Mr
Helena Lamptey
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Biography
Publications
Background: The protective effect of certain haemoglobinopathies, such as HbS, HbC, and α-thalassaemia, against severe malaria has long been established; however, there is only limited and equivocal evidence regarding their impact on asymptomatic parasitaemia. Here, we investigated the effect of HbS, HbC, and α-thalassaemia on asymptomatic P. falciparum parasitaemia and acquired immunity among children in Northern Ghana.
Materials and methods: A cross-sectional study was conducted among 1,017 healthy children (1-17 years) in 13 malaria-endemic communities in Northern Ghana. The children were screened for structural Hb phenotypes using SickleSCAN, for P. falciparum infection using anti-HRP2 malaria RDT and subsequently confirmed by capillary electrophoresis and PCR, respectively. α-thalassaemia genotyping was done using PCR. Levels of IgG specific for six recombinant malaria antigens (PfCSP, GLURP, MSP3, Pfs230, HB3VAR06, and IT4VAR60) and crude asexual blood-stage antigens were evaluated by ELISA.
Results: 266 out of the 1,017 participants had either HbAC (18%) or HbAS (8.4%), whereas 35% had α‐thalassaemia. Twenty-five percent and 6% HbAC individuals co-inherited heterozygous and homozygous α-thalassaemia respectively. Similarly, 25% and 10.5% of HbAS co-inherited heterozygous and homozygous α-thalassaemia. Asymptomatic parasitaemia rates were 23%, 24%, and 19% in those with HbAA, HbAC and HbAS, respectively. The overall parasite carriage rates in heterozygous (21%) and homozygous α-thalassaemia (25%) individuals were similar to that of individuals without α-thalassaemia (23%). P. falciparum parasite carriage risk was about three times higher among homozygous α-thalassaemia individuals with HbAC (OR = 2.97; 95% CI 0.83-10.62) and heterozygous carriers with HbAS variants (OR = 2.86; 95% CI 0.85-9.60) compared to the wildtype. In HbAS individuals, IgG levels to IT4VAR60 and HB3VAR06 were significantly lower, whereas anti-CSP levels were higher than in HbAA and HbAC.
Conclusions: Co-inheritance of HbAS and HbAC with α-thalassaemia increased the risk of asymptomatic parasitaemia, an indication of a negative epistatic effect between these Hb variants. Antibody levels against non-PfEMP1 antigens were slightly higher among HbAS children, but quite similar in all study groups, indicating differences in parasite exposure.
Purpose of review
Recent years have seen major investments into HIV cure research, seeking a permanent cure or remission. The purpose of this review is to consider how this important research agenda could be broadened to include issues of acceptability and appropriateness for different populations.
Recent findings
We discuss how the definitions of cure such as functional cure (remission) or complete cure (viral elimination) could be interpreted differently by various populations. We also discuss the different methods of cure and the importance of including Africa in cure research to ensure that emerging remedies could be trialled and utilized on the continent that bears the brunt of the AIDS pandemic
Summary
We propose that the social science research of HIV cure acceptability should be done concurrently with the basic and clinical sciences, to ensure that cure methods consider stakeholder preferences.