The IL17F and IL17RA Genetic Variants Increase Risk of Cerebral Malaria in Two African Populations

Cerebral malaria (CM) is a neurological complication of infection with Plasmodium falciparum that is partly caused by cytokine-mediated inflammation. It is not known whether interleukin-17 (IL-17) cytokines, which regulate inflammation, control the development of CM. To evaluate the involvement of IL-17 cytokines in CM, we analyzed 46 common polymorphisms in IL17A, IL17F, and IL17RA (which encodes the common receptor chain of the members of the IL-17 family) in two independent African populations. A case-control study involving 115 Nigerian children with CM and 160 controls from the community (CC) showed that IL17F reference single nucleotide polymorphism (SNP) 6913472 (rs6913472) (P = 0.004; odds ratio [OR] = 3.12), IL17F rs4715291 (P = 0.004; OR = 2.82), IL17RA rs12159217 (P = 0.01; OR = 2.27), and IL17RA rs41396547 (P = 0.026; OR = 3.15) were independently associated with CM. A replication study was performed in 240 nuclear Malian family trios (two parents with one CM child). We replicated the association for 3 SNPs, IL17F rs6913472 (P = 0.03; OR = 1.39), IL17RA rs12159217 (P = 0.01; OR = 1.52), and IL17RA rs41396547 (P = 0.04; OR = 3.50). We also found that one additional SNP, IL17RA rs41433045, in linkage disequilibrium (LD) with rs41396547, was associated with CM in both Nigeria and Mali (P = 0.002; OR = 4.12 in the combined sample). We excluded the possibility that SNPs outside IL17F and IL17RA, in strong LD with the associated SNPs, could account for the observed associations. Furthermore, the results of a functional study indicated that the aggravating GA genotype of IL17F rs6913472 was associated with lower IL-17F concentrations. Our findings show for the first time that IL17F and IL17RA polymorphisms modulate susceptibility to CM and provide evidence that IL-17F protects against CM.     

Life-threatening malaria in African children: a prospective study in a mesoendemic urban setting

BACKGROUND: The population exposed to malaria within African cities has steadily increased. However, comprehensive data on life-threatening malaria features and risk factors in children from urban areas with seasonal malaria transmission, such as in Bamako (Mali), are lacking. METHODS: Children admitted to the Gabriel Touré Hospital in Bamako with severe malarial anemia (SMA) and/or cerebral malaria (CM) were prospectively included in the study. Indicators of either SMA or CM were analyzed using logistic regression; and death hazard ratios (HRs) were estimated through survival analysis. RESULTS: The study included 455 children: 66% presented with CM, 34% with SMA, 3% with hypoglycemia (HG); 5% with dehydration; 17% with respiratory distress (RD); 25% with splenomegaly; and 92% with hepatomegaly. The children with CM were older than those with SMA. CM was more often associated with dehydration, HG, and RD, whereas SMA was more often associated with splenomegaly. The overall case fatality rate was 16%, and 94% of the children who died had CM. HG [HR: 2.37; 95% confidence interval (CI): 1.04-5.39; P = 0.040], RD (HR: 4.23; 95% CI: 2.46-7.30; P < 10(-6)) and a deep coma with a Blantyre score of less than 3 (HR: 6.78, 95% CI: 2.43-18.91; P < 10(-3)), were all independent predictors of death. CONCLUSIONS: These findings delineate the patterns of severe malaria in children in a West African mesoendemic urban setting. They validate practicable prognostic indicators of life-threatening malaria for use in the limited facilities available in African health centers and provide a frame of reference for further research addressing life-threatening malaria in this setting.     

In Vivo Efficacy and Parasite Clearance of Artesunate + Sulfadoxine–Pyrimethamine Versus Artemether–Lumefantrine in Mali

Although artemisinin resistance has yet to be reported in Africa, surveillance of the efficacy of artemisinin-based combination therapies (ACTs) is warranted. Here, the efficacy of artesunate + sulfadoxine–pyrimethamine (AS+SP) and artemether–lumefantrine (AL) was evaluated in Mali. Randomized open-label comparative in vivo assay of AS+SP versus AL were carried out using the 28-day follow-up World Health Organization protocol. Patients with uncomplicated falciparum malaria and at least 6 months of age were recruited between October 2010 and January 2014. A subset of these patients was selected to measure Plasmodium falciparum clearance time. Polymerase chain reaction-corrected adequate clinical and parasitological responses were 100% for AS+SP and 98.2% for AL with no significant difference (P = 0.06). The reinfection rates were comparable (P = 0.63) with 8.0% for AS+SP and 12.6% for AL. Individuals under 8 years were more susceptible to treatment failure (relative risk = 1.9; 95% confidence interval = 1.2, 3.3). Median parasite clearance half-life was 1.7 hours (interquartile range [IQR] = 1.3–2.2) for AS+SP and 1.9 hours (IQR = 1.5–2.5) for AL with no statistically significant difference (P = 0.24). Efficacy of AS+SP and AL was high. This study provides baseline information on parasite clearance half-lives after ACT treatment, particularly AS+SP, in Mali.     

A prospective study of the association between the human humoral immune response to Plasmodium falciparum blood stage antigen gp190 and control of malarial infections.

The human humoral immune response to the Plasmodium falciparum merozoite surface antigen gp190 was analyzed to determine the rate of reinfection by the parasite and the ability to control parasite density. The prospective study was carried out in a West African village where malaria is hyperendemic. No correlation between the antibody titers and protection against infection was observed within the group of children. Positive and negative associations of antibody specificities with protection against and/or control of parasitemia were, however, found for adolescents and adults, respectively. Thus, in adolescents, the presence of antibodies to gp190 fragment M6 correlates with a 50% reduced risk of P. falciparum infection and an increased ability to control parasitemia, whereas in adults, the humoral response to some of the polymorphic regions of gp190 associates with an increased risk of infection.     

Tissue and Bronchoalveolar Lavage Biomarkers in Idiopathic Pulmonary Fibrosis Patients on Pirfenidone

Background

Pirfenidone is a novel anti-fibrotic agent in idiopathic pulmonary fibrosis with proven clinical benefit. Better human tissue models to demonstrate the immunomodulatory and anti-fibrotic effect of pirfenidone are required.

Objectives

The purpose of the study was to use transbronchial lung cryobiopsy (TBLC), a novel technique which provides substantial tissue samples, and a large panel of biomarkers to temporally assess disease activity and response to pirfenidone therapy.

Methods

Thirteen patients with confirmed idiopathic pulmonary fibrosis (IPF) underwent full physiological and radiological assessment at diagnosis and after 6-month pirfenidone therapy. They underwent assessment for a wide range of potential serum and bronchoalveolar lavage biomarkers of disease activity. Finally, they underwent TBLC before and after treatment. Tissue samples were assessed for numbers of fibroblast foci, for Ki-67, a marker of tissue proliferation and caspase-3, a marker of tissue apoptosis.

Results

All patients completed treatment and investigations without significant incident. There was no significant fall in number of fibroblast foci per unit tissue volume after treatment (pre-treatment: 0.14/mm² vs. post-treatment 0.08/mm², p?=?0.1). Likewise, there was no significant change in other markers of tissue proliferation, Ki-67 or Caspase-3 with pirfenidone treatment. We found an increase in three bronchoalveolar lavage angiogenesis cytokines, Placental Growth Factor, Vascular Endothelial Growth Factor-A, and basic Fibroblast Growth Factor, two anti-inflammatory cytokines Interleukin-10 and Interleukin-4 and Surfactant Protein-D.

Conclusions

TBLC offers a unique opportunity to potentially assess the course of disease activity and response to novel anti-fibrotic activity in IPF.

     

Thiophene-Pyrazolourea Derivatives as Potent,Orally Bioavailable,and Isoform-Selective JNK3 Inhibitors

Potent JNK3 isoform selective inhibitors were developed from a thiophenyl-pyrazolourea scaffold. Through structure activity relationship (SAR) studies utilizing enzymatic and cell-based assays, and in vitro and in vivo drug metabolism and pharmacokinetic (DMPK) studies, potent and highly selective JNK3 inhibitors with oral bioavailability and brain penetrant capability were developed. Inhibitor 17 was a potent and isoform selective JNK3 inhibitor (IC₅₀ = 35 nM), had significant inhibition to only JNK3 in a panel profiling of 374 wild-type kinases, had high potency in functional cell-based assays, had high stability in human liver microsome (t_1/2 = 66 min) and a clean CYP-450 inhibition profile, and was orally bioavailable and brain penetrant. Moreover, cocrystal structures of compounds 17 and 27 in human JNK3 were solved at 1.84 Å, which showed that these JNK3 isoform selective inhibitors bound to the ATP pocket, had interactions in both hydrophobic pocket-I and hydrophobic pocket-II.     

Multiple Subepidermal Calcified Nodules on the Thigh Mimicking Molluscum Contagiosum

Abstract: Subepidermal calcified nodule (SCN) is a rare form of calcinosis cutis that presents as a solitary verrucous nodule on the face. Here, we report an unusual case of SCN. A healthy 2‐year‐old boy presented with multiple, round, hard, yellow‐white to erythematous lesions on his right thigh. Histopathologic examination of a punch biopsy specimen revealed deposition of calcium in the dermis.     

Hemoglobin C associated with protection from severe malaria in the Dogon of Mali, a West African population with a low prevalence of hemoglobin S

The malaria hypothesis proposes a survival advantage for individuals with hemoglobin variants in areas of endemic Plasmodium falciparum malaria. Hemoglobin C (HbC) is a possible example in West Africa, where this hemoglobin has a centric distribution with high frequencies among certain populations including the Dogon ethnic group. To test whether HbC is associated with protection from malaria, we performed a case-control study in the Dogon of Bandiagara, Mali. HbC was present in 68 of 391 (17.4%) of uncomplicated malaria control cases, whereas it was detected in only 3 of 67 cases (4.5%) of severe malaria (odds ratio [OR], 0.22; P =. 01). Further, HbC was present in only 1 of 34 cases (2.9%) with cerebral manifestations, the most common presentation of severe malaria in this population (OR, 0.14; P =.03). Episodes of uncomplicated malaria and parasitemias (4800-205 050/microL) were identified in cases of homozygous HbC (HbCC), which indicates that P falciparum parasites are able to efficiently replicate within HbCC erythrocytes in vivo. These findings suggest that HbC does not protect against infection or uncomplicated malaria but can protect against severe malaria in the Dogon population of Bandiagara, Mali. The data also suggest that the protective effect associated with HbC may be greater than that of HbS in this population.     

Association of Schistosoma haematobium infection with protection against acute Plasmodium falciparum malaria in Malian children

Plasmodium falciparum and Schistosoma haematobium are co-endemic parasitic diseases with worldwide distribution. Evidence suggests interactions occur between helminthic and malaria infections, although it is unclear whether this effect is beneficial or harmful to the host. Malian children 4-14 years of age with asymptomatic S. haematobium infection (SP) (n = 338) were prospectively matched by age, sex, and residence to children without schistosomiasis (SN) (n = 338) who were cleared of occult intestinal parasites, and followed-up for one malaria transmission season (25 weeks). The time to the first clinical malaria infection, incidence of malaria episodes, and parasitemia were recorded. Age associated protection from malaria in children with schistosomiasis was observed. SP children (4-8 years of age) compared with SN children demonstrated delayed time to first clinical malaria infection (74 versus 59 days; P = 0.04), fewer numbers of malaria episodes (1.55 versus 1.81 infections; P = 0.03) and lower geometric mean parasite densities (6,359 versus 9,874 asexual forms/mm(3); P = 0.07) at first infection. No association between schistosomiasis and P. falciparum malaria was observed in children 9-14 years of age. We conclude that underlying schistosomiasis is associated with protection against clinical falciparum malaria in an age-dependent manner.     

Polymorphisms in the K13-Propeller Gene in Artemisinin-Susceptible Plasmodium falciparum Parasites from Bougoula-Hameau and Bandiagara,Mali

Artemisinin-resistant Plasmodium falciparum malaria has been documented in southeast Asia and may already be spreading in that region. Molecular markers are important tools for monitoring the spread of antimalarial drug resistance. Recently, single-nucleotide polymorphisms (SNPs) in the PF3D7_1343700 kelch propeller (K13-propeller) domain were shown to be associated with artemisinin resistance in vivo and in vitro. The prevalence and role of K13-propeller mutations are poorly known in sub-Saharan Africa. K13-propeller mutations were genotyped by direct sequencing of nested polymerase chain reaction (PCR) amplicons from dried blood spots of pre-treatment falciparum malaria infections collected before and after the use of artemisinin-based combination therapy (ACT) as first-line therapy in Mali. Although K13-propeller mutations previously associated with delayed parasite clearance in Cambodia were not identified, 26 K13-propeller mutations were identified in both recent samples and pre-ACT infections. Parasite clearance time was comparable between infections with non-synonymous K13-propeller mutations and infections with the reference allele. These findings suggest that K13-propeller mutations are present in artemisinin-sensitive parasites and that they preceded the wide use of ACTs in Mali.