Relationships between biochemical markers of bone and cartilage degradation with radiological progression in patients with knee osteoarthritis receiving risedronate: the Knee Osteoarthritis Structural Arthritis randomized clinical trial.

OBJECTIVE: To investigate whether early changes in biochemical markers of bone (NTX-I) and cartilage (CTX-II [C-terminal crosslinking telopeptide of type II collagen]) degradation are associated with radiological progression in patients with knee osteoarthritis (OA) receiving risedronate. DESIGN: Two thousand four hundred and eighty three patients with medial compartment knee OA were randomized in two 24-month studies in North America (NA) and European Union (EU). Studies evaluated risedronate 5 mg/day, 35 mg/week (EU), 50 mg/week (NA), and 15 mg/day (NA and EU), compared to placebo in reducing signs and symptoms and in slowing radiographic progression. One thousand eight hundred and eighty five patients from the pooled EU and NA studies with available NTX-I/CTX-II at both baseline and 6 months and radiographs at baseline and at 24 months were analyzed. RESULTS: Risedronate produced a dose-dependent reduction of NTX-I and CTX-II observed at 6 months which continued up to 24 months. Patients who had CTX-II levels returned to low levels (<150 ng/mmol creatinine) at 6 months had a lower risk of radiographic progression at 24 months than patients whose CTX-II levels were increased both at baseline and 6 months [odds-ratio (95% confidence interval): 0.57 (0.39-0.85) after adjustment for demographics and joint space width]. The lowest risk of progression was observed in patients who had low CTX-II levels both at baseline and at 6 months [odds-ratio 0.36 (0.21-0.63)]. No significant association between NTX-I levels and radiological progression was observed. CONCLUSION: CTX-II decreased with risedronate in patients with knee OA and levels reached after 6 months were associated with radiological progression at 24 months. Monitoring a marker of cartilage degradation 6 months after initiating treatment may be instructive in identifying patients with low progression.

Schistosoma mansoni: stimulation of artificial granuloma formation in vivo by carbohydrate determinants.

A subset of Schistosoma mansoni egg glycoproteins that share a common carbohydrate epitope recognized by monoclonal antibody 128C3 was shown to induced formation of hepatic granulomata when conjugated to Sepharose beads and injected into the portal circulation of naive mice. Concanavalin-binding egg glycoproteins exhibited more granuloma-inducing activity than did total egg extract, although deglycosylated egg proteins also induced granulomata; thus, both amino acid and carbohydrate epitopes appeared to be involved. Glycoproteins derived from adult male worms also were active, indicating that immunological processes responsible for granuloma formation may not be absolutely stage specific.

Schistosoma mansoni: immunogenic glycoproteins of the cercarial glycocalyx.

Immunochemical studies at the level of the light and electron microscope showed that a monoclonal antibody, 128C3/3, was directed to an epitope in the glycocalyx of Schistosoma mansoni cercariae. Immunoprecipitation of surface labeled cercarial extracts with this monoclonal antibody demonstrated that the glycocalyx is composed of at least five components, including a very large molecular size polypeptide and polypeptides of 220, 180, 170, and 15 kDa. After transformation of cercariae to schistosomula, these polypeptides were shed from the surface and were therefore no longer accessible to surface labeling. Monoclonal antibody 128C3/3 was also reactive with a 38 kDa polypeptide from schistosomula; this polypeptide was weakly expressed on the surface of cercariae. Analysis of immunoprecipitates of radioiodinated protein extracts of cercariae, newly transformed schistosomula, and 36 hr in vitro cultured schistosomula showed that the 180 and 170 kDa polypeptides continued to be expressed within the organism following transformation, but were not accessible to surface labeling. Lectin binding studies revealed differences in the oligosaccharide composition of the six polypeptides. With the exception of the 15 kDa antigen, all the polypeptides reactive with 128C3/3 were highly immunogenic in infected mice and humans.

Molecular identity of a major antigen of Schistosoma mansoni which cross-reacts with Trichinella spiralis and Fasciola hepatica.

A glycoprotein cross-reactive among Schistosoma mansoni, Trichinella spiralis and Fasciola hepatica was identified and characterized by use of monoclonal antibodies prepared against S. mansoni glycoproteins. Four monoclonal antibodies recognized the same antigen which was one of the major S. mansoni glycoproteins precipitated by sera of hosts infected with either S. mansoni or T. spiralis. This antigen was expressed in S. mansoni cercariae, adult male and female worms, and eggs, and in S. haematobium but not in S. japonicum. Radio-immunoprecipitation and partial proteolytic digest mapping showed that the monoclonal antibodies each recognized a unique epitope. These epitopes were heat labile, sensitive to chaotropic agents, but resistant to reduction and alkylation or digestion with glycosidases, indicating that the recognition sites were amino acids and not carbohydrates. Epitopes recognized by the four monoclonal antibodies were expressed in F. hepatica, whereas only two were expressed in T. spiralis. Analysis by immunofluorescence microscopy showed that the antigen was expressed in S. mansoni in the parenchymal tissue and on the surface of the dorsal tubercles; in mature F. hepatica in the parenchymal tissue, vitelline glands and eggs; in immature F. hepatica only in the parenchymal tissue and in larval T. spiralis in the hypodermis.

Identification and characterization of a major Schistosoma mansoni glycoprotein antigen cross-reactive with Fasciola hepatica.

A major surface antigen of Schistosoma mansoni has been identified and characterized as a glycoprotein of 66,000 molecular weight (Mr) and isoelectric point of 6.2-6.1 (SM66-GP) by use of a monoclonal antibody. The antigen was expressed by schistosome eggs, cercariae, larvae, and adults, and was recognized by sera of schistosome infected hosts. Direct immunofluorescence microscopy showed the antigen was distributed in a uniform pattern on the entire worm surface. Indirect immunofluorescence microscopy revealed that it was present in the parenchymal tissue of immature and mature Fasciola hepatica, in the gut of the mature fluke, and in embryonated fasciola eggs. The cross-reactive F. hepatica epitope recognized was expressed on a polypeptide of Mr 220,000.

A Schistosoma mansoni surface glycoprotein cross-reactive with a T1 antigen of Fasciola hepatica.

An antigen recognized by monoclonal antibody 306B3/5 and present on the surface of S. mansoni was expressed by F. hepatica in the pattern typical of T1 antigens. A single polypeptide of molecular weight (Mr) 160,000 was precipitated from metabolically labeled concanavalin A-binding F. hepatica glycoproteins, whereas multiple polypeptides ranging from Mr greater than 200,000 to Mr 45,000 were precipitated from metabolically labeled glycoproteins of male S. mansoni. The polypeptides of both species were also precipitated by sera of infected hosts, and may account for some of the serological cross-reactivity between S. mansoni and F. hepatica in immunodiagnostic assays. These antigens may also represent potentially immunoprophylactic reagents.

A glycoprotein antigen of Schistosoma mansoni expressed on the gynecophoral canal of mature male worms.

A glycoprotein antigen of 80,000 apparent molecular weight expressed by S. mansoni eggs, cercariae, and male and female worms has been characterized by use of a monoclonal antibody prepared against cercarial glycoproteins. The antigen was expressed on the surface of both male and female worms. Its expression on the male surface, however, was restricted to the gynecophoral canal of male worms derived from fully patent infections. This pattern of surface expression suggests a role in schistosome sexual reproduction.

Gender-specific and pair-dependent glycoprotein antigens of Schistosoma mansoni.

Gender-specific and pair-dependent glycoprotein antigens of Schistosoma mansoni have been identified. Concanavalin A-binding glycoproteins of unisexually-and bisexually-reared male and female worms were labeled in vitro with 35S-methionine or 125iodine, and the two-dimensional maps of their polypeptides compared. The total protein compositions of male and female worms were very similar. In contrast, the patterns of glycoproteins immunoprecipitated by antisera from mice chronically infected with only male, only female, or both male and female worms were distinctive, indicating that the immune response elicited by the glycoproteins of male and female S. mansoni varied with the type of infection. Radioiodinated cercarial and egg proteins were also studied. Several polypeptides of cercariae and eggs, and 11 of 32 antigenic worm glycoproteins were recognized only by the antiserum from bisexually-infected mice, not by the antisera from unisexually-infected mice. These pair-dependent antigens may be relevant to the immune mechanisms involved in pathogenesis and resistance to reinfection.

Monoclonal antibody identification of protein antigens in the liver of mice infected with Schistosoma mansoni.

Protein antigens present in the hepatic lesions of mice infected with Schistosoma mansoni were identified by use of fluorochrome-conjugated monoclonal antibodies. All 26 monoclonal antibodies used in these experiments recognized antigenic determinants expressed by both cercariae and adult worms; 23 of these epitopes were also expressed by S. mansoni eggs. These results suggest considerable antigenic conservation during schistosome development. Two antibodies recognizing determinants absent from the egg nevertheless bound to schistosome antigens in hepatic granulomata; this result suggests that circulating worm antigens were also cleared in these lesions. Fifteen antigens were detected in perivascular spaces 5 weeks after infection, before the appearance of eggs in the liver.

Lung-stage expression of a major schistosome surface antigen.

The topographical expression of a glycoprotein of 180,000 molecular weight on the surface of lung-stage Schistosoma mansoni schistosomula was determined by immunofluorescence microscopy using a monoclonal antibody. Postfixation treatment with graded ethanols enhanced specific immunofluorescent staining of adult worms, and was required for detection of the antigen on the surfaces of lung-stage schistosomula. The epitope recognized by the monoclonal antibody was also present on the surfaces of adult Schistosoma haematobium, but not on those of Schistosoma japonicum.

Identification of species-specific and gender-specific proteins and glycoproteins of three human schistosomes.

Species-specific and gender-specific polypeptides of Schistosoma haematobium, Schistosoma japonicum, and Schistosoma mansoni have been identified. Proteins of these schistosomes were metabolically labeled in vitro with 35S-methionine and their total proteins, concanavalin-A binding glycoproteins, released (shed or secreted) proteins, and released glycoproteins compared by two-dimensional polyacrylamide electrophoresis. Many of the released proteins were glycosylated, and most of the synthesized glycoproteins were released. The most striking gender-specific and species-specific differences were observed in the released glycoproteins. These results provide a basis for investigating the molecular evolution of schistosomes, the occurrence of dioecy in the schistosomatidae , and for the development of improved serodiagnostic reagents.

Tegumental expression in larval and adult stages of a major schistosome structural glycoprotein.

A monoclonal antibody has been used to identify and characterize an antigenic tegumental surface membrane glycoprotein of Schistosoma mansoni. Direct binding of 125I-labeled monoclonal antibody showed that this glycoprotein was present in eggs, cercariae, and worms of both sexes. The glycoprotein had an apparent molecular weight of 180,000. Indirect and direct immunofluorescent microscopy showed that this antigen was located on the interlinked tegumental folds of both larval and adult parasites. These findings are discussed in relation to parasite development and the mechanism by which schistosomes evade the host's immune defenses.