Normative Fecal Calprotectin Concentrations in Guatemalan Preschoolers Are High Relative to Children Reported Elsewhere.

BACKGROUND: Calprotectin is a fecal marker of intraintestinal inflammation derived from activated enteric neutrophils and macrophages. It is useful as a clinical marker in inflammatory bowel diseases; furthermore, it may have a role in public health epidemiology. OBJECTIVES: The aim of the study was to describe the distribution of fecal calprotectin in Guatemalan preschool children sharing a common institutional diet; to relate it collectively to pediatric distributions in other geographic settings, and individually to concomitant indicators of intestinal infection or colonization and other descriptive features of the child. METHODS: Fecal samples were collected in 87 subjects, ages 2 to 7 years across 3 daycare centers sharing a common institutional menu, but from different ecological settings. Stools were examined, variously by routine light microscopy, quantitative egg counts, and a Giardia antigen test, for microbiological diagnosis, and an ELISA assay for fecal calprotectin (CalproLab). RESULTS: The median fecal calprotectin value was 58 mg/kg, with a mean of 98 ±â€Š136 mg/kg and a range from 10 to 950 mg/kg; 61% of values were above the manufacturer's cut-off for elevated concentration and 51% exceeded an age-adjusted criterion. There were no associations between sex, age, growth indicators, or fecal microbiological findings by microscopy or ELISA assays, alone or in combination. The central tendency (mean or median) and distribution were generally shifted to the right in relation to comparable reports from children across the world literature. CONCLUSIONS: Although specific, low-grade intestinal infections do not define calprotectin subgroups, right-shifted fecal calprotectin status in this population may reflect a general and diffuse stress of adverse environmental sanitation.

Role of leukotrienes on protozoan and helminth infections.

Leukotrienes (LTs), formed by the 5-lipoxygenase-(5-LO-) catalyzed oxidation of arachidonic acid, are lipid mediators that have potent proinflammatory activities. Pharmacologic or genetic inhibition of 5-LO biosynthesis in animals is associated with increased mortality and impaired clearance of bacteria, fungi, and parasites. LTs play a role in the control of helminth and protozoan infections by modulating the immune system and/or through direct cytotoxicity to parasites; however, LTs may also be associated with pathogenesis, such as in cerebral malaria and schistosomal granuloma. Interestingly, some proteins from the saliva of insect vectors that transmit protozoans and secreted protein from helminth could bind LTs and may consequently modulate the course of infection or pathogenesis. In addition, the decreased production of LTs in immunocompromised individuals might modulate the pathophysiology of helminth and protozoan infections. Herein, in this paper, we showed the immunomodulatory and pathogenic roles of LTs during the helminth and protozoan infections.

Helminth infections associated with multiple sclerosis induce regulatory B cells.

OBJECTIVE: To assess the importance of B-cell control during parasite infections in multiple sclerosis (MS) patients. METHODS: Peripheral blood CD19+ B cells from 12 helminth-infected MS patients, 12 MS patients without infection, 10 patients infected with Trypanosoma cruzi, 8 subjects infected with Paracoccidioides brasiliensis, and 12 healthy control subjects were purified using magnetic cell sorting. Interleukin (IL)-4, IL-6, IL-10, tumor necrosis factor-alpha, lymphotoxin, transforming growth factor-beta, brain-derived neurotrophic factor, and nerve growth factor secretion were evaluated after stimulation with CDw32 L cells and CD40 antibody using enzyme-linked immunosorbent assays. The production of anti-myelin oligodendrocyte glycoprotein IgG and IgM antibodies was evaluated by enzyme-linked immunosorbent spot assays. Cell phenotype was assessed by flow cytometry. RESULTS: Helminth infections in MS patients created a B-cell population producing high levels of IL-10, dampening harmful immune responses through a mechanism mediated, at least in part, by the ICOS-B7RP-1 pathway. The IL-10-producing B-cell phenotype detected expressed high levels of CD1d and was similar to the one observed in mature naive B2 cells (namely, CD11b(-), CD5(-), CD27(-), and IgD+). Moreover, B cells isolated from helminth-infected MS patients also produced greater amounts of brain-derived neurotrophic factor and nerve growth factor compared with those of normal subjects, T. cruzi-infected subjects, P. brasiliensis-infected subjects, or uninfected MS patients, raising the possibility that these cells may exert a neuroprotective effect on the central nervous system. INTERPRETATION: Increased production of B-cell-derived IL-10 and of neurotrophic factors are part of the parasite's regulation of host immunity and can alter the course of MS, potentially explaining environmental-related MS suppression observed in areas with low disease prevalence.