Browsing by Author "Appiah, Lambert Tetteh"

Now showing 1 - 2 of 2
  • Thumbnail Image
    Item
    Hepatitis C Virus (HCV) RNA screening and sequencing using dry plasma spots
    (Elsevier B.V., 2017-10) Phillips, Richard Odame; Geretti, Anna Maria; King, Simon; Adjei-Asante, Kwabena; Appiah, Lambert Tetteh; et. al
    Background: HCV RNA screening of large sample repositories provides data on HCV epidemic patterns that may help guide control policies. In resource-limited settings, shipment of frozen samples to molecular laboratory facilities and testing of individual samples may be prohibitively expensive. Objective: Our aim was to detect and sequence HCV RNA in a large HIV-positive cohort from Kumasi, Ghana, using pooled and individual dried plasma spots (DPS) produced from samples stored at −80 °C. Study design: In the validation phase, replicate DPS were prepared with six dilutions (500–10,000 IU/ml) of the 4th International Standard for HCV and tested in three independent experiments. In the testing phase, DPS prepared with plasma samples from 875 HIV-positive subjects were pooled for screening, followed by testing of individual DPS of positive pools. Input from individual DPS was two 6 mm punches; pools comprised two punches from each of five DPS. Genotypes were determined by Sanger sequencing of HCV core and NS5B. Results: With the dilution series, sensitivity of HCV RNA detection was ≥2500 IU/ml. Replicate DPS gave intraassay and inter-assay coefficients of variation ≤1.4%. With the stored samples, HCV RNA was detected in 5/175 DPS pools and in one DPS from each positive pool, yielding a HCV RNA prevalence of 5/875 (0.57%; 95% confidence interval 0.07-1.07%). The five samples were sequenced as HCV genotypes 2l and 2r. Discussion: DPS allowed reproducible HCV RNA detection, and pooling effectively contained the cost and labour of screening a previously untested, low-prevalence cohort. DPS were also suitable for HCV sequencing.
  • Thumbnail Image
    Item
    Liver Fibrosis by Transient Elastography and Virologic Outcomes After Introduction of Tenofovir in Lamivudine-Experienced Adults With HIV and Hepatitis B Virus Coinfection in Ghana
    (Oxford University Press, 2015-05-28) Stockdale, Alexander J.; Phillips, Richard Odame; Beloukas, Apostolos; Appiah, Lambert Tetteh; Chadwick, David; et. al
    Background. Antiretroviral treatment (ART) programs in sub-Saharan Africa have for many years included lamivudine as the sole hepatitis B virus (HBV) inhibitor. Long-term outcomes and the effects of introducing tenofovir as part of ART in these populations have not been characterized. Methods. The study comprised a cross-sectional analysis of 106 human immunodeficiency virus (HIV)/HBV– coinfected subjects maintained on lamivudine, as well as a prospective analysis of 76 lamivudine-experienced subjects who introduced tenofovir. Patients underwent assessment of liver fibrosis by transient elastography (TE) and testing to characterize HIV type 1 (HIV-1) and HBV replication. Results. After a median of 45 months of lamivudine treatment, HIV-1 RNA and HBV DNA were detectable in 35 of 106 (33.0%) and 54 of 106 (50.9%) subjects, respectively, with corresponding drug resistance rates of 17 of 106 (16.0%) and 31 of 106 (29.2%), respectively. Median TE values were 5.7 kPa (interquartile range, 4.7–7.2 kPa) and independently associated with HBV DNA load, aspartate aminotransferase levels, and platelet counts; 13 of 106 (12.3%) subjects had TE measurements >9.4 kPa. Twelve months after the first assessment, and a median of 7.8 months after introducing tenofovir, HBV DNA levels declined by a mean of 1.5 log10 IU/mL (P < .001). TE values changed by a mean of −0.2 kPa (P = .097), and declined significantly in subjects who had pretenofovir HBV DNA levels >2000 IU/mL (mean, −0.8 kPa; P = .048) or TE values >7.6 kPa (mean, −1.2 kPa; P = .021). HIV-1 RNA detection rates remained unchanged. Conclusions. A proportion of HIV/HBV-coinfected patients on long-term lamivudine-containing ART had poor HIV and HBV suppression, drug resistance, and TE values indicative of advanced liver fibrosis. Tenofovir improved HBV control and reduced liver stiffness in subjects with high HBV DNA load and TE values.