Hemozoin is generally considered a waste deposit that is formed for the sole purpose of detoxification of free heme that results from the digestion of hemoglobin by Plasmodium parasites. However, several observations of parasite multiplication, both in vertebrate and invertebrate hosts are suggestive of a wider, but overlooked, metabolic role for this product. The presence of clinical peripheral blood samples of P. falciparum with high parasitemia containing only hemozoin-deficient (non-pigmented) asexual forms has been repeatedly confirmed. Such samples stand in contrast with other samples that contain mostly pigmented circulating trophozoites and gametocytes, indicating that pigment accumulation is a prominent feature of gametocytogenesis. The restricted size, i.e. below detection by light microscopy, of hemozoin in asexual merozoites and ringforms of P. falciparum implies its continuous turnover, supporting a role in metabolism. The prominent interaction of hemozoin with several antimalarial drugs, the involvement of proteins in hemozoin formation, and the finding of plasmodial genes coding for a heme-oxygenase-like protein argue for a wider and more active role for hemozoin in the parasite’s metabolism. The observed association of hemozoin with crystalloids during ookinete development is consistent with a useful function to it during parasite multiplication in the invertebrate host. Finally, alternative mechanisms, other than hemozoin formation, provide substitute or additional routes for heme detoxification.
The MalariaWorld Journal
We evaluated the association between the use of intermittent preventive treatment with sulphadoxine- pyrimethamine (IPTp-SP) on pregnancy outcomes among women who delivered at a secondary hospital in Nsukka, Enugu State, Nigeria. Relevant obstetric data (e.g. IPTp-SP use), matched against pregnancy outcome data such as delivery method, stillbirth, maternal haematocrit test results and babies’ birth weights, were collected retrospectively from antenatal care (ANC) case files of women who delivered within a one-year period (2013). The prevalence of adverse pregnancy outcomes recorded out of the 500 ANC case files analysed were: low birth weight (LBW) 3.6% (15), anaemia 54.3% (114), caesarean section 31.6% (156) and stillbirth 3.6% (67). A total of 342 (68.4%) of the women received IPTp-SP during ANC and the receipt of IPTp-SP was significantly associated with reductions in the following events: LBW [OR = 0.26, 95% CI = 0.09 – 0.75], moderate anaemia [OR = 0.33, 95% CI = 0.17 – 0.63], caesarean section [OR = 0.36, 95% CI = 0.24 – 0.53] and stillbirth [OR = 0.10, 95% CI = 0.06 – 0.18]. In this area of high malaria transmission we demonstrated significant reductions in unfavourable maternal and infant health outcomes when using IPT-SP.