocytes/mm³ resulted in 49% of PD being underestimated and 15% being overestimated. The difference between the three calculation methods was considered statistically significant (p value <0.05). The use of 6 000 or 8 000 coefficients for the estimation of parasitaemia could lead to a significant underestimation of the parasite load.

Blood transfusion is a medical procedure used to treat patients with labile blood product. Each transfusion of globular concentrate exposes recipients to the risk of red blood cell alloimmunization. The test for red cell antibodies (RCA) ensures the immunohaematological safety of transfused patients. In Benin, this test is not performed in a systematic way or included either in the pre-transfusion or in the post-transfusion tests. The purpose of this study is to determine the presence of red cell antibodies among polytransfused patients. RCA was performed using indirect antiglobulin test on gel filtration in 51 polytransfused patients including 26 selected in the Department of Hematology and 25 in the Department of Nephrology at the National Hospital and University Center of Cotonou. After phenotyping alloimmunized patients, tests for detecting signs of hemolysis were performed. Clinical data as well as those on transfusion were collected from transfusion registries and medical records. The prevalence of alloimmunization in our study population was 13.73%. The antibodies identified had the following characteristics: association of anti-RH1 and anti-RH3, anti LE1, association of anti-RH3 and anti-FY1. Alloantibodies were more frequent in patients who had received more than 15 packed red blood cells. Laboratory tests showed signs of hemolysis in one alloimmunized patient. There was no correlation between age, sex, clinical diagnosis and the occurrence of red blood cell alloimmunization. The test for red cell antibodies should be systematically performed in polytransfused patients in order to ensure better transfusion recipient safety in Benin.

Drug-induced immune thrombocytopenia (DITP) is a life-threatening clinical syndrome that is under-recognized and difficult to diagnose. Many drugs can cause immune-mediated thrombocytopenia, but the most commonly implicated are abciximab, carbamazepine, ceftriaxone, eptifibatide, heparin, ibuprofen, mirtazapine, oxaliplatin, penicillin, quinine, quinidine, rifampicin, suramin, tirofiban, trimethoprim-sulfamethoxazole, and vancomycin. Several different mechanisms have been identified in typical DITP, which is most commonly characterized by severe thrombocytopenia due to clearance and/or destruction of platelets sensitized by a drug-dependent antibody. Patients with typical DITP usually bleed when symptomatic, and biological confirmation of the diagnosis is often difficult because detection of drug-dependent antibodies (DDabs) in the patient’s serum or plasma is frequently not possible. This is in contrast to heparin-induced thrombocytopenia (HIT), which is a particular DITP caused in most cases by heparin-dependent antibodies specific for platelet factor 4, which can strongly activate platelets in vitro and in vivo, explaining why affected patients usually have thrombotic complications but do not bleed. In addition, laboratory tests are readily available to diagnose HIT, unlike the methods used to detect DDabs associated with other DITP that are mostly reserved for laboratories specialized in platelet immunology.