Browsing by Author "Ngogang, Jeanne"

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    Open Access
    Association of variants at BCL11A and HBS1L-MYB with hemoglobin F and hospitalization rates among sickle cell patients in Cameroon
    (Public Library of Science, 2014) Wonkam, Ambroise; Bitoungui, Valentina J Ngo; Vorster, Anna A; Ramesar, Raj; Cooper, Richard S; Tayo, Bamidele; Lettre, Guillaume; Ngogang, Jeanne
    BACKGROUND: Genetic variation at loci influencing adult levels of HbF have been shown to modify the clinical course of sickle cell disease (SCD). Data on this important aspect of SCD have not yet been reported from West Africa. We investigated the relationship between HbF levels and the relevant genetic loci in 610 patients with SCD (98% HbSS homozygotes) from Cameroon, and compared the results to a well-characterized African-American cohort. Methods and FINDINGS: Socio-demographic and clinical features were collected and medical records reviewed. Only patients >5 years old, who had not received a blood transfusion or treatment with hydroxyurea were included. Hemoglobin electrophoresis and a full blood count were conducted upon arrival at the hospital. RFLP-PCR was used to describe the HBB gene haplotypes. SNaPshot PCR, Capillary electrophoresis and cycle sequencing were used for the genotyping of 10 selected SNPs. Genetic analysis was performed with PLINK software and statistical models in the statistical package R. Allele frequencies of relevant variants at BCL11A were similar to those detected in African Americans; although the relationships with Hb F were significant (p <.001), they explained substantially less of the variance in HbF than was observed among African Americans (∼ 2% vs 10%). SNPs in HBS1L-MYB region ( HMIP ) likewise had a significant impact on HbF, however, we did not find an association between HbF and the variations in HBB cluster and OR51B5/6 locus on chromosome 11p, due in part to the virtual absence of the Senegal and Indian Arab haplotypes. We also found evidence that selected SNPs in HBS1L-MYB region ( HMIP ) and BCL11A affect both other hematological indices and rates of hospitalization. CONCLUSIONS: This study has confirmed the associations of SNPs in BCL11A and HBS1L-MYB and fetal haemoglobin in Cameroonian SCA patients; hematological indices and hospitalization rates were also associated with specific allelic variants.
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    The co-inheritance of alpha-thalassemia and sickle cell anemia is associated with better hematological indices and lower consultations rate in Cameroonian patients and could improve their survival
    (Public Library of Science, 2014) Rumaney, Maryam Bibi; Bitoungui, Valentina Josiane Ngo; Vorster, Anna Alvera; Ramesar, Raj; Kengne, Andre Pascal; Ngogang, Jeanne; Wonkam, Ambroise
    BACKGROUND: Co-inheritance of α-thalassemia was reported to be associated with a delayed age of disease onset among Cameroonian Sickle Cell Anemia (SCA) patients. The present study aimed to explore the correlation between α-thalassemia, hematological indices, and clinical events in these patients. Methods and FINDINGS: We studied 161 Cameroonian SCA patients and 103 controls (59.1% HbAA) with median ages of 17.5 and 23 years. RFLP-PCR was used to confirm SCA genotype and to describe haplotypes in the HBB-like genes cluster. Multiplex Gap-PCR was performed to investigate the 3.7 kb α-globin gene deletions. SNaPshot PCR, capillary electrophoresis and cycle sequencing were used for the genotyping of 10 SNPs in BCL11A , HMIP1/2 , OR51B5/6 and HBG loci, known to influence HbF levels. Generalised linear regression models adjusted for age, sex and SNPs genotypes was used to investigate effects of α-thalassemia on clinical and hematological indices. The median rate of vaso-occlusive painful crisis and hospitalisations was two and one per year, respectively. Stroke was reported in eight cases (7.4%). Benin haplotype was the most prevalent (66.3%; n = 208 chromosomes). Among patients, 37.3% ( n = 60) had at least one 3.7 kb deletion, compared to 10.9% ( n = 6) among HbAA controls (p<0.001). Among patients, the median RBC count increased with the number of 3.7 kb deletions [2.6, 3.0 and 3.4 million/dl, with no, one and two deletions (p = 0.01)]. The median MCV decreased with the number of 3.7 kb deletion [86, 80, and 68fl, with no, one and two deletions (p<0.0001)], as well as median WBC counts [13.2, 10.5 and 9.8×10 9 /L (p<0.0001. The co-inheritance of α-thalassemia was associated with lower consultations rate (p = 0.038). CONCLUSION: The co-inheritance of α-thalassemia and SCA is associated with improved hematological indices, and lower consultations rate in this group of patients. This could possibly improve their survival and explain the higher proportion of α-thalassemia among patients than controls.
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    First-line antiretroviral therapy and dyslipidemia in people living with HIV-1 in Cameroon: a cross-sectional study
    (BioMed Central Ltd, 2011) Yone Pefura , Eric; Betyoumin, Awa; Kengne, Andre; Kaze Folefack, Francois; Ngogang, Jeanne
    BACKGROUND: Data on lipid profile derangements induced by antiretroviral treatment in Africa are scarce. The aim of this study was to determine the prevalence and characteristics of lipid profile derangements associated with first-line highly active antiretroviral therapy (ART) among Cameroonians living with human immunodeficiency virus (HIV) infection. METHODS: This cross-sectional study was conducted between November 2009 and January 2010, and involved 138 HIV patients who had never received ART (ART-naive group) and 138 others treated for at least 12 months with first line triple ART regimens that included nevirapine or efavirenz (ART group). Lipid profile was determined after overnight fast and dyslipidemia diagnosed according to the US National Cholesterol Education Program III criteria. Data comparison used chi-square test, Student t-test and logistic regressions. RESULTS: The prevalence of total cholesterol [greater than or equal to] 200 mg/dl was 37.6% and 24.6% respectively in ART group and ART-naive groups (p = 0.019). The equivalents for LDL-cholesterol [greater than or equal to] 130 mg/dl were 46.4% and 21% (p [less than or equal to] 0.001). Proportions of patients with total cholesterol/HDL-cholesterol ratio [greater than or equal to] 5 was 35.5% in ART group and 18.6% in ART-naive group (p [less than or equal to] 0.001). The distribution of HDL-cholesterol and triglycerides was similar between the two groups. In multivariable analysis adjusted for age, sex, body mass index, CD4 count and co-infection with tuberculosis, being on ART was significantly and positively associated with raised total cholesterol, LDL-cholesterol and TC/HDL cholesterol. The adjusted odd ratios (95% confidence interval, p-value) ART-treated vs. ART-naive was 1.82 (1.06-1.12, p = 0.02) for TC [greater than or equal to] 200 mg/dl; 2.99 (1.74-5.15), p < 0.0001) for LDL-cholesterol [greater than or equal to] 130 mg/dl and 1.73 (1.04-2.89, p = 0.03) for TC/HDL-cholesterol [greater than or equal to] 5. CONCLUSIONS: First-line antiretroviral therapy that includes nonnucleoside reverse transcriptase inhibitors is associated with pro-atherogenic adverse lipid profile in people with HIV-1 infection compared to untreated HIV-infected subjects in Yaounde. Lipid profile and other cardiovascular risk factors should be monitored in patients on such therapy so that any untoward effects of treatments can be optimally managed.
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    Prevalence and determinants of chronic kidney disease in rural and urban Cameroonians: a cross-sectional study
    (BioMed Central Ltd, 2015) Kaze, Francois; Meto, Diane; Halle, Marie-Patrice; Ngogang, Jeanne; Kengne, Andre-Pascal
    BACKGROUND: Chronic kidney disease (CKD) is a global public health problem that disproportionally affects people of African ethnicity. We assessed the prevalence and determinants of CKD and albuminuria in urban and rural adults Cameroonians. METHODS: This was a cross-sectional study of 6-month duration (February to July 2014), conducted in the health district of Dschang (Western Region of Cameroon), using a multistage cluster sampling. All adults diagnosed with albuminuria ([greater than or equal to]30mg/g) and/or decreased estimated glomerular filtration rate (eGFR) (<60ml/min/1.73m 2 ) were re-examined three months later. Logistic regression models were used to relate baseline characteristics with prevalent CKD. RESULTS: We included 439 participants with a mean age of 47+/-16.1years; with 185 (42.1%) being men and 119 (27.1%) being urban dwellers. There was a high prevalence of hypertension (25.5%), diabetes (9.8%), smoking (9.3%), alcohol consumption (59.7%), longstanding use of herbal medicine (90.9%) and street medications (87.5%), and overweight/obesity (53.3%) which were predominant in rural area. The prevalence of CKD was 13.2% overall, 14.1% in rural and 10.9% in urban participants. Equivalents figures for CKD stages G3-G4 and albuminuria were 2.5%, 1.6% and 5.0%; and 12.1%, 14.1% and 6.7% respectively. Existing hypertension and diabetes were associated with all outcomes. Elevated systolic blood pressure and the presence of hypertension and diabetes were the predictors of albuminuria and CKD while urban residence was associated with CKD stages G3-G4. CONCLUSION: The prevalence of CKD and albuminuria was high in this population, predominantly in rural area, and driven mostly by the commonest risk factors.
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    Prevalence and risk factors of chronic kidney disease in urban adult Cameroonians according to three common estimators of the glomerular filtration rate: a cross-sectional study
    (BioMed Central Ltd, 2015) Kaze, Francois; Halle, Marie-Patrice; Mopa, Hermine; Ashuntantang, Gloria; Fouda, Hermine; Ngogang, Jeanne; Kengne, Andre-Pascal
    BACKGROUND: Chronic kidney disease (CKD) is a major threat to the health of people of African ancestry. We assessed the prevalence and risk factors of CKD among adults in urban Cameroon. METHODS: This was a cross-sectional study of two months duration (March to April 2013) conducted at the Cite des Palmiers health district in the Littoral region of Cameroon. A multistage cluster sampling approach was applied. Estimated glomerular filtration rate (eGFR) was based on the Cockcroft-Gault (CG), the four-variable Modification of Diet in Renal Disease (MDRD) study and Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equations. Logistic regression models were used to investigate the predictors of CKD. RESULTS: In the 500 participants with a mean age of 45.3+/-13.2years included, we observed a high prevalence of overweight and obesity (60.4%), hypertension (38.6%) and diabetes (2.8%). The mean eGFR was 93.7+/-24.9, 97.8+/-24.9 and 99.2+/-31.4ml/min respectively with the MDRD, CG and CKD-EPI equations. The prevalence of albuminuria was 7.2% while the prevalence of decreased GFR (eGFR<60ml/min) and CKD (any albuminuria and/or eGFR<60ml/min) was 4.4 and 11% with MDRD, 5.4 and 14.2% with CG, and 8.8 and 10% with CKD-EPI. In age and sex adjusted logistic regression models, advanced age, known hypertension and diabetes mellitus, increasing body mass index and overweight/obesity were the predictors of albuminuria, decreased GFR and CKD according to various estimators. CONCLUSION: There is a high prevalence of CKD in urban adults Cameroonian, driven essentially by the commonest risk factors for CKD.