Enigma of the high prevalence of anti-SARS-CoV-2 antibodies in HIV-positive people with no symptoms of COVID-19 in Burkina Faso.

The severe acute respiratory syndrome due to the new coronavirus (SARS-CoV-2), responsible for coronavirus disease (COVID-19), has severely tested the global health response capacity, with predictions of a fatality for developing countries. To evaluate the prevalence of anti-SARS-CoV- 2 antibodies in People Living with HIV (PLHIV) with no COVID-19 symptoms in Burkina Faso. Seroprevalence was estimated by performing a qualitative screening test for SARS-CoV-2-specific immunoglobulins. The STANDARDTM Q COVID-19 IgM/IgG Combo Test kit from SD BIOSENSOR was used. Parameters like HIV plasma viral load, CD4 T cell count and C-Reactive Protein (CRP) expression were estimated. This study enrolled a total of 200 PLHIV aged 4-87 years who are asymptomatic for COVID-19. There were 36 (18%) positive for SARS-CoV-2 IgM and/or IgG of which three (1.50%) were positive for SARS-CoV-2 IgM and 33 (16.50%) for IgG. Among participants diagnosed as IgM positive, 66.67% (2/3) had the highest HIV viral loads with the lowest CD4 T cell counts (p<0.0001). The expression of CRP was relatively higher in COVID-19 IgG positive individuals (7.95±12.5 mg/L) than negative individuals (6.26±6.92 mg/L; p=0.37). The rate of IgG and IgM SARS-CoV-2 immunoglobulin carriage (18%), accompanied by a relatively high CRP levels, was revealed in this study among PLHIV. This serologic evidence and mild inflammation suggest that Burkina Faso escaped the worst, not necessarily because there were not many SARS-CoV-2 infections in its population, but because factors including genetic and environmental, might have resulted in many asymptomatic carriers.

KIR2DL5B and HLA DRB1*12 alleles seems to be associated with protection against HIV-1 in serodiscordant couples in Burkina Faso.

The human immunodeficiency virus (HIV) belongs to the Retroviridae family and remains a public health problem in sub-Saharan Africa. Recent reports from WHO have shown that 33 million people died from HIV infections. HIV is one of the most serious fatal human diseases of the 20th and 21st centuries. However, variations in genetic and immunological factors are associated with protection against HIV infection in uninfected people exposed to HIV. This is the case with naturals killers which play an important role in the progression or regression of HIV infection. The objective of this study is to characterize certain HLA (human leukocyte antigen) class II genes and KIR genes in HIV-1 serodiscordant couples in Burkina Faso. This study was carried out at Burkina Faso among nineteen (19) HIV-1 serodiscordant couples. Classical multiplex PCR (SSP-PCR) was used to characterize the presence or absence of the KIR genes and certain class II HLAs (DRB1*11 and DRB1*12). The characterization of the KIR and HLA genes DRB1*11, DRB1*12 in this study demonstrated that the inhibitor KIR2DL5B, would confer protection against HIV-1 infection in seronegative partners (odd ratio [OR] = 0.13 [0.02-0.72] and p = 0.029), and the HLA DRB1*12 allele was associated with protection against HIV-1 infection in seronegative partners (OR = 0.16 [0.03-0.77] and p = 0.038). AA and Bx haplotypes were not found to be associated with HIV-1 infection in serodiscordant couples. This study confirms the involvement of the KIR genes in viral pathologies such as HIV-1 infection. Future larger-scale studies may provide a better understanding of the molecular mechanism by which the KIR haplotype and combination of KIR/HLA are associated with protection against HIV infection.

A rapid spectrophotometric method to identify inhibitors of human erythropoiesis.

Erythropoiesis is a complex physiological process by which erythroid progenitors proliferate and differentiate into nonnucleated red blood cells. Several methods can be used to monitor in vitro the differentiation of erythroid precursors, and hence the toxic effects of drugs, chemicals, or pollutants. One of the most commonly available assay of erythropoiesis is the microscopic observation of differentiated cells after benzidine staining, which forms a blue complex with hemoglobin. However, this method is laborious and does not provide accurate results since it heavily relies on the reader's interpretation. Moreover, benzidine is a carcinogen and a highly reactive molecule which forces the reader to microscopically count differentiated and non-differentiated cells within a short time frame (5 min). Here we have developed a simple, inexpensive, in-vitro spectrophotometric assay to measure erythroid differentiation using K562 cell line as a model. Materials needed included 96-well round-bottomed microplates and a microplate reader. Remarkably, carcinogenic benzidine was replaced by its isomeric tetramethyl derivative, the 3,3', 5,5'- tetramethylbenzidine (TMB), which presents several advantages: it is cheap, not mutagenic and a ready-to-use chromogenic substrate. A small volume (50 µl) of TMB added to the samples forms a blue complex in 15 min, and the reaction can be easily stopped and stabilized by the addition of H2SO4. The yellow precipitate is then solubilized, and the absorbance is measured at 450 nm. In addition, the suitability of the assay to determine the effects of compounds on erythroid differentiation was further tested with known inhibitors (artemisinin derivatives) of K562 differentiation. Overall, the reported methodology permits to measure in an accurate and reproducible manner the K562 differentiation and can be used for medium throughput screenings (MTS) of compounds or environmental toxics with potential erythro-toxicity and ability to inhibit erythroid differentiation.

The Use of Antimalarial Drugs against Viral Infection.

In recent decades, drugs used to treat malaria infection have been shown to be beneficial for many other diseases, including viral infections. In particular, they have received special attention due to the lack of effective antiviral drugs against new emerging viruses (i.e., HIV, dengue virus, chikungunya virus, Ebola virus, etc.) or against classic infections due to drug-resistant viral strains (i.e., human cytomegalovirus). Here, we reviewed the in vitro/in vivo and clinical studies conducted to evaluate the antiviral activities of four classes of antimalarial drugs: Artemisinin derivatives, aryl-aminoalcohols, aminoquinolines, and antimicrobial drugs.

Structure-based drug design, synthesis and biological assays of P. falciparum Atg3-Atg8 protein-protein interaction inhibitors.

The proteins involved in the autophagy (Atg) pathway have recently been considered promising targets for the development of new antimalarial drugs. In particular, inhibitors of the protein-protein interaction (PPI) between Atg3 and Atg8 of Plasmodium falciparum retarded the blood- and liver-stages of parasite growth. In this paper, we used computational techniques to design a new class of peptidomimetics mimicking the Atg3 interaction motif, which were then synthesized by click-chemistry. Surface plasmon resonance has been employed to measure the ability of these compounds to inhibit the Atg3-Atg8 reciprocal protein-protein interaction. Moreover, P. falciparum growth inhibition in red blood cell cultures was evaluated as well as the cyto-toxicity of the compounds.

Salinomycin and other ionophores as a new class of antimalarial drugs with transmission-blocking activity.

The drug target profile proposed by the Medicines for Malaria Venture for a malaria elimination/eradication policy focuses on molecules active on both asexual and sexual stages of Plasmodium, thus with both curative and transmission-blocking activities. The aim of the present work was to investigate whether the class of monovalent ionophores, which includes drugs used in veterinary medicine and that were recently proposed as human anticancer agents, meets these requirements. The activity of salinomycin, monensin, and nigericin on Plasmodium falciparum asexual and sexual erythrocytic stages and on the development of the Plasmodium berghei and P. falciparum mosquito stages is reported here. Gametocytogenesis of the P. falciparum strain 3D7 was induced in vitro, and gametocytes at stage II and III or stage IV and V of development were treated for different lengths of time with the ionophores and their viability measured with the parasite lactate dehydrogenase (pLDH) assay. The monovalent ionophores efficiently killed both asexual parasites and gametocytes with a nanomolar 50% inhibitory concentration (IC50). Salinomycin showed a fast speed of kill compared to that of standard drugs, and the potency was higher on stage IV and V than on stage II and III gametocytes. The ionophores inhibited ookinete development and subsequent oocyst formation in the mosquito midgut, confirming their transmission-blocking activity. Potential toxicity due to hemolysis was excluded, since only infected and not normal erythrocytes were damaged by ionophores. Our data strongly support the downstream exploration of monovalent ionophores for repositioning as new antimalarial and transmission-blocking leads.

Modified quaternary ammonium salts as potential antimalarial agents.

A series of new quaternary ammonium salts containing a polyconjugated moiety has been synthesized and characterized; their biological activity as potential antimalarial agents was investigated, as well. All compounds were screened against chloroquine resistant W-2 (CQ-R) and chloroquine sensitive, D-10 (CQ-S) strains of Plasmodium falciparum showing IC50 in the submicromolar range and low toxicity against human endothelial cells.

Antiplasmodial and anti-inflammatory activities of Canthium henriquesianum (K. Schum), a plant used in traditional medicine in Burkina Faso.

ETHNOPHARMACOLOGICAL RELEVANCE: Canthium henriquesianum (K. Schum) is traditionally used in Burkina Faso for the treatment of malaria, but has not been properly investigated, yet. The aim of this study was to characterize in vitro the antiplasmodial and the anti-inflammatory activity of extracts from Canthium henriquesianum (K. Schum). In parallel, extracts of Gardenia sokotensis (Hutch) and Vernonia colorata (Willd), also traditionally used together in Burkina Faso and already reported with antimalarial activity, were compared. MATERIALS AND METHODS: Plant extracts were tested in vitro for antimalarial activity against chloroquine susceptible (D10) and resistant (W2) strains of Plasmodium falciparum using the lactate dehydrogenase assay. Cell cytotoxicity was assessed on human dermal fibroblast (HDF) by the MTT assay. The selectivity index (SI) was used as the ratio of the activity against the parasites compared to the toxicity of the plant extract against HDF. In vitro cytokine production was assessed by ELISA technique. RESULTS: Canthium henriquesianum aqueous extract had a moderate antimalarial activity (IC50<50 µg/ml) with a good selectivity index (SI=HDF/D10>7). Canthium henriquesianum diisopropyl ether extract was the most potent inhibitor of parasite growth with an IC50 9.5 µg/ml on W2 and 8.8 µg/ml on D10 and limited toxicity (SI>2). Gardenia sokotensis and Vernonia colorata aqueous extracts were shown to be significantly less active (IC50≥50 µg/ml) with substantial toxicity. In addition, when the production of IL-1ß and TNFα by lipopolysaccharide (LPS) or hemozoin (malaria pigment) stimulated human THP-1 monocytes was assayed, it was found that the extract of Canthium henriquesianum induced a dose-dependent inhibition of IL-1ß, but not of TNFα production, thus confirming its traditional use as antipyretic. By NMR analysis, the chromone was identified as the mostly represented compound in the diisopropyl ether extract of Canthium henriquesianum. Chromone however, was less active as antimalarial than the crude extract and it did not inhibit cytokine production at not toxic doses, indicating that other molecules in the total extracts contribute to the antiplasmodial and anti-inflammatory activity. CONCLUSION: Canthium henriquesianum seems to possess antimalarial activity in vitro and the ability to inhibit the production of the pyrogenic cytokine IL-1ß.

Sub-Saharan Rubiaceae: a review of their traditional uses, phytochemistry and biological activities.

Rubiaceae family is a large family of 630 genera and about 13000 species found worldwide, especially in tropical and warm regions. These plants are not only ornamental but they are also used in African folk medicine to treat several diseases. Based on online published data and library bibliographic research, we herein reported accumulated information related to their traditional usages in sub-Saharan traditional medicine, their chemical composition and the screened pharmacological activities. Indeed, more than 60 species are used for more than 70 medicinal indications including malaria, hepatitis, eczema, oedema, cough, hypertension, diabetes and sexual weakness. Through biological screening following leads supplied with traditional healers, many of these plants exhibited antimalarial, antimicrobial, antihypertension, antidiabetic, antioxidant and anti-inflammatory activities. Bioactive compounds including indole alkaloids, terpenoids and anthraquinones have been isolated from these bioguided fractionation studies. It is evidence that great attention has been paid to species such as Nauclea latifolia, Morinda lucida, Mitragyna inermis and Crossopteryx febrifuga; however, several compounds should be waiting to be discovered since none of these plants has been systematically investigated for its biochemical composition. According the current global health context with the recrudescence of HIV, much effort should be oriented towards this virus when screening Rubiaceae.

In vitro antiplasmodial activity of crude extracts from Togolese medicinal plants.

OBJECTIVE: To investigate the antimalarial effect of a few plants in Togo folk medicine. METHODS: After ethnobotanical survey, Opilia celtidifolia, Pavetta corymbosa (P. corymbosa) and Tamarindus indica (T. indica) were selected for screening. In vitro antimalarial tests were performed on crude extracts against fresh clinical isolates of Plasmodium falciparum using the semi microtest. RESULTS: Different IC(50) values of the extracts ranged from 2.042 to 100.000 µg/mL. According to the results, the methanol extract of aerial part of P. corymbosa followed by aqueous extract of fruit of T. indica were the most active (IC(50) of 2.042 and 4.786 µg/mL, respectively). Qualitative test revealed the presence of alkaloids in the leaves of P. corymbosa that may be responsible for the activity of the plant. CONCLUSIONS: Our study provides scientific evidence for usage of plant in the folk medicine, and further studies are needed for identification and purification of the active principles.

Towards the complete eradication of mother-to-child HIV/HBV coinfection at Saint Camille Medical Centre in Burkina Faso, Africa.

The coinfection of HIV and hepatitis B virus (HBV) and their vertical transmission constitute a public health problem in sub-Saharan countries of Africa. The objectives of this research are: i) identify the pregnant women that are coinfected by HIV and HBV at Saint Camille Medical Centre; ii) use three antiretroviral drugs (zidovudine, nevirapine and lamivudine) to interrupt the vertical transmission of HIV and HBV from infected mothers; and iii) use the PCR technique to diagnose children who are vertically infected by these viruses in order to offer them an early medical assistance. At Saint Camille Medical Centre, 115 pregnant women, aged from 19 to 41 years, were diagnosed as HIV-positive and, among them, 14 coinfected with HBV. They had at least 32 weeks of amenorrhoea and all of them received the HAART, which contained lamivudine. Two to six months after childbirth, the babies underwent PCR diagnosis for HIV and HBV. The results revealed that, among these mothers, 64.4% were housewives, 36.5% were illiterates, and only 1.7% had a university degree. The rate of vertical transmission of HIV and HBV was 0.0% (0/115) and 21.4% (3/14), respectively. The 3 mothers who transmitted the HBV to their children had all HBsAg, HbeAg, and HBV DNA positive. An antiretroviral therapy that in addition to zidovudine and nevirapine includes lamivudine could, as in the present study, block or reduce the vertical transmission in HIV positive pregnant women who are coinfected with HBV.

Towards the complete eradication of mother-to-child HIV/HBV coinfection at Saint Camille Medical Centre in Burkina Faso, Africa

The coinfection of HIV and hepatitis B virus (HBV) and their vertical transmission constitute a public health problem in sub-Saharan countries of Africa. The objectives of this research are: i) identify the pregnant women that are coinfected by HIV and HBV at Saint Camille Medical Centre; ii) use three antiretroviral drugs (zidovudine, nevirapine and lamivudine) to interrupt the vertical transmission of HIV and HBV from infected mothers; and iii) use the PCR technique to diagnose children who are vertically infected by these viruses in order to offer them an early medical assistance. At Saint Camille Medical Centre, 115 pregnant women, aged from 19 to 41 years, were diagnosed as HIV-positive and, among them, 14 coinfected with HBV. They had at least 32 weeks of amenorrhoea and all of them received the HAART, which contained lamivudine. Two to six months after childbirth, the babies underwent PCR diagnosis for HIV and HBV. The results revealed that, among these mothers, 64.4 percent were housewives, 36.5 percent were illiterates, and only 1.7 percent had a university degree. The rate of vertical transmission of HIV and HBV was 0.0 percent (0/115) and 21.4 percent (3/14), respectively. The 3 mothers who transmitted the HBV to their children had all HBsAg, HbeAg, and HBV DNA positive. An antiretroviral therapy that in addition to zidovudine and nevirapine includes lamivudine could, as in the present study, block or reduce the vertical transmission in HIV positive pregnant women who are coinfected with HBV.

Glucose-6-phosphate dehydrogenase deficiency and sickle cell disease in Burkina Faso.

Where malaria is endemic, there is an unexpected association between haemoglobinopathies and glucose-6-phosphate dehydrogenase (G-6-PD) deficiency. Their coexistence in a patient with sickle cell disease (SCD) can lead to hemolytic anemia, hemoglobinuria, sepsis, renal failure and vaso-occlusive attacks (VOA). The aim of this research was to determine the impact of G-6-PD deficiency in SCD patients. That is why, we screened haemoglobinopathies and G-6-PD deficiency in 7 villages and at 10 primary schools in Kadiogo Province, Burkina Faso. Hemoglobin electrophoresis was performed on blood from 18,383 people. From these results, we chose 342 subjects for a hemogram and the measure of the G-6-PD activity. The results were analyzed with Epilnfo-6 and Spss-10. Statistical significance was set at p < 0.05. We found a prevalence of 28.9% of Sickle Cell Trait (SCT), 1.3% of Major Sickle Cell Syndromes (MSCS), 12.3% of G-6-PD deficiency among women and 20.5% among men. We did not detect a statistically significant difference for counts of erythrocytes (p = 0.773), leucocytes (p = 0.227) and reticulocytes (0.292); hemoglobin levels (p = 0.998); annual vasoocclusive attacks (p = 0.869) between persons with SCD having a G-6-PD deficiency and those with normal G-6-PD activity. According to this study, G-6-PD deficiency does not seem to increase the severity of SCD. However, these patients should know their G-6-PD genotype in order to avoid consuming oxidative drugs that might provoke oxidative stress.

Prevalence of human herpes virus-8 and hepatitis B virus among HIV seropositive pregnant women enrolled in the Mother-to-Child HIV Transmission Prevention Program at Saint Camille Medical Centre in Burkina Faso.

The aims of this research are: i) to evaluate the prevalence of HHV-8, HBV and HIV among pregnant women, ii) to determine the percentage of these co-infections and iii) to estimate the frequency of the mother-to-child transmission of HIV among HBV and HHV-8 positive mothers. Thus, 379 pregnant women attending ante-natal consultation in Saint Camille Medical Centre were subject to HIV, HHV-8 antibodies and the viral marker Hepatitis B Surface Antigen (HBsAg) detection. We observed 48/379 (12.66%) HIV seropositive subjects. Among them, HIV-1 type infection was predominant (95.83%), only 2/48 (4.17%) subjects had a dual HIV-1 type and HIV-2 type infection, no single HIV-2 type infection was detected. 38/379 (10.02%) subjects were infected by HHV-8 and 30/379 (7.91%) were HBsAg positive. HHV-8 and HIV Co-infections rates were high within HBV positive patients and we had respectively 20.00 and 16.67%. 10.42% HIV positive women were coinfected by HBV while 12.50% were infected by HHV-8. Then, 15.79% subjects HHV-8 positive were co-infected by HBV or HIV. In spite of the PMTCT protocol application, five (10.42%) HIV positive women transmitted the virus to their children. Two HIV positive mothers were co-infected by HHV-8 and one by HBV. Among the 5 HIV infected, one mother (20.0%) was HBV positive and two (40.0%) HHV-8 positive. Although we did not have a large sample which would show large prélalences of the infections, we could put forward that the Co-infection of the HIV with one of these viruses (HBV or HHV-8) could favorite the mother-to-child transmission.

Toxoplasma gondii, HCV, and HBV seroprevalence and co-infection among HIV-positive and -negative pregnant women in Burkina Faso.

Toxoplasma gondii (T. gondii) infections can cause serious complications in HIV-infected pregnant women, leading to miscarriage, stillbirth, birth defects (e.g., mental retardation, blindness, epilepsy etc.) and could favor or enhance the mother-to-child transmission of HCV, HBV, and HIV vertical transmission. From May 20, 2004 to August 3, 2005, 336 18-45 years aged pregnant women, were enrolled for an investigation of the prevalence of serum antibodies against T. gondii, HCV, HBV, and HIV using ELISA. The prevalence of T. gondii, HCV, and HBV in pregnant women was 25.3%, 5.4%, and 9.8%, respectively and the HIV serostatus (61.6%) seems to be associated with greater prevalence rates of both T. gondii (28.5% vs. 20.2%) and HBV (11.6% vs. 7.0%). Without taking into account HIV, only 65.5% (220 of 336) of the women were not infected with these agents. The co-infection rate between HIV-infected and -negative women was different statistically: T. gondii/HBV 0.048 versus 0.015, T. gondii/HCV 0.014 versus 0.008, and HCV/HBV 0.005 versus 0.008, respectively. The elevated co-infection rate in HIV-positive women demonstrated that they are exposed to T. gondii, HCV, and HBV infections prevalently by sexual contact.