title: Association of splenomegaly with cerebral malaria and decreased concentrations of reactive nitrogen intermediates in Thailand.
abstract: The role of the spleen during Plasmodium falciparum malaria in humans is unclear. In Thailand, malaria transmission is low and splenomegaly is rarer than in high transmission areas. We compared the prevalence of splenomegaly between 52 cerebral malaria patients and 191 patients without complications despite a high parasite biomass. We also measured concentrations of reactive nitrogen intermediates (RNIs) in a fraction of these cases recruited in 1998 (24 cerebral malaria and 56 controls). Splenomegaly was significantly associated with cerebral malaria (adjusted odds ratio = 2.07 [95% confidence interval = 1-4.2]; P = 0.048). There was a linear trend for this association (P = 0.0003). After adjusting for potential confounders, concentrations of RNIs were significantly lower in the presence of splenomegaly (P = 0.01). These results suggest that in humans, as in animal models, the spleen may be involved in the pathogenesis of cerebral malaria. The relationship between RNI concentrations and the spleen suggest that nitric oxide may have a regulating role in the complex physiology of the spleen during malaria.
authors.affiliation: Institut National de la Santé et de la Recherche Médicale Unité 511, Immunobiologie Cellulaire et Moléculaire des Infections Parasitaires, Faculté de Médecine Pitié-Salpétrière, Paris, France. m_nacher@lycos.com
authors.forename: M
authors.initials: M
authors.lastname: Nacher
authors.forename: P
authors.initials: P
authors.lastname: Singhasivanon
authors.forename: S
authors.initials: S
authors.lastname: Treeprasertsuk
authors.forename: Y
authors.initials: Y
authors.lastname: Chantachum
authors.forename: S
authors.initials: S
authors.lastname: Vannaphan
authors.forename: B
authors.initials: B
authors.lastname: Traore
authors.forename: F
authors.initials: F
authors.lastname: Gay
authors.forename: S
authors.initials: S
authors.lastname: Looareesuwan
mesh_terms: D000328:Adult; D006801:Humans; D016779:Malaria, Cerebral / Q000150:complications* / Q000378:metabolism; D009569:Nitric Oxide / Q000096:biosynthesis; D018512:Parasitemia / Q000378:metabolism; D026361:Reactive Nitrogen Species; D012189:Retrospective Studies; D013163:Splenomegaly / Q000209:etiology*
chemical_list: D026361:Reactive Nitrogen Species; D009569:Nitric Oxide