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SummaryInflammation of the corneal stroma (stromal keratitis) is a serious complication of infection with the nematode parasite Onchocerca volvulus. Because stromal keratitis is believed to be immunologically mediated in humans, we used a murine model to examine the role ofT cells and T helper cell cytokines in the immunopathogenesis of these eye lesions. BALB/c mice immunized subcutaneously and injected intrastromally with soluble O. volvulus antigens (OvAg) developed pronounced corneal opacification and neovascularization. The corneal stroma was edematous and contained numerous eosinophils and mononuclear cells. Strornal keratitis in immunized mice was determined to be T cell dependent based on the following observations: (a) T cell-deficient nude mice immunized and injected intrastromally with OvAg fail to develop corneal pathology; and (b) adoptive transfer of spleen cells from OvAg-immunized BALB/c mice to naive nude mice before intrastromal injection of OvAg results in development of keratitis. OvAg-stimulated lymph node and spleen cell cytokine production was dependent on CD4 cells and included interleukin (IL)-4 and IL-5, but not interferon % indicating a predominant T helper type 2 cell-like response. Inflamed corneas from immunized BALB/c mice and from reconstituted nude mice had greatly elevated CD4 and IL-4 gene expression compared with interferon ~/. Mice in which the IL-4 gene was disrupted failed to develop corneal disease, demonstrating that IL-4 is essential in the immunopathogenesis of O. volvulus-mediated stroreal keratitis.

Laboratory tools to monitor infection burden are important to evaluate progress and determine endpoints in programs to eliminate lymphatic filariasis. We evaluated changes in Wuchereria bancrofti microfilaria, filarial antigen and Bm14 antibody in individuals who participated in a five-year mass drug administration trial in Papua New Guinea. Comparing values before treatment and one year after four annual treatments, the proportion of microfilaria positive individuals declined to the greatest degree, with less marked change in antibody and antigen rates. Considering children as sentinel groups who reflect recent transmission intensity, children surveyed before the trial were more frequently microfilaria and antibody positive than those examined one year after the trial stopped. In contrast, antigen positive rates were similar in the two groups. All infection indicators continued to decline five years after cessation of mass drug administration; Bm14 antibody persisted in the greatest proportion of individuals. These data suggest that Bm14 antibody may be a sensitive test to monitor continuing transmission during and after mass drug administration aimed at eliminating transmission of lymphatic filariasis.

The purpose of this study was to examine the murine T-helper-cell (Th) cytokine response to the human filarial parasite Brugia malayi. In the first 14 days following intraperitoneal inoculation of live microfilariae into BALB/c mice, filarial antigen-driven splenic lymphoid cells produced gamma interferon (IFN-y) and little or no interleukin-5 (IL-5). After this time, IL-5 production increased (to 10 to 12 ng per 5 x 106 cells) coincident with a marked diminution in IFN-y generation. A single subcutaneous immunization with soluble microfilarial antigens also induced an IFN-y but no IL-5 response, whereas immunization three times elicited a predominant Th2-like reaction characterized by IL-4 and IL-5 production by CD4+ Iymph node lymphocytes and a 10-fold increase in serum immunoglobulin E. The importance of IL-10 in establishing the balance between parasite-specific Thl and Th2 responses was demonstrated by the ability of neutralizing monoclonal antibody to this cytokine to increase IFN-y production by splenic and lymph node cells from mice chronically exposed to live microfilariae or immunized multiple times with soluble filarial antigens.

The efficacy of diethylcarbamazine alone was compared with diethylcarbamazine plus albendazole in residents of an island in Papua New Guinea endemic for Wuchereria bancrofti. There was no statistically significant difference between the two drug regimens in decreasing the microfilaria positive rate at 12 and 24 months after a single-dose treatment with either regimen, e.g., 50.0% clearance of microfilaria at 24 months for diethylcarbamazine alone versus 65.7% clearance of microfilaria for diethylcarbamazine plus albendazole (P > 0.05). In contrast, diethylcarbamazine plus albendazole resulted in a significant decrease in Og4C3 antigen prevalence (17%; P = 0.003) at 24 months whereas diethylcarbamazine did not (10%; P = 0.564). These data showed no statistically significant difference in the efficacy of the two drug regimens in lowering the microfilaria reservoir, but they support the use of diethylcarbamazine combined with albendazole in mass treatment programs on the basis of greater activity against adult worms.

We examined 906 residents of an area of Papua New Guinea where bancroftian filariasis is endemic for genetic polymorphisms in three innate immunity genes suspected of contributing to susceptibility to infection and lymphatic pathology. Active infection was confirmed by the presence of blood-borne microfilariae and circulating filarial antigen in plasma. Disease was ascertained by physical examination for the presence of overt lymphedema (severe swelling of an arm or leg) or hydrocele. There was no association of infection status, lymphedema of an extremity, or hydrocele with chitotriosidase genotype (CHIT1). Polymorphisms of toll-like receptor-2 and toll-like receptor-4 genes (TLR4 A896G; TLR2 T2178A, G2258A) were not detected (N¼200-625 individuals genotyped) except for two individuals heterozygous for a TLR2 mutation (C2029 T). These results indicate that a CHIT1 genotype associated previously with susceptibility to filariasis in residents of southern India and TLR2 and TLR4 polymorphisms do not correlate with infection status or disease phenotype in this Melanesian population. Genes and Immunity (2003) 4, 524-527. doi:10.1038/sj.gene.6364015Keywords: filariasis; chitotriosidase; toll-like receptor; polymorphism; genetics Lymphatic filariasis is a mosquito-transmitted helminth infection endemic in sub-Saharan Africa, Asia, tropical islands of the Pacific Ocean, and focal areas of Latin America. Humans are infected when mosquitoes inoculate infective larvae into the skin that develop into lymphatic-dwelling adult worms and produce millions of microfilariae that circulate in the bloodstream. The life cycle is completed when microfilariae are taken up in the blood meal of the mosquito vector, where they develop into infective larvae over 10-14 days. The pathological consequences of Wuchereria bancrofti infection (there are also two less common filarial species that infect humans, Brugia malayi and B. timori) are mainly due to lymphatic dysfunction clinically manifested as lymphedema of the extremities or elephantiasis and disfigurement of the genitalia, especially hydroceles in men.Infection and disease due to W. bancrofti have a characteristic distribution in populations living in endemic areas. The frequency of infection is generally higher in adults than children, consistent with the notion that the parasite burden increases with cumulative exposure to mosquito-borne larvae. The prevalence of overt clinical manifestations among adult residents of endemic areas is usually less than 10% despite the fact that most individuals are presumably inoculated with infective larvae throughout life. In high transmission areas of Papua New Guinea, for example, communityspecific infection rates documented by the presence of blood-borne microfilariae and filarial antigenemia range from 50% to over 80% in persons older than 20 years of age, whereas fewer than 10% have lymphedema of the extremities.

OBJECTIVETo define a panel of novel protein biomarkers of renal disease.RESEARCH DESIGN AND METHODSAdults with type 1 diabetes in the Coronary Artery Calcification in Type 1 Diabetes study who were initially free of renal complications (n = 465) were followed for development of micro- or macroalbuminuria (MA) and early renal function decline (ERFD, annual decline in estimated glomerular filtration rate of ≥3.3%). The label-free proteomic discovery phase was conducted in 13 patients who progressed to MA by the 6-year visit and 11 control subjects, and four proteins (Tamm-Horsfall glycoprotein, α-1 acid glycoprotein, clusterin, and progranulin) identified in the discovery phase were measured by enzyme-linked immunosorbent assay in 74 subjects: group A, normal renal function (n = 35); group B, ERFD without MA (n = 15); group C, MA without ERFD (n = 16); and group D, both ERFD and MA (n = 8).RESULTSIn the label-free analysis, a model of progression to MA was built using 252 peptides, yielding an area under the curve (AUC) of 84.7 ± 5.3%. In the validation study, ordinal logistic regression was used to predict development of ERFD, MA, or both. A panel including Tamm-Horsfall glycoprotein (odds ratio 2.9, 95% CI 1.3–6.2, P = 0.008), progranulin (1.9, 0.8–4.5, P = 0.16), clusterin (0.6, 0.3–1.1, P = 0.09), and α-1 acid glycoprotein (1.6, 0.7–3.7, P = 0.27) improved the AUC from 0.841 to 0.889.CONCLUSIONSA panel of four novel protein biomarkers predicted early renal damage in type 1 diabetes. These findings require further validation in other populations for prediction of renal complications and treatment monitoring.

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