Blood groups and malaria:fresh insights into pathogenesis and identification of targets for intervention

PURPOSE OF REVIEW: This review summarizes recent advances in our understanding of the interaction between malaria parasites and blood group antigens and discusses how the knowledge gleaned can be used to target the development of new antimalarial treatments and vaccines. RECENT FINDINGS: Studies of the interaction between Plasmodium vivax and the Duffy antigen provide the clearest example of the potential for basic research on blood groups and malaria to be translated into a vaccine that could have a major impact on global health. Progress is also being made in understanding the effects of other blood group antigens on malaria. After years of controversy, the effect of ABO blood groups on falciparum malaria has been clarified, with the non-O blood groups emerging as significant risk factors for life-threatening malaria, through the mechanism of enhanced rosette formation. The Knops blood group system may also influence malaria susceptibility, although conflicting results from different countries mean that further research is required. Unanswered questions remain about the interactions between malaria parasites and other blood group antigens, including the Gerbich, MNS and Rhesus systems. SUMMARY: The interplay between malaria parasites and blood group antigens remains a fascinating subject with potential to contribute to the development of new interventions to reduce the global burden of malaria

Role of Rilpivirine and Etravirine in Efavirenz and Nevirapine-Based Regimens Failure in a Resource-Limited Country: A Cross- Sectional Study

<div><p>Introduction</p><p>Etravirine(ETR) can be used for patients who have failed NNRTI-based regimen. In Thailand, ETR is approximately 45 times more expensive than rilpivirine(RPV). However, there are no data of RPV use in NNRTI failure. Therefore, we assessed the susceptibility and mutation patterns of first line NNRTI failure and the possibility of using RPV compared to ETV in patients who have failed efavirenz(EFV)- and nevirapine(NVP)-based regimens.</p><p>Methods</p><p>Clinical samples with confirmed virological failure from EFV- or NVP-based regimens were retrospectively analyzed. Resistance-associated mutations (RAMs) were interpreted by IAS-USA Drug Resistance Mutations. Susceptibility of ETR and RPV were interpreted by DUET, Monogram scoring system, and Stanford University HIV Drug Resistance Database.</p><p>Results</p><p>1,279 and 528 patients failed EFV- and NVP-based regimens, respectively. Y181C was the most common NVP-associated RAM (54.3% vs. 14.7%, p<0.01). K103N was the most common EFV-associated RAM (56.5% vs. 19.1%, P<0.01). The results from all three scoring systems were concordant. 165(11.1%) and 161(10.9%) patients who failed NVP-based regimen were susceptible to ETR and RPV, respectively (p = 0.85). 195 (32.2%) and 191 (31.6%) patients who failed EFV-based regimen, were susceptible to ETR and RPV, respectively (p = 0.79). The susceptibility of ETV and RPV in EFV failure was significantly higher than NVP failure (p<0.01).</p><p>Conclusion</p><p>The mutation patterns for ETR and RPV were similar but 32% and 11% of patients who failed EFV and NVP -based regimen, respectivly were susceptible to RPV. This finding suggests that RPV can be used as the alternative antiretroviral agent in patients who have failed EFV-based regimen.</p></div

Top 10 NNRTI-RAMs found in patients who failed either the NVP- or EFV-based regimen.

<p>Top 10 NNRTI-RAMs found in patients who failed either the NVP- or EFV-based regimen.</p

Susceptibility pattern of etravirine and rilpivirine in patients who failed nevirapine and efavirenz-based regimens.

<p>Susceptibility pattern of etravirine and rilpivirine in patients who failed nevirapine and efavirenz-based regimens.</p

Number of patients susceptible to etravirine and rilpivirine.

<p>Number of patients susceptible to etravirine and rilpivirine.</p

Baseline characteristics of the patients.

<p>Baseline characteristics of the patients.</p